EFFECT OF OMENTECTOMY ON ADHESION FORMATION IN HORSES

Objective - To determine if omentectomy would decrease the frequency o f postoperative intraabdominal adhesions. Study Design - Retrospective study. Animals or Sample Population - 44 horses that had either two v entral median celiotomies or a ventral median celiotomy and a necropsy more than 4 days later; 19 of these horses had their omentum removed at the initial surgery. Methods - Data retrieved from the records incl uded location and type of intraabdominal adhesions; location of the su rgical lesion; relationship of adhesions to the surgical lesion; surgi cal procedures; duration of initial surgery; time interval between pro cedures; age, gender, and breed of the horse; and clinical outcome. Fi sher's exact test was used to evaluate the association between categor ical explanatory and outcome variables. The effect of potential risk f actors on the incidence rate of adhesion formation was estimated using a proportional hazards regression model. Results - Of 25 horses in th e nonomentectomy group, 15 (60%) had postoperative adhesions that resu lted in the need for a second surgical intervention, whereas of 19 hor ses that had omentectomy initially, only 4 (21%) had postoperative adh esions that required a second procedure. Rate of adhesion formation wa s higher in horses that did not have omentectomy initially (incidence ratio rate [IRR], 0.46; 90% confidence interval [CI], 0.18 to 1.19). A t initial surgery, 24 horses had a small intestinal lesion, and 20 hor ses had a large intestinal lesion. Fifteen horses (63%) with small int estinal lesions subsequently developed adhesions compared with four ho rses (20%) with an initial large intestinal lesion (P = .006). At the second procedure, small intestine lesions were identified in 32 horses and large intestine lesions in 12 horses (1 horse had both small and large intestine lesions), and 1 horse had a gastric lesion. Adhesions were identified as the cause of colic signs in 19 (61%) horses with sm all intestinal lesions and in none of the horses with large intestine lesions. The frequency of adhesion development leading to colic associ ated with only the small intestine at the second surgery or necropsy w as significantly greater (P = .001) than the frequency only in the lar ge intestine. Conclusions - Omentectomy reduced the rate of postoperat ive adhesion formation. Adhesions are more likely to occur after small intestinal surgery and if they do occur likely involve the small inte stine. Clinical Relevance - Omentectomy is a safe procedure and should be considered prophylactically for reduction of adhesion formation af ter abdominal surgery in horses. (C) Copyright 1998 by The American Co llege of Veterinary Surgeons.