Surgical techniques in equine colic

Emergency equine abdominal surgery is easiest and most efficiently carried out with a team of surgeons. The surgical site should be as protected as possible by the use of sterile drapes and wound protectors. A ventral midline laparotomy incision has been found to be the most convenient approach to most equine intestinal obstructions. A standing laparotomy through the left paralumbar fossa gives adequate exposure for exploration of the abdomen and is, therefore, useful as a diagnostic tool. Horses tolerate having both ventral midline and left paralumbar laparotomy incisions well. If the cause of the intestinal obstruction is not readily apparent upon opening the abdominal cavity, a thorough systematic exploration of the abdominal cavity is necessary. If the problem cannot be found with the bowel in situ, intestine must be exteriorized for examination. The decision as to the extent of adequate bowel resection often depends on a subjective assessment of bowel function. In equivocal cases, the surgeon should choose to resect some normal bowel rather than taking a chance on leaving compromised bowel in place. Incarcerations are frequent causes of small intestinal obstructions. The small intestine may become incarcerated in the epiploic foramen, the inguinal canal or in an umbilical hernia. Thromboembolic compromise to intestinal vessels results in the longest lengths of embarrassed bowel requiring resection. Impactions are the most common obstructions associated with the caecum. Large colon torsions of 270 degrees or less may be corrected by surgical manipulation; with 360 degrees torsions of the large colon, however, vascular compromise is usually sufficient to devitalize this organ. Enterotomy of the large colon allows retrieval of most enteroliths from its lumen. Enterotomy of the right dorsal colon is also useful for removal of foreign bodies which cause obstruction of the most proximal portion of the small colon. In our Clinic a two-layer end to end anastomosis is usually utilized. Recently introduced automated stapling and ligating instruments have been useful in decreasing surgical time. Antibiotics, usually furacin and sodium or potassium penicillin in 2 litres of Normasol-R, are placed in the peritoneal cavity before closure of the abdomen. A Penrose drain is commonly placed into the abdominal cavity to provide drainage of the peritoneal cavity after surgery. The peritoneum is sutured with No 0 chromic gut in a simple continuous pattern. A second Penrose drain may be placed between peritoneum and ventral body wall, with its ends retracted through stab incisions in the skin. The linea alba is closed with simple interrupted sutures of stainless steel wire or No. 3 chromic gut. Employing the above described principles and techniques has increased the success of abdominal surgery in our Clinic.