Читать книгу Small Animal Laparoscopy and Thoracoscopy онлайн

232 страница из 232

An ultrasonic generator delivers an alternating polarity electrical current that is modulated by the generator, directed through the transducer, and converted to sound energy. This conversion of current into sound energy occurs as the piezoelectric current is directed through a series of stacked ceramic plates within the transducer. The vibration of the ceramic plates at 55 500 times per second produces sound waves or harmonic frequency, which generates mechanical energy. Sound energy propagates down the shaft of the instrument to the tip, leading to axial displacement of the instrument tip. An increase in power on the generator leads to an increase in axial displacement of the instrument tip, leading to an increased cutting rate.

Ultrasonic energy devices generate minimal heat and, therefore, very little lateral thermal spread (<1.5 mm). Despite generating minimal thermal spread, these devices store heat in the blade even after deactivation, and care must be taken to prevent inadvertent tissue injury to surrounding visceral tissue immediately after activation. Most ultrasonic energy devices can seal vessels up to 3 mm in diameter. ssss1 lists various currently available ultrasonic dissectors as well as tissue fusion devices.

A study by Newcomb et al. [17] compared vessel sealing in a porcine model with electrosurgical and ultrasonic devices. They found that vessel sealant devices had the highest mean burst pressures compared with ultrasonic dissectors. More seal failures were seen overall with the ultrasonic dissector than with the vessel sealant devices. However, for vessels 2–3 mm in diameter, the ultrasonic dissector did not have any seal failures, but the vessel sealant devices did. This study emphasizes the fact that ultrasonic dissectors consistently seal vessels less than 3 mm but perform inconsistently with larger vessel diameters.

Medtronic introduced a new generation of Sonicision, a cordless, curved jaw ultrasonic dissection system (ssss1). The intensity of the ultrasonic energy is controlled by the operator with a dual‐mode energy button, where a half depression is indicated with slower dissection when increased hemostasis is desired and a complete depression of the dual‐energy mode button leads to faster dissection. In contrast to other ultrasonic devices, Sonicision is approved for use with vessels up to and including 5 mm in diameter. This device has an autoclavable generator that can be used up to 150 times. The rechargeable battery is designed for 200 uses. The ultrasonic dissector is designed for single use, but resterilization is common in veterinary medicine. No studies currently exist on the safety of resterilization of the ultrasonic dissector. The authors have currently resterilized the ultrasonic dissector greater than ten times using hydrogen peroxide sterilization and have not experienced any known failures or infections due to device reuse and resterilization.

ssss1 Sonicision is a cordless ultrasonic dissector that is approved for sealing vessels up to 5 mm in diameter.

Source: Courtesy of Medtronic, Minneapolis, MN.

Microwave ablation (MWA) uses electromagnetic methods to induce the destruction of tumors via thermal energy at frequencies ≥ 900 MHz [33]. A generator emits an electromagnetic wave through an antenna resulting in the application of heat to tissues. It has several advantages over radiofrequency ablation, including consistently higher intratumoral temperatures leading to larger ablation zones and shorter treatment times; it has an active heating mechanism that allows for more uniform tumor necrosis even in close proximity to large blood vessels; it can be effective in tissues with high impedance such as lung or charred, desiccated tissue; and multiple tumors can be treated simultaneously with an additional antenna [34, 35].

The most common generators include Emprint^TM (Medtronic, Boulder, CO) and Neuwave^TM (NeuWave Medical, Madison, WI). The Medtronic antennas come in three different shaft lengths, 15, 20, and 30 cm, but the radiating (green) section of the probe that becomes hot with use is 2.8 cm on all probes. The NeuWave probes vary in size from 13to17 gauge and lengths of 15, 20, and 25 cm. Power and time settings are recommended by the manufacturer depending on the tissue type, size of the lesion, and number of probes used.

In people, MWA has been described via an open approach, percutaneously via image guidance and with laparoscopy and thoracoscopy. There is limited published information on MWA in veterinary medicine and even more limited information on its use with laparoscopy and thoracoscopy. Yang et al. [36] described the use of MWA with an open approach for the treatment of hepatic neoplasia in five dogs. More recently, Oramas et al. [37] described the feasibility of laparoscopic access to the liver lobes in cadaveric dogs and then detailed the use of MWA with laparoscopy in two clinical cases of hepatic neoplasia. Video‐assisted MWA of pulmonary metastasis has also been reported in a dog [38].

Hemostatic clips have been adapted for endoscopic use. These are C‐shaped clips, in which the tip of the clip closes first, preventing tissue from slipping out of the tip as the clip is closed. Endoclips (Medtronic, Minneapolis, MN) are made in both a 5‐ and a 10‐mm shaft diameter (ssss1). The 10‐mm clips have three sizes: medium, medium/large, and large. The 5‐mm clip is available in medium/large sizes. Ethicon also manufactures hemostatic clips for endoscopic use (LigaMax; Ethicon Endo‐Surgery, Cincinnati, OH), which are available in 5, 10, and 12mm shaft diameters. Locking clip designs with the intent to provide superior clip stability are also available (Reflex ELC 530, Utica, NY). All devices have an indicator on the instrument that details the number of clips left in the device. Complications with clip application include placing too much tissue within the jaws of the clip and clip slippage. Importantly, clips should not be applied to tissue under tension because this can result in changes in diameter of the tissues and clip slippage when the tension is released.

ssss1 Endoclips come in different shaft diameters and clip sizes. They apply C‐shaped clips that close from the tip first. (A) Endoclip applicator. (B) The instrument provides instruments on number of clips left. (C) Tip of clip applier.

Source: From Huhn [3].

ssss1 Endoscopic gastrointestinal anastomosis staplers have a 10‐mm‐diameter shaft that has three different length staplers with four different staple sizes. The largest staple leg length (5 mm, black) requires a 15‐mm port because of the larger diameter of the stapler.

Source: Image courtesy of Medtronic (Minneapolis, MN).

Endoscopic staplers are commonly used in MIS. The most commonly used device is the Endo GIA stapler (Medtronic, Minneapolis, MN) (ssss1), but the Endo TA (Medtronic, Minneapolis, MN) stapler is also available. These are sold as multi‐fire handpieces with disposable cartridges. The Endo GIA comes in three different lengths (30, 45, and 60 mm) and four different staple height sizes (ssss1). This stapler fires six rows of staples and then cuts in between, leaving three rows of staples behind. The new tri‐staple technology allows for graduated compression improving perfusion to the staple line. The Endo GIA is also available reticulated, which allows a more precise placement of the cartridge of staples. The Endo TA stapler is available in a 30‐mm length. It fires a triple staggered row of staples in either 2.5 or 3.5mm leg length. These staples are composed of titanium and are B shaped when compressed, which allows for microvascular perfusion to the staple line, preventing necrosis, which could lead to delayed hemorrhage or leakage.

A study comparing two Endo GIA 30 vascular staple cartridges in a porcine model found both the 2.0 and the 2.5mm staple height to be equivalent for hemostasis of large blood vessels (renal artery and vein, caudal vena cava, and aorta). Both achieved vessel sealing greater than 310 mmHg and were able to seal arteries up to 17 mm and veins up to 22 mm [39]. Lansdowne et al. [40] reported thoracoscopic lung lobectomy in nine dogs. They recommended using the 3.5mm staple height and longer staple cartridges because the 30mm length alone often was not long enough to span the hilus of the lung lobe. Imhoff and Monnet evaluated the Tri‐staple^TM technology in an ex vivo model for lung biopsy and found leakage at lower pressures when compared to standard staples with a nongraduated compression [41]. Despite these ex vivo results, the Tri‐staple^TM technology is commonly used during thoracoscopic lung lobectomy.

ssss1 Internal stapling heights for medtronic Tri‐Staple technology for Endo GIA.

Source: Adapted from Medtronic (Minneapolis, MN).

Tri‐Staple^TM technology for ENDO GIA – laparoscopic and open procedures Cartridge color Open staple height Closed staple height Tissue type Grey 2, 2, 2 mm 0.75, 0.75, 0.75 mm Vascular Tan 2, 2.5, 3 mm 0.75, 1, 1.25 mm Vascular/medium Purple 3, 3.5, 4 mm 1.25, 1.5, 1.75 mm Medium/thick Black (15 mm Port) 4, 4.5, 5 mm 1.75, 2, 2.25 mm Extra‐thick

1 1 Dubiel, B., Shires, P.K., Korvick, D., and Chekan, E.G. (2010). Electromagnetic energy sources in surgery. Vet. Surg. 39 (8): 913.

2 2 d’Arsonval, M.A. (1891). Action physiologique des courants alternatifs. CR Soc. Biol. 43: 283–286.

3 3 Huhn, J.C. (2011). Stapling and energy devices for endoscopic surgery. In: Small Animal Endoscopy, 3e (eds. T.R. Tams and C.A. Rawlings), 365. St. Louis: Elsevier.

4 4 Wang, K. and Advincula, A.P. (2007). “Current thoughts” in electrosurgery. Int. J. Gynaecol. Obstet. 97 (3): 245–250.

5 5 Taheri, A., Mansoori, P., Sandoval, L.F. et al. (2014). Electrosurgery: part I. Basics and principles. J. Am. Acad. Dermatol. 70 (4): 591.

6 6 Hanrath, M. and Rodgerson, D.H. (2002). Laparoscopic cryptorchidectomy using electrosurgical instrumentation in standing horses. Vet. Surg. 31 (2): 117–124.

7 7 Toombs, J.P. and Crowe, D.T. (1985). Operative techniques. In: Textbook of Small Animal Surgery, 1e (ed. D. Slatter), 310–334. Philadelphia: WB Saunders.

8 8 Lee, J. (2002). Update on electrosurgery. Outpatient Surg. 2 (2): 44–53.

9 9 Feldman, L.S., Fuchshuber, P.R., and Jones, D.B. (2012). The SAGES Manual on the Fundamental Use of Surgical Energy (FUSE). New York: Springer.

10 10 Thompson, S.E. and Potter, L. (1999). Electrosurgery, lasers, and ultrasonic energy. In: Veterinary Endosurgery (ed. L.J. Freeman), 61–72. St. Louis: Mosby.

11 11 Massarweh, N.N., Cosgriff, N., and Slakey, D.P. (2006). Electrosurgery: history, principles, and current and future uses. J. Am. Coll. Surg. 202 (3): 520–530.

12 12 Spivak, H., Richardson, W.S., and Hunter, J.G. (1998). The use of bipolar cautery, laparosonic coagulating shears, and vascular clips for hemostasis of small and medium‐sized vessels. Surg. Endosc. 12 (2): 183–185.

13 13 Phillips, C.K., Hruby, G.W., Durak, E. et al. (2008). Tissue response to surgical energy devices. Urology 71 (4): 744–748.

14 14 Hruby, G.W., Marruffo, F.C., Durak, E. et al. (2007). Evaluation of surgical energy devices for vessel sealing and peripheral energy spread in a porcine model. J. Urol. 178 (6): 2689–2693.

15 15 Carbonell, A.M., Joels, C.S., Kercher, K.W. et al. (2003). A comparison of laparoscopic bipolar vessel sealing devices in the hemostasis of small‐, medium‐, and large‐sized arteries. J. Laparoendosc. Adv. Surg. Tech. 13 (6): 3773–3780.

16 16 Harold, K.L., Pollinger, H., Matthews, B.D. et al. (2003). Comparison of ultrasonic energy, bipolar thermal energy, and vascular clips for the hemostasis of small‐, medium‐, and large‐sized arteries. Surg. Endosc. 17 (8): 1228–1230.

17 17 Newcomb, W.L., Hope, W.W., Schmelzer, T.M. et al. (2009). Comparison of blood vessel sealing among new electrosurgical and ultrasonic devices. Surg. Endosc. 23 (1): 90–96.

18 18 Sindram, D., Martin, K., Meadows, J.P. et al. (2011). Collagen‐elastin ratio predicts burst pressure of arterial seals created using a bipolar vessel sealing device in a porcine model. Surg. Endosc. 25 (8): 2604–2612.

19 19 Mayhew, P.D., Culp, W.T., Pascoe, P.J. et al. (2012). Use of the ligasure vessel‐sealing device for thoracoscopic peripheral lung biopsy in healthy dogs. Vet. Surg. 41 (4): 523–528.

20 20 Barrera, J.S. and Monnet, E. (2012). Effectiveness of a bipolar vessel sealant device for sealing uterine horns and bodies from dogs. Am. J. Vet. Res. 73 (2): 302–305.

21 21 Risselada, M., Ellison, G.W., Bacon, N.J. et al. (2010). Comparison of 5 surgical techniques for partial liver lobectomy in the dog for intraoperative blood loss and surgical time. Vet. Surg. 39 (7): 856–862.

22 22 Brdecka, D.J., Rawlings, C.A., Perry, A.C. et al. (2008). Use of an electrothermal, feedback‐controlled, bipolar sealing device for resection of the elongated portion of the soft palate in dogs with obstructive upper airway disease. J. Am. Vet. Med. Assoc. 233 (8): 1265–1269.

