Gastrointestinal Resection and Anastomosis in Small Mammals

Gastrointestinal resection and anastomosis is the name given to any surgical procedure in which a portion of the gastrointestinal tract is excised or resected, and the remaining ends of the tract are reattached (anastomosis). This procedure is typically performed only in ferrets and rabbits. Size and cost concerns often prohibit this procedure from being performed in smaller animals but can be successfully performed by an experienced surgeon.

Causes

• Ingestion of a foreign body that subsequently becomes lodged in the small intestine is a common condition that requires resection and anastomosis. The obstruction can lead to necrosis, which is dying of the wall of the intestine, and ultimately to intestinal perforation. The entire length of damaged intestine is removed and the two ends that are reattached are healthy.
• Intussusception is a condition in which a portion of the gastrointestinal tract advances into the intestine adjacent to it, similar to an old-fashioned telescope. If the intussusception cannot be undone, resection and anastomosis is performed.
• Neoplasia (cancer) or benign tumors can occur in any region of the gastrointestinal tract. The stomach, small intestines, large intestines and rectum can develop tumors that may require resection and anastomosis to treat.

Depending on the underlying condition that requires that resection and anastomosis be performed, the prognosis is variable. For benign conditions, such as foreign body obstruction, intussusception, and benign tumors, the prognosis is generally excellent. If perforation of the gastrointestinal tract has occurred due to any cause, the abdominal contents are usually inflamed (peritonitis) and the anastomosis may not heal well. Thus, the presence of abdominal infection generally warrants a guarded prognosis. Some neoplastic conditions carry a poor prognosis because of possible recurrence, while others may be cured with surgery.

Any gastrointestinal resection and anastomosis procedure can be associated with post-operative complications. The most common and serious complication is leakage at the site of the anastomosis. Leakage can be secondary to poor surgical technique, but is usually the result of dehiscence (splitting open) because the edges of the reattached tract were not completely healthy and did not heal well. This complication usually occurs within the first 3 to 5 days after surgery. If dehiscence occurs, gastrointestinal contents leak into the abdomen and cause infection. This requires emergency surgery or euthanasia.

Diagnosis In-depth

• Resection and anastomosis is a technique that is usually deemed necessary only after the surgeon has had an opportunity to assess the extent and nature of the disease process affecting the gastrointestinal tract. That assessment is usually based on direct visualization and palpation of the affected tissues during an exploratory surgery.
• Tests performed before surgery may suggest that a resection and anastomosis are needed, and may help in determining that exploratory surgery should be performed. Complete physical examination is extremely important in any patient with symptoms related to the gastrointestinal tract, such as vomiting, diarrhea, poor appetite and weight loss. Thorough palpation of your pet's abdomen by your veterinarian may reveal fluid build-up in the abdominal cavity, pain or tumors.
• X-rays of the chest and abdomen may reveal a foreign object within the gastrointestinal tract and may show fluid or gas in the chest or abdomen. Occasionally, your pet is fed a contrast material that helps to outline the gastrointestinal tract before additional radiographs are taken.
• Ultrasound examination is a useful tool for non-invasive examination of the abdominal organs. It is also helpful in retrieving samples of fluid from the abdominal cavity (abdominocentesis) when only a small amount may be present, and in diagnosing intussusception.

Treatment In-depth

• Gastrointestinal resection and anastomosis can be performed by suturing the two ends of the gastrointestinal tract back together, or specialized stapling equipment can be used. The use of stapling equipment can greatly reduce the surgery and anesthesia time, but it may increase the cost.
• The removed portion of the gastrointestinal tract may be submitted to a laboratory for histopathological examination (biopsy).
• Your pet is usually kept in the hospital for 1 to 2 days after surgery in order to continue intravenous fluid therapy and to allow antibiotics and pain medications (analgesics) to be administered. Your pet is closely monitored during this time for evidence of infection or other complications.

Home Care

• Your pet will often be kept in the hospital for a few days for continued treatment and monitoring after a gastrointestinal resection and anastomosis has been performed.
• Once your pet is discharged from the hospital you need to restrict his/her activity for several weeks. You also need to monitor the skin incision for redness, swelling, or discharge.
• Your pet may be sent home on a restricted diet, restricted in either volume or type of food fed, and/or medications.
• Your veterinarian will typically ask you to return for a recheck appointment in two weeks so that he/she can monitor your pet's progress and to remove the skin sutures.