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.
7 Anesthesia Management of Dogs and Cats for Laparoscopy
Marlis L. de Rezende and Khursheed Mama
Key Points
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.
Introduction
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.
Anesthesia Considerations Related to Disease
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].
Anesthesia Considerations Related to Surgery