23 23 Landman, J., Kerbl, K., Rehman, J. et al. (2003). Evaluation of a vessel sealing system, bipolar electrosurgery, harmonic scalpel, titanium clips, endoscopic gastrointestinal anastomosis vascular staples and sutures for arterial and venous ligation in a porcine model. J. Urol. 169 (2): 697–700.

24 24 Lamberton, G.R., Hsi, R.S., Jin, D.H. et al. (2008). Prospective comparison of four laparoscopic vessel ligation devices. J. Endourol. 22 (10): 2307–2312.

25 25 Gardeweg, S., Bockstahler, B., and Dupré, G. (2019). Effect of multiple use and sterilization on sealing performance of bipolar vessel sealing devices. PLoS One 14 (8): e0221488. https://doi.org/10.1371/journal.pone.0221488.

26 26 Blake, J.S., Trumpatori, B.J., Mathews, K.G. et al. (2017). Carotid artery bursting pressure and seal time after multiple uses of a vessel sealing device. Vet. Surg. 46 (4): 501–506.

27 27 Kuvaldina, A., Hayes, G., Sumner, J. et al. (2018). Influence of multiple reuse and resterilization cycles on the performance of a bipolar vessel sealing device (LigaSure) intended for single use. Vet. Surg. 47 (7): 951–957.

28 28 Matz, B.M., Tillson, D.M., Boothe, H.W. et al. (2014). Effect of vascular seal configuration using the LigaSure on arterial challenge pressure, time for seal creation, and histologic features. Vet. Surg. 43 (6): 761–764.

29 29 Santini, M., Vicidomini, G., Baldi, A. et al. (2006). Use of an electrothermal bipolar tissue sealing system in lung surgery. Eur. J. Cardiothorac. Surg. 29 (2): 226–230.

30 30 Marvel, S. and Monnet, E. (2013). ex vivo evaluation of canine lung biopsy techniques. Vet. Surg. 42 (4): 473–477.

31 31 Valenzano, D., Hayes, G., Gludish, D. et al. (2019). Performance and microbiological safety testing after multiple use cycles and hydrogen peroxide sterilization of a 5‐mm vessel‐sealing device. Vet. Surg. 48 (5): 885–889.

32 32 Quitzan, J.G., Singh, A.S., Beaufrere, H. et al. (2020). Evaluation of the performance of an endoscopic 3‐mm electrothermal bipolar vessel sealing device intended for single use after multiple use‐and‐resterilization cycles. Vet. Surg. 49: O120–O130.

33 33 Lubner, M.G., Brace, C.L., Hinshaw, J.L. et al. (2010). Microwave tumor ablation: mechanism of action, clinical results, and devices. J. Vasc. Interv. Radiol. 21: S192–S203.

34 34 Skinner, M.G., Iizuka, M.N., Kolios, M.C. et al. (1998). A theoretical comparison of energy sources‐microwave, ultrasound, and laser‐for interstitial thermal therapy. Phys. Med. Biol. 43: 3535–3547.

35 35 Wright, A.S., Sampson, L.A., Warner, T.F. et al. (2005). Radiofrequency versus microwave ablation in a hepatic porcine model. Radiology 236: 132–139.

36 36 Yang, T., Case, J.B., Boston, S. et al. (2017). Microwave ablation for treatment of hepatic neoplasia in five dogs. J. Am. Vet. Med. Assoc. 250 (1): 79–85.

37 37 Oramas, A., Case, J.B., Toskich, B.B. et al. (2019). Laparoscopic access to the liver and application of laparoscopic microwave ablation in 2 dogs with liver neoplasia. Vet. Surg. 48: 91–98.

38 38 Mazzaccari, K., Boston, S.E., Toskich, B.B. et al. (2017). Video‐assisted microwave ablation for the treatment of a metastatic lung lesion in a dog with appendicular osteosarcoma and hypertrophic osteopathy. Vet. Surg. 46: 1161–1165.

39 39 El‐Hakim, A., Cai, Y., Marcovich, R. et al. (2004). Effect of Endo‐GIA vascular staple size on laparoscopic vessel sealing in a porcine model. Surg. Endosc. 18 (6): 961–963.

40 40 Lansdowne, J.L., Monnet, E., Twedt, D.C. et al. (2005). Thoracoscopic lung lobectomy for treatment of lung tumors in dogs. Vet. Surg. 34 (5): 530–535.

41 41 Imhoff, D.J. and Monnet, E. (2016). Inflation pressures for ex vivo lung biopsies after application of graduated compression staples. Vet. Surg. 45 (1): 79–82.

Chris Thomson and Jeffrey J. Runge

 The platforms of single‐incision, single‐port, and laparoendoscopic single‐site surgery provide a natural progression to a less invasive surgical approach, when compared to the multiport laparoscopic platform.

 Single‐incision and single‐port surgery can be achieved using an operating laparoscope but is more commonly performed with commercially available single‐port devices.

 Articulating instruments can be used to offset the limitations on triangulation that are inherent to the approach, although the use of rigid instrumentation is also possible.

 Within veterinary medicine, this platform has expanded beyond the abdominal cavity to also include surgery within the thoracic and retroperitoneal spaces.

 Single‐incision, single‐port, and laparoendoscopic single‐site surgery have secured a comfortable niche within veterinary minimally invasive surgery. Reducing invasiveness while maintaining the safety and efficacy of operative procedures should be our top priority as veterinary surgeons.

Surgery is forever evolving. As new evidence emerges on how to treat disease, the methods by which we apply this new knowledge to daily patient care are constantly refined. Within the past century, arguably one of the most important advancements to occur within the surgery is the development of laparoscopy. This approach has completely revolutionized modern surgical practices, significantly changing the surgical way of thinking, operative techniques, and all other aspects of modern surgical care [1]. Laparoscopy gained acceptance among surgeons and patients alike because of its unquestionable advantages, which include smaller incisions, reduced postoperative pain, shorter hospital stays, and faster return to everyday living compared with the traditional open approach [2]. After the laparoscopic revolution occurred in humans during the 1980s, it was not long before diseases once commonly addressed through open surgery began to be performed by laparoscopic means. The tremendous advantages and benefits of laparoscopy witnessed in human health care impacted companion animal health as well, eventually changing the way many common operative procedures could be performed in veterinary surgery. To date, veterinary surgeons now have the ability to use a minimally invasive approach for almost every type of intrathoracic and intra‐abdominal procedure offered in canine and feline surgery.

Another revolution in the field of laparoscopic surgery has occurred with striking technical advancements leading to the development of even less invasive operative procedures in both humans and animals. The journey to make minimally invasive techniques even less invasive has generated a drive within the surgical community to explore novel ways of achieving this paradigm [3]. New approaches to minimally invasive abdominal entry have included decreasing the overall number of trocars–cannula assemblies placed through the abdominal wall and attempting to eliminate them completely by using a natural orifice. These concepts have led to the birth of several new minimally invasive access platforms, with the most notable being single‐port style surgery. For the purpose of this chapter, and to be consistent with previous veterinary literature, we will use the term single‐port surgery to broadly encompass the single‐incision and single‐port style of laparoscopic approaches. Additionally, the concept of reduced port surgery will also be briefly discussed as a segue and bridge for reducing the overall number of ports it pert when discussing this platform in veterinary medicine.

Of note, the specific terminology for describing the various approaches and surgical procedures completed through a single laparoscopic incision or single port has varied. This confusion has led to a great deal of debate among a number of the leading human laparoscopic surgeons as to what proper nomenclature and terminology should be used for the literature. An international consortium of experts within human laparoscopy elected to attempt to utilize the term Laparoendoscopic Single‐Site Surgery (LESS) [4]. This was done to standardize the field and promote a more rapid dissemination of the associated research. However, that term is still not entirely accepted and continues to be a confusing topic. Additional terminology and acronyms are described in ssss1.

ssss1 Acronyms used in text.

Acronym Full procedure name LESS Laparoendoscopic single‐site surgery NOTES Natural orifice transluminal endoscopic surgery SPA Single‐port access SILS Single‐incision laparoscopic surgery SILAIS Single‐incision laparoscopic‐assisted intestinal surgery SPAGO Single‐port access gastropexy and ovariectomy SPLC Single‐incision laparoscopic cryptorchidectomy

Interestingly, natural orifice transluminal endoscopic surgery (NOTES) has remained in its experimental stages and continues to suffer from numerous hurdles preventing its broad implementation. Single‐incision, single‐port, and reduced port laparoscopic surgery has emerged as the more acceptable choice for most surgeons [5]. The acceptance of these newer platforms, unlike NOTES, remains within the comfort zone of most surgeons because the instrumentation and techniques are similar to those used in standard laparoscopy [6].

Whereas conventional laparoscopy requires multiple, individually spaced incisions to accommodate ports ranging from 5 to 10 mm in length, the single‐incision and single‐port platform differs from this by placing all instruments through one single (1.5–3 cm) incision into the abdomen. In humans, at present, procedures such as single‐port cholecystectomy and hemicolectomy are gaining significant popularity.

Additionally, the development of the reduced‐port surgery concept has evolved as the middle ground between true multiport laparoscopy and single port. Reduced port surgery is gradual, step‐wise, incremental reduction of ports/incisions for a given procedure to reduces overall invasiveness. An example is going from 4 to 5 port cholecystectomy to a two‐port procedure. This reduced port platform is positioning itself to potentially replace conventional dogmatic style of multiport laparoscopic procedures by achieving reduced postoperative pain and optimized cosmetic results compared with the multiport procedure [7, 8].

The early history of single‐port style laparoscopic surgery may date back to its early use in laparoscopic gynecologic surgery when Wheeless and Thompson described more than 1000 tubal ligations using a single puncture laparoscope with an offset eye piece [9]. However, purists within the contemporary single‐port arena argue that operative laparoscopy differs significantly from modern‐day single‐port surgery, and the origins of the single‐port surgical revolution were developed more recently. The first use of separate instruments and ports through a single incision was initially described in 1997 by Navarra et al., when they published their “one wound cholecystectomy” using two transumbilical trocars [10]. At that time, single‐port surgery seemed as if it was not ready to emerge as a viable access platform for the mainstream and even Navarra himself questioned the validity of that approach in terms of its safety, efficacy, and operative time. It was not until 2007, when Curcillo revisited Navarra's work and described a stepwise approach for the reduction of port sites and consolidation of trocars, resulting in one umbilical incision for laparoscopic cholecystectomy named single‐port access (SPA) [11]. Since 2007, a massive emergence of single‐port procedures has been successfully adapted to many common multiport laparoscopic abdominal procedures in both children and adults with the ultimate goal of reducing overall surgical invasiveness. The single‐port platform evolved rapidly with the objectives of minimizing overall surgical trauma, reducing postoperative pain, shortening convalescence, and improving cosmesis [11]. In humans, it is speculated that the potential advantages that single‐port surgery has over conventional multiport laparoscopy include superior cosmesis from a relatively hidden umbilical scar; a possible decrease in morbidity related to visceral and vascular injury during trocar placement; and risk reduction of postoperative wound infection, hernia formation, and elimination of multiple trocar site closures [12]. To date, there have been several systematic reviews and metanalyses describing the comparison of conventional laparoscopic and single‐port procedures, as well as a handful of prospective, randomized controlled trials [8,13–19]. Although a broad generalization cannot be made; there is a general trend toward shorter hospitalization stays, less need for postoperative analgesia, and lower pain scores associated with single‐port surgery when compared to conventional laparoscopy.

It should also be noted that within the human literature, including both clinical case series and laboratory‐based skill acquisition studies, evidence has demonstrated unique requirements of single‐port surgery. Skill sets and ergonomic demands cannot be directly adapted from existing laparoscopic experience, and the implementation of an evidence‐ and competency‐based single‐port training curriculum is necessary to ensure appropriate training of future single‐port surgeons [19]. An evaluation of the learning curve for the single‐port ovariectomy for a board‐certified veterinary surgeon has also been reported [20]. The study described that the learning curve for single‐port ovariectomy was short (optimal performance after approximately eight procedures), and proficiency can be achieved within a definable period.

Within veterinary laparoscopic surgery, reducing the number of portals of entry has been a concept embraced by many veterinarians for a number of common techniques. In 2009, Dupre et al. described the one portal operating laparoscopic ovariectomy (OVE) using a 10‐mm telescope that incorporates a working channel that can accommodate 5‐mm instruments [21]. An array of two‐port laparoscopic‐assisted techniques, including gastropexy [22], cystopexy [23], urinary calculi removal [24], and cryptorchidectomy [25], have also been described. These two‐port techniques enabled many common elective procedures to be done routinely by veterinary laparoscopic surgeons. It was only recently that many of the two‐port procedures in veterinary laparoscopy took a leap toward the single‐port platform in which multiple instruments, as well as the telescope, are consolidated to one point of entry for completion of the entire procedure. The earliest abstract reports on laparoscopic single‐port veterinary techniques that did not use an operating laparoscope emerged in 2011 [25, 26]. The single‐port platform gained rapid popularity among veterinary laparoscopic surgeons. Shortly after the initial single‐port abstracts, a total laparoscopic ovariectomy using standard rigid instrumentation was described [27] using a commercially available single‐port device (SILS [single‐incision laparoscopic surgery] port, Covidien, Mansfield, MA). Shortly after, the SPA ovariectomy technique was reported [28]. Other single‐port devices, as well as novel bent and articulating instruments, emerged as feasible instrumentation that could be used in veterinary single‐port laparoscopy [29]. More recently, other techniques using the LESS approach have been reported and are summarized in ssss1.

ssss1 Examples of procedures that have been adopted with single‐port, single‐incision, and LESS in clinical cases within veterinary surgery.

