Post-Surgical Complications of Colic: It’s Not Over Yet
Janine Antonia Barrett
Daniel J. Burba, DVM, Dipl. ACVS


Introduction

Colic; this one term encompasses a great myriad of abdominal diseases. Most horse-people are aware of the dangers of colic but it is important to realize that colic never happens alone. The nature of colic opens the door for a number of life threatening complications that can occur even months after the initial episode. Diagnosis and treatment of the problem is also not with out inherent risks that add to the already numerous complications that can occur.

Common Complications Associated with Colic:
· Intestinal Tissue Compromise/Necrosis
· Dependent Edema
· Endotoxic Shock
· Laminitis
· Intestinal/Gastric Rupture
· Dehydration/Diarrhea
· NSAID toxicity/Gastric Ulcers
· Rectal Tear
· Adynamic Ileus
· Adhesions
· Peritonitis
· Death

Fig. 1 An episode of rolling during colic

Surgery is an often-inevitable treatment of serious colic and complications are common. It is imperative that you are aware of the risk and the expense involved with colic surgery and the intensive care and management that are necessary after the surgery. The most common and serious problems that arise after surgery include adynamic ileus, adhesions, and peritonitis and consequently recurrent colic or abdominal pain (Fig. 1).


Adynamic Ileus

What is it?
Adynamic ileus is a potentially life threatening condition of decreased or absent gut motility that occurs in most horses after abdominal surgery. This means that the intestinal contents are not moving through the gut and causing a backup of fluid, feed, and gas in the bowel. For most horses the ileus resolves with little problem soon after surgery, but others are not so lucky. Post-operative ileus in these horses usually occurs twelve to thirty-six hours especially after surgery involving the small intestine. Signs are related to progressive distention of the stomach and intestine and include gastric reflux, abdominal pain and depression, as well as a lack of defecation.

Why does it occur?
Although no one knows for sure why this phenomenon occurs, it is thought to be related to inflammation, decreased blood supply to and distention of the intestine as well as endotoxemia and prolonged surgery time (increased anesthesia and handling of the intestine). As was previously mentioned most, if not all horses (and even people), experience ileus after abdominal surgery but is only considered a problem if signs persist.

Treatment/Management?
Treatment of this problem consists mainly of intensive supportive care as well as IV fluids, decompression of the stomach with a tube, and various drugs to modify gut motility. Obviously the horse must remain in a hospital setting in order to receive appropriate care and therefore costs rise quickly. Most horses will recover with proper care and enough time but economics are often a limiting factor with difficult cases. Intractable cases of ileus are unfortunately commonly euthanized due to cost. Regrettably, ileus itself is not without its own set of complications such as rupture of the stomach and especially the formation of adhesions.

Adhesions

What is it?
Adhesions are fibrous tags that form between pieces of intestine (Fig. 2) or between the intestine and the body wall. It is believed that these adhesions originally form to help supply blood to a compromised piece of intestine but troubles arise when these beneficial adhesions do not break down and begin to cause potentially fatal problems. These consequences can include intestinal obstruction and strangulation, decreased gut motility and ileus, as well as recurrent abdominal pain and colic. Fig. 2 Jejunal adhesion

Why does it occur?
Any insult to the peritoneum (the tissue lining the body wall) or the surface of the intestine will open the door to adhesion formation. Decreased blood supply, distention, drying, and abrasion of the intestine or peritoneum during surgical manipulation or the initial insult are all predisposing factors.


Treatment/Management?
Adhesion management is mainly centered on prevention. Proper surgical technique, minimal surgery time and tissue handling, use of adhesion preventing compounds during surgery and early recognition and rectification of predisposing conditions such as ileus and peritonitis can go a long way to decreasing the incidence of adhesions. However, even after a seemingly successful surgery and recovery a horse may still succumb, and unfortunately adhesions are a major reason for euthanasia and death after abdominal surgery. Occasionally, a second surgery may be necessary in an attempt to break down the adhesions but this is generally unsuccessful and the adhesions usually reform with even more complications.


Peritonitis

What is it?
Along with ileus and adhesions, peritonitis is one of the most fatal post-surgical complications following abdominal surgery. Peritonitis is an inflammation of the abdominal body wall and surface of the abdominal organs. Signs include mild colic, depression, anorexia, ileus, diarrhea, fever, increased heart rate, and increased respiration. These signs normally do not occur until three to five days after abdominal surgery and depend on the severity of the infection.

Why does it occur?
Peritonitis occurs because of contamination of the abdominal cavity. This contamination can result from the death of the affected intestinal segment, leakage of gut contents before, during, or after surgery, abdominal trauma, and any kind of foreign body or material in the abdomen. Risk of peritonitis increases greatly if the intestine must be opened during the surgery as it intensifies the chance of contamination with and leakage of gut contents into the abdomen. Compromised intestinal blood supply also allows the leakage of bacteria through the intestinal wall and subsequent peritonitis.

Treatment/Management?
As with adhesions, prevention is the name of the game, however, prevention is sometimes not an option. Treatment centers on resolving the primary problem, decreasing the inflammation, and preventing complications such as adhesion formation, endotoxemia and intra-abdominal abscesses. IV fluids, antibiotics, and peritoneal lavage are integral in the treatment regime and must be conducted in the hospital with proper monitoring. A second surgery may be warranted if leakage of the surgery site or perforation is suspected. Often, treatment of severe cases is unrewarding but aggressive and early management of milder cases resolves nicely.


In Conclusion

Each of these complications is unfortunately frequently life threatening. This, however, does not mean that all is lost. Newer treatment techniques and constant vigilance make survival rates better than ever but it is not an inexpensive undertaking. These problems require intense monitoring and care (Fig. 3) and expense is often a limiting factor. You need to remember that colic is usually never just colic and the complications can be worse than the problem that started it all.

Fig. 3 Intensive Care






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