Surgical innovations in canine gonadectomy

Abstract

In this thesis some recent technological developments in human surgery are evaluated for their potential use in veterinary medicine by introducing them as surgical innovations for canine gonadectomy. Barbed sutures achieve wound apposition without surgical knot tying and thus avoid knot-associated negative consequences (lengthy placement, impaired wound healing around bulky knots, and the effect of unsightly knots on cosmetics). A study in 9 dogs found that celiotomy closure was easily achieved, no intraoperative or postoperative complications occurred, and ultrasonographic characteristics during wound healing were comparable to conventional sutures. Ovariectomy is technically less complicated, less time consuming, and is associated with decreased morbidity (smaller incision, less intraoperative trauma, decreased discomfort) compared with ovariohysterectomy. For the incidence of long-term urogenital problems, including endometritis/pyometra and urinary incontinence, no differences between techniques were observed. This makes ovariectomy the preferred method for elective gonadectomy. Neuromuscular blocking agents induce abdominal muscle wall relaxation and might lead to a larger intra-abdominal working space and improved surgical efficiency. However, the duration of ovarian pedicle transection in 40 dogs was not significantly changed (5.7 ± 2.3 versus 5.9 ± 1.9 minutes), arterial blood pressure decreased 5%, and the occurrence of intraoperative complications did not differ. There was no advantage to add NMB to the anesthetic protocol. Newly developed energy-based hemostatic surgical devices were evaluated during laparoscopic ovariectomy. When a bipolar electrocoagulation grasping forceps was compared with monopolar electrocoagulation on 103 dogs, it decreased laparoscopic ovariectomy time (41 versus 53 minutes), decreased intraoperative hemorrhage (8 versus 13% dogs), and facilitated exteriorization of the ovaries. Obesity (56 versus 42 minutes) and intraoperative mesovarial bleeding (56 versus 46 minutes) increased surgical time. Dog age, estrus, and pseudopregnancy did not influence surgical time. When a vessel sealing device was compared to the bipolar electrocoagulation grasping forceps in 40 dogs, the surgical time was reduced (3.5 ± 2.7 versus 8.1 ± 4.2 minutes), with less bleeding (0 versus 10%), and with less thermal coagulation damage based on histological scoring. Surgical times were influenced by surgeon experience, and ovarian pedicle fat scores. When the vessel sealing device was compared to a bipolar electrocoagulation cutting forceps in 21 dogs, excision of the ovaries was faster (2.5 ± 1.2 versus 4.8 ± 1.8 minutes), bleeding occurred less (0 versus 29%), and thermal coagulation damage was less (93.4 ± 85.8 versus 130.9 ± 101.2 µm). Surgical times increased in obese animals. A vessel sealing device for open ovariectomy was compared with conventional suture ligation in 20 dogs, and resulted in reduced surgical times (2.22 ± 0.58 versus 4.10 ± 1.13 min). Limited reuse of the disposable instrument was possible, untill eventually the electrode failed. Ovarian remnant tissue in 32 dogs was removed laparoscopically. Surgical time was 107 ± 33 minutes, with a convalescence duration of 1.5 ± 0.7 days. No major complications occurred. Minor hemorrhage (12%) and the presence of adhesions (79%) increased surgical times. After a median follow-up period of 22.5 months absence of clinical signs and hormonal assays testing confirmed 100% treatment efficacy.