References Ovariectomy in dogs and cats [20, 27, 28,30–35] Ovariohysterectomy [36] Cryptorchidectomy [37, 38] Intestinal surgery [34,39–44] Adrenalectomy [45] Splenectomy [46, 47] Artificial urethral sphincter placement [48] Gastropexy [22,49–52] Cholecystectomy [53–55] Ureteronephrectomy [56]

Despite the wider adoption of single‐port surgery in veterinary medicine, there has been little comparative analysis of the potential advantages or disadvantages to conventional, multiport laparoscopic surgery. A retrospective case series reviewed multiport and a SPA system for a variety of laparoscopic procedures [57]. Surgical time and intraoperative complications were found reduced for patients undergoing single‐port surgery. Conversely, a prospective, randomized trial comparing multiport and single‐port ovariectomy demonstrated that surgical difficulty was subjectively higher for single‐port surgery [58]. Complications were, however, not identified in any case (0/10). Given the additional technical challenges, different and often expensive disposables required, and potentially longer learning curve, additional study is warranted on the value and safety of LESS over existing techniques.

This uses a traditional simple operative endoscope that incorporates a 5‐mm working channel through which instruments can be passed (ssss1). Advanced operating laparoscopes include a triangulating operating platform, 30 such as the SPIDER surgical system (TransEnterix Surgical Inc, Durham, NC), which gives a surgeon multiple independent, flexible arms that can be extended through a rigid operating laparoscope shaft.

This uses a single skin incision (usually at the umbilicus), but separate individual facial incisions through which traditional trocar–cannula assemblies are passed through the abdominal wall (ssss1). SPS has also been adapted for a paramedian approach (laparoscopic‐assisted gastropexy) [51], transvaginal approach (ovariectomy) [59], and retroperitoneal access (adrenalectomy) [45, 60].

ssss1 This operating laparoscope (Karl Storz Endoscopy, Goleta, CA) incorporates a 5‐mm working channel through which 5‐mm rigid instrumentation can be passed.

Source: © 2014 Photo Courtesy of KARL STORZ GmbH & Co. KG.

ssss1 Single‐port access laparoscopy is performed by the passage of three separate cannulae through one skin incision but separate fascial incisions.

These devices have been specifically manufactured for single‐port surgery and are intended to be inserted through a single full‐thickness abdominal incision. These commercially available SPA devices can have multiple 5‐ to 12‐mm access channels to enable an array of instrumentation to enter the abdominal cavity (ssss1).

The principles of single‐port surgery are very similar to those of conventional multiport laparoscopy, although differences exist associated with the way triangulation is achieved. Having one point of entry inherently prevents the traditional principles of instrument triangulation. The close proximity of the instruments and optics, both intra‐abdominal and extra‐abdominal, causes the surgeon to perform the procedure with suboptimal working space intra‐abdominally. This ultimately causes increased technical complexity for any procedures because of inadequate triangulation, a compromised field of view, inadequate exposure, and frequent instrument collisions, which all occur as a result of the common entry point for the camera and instruments [29]. Single‐port laparoscopy has been able to somewhat overcome this lack of triangulation by using angled optical telescopes, crossing instruments, or bent and articulating instruments. This novel arrangement of both the optics and instruments creates more internal and external working space, allowing for some triangulation that prevents instrument crowding. Although standard instruments can be used for single‐port surgery, numerous instruments and devices have been developed to simplify and make single‐port surgery more user friendly.

2

The devices and equipment used for single‐port surgery can be broadly classified as: (i) specifically manufactured devices for single‐port surgery, (ii) standard instruments and trocar–cannula assemblies used for conventional laparoscopy inserted through one skin incision, or (iii) innovative adoptions of existing equipment not primarily intended for laparoscopy.

GelPOINT Access System

A 2‐ to 3‐cm mini‐laparotomy is created in advance for insertion of the port. To insert this single‐port device, a small amount of sterile lubricant is applied to its soft base (Video 6.2). The port is inserted into its 2‐ to 3‐cm abdominal incision by clamping two curved Rochester‐carmalt forceps at the base in a staggered fashion. Varying techniques have been described for insertion into the incision: it can be performed without abdominal wall countertraction or with a form of countertraction such as grasping the facial edges with two large rat‐toothed tissue forceps, Army‐Navy retractors, or stay sutures. Regardless of traction, the tips of the Rochester‐carmalts are directed into the incision in a cranial direction toward the diaphragm or away from any underlying viscera. When the base is seeded within the incision, the clamps are then released to allow the bottom portion of the port to expand and fit snugly within the incision. Three 5‐mm cannulae (supplied with the port) are then partially inserted into the three inner cylinders with the aid of a 5‐mm blunt obturator. The SILS port is also supplied with a 12‐ to 15‐mm trocar–cannula assembly to allow larger instruments to be inserted with two other 5‐mm cannulae. The heights of the cannulae are staggered to minimize cannula contact (ssss1). Insufflator tubing is then attached, and the abdomen is insufflated to 8–10 mmHg with carbon dioxide using a pressure‐regulating mechanical insufflator. Once insufflation is complete, the three canulae can then be inserted deeper into the port. The multitrocar port can be positioned to have the three 5‐mm cannulae at the 12, 4, and 8 o’clock positions relative to the surgical site, although any arrangement is possible. Advantages of this port include the relative ease of insertion and reinsertion during a procedure and its ability to fit snugly within the incision, preventing loss of pneumoperitoneum.

Despite being sold as single‐use instruments, it is not uncommon to reuse various minimally invasive surgery devices in veterinary medicine for economic reasons. Multiple studies have been conducted to test the reusability of the SILS devices [61–63]. Results indicate that the ports can be decontaminated and sterilized by ethylene oxide and hydrogen peroxide vapor for repeated use. In one study [62], the foam component was found to have positive light growth after eight uses. The reuse of the SILS ports appears to carry a low risk of infection to the patient; however, the mechanical stability of the ports after reuse has yet to be widely tested.

ssss1 With the SILS (single‐incision laparoscopic surgery) device (Karl Storz Endoscopy, Goleta, CA), it is recommended to stagger the cannulae to minimize interference.

ssss1 With some port devices, some triangulation can still be maintained, but this varies by device.

Single‐Port Access Technique

A 1.5‐ to 2‐cm skin incision is made on the ventral midline in the region of the umbilicus. Using the Hasson abdominal access technique, a 5‐mm blunt laparoscopic low‐profile trocar–cannula assembly is inserted into the abdomen. The abdomen is insufflated using a pressure‐regulating mechanical insufflator to an intraabdominal pressure between 9 and 12 mmHg. After brief abdominal exploration with a 30° telescope, two additional very‐low‐profile 5‐mm trocar–cannula assemblies are then inserted in a triangular pattern adjacent to the initial port. For the second and third low‐profile trocar–cannula insertions, the abdomen is partially desufflated to approximately 6–8 mmHg to facilitate mobilization of the skin and soft tissue associated with the initial skin incision and to enable a small soft tissue flap to be created, which allows for tunneling of the ports adjacent to the initial trocar. Using minimal blunt dissection, a tunnel is undermined 1–2 cm laterally and caudally on either side of the initial 5‐mm trocar–cannula assembly using a Kelly hemostat. Through those tunneled paths, the two low‐profile trocar–cannula assemblies are inserted through the abdominal wall into the peritoneal cavity using the sharp trocars under optical visualization. The three trocars are arranged in a deliberate triangular arrangement that causes the skin to stretch in a lateral direction. This arrangement enables each low‐profile cannula to enter the abdomen through separate facial openings but enters through the same 2‐cm skin incision. Advantages with this entry method rely on the fact that existing standard metal and reusable trocar–cannula assemblies can be used, avoiding the cost associated with purchasing disposable equipment.

2

ssss1 A wound retractor with latex glove and finger ports can be used as an inexpensive single‐port device.

ssss1 This wound retractor (Alexis; Applied Medical, Rancho Santa Margarita, CA) provides a protected retracted access incision through which organs can be exteriorized.

Conventional multiport laparoscopy is governed by the rule of triangulation such that a view is established in tandem with the simultaneously working extension of the human hand by means of the instruments [3]. Because the single‐port platform follows the premise that all instruments enter the abdomen at the same site, one is forced to challenge the laws of traditional instrument triangulation. The single‐port platform creates significant physical and ergonomic constraints that make traditional procedures more difficult to learn and perform compared with traditional laparoscopic surgery. The proximity and parallel trajectory of the telescope and operating instruments placed through the single‐site led to the inevitable instrument and cannula collision, which ultimately interferes with smooth movements and makes the procedure more demanding than standard multiport laparoscopy.

ssss1 The wound retractor in figure 11 can be used with a laparoscopic cap for insufflation

Source: Courtesy Boel Fransson Washington State University.

In trying to overcome some of the technical difficulties associated with single‐port surgery, bent and articulating instruments have been developed to reproduce the triangulation that is experienced with conventional multiport laparoscopy and to limit some of the stated difficulties associated with using standard rigid instrumentation in single‐port surgery [29].

However, it should be noted that single‐port surgery could successfully be performed using rigid instrumentation. An extensive body of literature exists describing single‐port procedures completed by means of standard rigid laparoscopic instruments in both humans and veterinary patients. An array of articulating and double pre‐bent laparoscopic instruments have been developed and marketed specifically for the single‐port platform in an effort to correct the difficulties resulting from the loss of triangulation. Bent or coaxial deviating instruments are in a fixed position and were designed to be offset from the straight axis of a standard instrument, enabling the surgeon to have internal and external working space [65–70]. The curved design provides acceptable intracorporeal triangulation and good ergonomic positioning for the hands (ssss1). The articulating instruments have a design that mimics the movements of a surgeon's wrist and have a distal tip that can deflect relative to their shaft, offering seven degrees of freedom of movement [3]. Many of these instruments also offer axial 360° rotation for tip orientation similar to conventional rigid instruments. All of the articulating instruments can be introduced in both single‐port devices and conventional rigid trocar–cannula assemblies. The double pre‐bent instruments are intended to mimic triangulation through a curved design of both ends of the instrument shaft, which leads to antipodal directions of the tips and handles when the instruments are held in parallel [71]. The double‐bent instruments can only be used with soft, flexible, or specifically designed entry devices for bent instruments because the bends in these instruments prevent their introduction into a rigid trocar–cannula assembly.

ssss1 Coaxial instruments used through single‐port devices can obviate some of the disadvantages encountered when the ability to triangulate is compromised.

Source: Courtesy of J. Brad Case.

ssss1 A right‐angle adaptor placed onto the connection between the light cable and telescope can reduce interference between the light cable and instruments during single‐port surgery.

With the close proximity of the telescopes and instruments in single‐port surgery, adjustments are required to create space both internally and externally to avoid instrument and optic interference. The easiest way to avoid optics and instrument clashing during the procedure is the use of an angled telescope. The most common telescope used for single‐port laparoscopy in veterinary medicine is a telescope with a 30° angle. To further reduce the external clashing of instruments with the light cable, a right‐angle adaptor for the light cable can be used (ssss1). Recently, the development of advanced laparoscopes geared specifically for single‐port surgery has emerged. A variety of deflectable telescopes with different mechanical design properties have recently been shown to be effective. One design involves a traditional fixed‐rod design that contains a rotating lens at the distal end (EndoCAMeleon, Karl Storz Endoscopy), or alternatively a design that uses the “chip on the tip” concept by placing an image processor at the distal tip of an articulating laparoscope (EndoEye, Olympus; Idealeye Stryker, Kalamazoo, MI) [72]. During veterinary single‐port surgery, it has been shown that using either a 30° telescope or an advanced deflecting optic enables the telescope's camera head and tip to be directed away from the other instruments during the procedure, improving working space while simultaneously maintaining excellent visualization.

The single‐port platform is a recent innovation in minimally invasive surgery. This platform may represent the next step forward in minimally invasive techniques. Early reports in the veterinary literature have shown this access method as a feasible and potentially more attractive approach for many common veterinary procedures. The focus of all new surgical techniques should be feasibility, safety, and efficacy, and they should provide a clinical advantage over other existing methods. Further studies are needed to determine if this platform for surgery can be considered a comparable alternative to multiport laparoscopy. Continually pursuing these types of research initiatives will help to drive emerging minimally invasive techniques and technology that ultimately benefits both human and veterinary patients alike.

1 1. Darzi, A. and Munz, Y. (2004). The impact of minimally invasive surgical techniques. Annu. Rev. Med. 55: 223–237.

