Ex vivo comparison of sliding knot ligatures vs. haemostatic clips for equine small intestinal mesenteric vessel occlusion

Background: In equine abdominal surgery, resection and anastomosis of strangulated intestine is a commonly performed procedure. To date, ligatures, vessel sealing devices and the ligate-divide stapler have been described for this use in horses. The objective of this study was to compare the application of haemostatic clips and ligatures to occlude equine mesenteric vessels. Portions of jejunum with ten associated mesenteric vessels were collected from 12 horses at a local abattoir and divided into two groups. Portions of intestine were divided into two sections comprising five vessels each and assigned to Group A or Group B. Each vessel was occluded with a triple ligature. In Group A, vessels were ligated with three circumferential ligatures tied with a sliding knot with two overthrows. In Group B, vessels were occluded with application of three haemoclips. The procedures were performed by the same experienced surgeon. Intestinal length, construction time and vessel leaking pressure were measured and compared between groups. Results: The intestinal length (mean ± SD) was 3.78 ± 0.43 m in Group A and 3.04 ± 0.83 m in Group B. The difference was not significant (p = 0.297). The construction time (mean ± SD) was 7.03 ± 0.34 min in Group A and 2.40 ± 0.43 min in Group B. The difference was significant (p < 0.0001). The leaking pressure was 1000 (750-1050) mmHg (median, IQ range) in Group A and 1050 (800-1050) mmHg (median, IQ range) in Group B. The difference was not significant (p = 0.225). Conclusions: Haemoclip application is comparable in terms of leaking pressure but quicker than sliding knots to apply.