Description and Executability of a Novel Pre-tied Mini Ligature (Miniloop) in Laparocopic Ovariectomy in Cats

Abstract

Background: Ovariectomy(OVE) and ovariohysterectomy (OVH) are the most performed surgical procedures in Veterinary Medicine. In videosurgery, both in stray animals at sterilization campaigns and in the increasing demand of tutors to perform the technique. Laparoscopy results in reduced tissue damage, due to minimal organ manipulation and surgical access hemostasis can be performed by several methods, such as electro-coagulation, clips, and intra and extracorporeal ligatures. A pre-tied ligature system, or endoloop, is a haemostatic technique comprised of a slipknot and knot pusher, which is inserted into the abdominal cavity through one of the laparoscopic ports. The aim of this study was to describe a novel OVE technique in cats, in which haemostasis was performed using miniloop, aimed at reducing the number of ports needed for knot tying. Material, Methods & Results: Ten healthy not spayed female cats, aged 6 months to 5 years, were selected for this study. They were submitted to an OVE using miniloop as haemostasis method. Access to the peritoneal cavity was through two 5 mm ports on the midline of the ventral abdomen, 5 cm apart, with one immediately caudal to the umbilical scar and the other in between the last pair of teats. The first trocar was inserted at the caudal incision using the Hasson technique and a 5 mm zero-degree optics attached to a camera was introduced through it. The placement of the second access port was video assisted. For ovary exposure, the patients were positioned in lateral recumbency on the contralateral side to the ovary being removed. The miniloop was composed of a 2 mm diameter minitrocar, a 1.8 mm knot pusher, and a pre-tied slipknot. It was introduced percutaneously at the lateral abdominal wall. It was inserted attached to a pre-tied loop ligature. A Babcock forceps was used to guide the slipknot until it enveloped the ovarian vessels and the proximal part of the uterine horn. Subsequently, the knot was tightened with the aid of the knot pusher. A second miniligature was applied. The forceps was removed and a Metzenbaum scissors inserted to cut between the ligatures, releasing the ovary with the nylon ligature but keeping the PDS knot. It was performed at both ovary. Mean (+/- SD) surgical time was 44.8 min (+/- 13.4) and varied significantly (P = 0.0006) between animals, with the shortest time being 29 min and the longest 66 min. Positioning of the patients in lateral decubitus allowed for good ovarian exposure, without the need for excessive manipulation of the intestinal loops or other abdominal organs. Rupture of the suture thread was the only trans-operative complication observed and occurred in two animals. A second ligature (miniloop) was needed to ensure haemostasis. One cat showed eventration at the site of the caudal port on the second day post-operative. Discussion: The mean surgical time in the present study was lower than reported by some authors, but longer than anothers. Furthermore, the surgical time from this study is similar to that of other studies in cats in which haemostasis of the OAVC was achieved using bipolar electrocoagulation. Surgical team expertise is of outmost importance in minimizing complications and overcoming problems during videosurgical procedures in order to reduce surgical time, such as gas leakage, extensive incision, and difficulty in manipulating surgical instruments.