2 2. Keus, F., de Jong, J., Gooszen, H.G. et al. (2006). Laparoscopic versus open cholecystectomy for patients with symptomatic cholecystolithiasis. Cochrane Database Syst. Rev. 4: CD006229.

3 3. Kommu, S.S. and Rane, A. (2009). Devices for laparoendoscopic single‐site surgery in urology. Expert Rev. Med. Devices 6: 95–103.

4 4. Gill, I.S. (2010). Consensus statement of the consortium for laparoendoscopic single‐site surgery. Surg. Endosc. 24 (4): 262–268.

5 5. Islam, A., Castellvi, A.O., Tesfay, S.T. et al. (2011). Early surgeon impressions and technical difficulty associated with laparoendoscopic single‐site surgery: a society of American gastrointestinal and endoscopic surgeons learning center study. Surg. Endosc. 8: 2597–2603. (previous 4).

6 6. Galvao Neto, M., Ramos, A., and Campos, J. (2009). Single port laparoscopic access surgery. Gastrointest. Endosc. 11: 84–93.

7 7. Qiu, J., Yuan, H., Chen, S. et al. (2013). Single‐port versus conventional multiport laparoscopic cholecystectomy: a meta‐analysis of randomized controlled trials and nonrandomized studies. J. Laparoendosc. Adv. Surg. Tech. 23: 815–831.

8 8. Liu, X., Yang, W.H., Jiao, Z.G. et al. (2019). Systematic review of comparing single‐incision versus conventional laparoscopic right hemicolectomy for right colon cancer. World J. Surg. Oncol. 17: 179. https://doi.org/10.1186/s12957‐019‐1721‐6.

9 9. Wheeless, C.R. Jr. and Thompson, B.H. (1973). Laparoscopic sterilization. Review of 3600 cases. Obstet. Gynecol. 42: 751–758. (previous 7).

10 10 Navarra, G., Pozza, E., Occhionorelli, S. et al. (1997). One‐wound laparoscopic cholecystectomy. Br. J. Surg. 84: 695.

11 11 Podolsky, E.R., Rottman, S.J., Pobete, H. et al. (2009). Single port access (SPA) cholecystectomy: a completely transumbilical approach. J. Laparoendosc. Adv. Surg. Tech. 19: 219–222.

12 12 Fader, A.N., Levinson, K.L., Gunderson, C.C. et al. (2011). Laparoendoscopic single‐site surgery in gynaecology: a new frontier in minimally invasive surgery. J. Minim. Access Surg. 7: 71–77.

13 13 Lin, Y., Liu, M., Ye, H. et al. (2020). Laparoendoscopic single‐site surgery compared with conventional laparoscopic surgery for benign ovarian masses: a systematic review and meta‐analysis. BMJ Open 10 (2): e032331. https://doi.org/10.1136/bmjopen‐2019‐032331. PMID: 32066600; PMCID: PMC7045036.

14 14 Feng, D., Cong, R., Cheng, H. et al. (2019). Laparoendoscopic single‐site nephrectomy versus conventional laparoendoscopic nephrectomy for kidney tumor: a systematic review and meta‐analysis. Biosci. Rep. 39 (8): BSR20190014. https://doi.org/10.1042/BSR20190014. PMID: 31358687; PMCID: PMC6689106.

15 15 Chauhan, N., Kenwar, D.B., Singh, N. et al. (2018). Retroperitoneal single port versus transperitoneal multiport donor nephrectomy: a prospective randomized control trial. J. Endourol. 32 (6): 496–501. https://doi.org/10.1089/end.2017.0829. Epub 2018 Apr 12. PMID: 29641348.

16 16 Sandberg, E.M., la Chapelle, C.F., van den Tweel, M.M. et al. (2017). Laparoendoscopic single‐site surgery versus conventional laparoscopy for hysterectomy: a systematic review and meta‐analysis. Arch. Gynecol. Obstet. 295 (5): 1089–1103. https://doi.org/10.1007/s00404‐017‐4323‐y. Epub 2017 Mar 29. PMID: 28357561; PMCID: PMC5388711.

17 17 Mencaglia, L., Mereu, L., Carri, G. et al. (2013). Single port entry—are there any advantages? Best Pract. Res. Clin. Obstet. Gynaecol. 27: 441–455.

18 18 Antoniou, S.A., Koch, O.O., and Antoniou, G. (2014). Meta‐analysis of randomized trials on single‐incision laparoscopic versus conventional laparoscopic appendectomy. Am. J. Surg. 207: 613–622.

19 19 Pucher, P.H., Sodergren, M.H., Singh, P. et al. (2012). Have we learned from lessons of the past? A systematic review of training for single incision laparoscopic surgery. Surg. Endosc. 27: 1478–1484.

20 20 Runge, J.J., Boston, R.C., Ross, S.B. et al. (2014). Evaluation of the learning curve for a board‐certified surgeon performing laparoendoscopic single‐site ovariectomy in dogs. J. Am. Vet. Med. Assoc. 245: 828–835.

21 21 Dupré, G., Fiorbianco, V., Skalicky, M. et al. (2009). Laparoscopic ovariectomy in dogs: comparison between single portal and two‐portal access. Vet. Surg. 38: 818–824.

22 22 Rawlings, C.A., Foutz, T.L., Mahaffey, M.B. et al. (2001). A rapid and strong laparoscopic‐assisted gastropexy in dogs. Am. J. Vet. Res. 62: 871–875.

23 23 Rawlings, C.A., Howerth, E.W., Mahaffey, M.B. et al. (2002). Laparoscopic‐assisted cystopexy in dogs. Am. J. Vet. Res. 63: 1226–1231.

24 24 Rawlings, C.A., Mahaffey, M.B., Barsanti, J.A. et al. (2003). Use of laparoscopic‐assisted cystoscopy for removal of urinary calculi in dogs. J. Am. Vet. Med. Assoc. 222: 759–761.

25 25 Miller, N.A., Van Lue, S.J., and Rawlings, C.A. (2004). Use of laparoscopic‐assisted cryptorchidectomy in dogs and cats. J. Am. Vet. Med. Assoc. 224: 875–878.

26 26 Wilson, D. and Monnet, E. (2011). Utilization of SILS Port with standard instrumentation to perform laparoscopic procedures in dogs. Proceedings of the 8th Annual Meeting of the Veterinary Endoscopy Society, San Pedro, Belize (5–7 May 2011), p. 12.

27 27 Manassero, M., Leperlier, D., Vallefuoco, R. et al. (2012). Laparoscopic ovariectomy in dogs using a single‐port multiple‐access device. Vet. Rec. 171: 69.

28 28 Runge, J.J., Curcillo, P.G. II, King, S.A. et al. (2012). Initial application of reduced port surgery using the single port access technique for laparoscopic canine ovariectomy. Vet. Surg. 41: 803–806.

29 29 Runge, J.J. (2012). The cutting edge: introducing reduced port laparoscopic surgery. Today’s Vet. Pract. January/February 2012: 14–20.

30 30 Runge, J.J. and Curcillo, P.G. (2011). Reduced port surgery: single port access (SPA) technique for laparoscopic canine ovariectomy. Proceedings of the 8th Annual Meeting of the Veterinary Endoscopy Society, San Pedro, Belize (5–7 May 2011), p. 13.

31 31 Binder, C., Katić, N., Aurich, J.E., and Dupré, G. (2018). Postoperative complications and owner assessment of single portal laparoscopic ovariectomy in dogs. Vet. Rec. 183 (24): 745.

32 32 Keeshen, T.P., Case, J.B., Runge, J.J. et al. (2017). Outcome of laparoscopic ovariohysterectomy or ovariectomy in dogs with von Willebrand disease or factor VII deficiency: 20 cases (2012–2014). J. Am. Vet. Med. Assoc. 251 (9): 1053–1058.

33 33 van Nimwegen, S.A., Van Goethem, B., de Gier, J., and Kirpensteijn, J. (2018). A laparoscopic approach for removal of ovarian remnant tissue in 32 dogs. BMC Vet. Res. 14 (1): 333.

34 34 Rubin, J.A., Shigemoto, R., Reese, D.J., and Case, J.B. (2015). Single‐incision, laparoscopic‐assisted jejunal resection and anastomosis following a gunshot wound. J. Am. Anim. Hosp. Assoc. 51 (3): 155–160.

35 35 Coisman, J.G., Case, J.B., Shih, A. et al. (2013). Comparison of surgical variables in cats undergoing single‐incision laparoscopic ovariectomy using a LigaSure or extracorporeal suture versus open ovariectomy. Vet. Surg. 43: 38–44.

36 36 Becher‐Deichsel, A., Aurich, J.E., Schrammel, N., and Dupré, G. (2016). A surgical glove port technique for laparoscopic‐assisted ovariohysterectomy for pyometra in the bitch. Theriogenology 86 (2): 619–625.

37 37 Runge, J.J., Mayhew, P.D., Case, J.B. et al. (2014). Single‐port cryptorchidectomy in dogs and cats: 25 cases (2009–2014). J. Am. Vet. Med. Assoc. 245: 1258–1265.

38 38 Carr, J.G., Heng, H.G., Ruth, J., and Freeman, L. (2015). Laparoscopic treatment of testicular torsion in a puppy. J. Am. Anim. Hosp. Assoc. 51 (2): 97–100.

39 39 Case, J.B. and Ellison, G. (2013). Single Incision laparoscopic‐assisted intestinal surgery (SILAIS) in 7 dogs and 1 cat. Vet. Surg. 42: 629–634.

40 40 Mitterman, L., Bonczynski, J., Hearon, K., and Selmic, L.E. (2016). Comparison of perioperative and short‐term postoperative complications of gastrointestinal biopsies via laparoscopic‐assisted technique versus laparotomy. Can. Vet. J. 57 (4): 395–400.

41 41 Shamir, S.K., Singh, A., Mayhew, P.D. et al. (2019). Evaluation of minimally invasive small intestinal exploration and targeted abdominal organ biopsy with use of a wound retraction device in dogs: 27 cases (2010–2017). J. Am. Vet. Med. Assoc. 255 (1): 78–84.

42 42 Otomo, A., Singh, A., Valverde, A. et al. (2019). Comparison of outcome in dogs undergoing single‐incision laparoscopic‐assisted intestinal surgery and open laparotomy for simple small intestinal foreign body removal. Vet. Surg. 48 (S1): O83–O90.

43 43 Barry, K.S., Case, J.B., Winter, M.D. et al. (2017). Diagnostic usefulness of laparoscopy versus exploratory laparotomy for dogs with suspected gastrointestinal obstruction. J. Am. Vet. Med. Assoc. 251 (3): 307–314.

44 44 McClaran, J.K., Skerrett, S.C., Currao, R.L. et al. (2017). Comparison of laparoscopic‐assisted technique and open laparotomy for gastrointestinal biopsy in cats. Vet. Surg. 46 (6): 821–828.

45 45 Ko, J., Jeong, J., Lee, S. et al. (2018). Feasibility of single‐port retroperitoneoscopic adrenalectomy in dogs. Vet. Surg. 47 (S1): O75–O83.

46 46 Wright, T., Singh, A., Mayhew, P.D. et al. (2016). Laparoscopic‐assisted splenectomy in dogs: 18 cases (2012–2014). J. Am. Vet. Med. Assoc. 248 (8): 916–922.

47 47 Mayhew, P.D., Sutton, J.S., Singh, A. et al. (2018). Complications and short‐term outcomes associated with single‐port laparoscopic splenectomy in dogs. Vet. Surg. 47 (S1): O67–O74.

48 48 Luckring, E.J., Ham, K., Adin, C.A. et al. (2016). Laparoscopic placement and urodynamic effects of an artificial urethral sphincter in cadaveric dogs. Vet. Surg. 45 (S1): O20–O27.

49 49 Stiles, M., Case, J.B., and Coisman, J. (2016). Elective gastropexy with a reusable single‐incision laparoscopic surgery port in dogs: 14 cases (2012–2013). J. Am. Vet. Med. Assoc. 249 (3): 299–303.

50 50 Gandini, M. and Giusto, G. (2016). Laparoscopic single‐port ovariectomy and gastropexy in dogs. Schweiz. Arch. Tierheilkd. 158 (11): 755–758.

51 51 Baron, J.K., Casale, S.A., Monnet, E. et al. (2020). Paramedian incisional complications after prophylactic laparoscopy‐assisted gastropexy in 411 dogs. Vet. Surg. 49 (Suppl 1): O148–O155.

52 52 Coleman, K.A., Adams, S., Smeak, D.D., and Monnet, E. (2016). Laparoscopic gastropexy using knotless unidirectional suture and an articulated endoscopic suturing device: seven cases. Vet. Surg. 45 (S1): O95–O101.

53 53 Scott, J., Singh, A., Mayhew, P.D. et al. (2016). Perioperative complications and outcome of laparoscopic cholecystectomy in 20 dogs. Vet. Surg. 45 (S1): O49–O59.

54 54 Simon, A. and Monnet, E. (2020). Laparoscopic cholecystectomy with single port access system in 15 dogs. Vet. Surg. 49 (Suppl 1): O156–O162.

