Intestinal surgery (part 2) (Proceedings)
Intestinal resection and anastomosis is a relatively commonly performed surgical procedure in small animals. Observing surgical principles and utilizing selected ancillary techniques help to reduce complications. Ancillary techniques that help reduce complications of intestinal resection and anastomosis include enteroplication and intra-operative peritoneal lavage. Potential indications for enteroplication will be reviewed, as its use is somewhat controversial in veterinary patients.
Intestinal resection and anastomosis
Indications for intestinal resection and anastomosis include intussusception, neoplasia, focal necrosis (e g, foreign body, volvulus, trauma), perforation(s) (e.g., linear foreign body, gunshot wound, penetrating abdominal injury), and focally infiltrative disease (e.g., pythiosis). Extent of the resection should be based on extent of the disease process and assessment of the viability of the affected intestine. Excision of the dilated portion of the intestine is not usually performed, because the dilatation usually results from partial or complete obstruction. Intestinal viability is assessed visually, and such assessment is used to determine extent of resection. Criteria for assessing intestinal viability include presence of arterial pulsations, tissue color, character of blood from a partial-thickness test incision, wall texture, and peristalsis. The single most reliable criterion for assessing intestinal viability is the presence of arterial pulsations. Neoplastic and focally infiltrative lesions should be excised with wide margins of normal tissue. Plan the resection to preserve as much intestine as possible but also to avoid multiple anastomotic sites. Evisceration with self-inflicted intestinal trauma or mesenteric volvulus may necessitate massive resection and anastomosis and potentially result in short bowel syndrome.Exteriorize and isolate the affected segment of intestine, and pack it off with moistened laparotomy sponges. Resection and anastomosis of the caudal duodenal flexure (duodenojejunal junction) and the ileocolic junction present additional challenges, in part, because of the short mesentery at these locations that tends to limit exteriorization of these segments. Presence of a linear foreign body with plicated intestine also presents challenges regarding exteriorization of intestine. Removal of the linear foreign body is indicated prior to the performance of a resection and anastomosis. Ligate the mesenteric vessels to the affected area, and incise the mesentery so as to preserve as much mesentery to make closure of the mesenteric defect easier. Occlude the intestinal segments atraumatically near the point of resection (assistant's fingers are least traumatic; Doyen intestinal forceps are also acceptable). Excise the affected intestine using a scalpel blade. Orient incisions to leave the antimesenteric border shorter than the mesenteric border on the remaining intestine. Correct any luminal disparity by longitudinally incising the antimesenteric aspect of the smaller end. Use 3-0 or 4-0 synthetic absorbable suture (e.g., polydioxanone) with an appropriately-sized swaged-on taper needle (e.g., SH) to perform the anastomosis. Place the first suture at the mesenteric border and the second suture at the antimesenteric border. Leave these initial sutures long to act as stay sutures when manipulating the intestine. Place sutures 3 to 4 mm apart, 4 to 5 mm from the wound margin, and through the full thickness of the intestinal wall to complete the anastomosis. Check for integrity of the anastomotic line by injecting saline (8 to 10 ml in a 6 cm segment of intestine) into the lumen of the occluded segment and observing for leaks. Place additional sutures, if leaks are observed. Cover the anastomosis with omentum, and close the mesenteric defect with a continuous suture line, while carefully avoiding mesenteric vessels.