55 55 Lovell, S., Singh, A., Zur Linden, A. et al. (2019). Gallbladder leiomyoma treated by laparoscopic cholecystectomy in a dog. J. Am. Vet. Med. Assoc. 255 (1): 85–89.

56 56 Hart, E., Singh, A., Peregrine, A. et al. (2020). Laparoscopic ureteronephrectomy for the treatment of giant kidney worm infection in 2 dogs. Can. Vet. J. 61 (11): 1149–1154. PMID: 33149350; PMCID: PMC7560772.

57 57 Gonzalez‐Gasch, E. and Monnet, E. (2015). Comparison of single port access versus multiple port access systems in elective laparoscopy: 98 dogs(2005–2014). Vet. Surg. 44 (7): 895–899.

58 58 Tapia‐Araya, A.E., Martin‐Portugués, I.D.G., Bermejo, L.F., and Sánchez‐Margallo, F.M. (2015). Laparoscopic ovariectomy in dogs: comparison between laparoendoscopic single‐site and three‐portal access. J. Vet. Sci. 16 (4): 525–530.

59 59 Arntz, G.‐J.H.M. (2019). Transvaginal laparoscopic ovariectomy in 60 dogs: description of the technique and comparison with 2‐portal‐access laparoscopic ovariectomy. Vet. Surg. 48 (5): 726–734.

60 60 Jeong, J., Ko, J., Lim, H. et al. (2016). Retroperitoneal laparoscopy in dogs: access technique, working space, and surgical anatomy. Vet. Surg. 45 (S1): O102–O110.

61 61 Coisman, J.G., Case, J.B., Clark, N.D. et al. (2013). Efficacy of decontamination and sterilization of a single‐use single‐incision laparoscopic surgery port. Am. J. Vet. Res. 74: 934–938.

62 62 Petrovsky, B. and Monnet, E. (2018). Evaluation of efficacy of repeated decontamination and sterilization of single‐incision laparoscopic surgery ports intended for 1‐time use. Vet. Surg. 47 (S1): O52–O58.

63 63 Scharf, V.F., Dent, B., Jacob, M.E., and Moore, B. (2019). Efficacy of vaporized hydrogen peroxide for repeated sterilization of a single‐use single‐incision laparoscopic surgery port. Vet. Surg. 48 (S1): O59–O65.

64 64 Bydzovsky, N.D., Bockstahler, B., and Dupré, G. (2019). Single‐port laparoscopic‐assisted ovariohysterectomy with a modified glove‐port technique in dogs. Vet. Surg. 48 (5): 715–725.

65 65 Rieder, E., Martinec, D.V., Cassera, M.A. et al. (2011). A triangulating operating platform enhances bimanual performance and reduces surgical workload in single‐incision laparoscopy. J. Am. Coll. Surg. 212: 378–384.

66 66 Shussman, N., Kedar, A., Elazary, R. et al. (2014). Reusable single‐port access device shortens operative time and reduces operative costs. Surg. Endosc. 28: 1902–1907.

67 67 Podolsky, E.R. and Curcillo, P.G. (2010b). Single port access (SPA) surgery—a 24‐month experience. J. Gastrointest. Surg. 14: 759–767.

68 68 Podolsky, E.R. and Curcillo, P.G. (2010a). Reduced‐port surgery: preservation of the critical view in single‐port‐access cholecystectomy. Surg. Endosc. 24: 3038–3043.

69 69 Tsai, Y.‐C., Lin, V.C.‐H., Chung, S.‐D. et al. (2012). Ergonomic and geometric tricks of laparoendoscopic single‐site surgery (LESS) by using conventional laparoscopic instruments. Surg. Endosc. 26: 2671–2677.

70 70 Yilmaz, H. and Alptekin, H. (2013). Single‐incision laparoscopic transabdominal preperitoneal herniorrhaphy for bilateral inguinal hernias using conventional instruments. Surg. Laparosc. Endosc. Percutan. Tech. 23: 320–323.

71 71 Miernik, A., Schoenthaler, M., Lilienthal, K. et al. (2012). Pre‐bent instruments used in single‐port laparoscopic surgery versus conventional laparoscopic surgery: comparative study of performance in a dry lab. Surg. Endosc. 26: 1924–1930.

72 72 Goldsmith, Z.G., Astroza, G.M., Wang, A.J. et al. (2012). Optical performance comparison of deflectable laparoscopes for laparoendoscopic single‐site surgery. J. Endourol. 26: 1340–1345.

Section III Fundamental Techniques in Laparoscopy

Marlis L. de Rezende and Khursheed Mama

 Anesthesia management requires the understanding of the physiological effects associated with abdominal insufflation and body positions often required for the laparoscopic approach.

 Increased abdominal pressures and CO2 absorption through the peritoneum can significantly impact the cardiovascular and respiratory systems.

 Specific patient positioning, such as the Trendelenburg (head‐down) and reverse Trendelenburg (head‐up) positions, can further impact venous return and cardiac output, as well as oxygenation and ventilation.

 Albeit rare, an insufflation gas embolus to the heart is possible and can lead to cardiac arrest.

 Ventilatory support and monitoring, including electrocardiography, capnography, pulse oximetry, and arterial blood pressures, is strongly recommended for patients undergoing laparoscopic procedures. Direct arterial blood pressure and blood gas analysis may be required in higher‐risk patients.

Laparoscopic interventions are well established in veterinary medicine and offer several benefits when compared to standard laparotomy [1–6]. Reduced tissue trauma, with minimized incision size, and decreased manipulation of the gastro‐intestinal tract leading to improved comfort and faster recovery times are some of its major advantages [3, 5,7–12]. A decrease in inflammatory mediators (e.g., C‐reactive protein, interleukin‐6) and cells (e.g., WBC's) and a decrease in metabolic responses suggestive of stress (e.g., hyperglycemia) in patients undergoing laparoscopic versus open surgical intervention are taken as support of this [9,13–15]. In addition, direct and indirect evidence from animal studies [3, 13, 16] supports that as for human patients there is less pain associated with a laparoscopic versus traditional surgical approaches for the same procedure. The consequent reduced need for analgesic drugs and shortened hospital stays are well established in human patients and seem to be also true in animals [12]. Additional advantages include reduced adhesion formation [17], lower infection rates [5, 18, 19], a shorter healing time, improved cosmetic results, and quicker return to function [3,20–22]. Because of these benefits, laparoscopy is being used both as a diagnostic [23, 24] and surgical tool [25–27] with increasing frequency, as well as complexity, in veterinary medicine.

Despite the many advantages associated with laparoscopic versus traditional approaches, laparoscopic procedures have their own specific risks and potential complications. In additions to effects related to the disease state of the animal, the positioning for surgery, and the surgical procedure itself, the anesthetist must consider the physiological changes associated with insufflating gas into the abdomen and the consequences to various organ systems, specially the cardiovascular and respiratory systems. These considerations will be the focus of this chapter and are discussed in more detail in the subsequent text.

In addition to routine procedures in healthy dogs and cats, animals with significant disease are increasingly presented for laparoscopy. The anesthetist must therefore be aware of the considerations related to the primary and any secondary disease processes in these patients. This information is available in broad based anesthesia textbooks. As an example, consider the patient presenting for a liver biopsy. On the surface, this would seem a fairly straightforward procedure. However, if circulation is compromised due to hypoproteinemia, acid–base and electrolyte changes, insufflation of the abdomen can result in serious hypotension. If coagulation status is also compromised, significant blood loss from the biopsy site may exacerbate this and the animal may require a transfusion. If lung metastases are present, respiratory complications are possible. The potential for side effects tends to increase with more complex procedures as in an animal with an adrenal pheochromocytoma where manipulation can increase catecholamine release and result in hypertension and cardiac rhythm abnormalities. Timely intervention is facilitated if these potential complications are anticipated.

Patients with significant cardiovascular and pulmonary disease (congenital heart defects, valvular heart disease, congestive heart failure, and pulmonary hypertension) are at a higher risk for complications related to the hemodynamic and ventilatory changes associated with the increase in intra‐abdominal pressure [28]. These patients may be unable to compensate, leading to further worsening of their condition [29]. Understanding the influence of the unique physiological effects of the laparoscopic approach on the pathophysiology of the disease process allows for adequate patient preparation and tailored perioperative monitoring and management to mitigate adverse outcomes [30, 31].

Reported surgical complication rates for laparoscopy and laparotomy vary. Initial reports suggested that surgical complications occurred with a lower frequency for laparoscopy, but as the complexity of procedures performed using this approach has increased, the complication rate is now more comparable [32, 33]. Complication rates and surgical time, which can additionally contribute to morbidity, tend to decrease with surgeon experience [12].

Surgical complications may be related specifically to the procedure, positioning for the procedure (discussed later), or be of a more general nature. Again, prior preparation will facilitate rapid treatment should this occur.

Hemorrhage from inadvertent puncture of organs or vessels during placement of the Veress needle or introduction of the trocars is a reported complication in human and animal patients (ssss1) even during entry into the abdomen for routine procedures and requires a quick response from the anesthetist [32–38]. Hemorrhage from either cause might also necessitate conversion from the laparoscopic to open approach during which time the patient will need to continue to be supported aggressively until the surgeon can visualize and control the source of hemorrhage. A recent report in veterinary patients indicates excessive hemorrhage as one of the significant causes for conversion to celiotomy during diagnostic procedures [39]. Although the occurrence of hemorrhage within the pneumoperitoneum is typically readily identified, the increased intra‐abdominal pressure may cause venous tamponade and delay recognition of active bleeding into the postoperative period [7]. Hemorrhage has also been reported at the surgical site during routine procedures such as ovariectomy in dogs [35, 40] suggesting vigilance on the part of the anesthetist for this complication is important. A recent study in 161 dogs undergoing laparoscopic ovariectomy performed by supervised novice surgeons, reported only minor blood loss, caused by splenic puncture during insertion of the Veress needle (12.4%), and bleeding from the ovarian pedicle (2.5%), but conversion to laparotomy was not required in any dogs [37].

ssss1 Inadvertent splenic puncture.

Source: Courtesy of Eric Monnet.

ssss1 Radiographic image showing inadvertent placement of insufflation gas into the bladder.

Source: Courtesy of David Twedt.

In addition to vascular entry and organ puncture with subsequent hemorrhage as previously mentioned, surgical complications include bladder (ssss1), bowel or stomach puncture and gas distention, trauma to the bile duct, peritoneal detachment, etc. A 7.5% emergent conversion rate from laparoscopy to laparotomy due to surgical complications such as hemorrhage and biliary tract rupture was reported in dogs and cats [39].

Other causes of surgical complications are related to the unique equipment used for intervention. Just as it is important for the surgeon to have basal knowledge of anesthesia, it is important for the anesthetist to have at least a similar level of understanding of the surgical equipment used to facilitate laparoscopy. Complications associated with puncture of organs/vessels with the Veress needle have already been discussed. Additional complications may arise from use (intentional or accidental) of high insufflation pressures, intra‐abdominal use of cautery (especially if a potentially flammable gas is used), heat from the light source and cable, etc.

2

As insufflation pressures increase into the range of 10–15 mmHg, hepatic, renal, and mesenteric blood flows are decreased. In studies with pigs, intra‐abdominal pressures greater than 10 mmHg were associated with significant reductions in hepatic artery and splanchnic blood flow [53, 54]. In dogs intra‐abdominal pressures in the range of 16–20 mmHg decreased portal venous and mesenteric arterial flow [55, 56]. Impairment of blood flow in other vessels (e.g., celiac artery) and to the intestinal mucosa is also reported for both dogs and pigs in this similar pressure range [42, 54, 57]. Oliguria is reported with pressures in the 15–20 mmHg range and anuria may be seen when pressures exceed this ranges [42, 57, 58]. The decrease in renal blood flow leads to an increase in renin and aldosterone levels [59]. In dogs, renal blood flow and glomerular filtration were decreased by over 75% with intra‐abdominal pressures of 20 mmHg, and anuria was observed when abdominal pressures reached 40 mmHg [42, 58]. Similar findings were reported in pigs, where oliguria was observed with pressures over 15 mmHg [57]. Albeit uncommon, patients with chronic kidney disease may be at higher risk for acute kidney injury during laparoscopic surgery [60–62].

Interestingly, in a single study in healthy cats, pneumoperitoneum up to an intra‐abdominal pressure of 16 mmHg with carbon dioxide as the insufflation gas did not significantly influence cardiovascular parameters, albeit ventilation seemed to be negatively impacted; regional blood flow was not evaluated [63]. While healthy cats did not show changes in measured parameters during peritoneal insufflation, it is important to remember that cardiovascular function may be further influenced by the patient's health status, positioning during anesthesia and surgery, duration of the procedure, and the type of insufflation gas.

ssss1 Dog prepared for laparoscopic intervention in Fowler position (reverse Trendelenburg).

For example, head up – also known as Fowler or reverse Trendelenburg – (ssss1) positioning can compromise venous return and cardiac output due to gravitational effects. This is of greater consequence during anesthesia due to the blunting of baroreceptor reflexes. During Trendelenburg positioning, there is an increase in venous return from the pelvic limbs. However, cardiac output again decreases, but the reasons differ and include decreases in heart rate and vasomotor tone [64, 65]. In anesthetized dogs, both body positions have further compromised cardiac output during pneumoperitoneum, with the reverse Trendelenburg position having the most significant impact [47]. There is also increasing concern regarding changes in intracranial pressure, which will compound those seen with carbon dioxide pneumoperitoneum. A recent study has shown a correlation between laparoscopic insufflation pressures and intracranial pressure in human patients undergoing laparoscopic ventriculoperitoneal shunt placement [66]. While unlikely to be serious in healthy patients, this could be of great significance in patients with intracranial disease.

Peritoneum distension due to abdominal insufflation may increase vagal tone and cause bradyarrhythmias, with a reported incidence between 14 and 27% in healthy young humans [67, 68]. Bradycardia should be addressed quickly as it may be an early indication of cardiac arrest [69, 70].

Respiratory function is also altered during laparoscopic intervention. The increase in abdominal pressure and volume limits diaphragmatic excursion and reduces pulmonary compliance, functional residual capacity, and vital capacity of the lung and may lead to ventilation/perfusion mismatch [42, 48,71–73]. Hence, it is not surprising that the effects tend to be proportional to insufflation pressures as is shown in young swine [74] and adult dogs [48, 75]. In spontaneously breathing dogs, respiratory rate remained unchanged with abdominal insufflation, but a significant reduction in tidal volume was reported [75]. With volume‐controlled ventilation maintenance of tidal volume results in an increase in peak inspiratory pressure [48], and hypercapnia and hypoxemia might still occur. Similarly, when using pressure‐controlled ventilation, the peak inspiratory pressure must be increased, to overcome the decrease in lung compliance and avoid a reduction in tidal volume. The resulting positive pressure in the chest has an additional impact on reducing venous return and thus cardiac output could be further compromised.

In spontaneously breathing animals, the decrease in tidal volume and increase in end‐tidal carbon dioxide are proportional to increasing insufflation pressure and the negative impact lasts longer in animals exposed to the higher pressures [75]. This reflects fatigue on the part of the patient and has led to the common recommendation for mechanical ventilation in patients in whom the procedure is anticipated to last longer than 15–30 minutes.

222222

222

222

22222222222

22222222222

2222222

While there are some unique aspects to laparoscopic intervention as noted in the preceding text, the basic principles of anesthesia must first be applied. General anesthesia should be a reversible event that provides amnesia, analgesia, unconsciousness, and muscle relaxation while supporting thermoregulation, cardiovascular, respiratory, neurologic, hepatic, and renal functions. To meet these basic principles, care should be individualized for the animal with consideration given to the reason for the presentation, the animal's signalment, general health status, etc. Procedure‐related risks should also be considered, and it may be warranted to consider the expertise of the surgical team when selecting anesthetic drugs and the support and monitoring plan. Additionally, one must factor in the pathophysiological implications of laparoscopic intervention as discussed earlier in this chapter.

The young healthy dog or cat presented for an elective procedure is unlikely to have restrictions when selecting anesthetic drugs. In our practice, an opioid would likely be used for premedication to provide analgesia and some sedation. The additional use of a tranquilizer or sedative might be warranted if the animal is excited or fractious. An anticholinergic could be considered to offset the bradycardia seen with many opioids and sometimes associated with peritoneal distention and visceral traction. Propofol (or another preferred induction agent) could be used for anesthesia induction and to facilitate intubation. While many drugs including ketamine, propofol, and more recently alfaxalone have been shown to increase splenic size to some degree, [130–133] thiopental, which is still available internationally, has been historically associated with the greatest potential to cause splenic enlargement [134] While earlier studies have shown that propofol did not seem to affect splenic volume, [130, 131] a more recent study, which used computed tomography as the evaluating method, has shown comparable spleen enlargement with both thiopental and propofol. [132] Spleen enlargement may increase the potential for puncture of the spleen on entry into the abdomen and could compromise surgical visualization during cranial abdominal procedures, so awareness of the effects of anesthetic drugs on splenic size is important. Following intubation, the patient is commonly transitioned to maintenance with an inhaled anesthetic (isoflurane or sevoflurane). Local anesthetic infiltration at portal sites and a nonsteroidal anti‐inflammatory drug when not contraindicated are used in addition to postoperative opioids to provide additional analgesia. More recently, a sustained‐release bupivacaine formulation (liposomal bupivacaine), which is reported to provide analgesia for 72 hours, has been used with increased frequency for portal site infiltration and for ultrasound‐guided transversus abdominis plane block (TAP block) at our institution. In humans, the use of liposomal bupivacaine for TAP blocks has been described to provide better pain control than traditional bupivacaine in patients undergoing laparoscopic nephrectomy and colon resection and is associated with lower use of postoperative opioids [135–137]. For debilitated or critically ill animals, as well as for more complex laparoscopic procedures, the anesthetic plan should be modified as appropriate.

In addition to the anesthetic drug plan, when considering the investment in time, training, and equipment for surgical aspects of laparoscopy, the veterinarian must consider whether the appropriate anesthesia equipment is available to support and monitor the patient during these procedures.

In addition to monitoring body temperature and providing external heat as appropriate, the heart rate and cardiac rhythm, which can vary during gas insufflation and organ manipulation (e.g., bradycardia with urinary bladder traction), should be monitored using an electrocardiogram. Blood pressure monitoring is essential and will alert the anesthetist to both anesthetic drug and insufflation‐related changes. Intravenous fluids (crystalloid or colloids as appropriate for the animal) are used to help maintain vascular volume and counteract the vasodilating effects of tranquilizers (e.g., acepromazine) and anesthetic drugs (e.g., propofol), as well as the additional influence of abdominal distention with insufflation gas, and postural changes on venous return and subsequently cardiac output. Hypotension may be treated with rapid administration (bolus) of intravenous fluids, reducing the anesthetic dose or decreasing insufflation pressure. When these interventions are not possible or not adequate, inotropes (e.g., dobutamine, dopamine) or vasoactive medications may be necessary.

222222

222

2

222

2

As laparoscopic interventions become well established in veterinary medicine, it is important that the veterinary team is well versed in both surgical and anesthetic aspects of management to ensure a successful outcome.

1 1 Beedorn, J.A., Dykema, J.L., and Hardie, R.J. (2013). Minimally invasive surgery in veterinary practice: a 2010 survey of diplomates and residents of the American college of veterinary surgeons. Vet. Surg. 42: 635–642.

2 2 Milovancev, M. and Townsend, K. (2015). Current concepts in minimally invasive surgery of the abdomen. Vet. Clin. N. Am. Small Anim. Pract. 45: 507–522.

3 3 Culp, W.T., Mayhew, P.D., and Brown, D.C. (2009). The effect of laparoscopic versus open ovariectomy on postsurgical activity in small dogs. Vet. Surg. 38: 811–817.

4 4 Petre, S., McClaran, J., Bergman, P. et al. (2012). Safety and efficacy of laparoscopic hepatic biopsy in dogs: 80 cases (2004–2009). J. Am. Vet. Med. Assoc. 240: 181–185.

5 5 Mayhew, P., Freeman, L., Kwan, T. et al. (2012). Comparison of surgical site infection rates in clean and clean‐contaminated wounds in dogs and cats after minimally invasive versus open surgery: 179 cases (2007–2008). J. Am. Vet. Med. Assoc. 240: 193–198.

6 6 Balsa, I.M. and Culp, W.T.N. (2019). Use of minimally invasive surgery in the diagnosis and treatment of cancer in dogs and cats. Vet Sci 6: 33. https://doi.org/10.3390/vetsci6010033.

7 7 Hayden, P. and Cowman, S. (2011). Anesthesia for laparoscopic surgery. Br. J. Anaesth. ‐Continuing Education in Anesthesia, Critical Care and Pain 1: 177–180.

8 8 Case, J.B., Boscan, P.L., Monnet, E.L. et al. (2015). Comparison of surgical variables and pain in cats undergoing ovariohysterectomy, laparoscopic‐assisted ovariohysterectomy, and laparoscopic ovariectomy. J. Am. Anim. Hosp. Assoc. 51: 1–7.

9 9 Devitt, C.M., Cox, R.E., and Hailey, J.J. (2005). Duration, complications, stress and pain of open ovariohysterectomy versus a simple method of laparoscopic‐assisted ovariohysterectomy in dogs. JAVMA 6: 921–927.

10 10 Hancock, R.B., Lanz, O.I., Waldron, D.R. et al. (2005). Comparison of postoperative pain after ovariohysterectomy by harmonic scalpel‐assisted laparoscopy compared with median celiotomy and ligation in dogs. Vet. Surg. 34: 273–282.

11 11 Davidson, E.B., Moll, H.D., and Payton, M.E. (2004). Comparison of laparoscopic ovariohysterectomy and ovariohysterectomy in dogs. Vet. Surg. 33: 62–69.

12 12 Mayhew, P., Culp, W., Hunt, G. et al. (2014). Comparison of perioperative morbidity and mortality rates in dogs with noninvasive versus open adrenalectomy. J. Am. Vet. Med. Assoc. 245: 1028–1035.

13 13 Jakeways, M.S., Mitchell, V., and Hashim, I.A. (1994). Metabolic and inflammatory responses after open or laparoscopic cholecystectomy. Br. J. Surg. 81: 127–131.

14 14 Joris, J., Cigarini, I., Legrand, M. et al. (1992). Metabolic and respiratory changes after cholecystectomy performed via laparotomy or laparoscopy. Br. J. Anaesth. 69: 341–345.

15 15 Mealy, K., Gallagher, H., Barry, M. et al. (1992). Physiological and metabolic responses to open and laparoscopic cholecystectomy. Br. J. Surg. 79: 1061–1064.

16 16 Gauthier, O., Holopherne‐Doran, D., Gendarme, T. et al. (2015). Assessment of postoperative pain in cats after ovariectomy by laparoscopy, median celiotomy, or flank laparotomy. Vet. Surg. 44: 23–30.

17 17 Schippers, E., Tittel, A., Ottinger, A. et al. (1988). Laparoscopy versus laparotomy: comparison of adhesion‐formation after bowel resection in a canine model. Dig. Surg. 15: 145–147.

18 18 Barnett, J.C., Havrilesky, L.J., Bondurant, A.E. et al. (2011). Adverse events associated with laparoscopy vs laparotomy in the treatment of endometrial cancer. Am. J. Obstet. Gynecol. 205: 143.e1–143.e6.

19 19 Varela, J.E., Wilson, S.E., and Nguyen, N.T. (2010). Laparoscopic surgery significantly reduces surgical‐site infections compared with open surgery. Surg. Endosc. 24: 270–276.

20 20 Gal, D., Lind, L., Lovecchio, J.L. et al. (1995). Comparative study of laparoscopy vs. laparotomy for adnexal surgery: efficacy, safety and cyst rupture. J. Gynecol. Surg. 11: 153–158.

21 21 Grace, P.A., Quereshi, A., Coleman, J. et al. (1991). Reduced postoperative hospitalization after laparoscopic cholecystectomy. Br. J. Surg. 78: 160–162.

22 22 Gerges, F.J., Kanazi, G.E., and Jabbour‐Khoury, S.I. (2006). Anesthesia for laparoscopy: a review. J. Clin. Anesth. 18: 67–78.

23 23 Robertson, E., Twedt, D., and Webb, C. (2014). Diagnostic laparoscopy in the cat: 1. Rationale and equipment. J. Feline Med. Surg. 16 https://doi.org/10.1177/1098612X13516567.

24 24 Radhakrishnan, A. and Mayhew, P.D. (2013). Laparoscopic splenic biopsy in dogs and cats: 15 cases (2006–2008). J. Am. Anim. Hosp. Assoc. 49: 41–45.

25 25 Smith, R.R., Mayhew, P.D., and Berent, A.C. (2012). Laparoscopic adrenalectomy for management of a functional adrenal tumor in a cat. J. Am. Vet. Med. Assoc. 241: 368–372.

26 26 Menendez, I.M. and Fitch, G. (2012). Use of a laparoscopic retrieval device for urolith removal through a perineal urethrotomy. Vet. Surg. 41: 629–633.

27 27 Naan, E.C., Kirpensteijn, J., Dupre, G. et al. (2013). Innovative approach to laparoscopic adrenalectomy for treatment of unilateral adrenal gland tumors in dogs. Vet. Surg. 42: 710–715.

28 28 Boersma, E., Kertai, M.D., Schouten, O. et al. (2005). Perioperative cardiovascular mortality in non‐cardiac surgery: validation of the Lee cardiac risk index. Am. J. Med. 118: 1134–1141.

29 29 Odeberg‐Wernerman, S. (2000). Laparoscopic surgery: effects on circulatory and respiratory physiology: an overview. Eur. J. Surg. Suppl166: 4–11.

30 30 Crystal, G.J. (2015). Carbon dioxide and the heart: physiology and clinical implications. Anesth. Analg. 121: 610–623.

31 31 Atkinson, T.M., Giraud, G.D., Togioka, B.M. et al. (2017). Cardiovascular and ventilatory consequences of laparoscopic surgery. Circulation 135: 700–710.

32 32 Joris, J.L. (2010). Anesthesia for laparoscopic surgery. In: Millers Anesthesia, 7e (ed. R.D. Miller), 2185–2202. Philadelphia: Churchill Livingstone/Elsevier Publishing.

33 33 Cunningham, A.J. (1998). Anesthetic implications of laparoscopic surgery. Yale J. Biol. Med. 71: 551–578.

34 34 Strasberg, S.M., Sanabria, J.R., and Clavien, P.A. (1992). Complications of laparoscopic cholecystectomy. Can. J. Surg. 35: 275–280.

35 35 Case, J.B., Marvel, S.J., Boscan, P. et al. (2011). Surgical time and severity of postoperative pain in dogs undergoing laparoscopic ovariectomy with one, two or three instrument cannulas. J. Am. Vet. Med. Assoc. 239: 203–208.

36 36 Desmaiziere, L.M., Martinot, S., Lepage, O.M. et al. (2003). Complications associated with cannula insertion techniques used for laparoscopy in standing horses. Vet. Surg. 32: 501–506.

37 37 Nylund, A.M., Drury, A., Weir, H. et al. (2017). Rates of intraoperative complications and conversion to laparotomy during laparoscopic ovariectomy performed by veterinary students:161 cases (2010–2014). J. Am. Vet. Med. Assoc. 251: 95–99.

38 38 Anderson, S.J. and Frasson, B.A. (2019). Complications related to entry techniques for laparoscopy in 159 dogs and cats. Vet. Surg. 48: 707–714.

39 39 Buote, N.J., Kovk‐McClaran, J.R., and Schold, J.D. (2011). Conversion from diagnostic laparoscopy to laparotomy: risk factors and occurrence. Vet. Surg. 40: 106–114.

40 40 Dupre, G., Fiorbianco, V., Skalicky, M. et al. (2009). Laparoscopic ovariectomy in dogs: comparison between single portal and two‐portal access. Vet. Surg. 38: 818–824.

41 41 Ivankovich, A.D., Miletich, D.J., Albrecht, R.F. et al. (1975). Cardiovascular effects of intraperitoneal insufflation with carbon dioxide and nitrous oxide in the dog. Anesthesiology 42: 281–287.

42 42 Barnes, G.E., Laine, G.A., Giam, P.Y. et al. (1985). Cardiovascular responses to elevation of intra‐abdominal hydrostatic pressure. Am. J. Phys. 248: R208–R213.

43 43 Joris, J.L., Noirot, D.P., Legrand, M.J. et al. (1993). Hemodynamic changes during laparoscopic cholecystectomy. Anesth. Analg. 76: 1067–1071.

44 44 Kashtan, J., Green, J.F., Parsons, E.Q. et al. (1981). Hemodynamic effects of increased abdominal pressure. J. Surg. Res. 30: 249–255.

45 45 Johannsen, G., Andersen, M., and Juhl, B. (1989). The effect of general anaesthesia on the haemodynamic events during laparoscopy with CO2‐insufflation. Acta Anaesthesiol. Scand. 33: 132–136.

46 46 Cunningham, A.J., Turner, J., Rosenbaum, S. et al. (1993). Transoesophageal echocardiographic assessment of haemodynamic function during laparoscopic cholecystectomy. Br. J. Anaesth. 70: 621–625.

47 47 Williams, M.D. and Murr, P.C. (1993). Laparoscopic insuflation of the abdomen depresses cardiopulmonary function. Surg. Endosc. 7: 12–16.

48 48 Richardson, J.D. and Trinkle, J.K. (1976). Hemodynamic and respiratory alterations with increased intra‐abdominal pressure. J. Surg. Res. 20: 401–404.

49 49 Dec, M. and Andruszkiewicz, P. (2016). Anesthesia for minimally invasive surgery. Wideochir. Inne Tech. Maloinwazyjne 10: 509–514.

50 50 Melville, R.J., Frizis, H.I., Forsling, M.L. et al. (1985). The stimulus for vasopressin release during laparoscopy. Surg. Gynecol. Obstet. 161: 253–256.

51 51 Solis‐Herruzo, J.A., Moreno, D., Gonzalez, A. et al. (1991). Effect of intrathoracic pressure on plasma arginine vasopressine levels. Gastroenterology 101: 607–617.

52 52 Hirvonen, E.A., Nuutinen, L.S., and Vuolteenaho, O. (1997). Hormonal responses and cardiac filling pressures in head‐up or head‐down position and pneumoperitoneum in patients undergoing operative laparoscopy. Br. J. Anaesth. 78: 128–133.

53 53 Diebel, L.N., Wilson, R.F., Dulchavsky, S.A. et al. (1992). Effect of increased intra‐abdominal pressure on hepatic arterial, portal venous, and hepatic microcirculatory blood flow. J. Trauma 33: 279–283.

54 54 Diebel, L.N., Dulchavsky, S.A., Wilson, R.F. et al. (1992). Effect of increased intra‐abdominal pressure on mesenteric arterial and intestinal mucosal blood flow. J. Trauma 33: 45–48.

55 55 Ishizaki, Y., Bandai, Y., Shimomura, K. et al. (1993). Safe Intraabdominal pressure of carbon dioxide pneumoperitoneum during laparoscopic surgery. Surgery 114: 549–554.

56 56 Ishizaki, Y., Bandai, Y., Shimomura, K. et al. (1993). Changes in splanchnic blood flow and cardiovascular effects following peritoneal insufflation of carbon dioxide. Surg. Endosc. 7: 420–423.

57 57 Bongard, F., Pianim, N., Dubecz, S. et al. (1995). Adverse consequences of increased intra‐abdominal pressure on bowel tissue. J. Trauma 39: 519–525.

58 58 Harman, P.K., Kron, I.L., Mclachlan, H.D. et al. (1982). Elevated intra‐abdominal pressure and renal function. Ann. Surg. 196: 594–597.

59 59 O’Leary, E., Hubbard, K., Tormey, W. et al. (1996). Laparoscopic cholecystectomy: haemodynamic and neuroendocrine responses after pneumoperitoneum and changes in position. Br. J. Anaesth. 76: 640–644.

60 60 Dunn, M.D. and McDougall, E.M. (2000). Renal Physiology: laparoscopic considerations. Urol. Clin. North Am. 27: 609–614.

61 61 de Seigneux, S., Klopfenstein, C.E., Iselin, C. et al. (2011). The risk of acute kidney injury following laparoscopic surgery in a chronic kidney disease patient. NDT Plus 4: 339–341.

62 62 Li, W., Cao, Z., Yu, W. et al. (2019). Acute kidney injury induced by pneumoperitoneum pressure via a mitochondrial injury‐dependent mechanism in a rabbit model of different degrees of hydronephrosis. Urology 127: 134.e1–134.e7.

63 63 Mayhew, P.D., Pascoe, P.J., Kass, P.H. et al. (2013). Effects of pneumoperitoneum induced at various pressures on cardiorespiratory function and working space during laparoscopy in cats. Am. J. Vet. Res. 74: 1340–1346.

64 64 Abel, F.L., Pierce, J.H., and Guntheroth, W.G. (1963). Baroreceptor influence on postural chenges in blood pressure and carotid blood flow. Am. J. Phys. 285: 360–364.

65 65 Slinker, B.K., Campbell, K.B., Alexander, J.E. et al. (1982). Arterial baroreflex control of the heart rate in the horse, pig, and calf. Am. J. Vet. Res. 43: 1926–1933.

66 66 Kamine, T.H., Papavassiliou, E., and Schneider, B.E. (2014). Effect of abdominal insuflation for laparoscopy on intracranial pressure. JAMA Surg. 149: 380–382.

67 67 Gutt, C.N., Oniu, T., Mehrabi, A. et al. (2004). Circulatory and respiratory complications of carbon dioxide insufflation. Dig. Surg. 21: 95–105.

68 68 Myles, P.S. (1991). Bradyarrhythmias and laparoscopy: a prospective study of heart rate changes with laparoscopy. Aust. N. Z. J. Obstet. Gynaecol. 31: 171–173.

69 69 Yong, J., Hibbert, P., Runciman, W.B. et al. (2015). Bradycardia as an early warning sign for cardiac arrest during routine laparoscopy surgery. Int. J. Qual. Health Care 27: 473–478.

70 70 Heyba, M., Khalil, A., and Elkenany, Y. (2020). Severe intraoperative bradycardia during laparoscopic cholecystectomy due to rapid peritoneal insufflation. Case Rep. Anesthesiol. https://doi.org/10.1155/2020/8828914.

71 71 Obeid, F., Saba, A., Fath, J. et al. (1995). Increases in intra‐abdominal pressure affect pulmonary compliance. Arch. Surg. 130: 544–547.

72 72 Oikkonen, M. and Tallgren, M. (1995). Changes in respiratory compliance at laparoscopy: measurements using side stream spirometry. Can. J. Anaesth. 42: 495–497.

73 73 Duke, T., Steinacher, S.L., and Remedios, A.M. (1996). Cardiopulmonary effects of using carbon dioxide for laparoscopic surgery in dogs. Vet. Surg. 25: 77–82.

74 74 Liem, T., Applebaum, H., and Herzberger, B. (1994). Hemodynamic and ventilatory effects of abdominal CO2 insufflation at various pressures in the young swine. J. Pediatr. Surg. 29: 966–969.

75 75 Gross, M.E., Jones, B.D., Bergstresser, D.R. et al. (1993). Effects of abdominal insufflation with nitrous oxide on cardiorespiratory measurements in spontaneously breathing isoflurnane‐anestehtized dogs. Am. J. Vet. Res. 54: 1352–1358.

76 76 Rademaker, B.M., Odoom, J.A., de Wit, L. et al. (1994). Haemodynamic effects of pneumoperitoneum for laparoscopic surgery: a comparison of CO2 with N2O insufflation. Eur. J. Anaesthesiol. 11: 301–306.

77 77 Rademaker, B.M.P., Bannenberg, J.J.G., Kalkman, C.J. et al. (1995). Effects of pneumoperitoneum with helium on hemodynamics and oxygen transport: a comparison with carbon dioxide. J. Laparoendosc. Surg. 5: 15–20.

78 78 Rammohan, A., Manimaran, A.B., Manohar, R.R. et al. (2011). Nitrous oxide for pneumoperitoneum: no laughing matter this! A prospective single blind case controlled study. Int. J. Surg. 9: 173–176.

79 79 Srivastava, A. and Niranjan, A. (2010). Secrets of safe laparoscopic surgery: anesthetic and surgical considerations. J. Minim. Access Surg. 6: 91–94.

80 80 Fujii, Y., Tanaka, H., Tsuruoka, S. et al. (1994). Middle cerebral artery blood flow velocity increases during laparoscopic cholecystectomy. Anesth. Analg. 78: 80–83.

81 81 Schob, O.M., Allen, D.C., Benzel, E. et al. (1996). A comparison of the pathophysiologic effects of carbon dioxide, nitrous oxide, and helium pneumoperitoneum on intracranial pressure. Am. J. Surg. 172: 248–253.

82 82 Huettemann, E., Terborg, C., Sakka, S.G. et al. (2002). Preserved CO2 reactivity and increase in middle cerebral arterial blood flow velocity during laparoscopy surgery in children. Anesth. Analg. 94: 255–258.

83 83 Clowes, G.H.A. Jr., Kretchmer, H.E., McBurney, R.W. et al. (1953). The electro‐encephalogram in the evaluation of the effects of anesthetic agents and carbon dioxide accumulation during surgery. Ann. Surg. 138: 558–568.

84 84 Bailey, J.E. and Pablo, L.S. (1999). Anesthetic and physiologic considerations for veterinary endosurgery. In: Veterinary Endosurgery (ed. L.J. Freeman), 24–43. St Louis: Mosby.

85 85 Fahy, B.G., Barnas, G.M., Flowers, J.L. et al. (1995). The effects of increased abdominal pressure on lung and chest wall mechanics during laparoscopy surgery. Anesth. Analg. 81: 744–750.

86 86 Mutoh, T., Lamm, W.J.E., Embree, L.J. et al. (1991). Abdominal distension alters regional pleural pressures and chest wall mechanics in pigs in vivo. J. Appl. Physiol. 70: 2611–2618.

87 87 Pelosi, P., Foti, G., Cereda, M. et al. (1996). Effects of carbon dioxide insufflation for laparoscopic cholecystectomy on the respiratory system. Anaesthesia 51: 744–749.

88 88 Peroni, J. and Fischer, A.T. Jr. (1995). Effects of carbon dioxide insufflation and body position on blood gas values and cardiovascular parameters in the anesthetized horse undergoing laparoscopy. ACVS Veterinary Symposium 30, Chicago, Ill (29 October–1 November 1995).

89 89 Kadono, Y., Yaegashi, H., Machioka, K. et al. (2013). Cardiovascular and respiratory effects of the degree of head‐down angle during robot assisted laparoscopic radical prostatectomy. Int. J. Med. Robot. Comput. Assist. Surg. 9: 17–22.

90 90 Salihoglu, Z., Demiroluk, S., Cakmakkaya, S. et al. (2002). Influence of the patient positioning on respiratory mechanics during pneumoperitoneum. Middle East J. Anesthesiol. 16: 521–528.

91 91 Wahba, R.W. and Mamazza, J. (1993). Ventilatory requirements during laparoscopic cholecystectomy. Can. J. Anaesth. 40: 206–210.

92 92 Hofmeister, E., Peroni, J.F., and Fisher, A.T. Jr. (2008). Effects of carbon dioxide insufflation and body position on blood gas values in horses anesthetized for laparoscopy. J. Equine Vet. Sci. 28: 549–553.

93 93 Hardie, R.J., Flanders, J.A., Schmidt, P. et al. (1996). Biomechanical and histological evaluation of a laparoscopic stapled gastropexy technique in dogs. Vet. Surg. 25: 127–133.

94 94 Kim, Y.K., Park, S.J., Lee, S.Y. et al. (2013). Laparoscopic nephrectomy in dogs: an initial experience of 16 experimental procedures. Vet. J. 198: 513–517.

95 95 Leonardi, F., Properzi, R., Rosa, J. et al. (2020). Combined laparoscopic ovariectomy and laparoscopic‐assisted gastropexy versus combined laparoscopic ovariectomy and total laparoscopic gastropexy: a comparison of surgical time, complications and postoperative pain in dogs. Vet. Med. Sci. 6: 321–329.

96 96 Mullet, C.E., Viale, J.P., Sagnard, P.E. et al. (1993). Pulmonary CO2 elimination during surgical procedures using intra‐ or extraperitoneal CO2 insufflation. Anesth. Analg. 76: 622–626.

97 97 Dehours, E., Valle, B., Bournes, V. et al. (2013). A pneumomediastinum with diffuse subcutaneous emphysema. J. Emerg. Med. 44: e81–e82.

98 98 Philips, S. and Falk, G.L. (2011). Surgical tension pneumothorax during laparoscopic repair of massive hiatus hernia: a different situation requiring different management. Anesth. Intensive Care 39: 1120–1123.

99 99 Suresh, Y.V., Suresh, A.Y., and Sequeira, T.F. (2014). Laparoscopy‐pneumothorax and ocular emphysema, a rare complication – a case report. J. Clin. Diagn. Res. 8: GD01–GD02.

100 100 Joris, J.L., Chiche, J.D., and Lamy, M.L. (1995). Pneumothorax during laparoscopic fundoplication: diagnosis and treatment with positive end‐expiratory pressure. Anesth. Analg. 81: 993–1000.

101 101 Bendinelli, C., Leonardi, F., and Properzi, R. (2019). Spontaneous pneumothorax in two dogs undergoing combined laparoscopic ovariectomy and total laparoscopic gastropexy. J. Vet. Sci. 20: e25.

102 102 Monnet, E. (2020). Laparoscopic correction of sliding hiatal hernia in eight dogs: description of the technique, complications, and short‐term outcome. Vet. Surg. https://doi.org/10.1111/vsu.13541. Epub ahead of print.

103 103 Ko, M.L. (2010). Pneumopericardium and severe subcutaneous emphysema after laparoscopic surgery. J. Minim. Invasive Gynecol. 17: 531–533.

104 104 Knos, G.B., Sung, Y.F., and Toledo, A. (1991). Pneumopericardium associated with laparoscopy. J. Clin. Anesth. 3: 56–59.

105 105 Falk, G.L., D’Netto, T.J., Phillips, S. et al. (2018). Pneumothorax: laparoscopic intraoperative management during fundoplication facilitates management of cardiopulmonary instability and surgical exposure. J. Laparoendosc. Adv. Surg. Tech. 28: 1371–1373.

106 106 Couture, P., Boudreault, D., Derouin, M. et al. (1994). Venous carbon dioxide embolism in pigs: an evaluation of end‐tidal carbon dioxide, transesophageal echocardiography, pulmonary artery pressure, and precordial auscultation as monitoring modalities. Anesth. Analg. 79: 867–873.

107 107 Staffieri, F., Lacitignola, L., De Siena, R. et al. (2007). A case of spontaneous venous embolism with carbon dioxide during laparoscopic surgery in a pig. Vet. Anesth. Analg. 34: 63–66.

108 108 Gilroy, B.A. and Anson, L.W. (1987). Fatal air embolism during anesthesia for laparoscopy in a dog. J. Am. Vet. Med. Assoc. 190: 552–554.

109 109 Lantz, P.E. and Smith, J.D. (1994). Fatal carbon dioxide embolism complicating attempted laparoscopic cholecystectomy ‐ case report and literature review. J. Forensic Sci. 39: 1468–1480.

110 110 Haroun‐Bizri, S. and ElRassi, T. (2001). Successful resuscitation after catastrophic carbon dioxide embolism during laparoscopic cholecystectomy. Eur. J. Anaesthesiol. 18: 118–121.

111 111 Hong, J.Y., Kim, W.O., and Kil, H.K. (2010). Detection of subclinical CO2 embolism by transesophageal echocardiography during laparoscopic radical prostatectomy. Urology 75: 581–584.

112 112 Kim, C.S., Kim, J.Y., Kwon, J.Y. et al. (2009). Venous air embolism during total laparoscopic hysterectomy. Anesthesiology 111: 50–54.

113 113 Schmandra, T.C., Mierdl, S., Bauer, H. et al. (2002). Transoesophageal echocardiography shows high risk of gas embolism during laparoscopic hepatic resection under carbon dioxide pneumoperitoneum. Br. J. Surg. 89: 870–876.

114 114 Derouin, M., Couture, P., Boudreault, D. et al. (1996). Detection of gas embolism by transesophageal echocardiography during laparoscopic cholecystectomy. Anesth. Analg. 82: 119–124.

115 115 Menes, T. and Spivak, H. (2000). Laparoscopy: searching for the proper insufflation gas. Surg. Endosc. 14 (11): 1050–1056.

116 116 Park, E.Y., Kwon, J.Y., and Kim, K.J. (2012). Carbon dioxide embolism during laparoscopic surgery. Yonsei Med. J. 53: 459–466.

117 117 de Jong, K.I.F. and de Leeuw, P.W. (2019). Venous carbon dioxide embolism dureing laparoscopic cholecystectomy a literature review. Eur. J. Intern Med. 60: 9–12.

118 118 Hamza, M.A., Schneider, B.E., White, P.F. et al. (2005). Heated and humidified insufflation during laparoscopic gastric bypass surgery: effect on temperature, postoperative pain, and recovery outcomes. J. Laparoendosc. Adv. Surg. Tech. 15: 6–12.

119 119 Erikoglu, M., Yol, S., Avunduk, M.C. et al. (2005). Electron‐microscopic alterations of the peritoneum after both cold and heated carbon dioxide pneumoperitoneum. J. Surg. Res. 125: 73–77.

120 120 Peng, Y., Zheng, M., Ye, Q. et al. (2009). Heated and humidified CO2 prevents hypothermia, peritoneal injury, and intra‐abdominal adhesions during prolonged laparoscopic insufflations. J. Surg. Res. 151: 40–47.

121 121 Mouton, W.G., Bessel, J.R., Millard, S.H. et al. (1999). A randomized controlled trial assessing the benefit of humidified insufflation gas during laparoscopic surgery. Surg. Endosc. 13: 106–108.

122 122 Farley, D.R., Greenlee, S.M., Larson, D.R. et al. (2004). Double‐blind, prospective, randomized study of warmed, humidified carbon dioxide insufflation vs standard carbon dioxide for patients undergoing laparoscopic cholecystectomy. Arch. Surg. 139: 739–744.

123 123 Sammour, T., Kahokehr, A., and Hill, A.G. (2008). Meta‐analysis of the effect of warm humidified insufflation on pain after laparoscopy. Br. J. Surg. 95: 950–956.

124 124 Nguyen, N.T., Furdui, G., Fleming, N.W. et al. (2002). Effect of heated and humidified carbon dioxide gas on core temperature and postoperative pain: a randomized trial. Surg. Endosc. 16: 1050–1054.

125 125 Manwaring, J.M., Readman, E., and Maher, P.J. (2008). The effect of heated humidified carbon dioxide on postoperative pain, core temperature, and recovery times in patients having laparoscopic surgery: a randomized controlled trial. J. Minim. Invasive Gynecol. 15: 161–165.

126 126 Scott, J.E., Singh, A., Valverde, A. et al. (2018). Effect of pneumoperitoneum with warmed humidified or standard‐temperature carbon dioxide during laparoscopy on core body temperature, cardiorespiratory and thromboelastography variables, systemic inflammation, peritoneal response, and signs of postoperative pain in healthy mature dogs. Am. J. Vet. Res. 79: 1321–1334.

127 127 Birch, D.W., Manouchehri, N., Shi, X. et al. (2011). Heated CO2 with or without humidification for minimally invasive abdominal surgery. Cochrane Database Syst. Rev. 1: CD007821.

128 128 Brisson, B.A., Reggeti, F., and Bienzle, D. (2006). Portal site metastasis of invasive mesothelioma after diagnostic thoracoscopy in a dog. J. Am. Vet. Med. Assoc. 229: 980–983.

129 129 Cai, W., Dong, F., Wang, Z. et al. (2014). Heated and humidified CO2 pneumoperitoneum inhibits tumor cell proliferation, migration and invasion in colon cancer. Int. J. Hyperth. 30: 201–209.

130 130 Wilson, D.V., Evans, A.T., Carpenter, R.A. et al. (2004). The effect of four anesthetic protocols on splenic size in dogs. Vet. Anaesth. Analg. 31: 102–108.

131 131 O’Brien, R.T., Waller, K.R. 3rd, and Osgood, T.L. (2004). Sonographic features of drug‐induced splenic congestion. Vet. Radiol. Ultrasound 45: 225–227.

132 132 Baldo, C.F., Garcia‐Pereira, F.L., Nelson, N.C. et al. (2012). Effects of anesthetic drugs on canine splenic volume determined via computed tomograghy. Am. J. Vet. Res. 73: 1715–1719.

133 133 Hasiuk, M.M.M., Garcia‐Pereira, F.L., Berry, C.R. et al. (2018). Effects of a single intravenous bolus injection of alfaxalone on canine splenic volume as determined by computed tomography. Can. J. Vet. Res. 82: 203–207.

134 134 Hausner, E., Essex, H.E., and Mann, F.C. (1938). Roentologic observations of the spleen of the dog under ether, sodium amytal, pentobarbital sodium and pentothal sodium anesthesia. Am. J. Phys. 121: 387–391.

135 135 Hutchins, J.L., Kesha, R., Blanco, F. et al. (2016). Ultrasound‐guided subcostal transversus abdominis plane blocks with liposomal bupivacaine vs non‐liposomal bupivacaine for postoperative pain control after laparoscopic hand‐assisted donor nephrectomy: a prospective randomized observer‐blinded study. Anaesthesia 71: 930–937.

136 136 Stokes, A.L., Adhikary, S.D., Quintili, A. et al. (2017). Liposomal bupivacaine use in transversus abdominis plane blocks reduces pain and postoperative intravenous opioid requirement after colorectal surgery. Dis. Colon Rectum 60: 170–177.

137 137 Guerra, L., Philip, S., Lax, E.A. et al. (2019). Transversus abdominis plane blocks in laparoscopic colorectal surgery: better pain control and patient outcomes with liposomal bupivacaine than bupivacaine. Am. Surg. 85: 1013–1016.

138 138 Vegfors, M., Engborg, L., and Gupta, A. (1994). Changes in end‐tidal carbon dioxide during gynecologic laparoscopy: spontaneous versus controlled ventilation. J. Clin. Anesth. 6: 199–203.

139 139 Di Bella, C., Lacitignola, L., Grasso, S. et al. (2018). An alveolar recruitment maneuver followed by positive end‐expiratory pressure improves lung function in healthy dogs undergoing laparoscopy. Vet. Anaesth. Analg. 45: 618–629.

140 140 Atashkhoei, S., Yavari, N., Zarrintan, M. et al. (2020). Effect of different levels of positive end‐expiratory pressure (PEEP) on respiratory status during gynecologic laparoscopy. Anesth. Pain Med. 10: e100075.

141 141 Choi, E.‐S., Oh, A.‐Y., In, C.‐B. et al. (2017). Effects of recruitment manoeuvre on perioperative pulmonary complications in patients undergoing robotic assisted radical prostatectomy: a randomized single‐blinded trial. PLoS One 12: e0183311.

Текст предоставлен ООО «ЛитРес».

Прочитайте эту книгу целиком, купив полную легальную версию на ЛитРес.

Безопасно оплатить книгу можно банковской картой Visa, MasterCard, Maestro, со счета мобильного телефона, с платежного терминала, в салоне МТС или Связной, через PayPal, WebMoney, Яндекс.Деньги, QIWI Кошелек, бонусными картами или другим удобным Вам способом.