This month’s dilemma:
Internal hernias following gastric bypass operations
This month’s expert:
Alan Wittgrove, MD, FASMBS
Dr. Wittgrove is Medical Director, Bariatric Program, Scripps Memorial Hospital, La Jolla, California.
A 21-year-old woman had a Roux-en-Y gastric bypass two and a half years ago complicated by an internal hernia a year later, necessitating massive small bowel resection for necrotic small bowel and resulting in short gut syndrome. She was placed on total parenteral nutrition on account of short gut and intolerable symptoms of dumping syndrome. Her course was complicated by multiple periods of admission for line sepsis, poorly controlled diarrhea, and abdominal pain.
What would further management of this patient entail?
This case involves several interesting and important issues regarding internal hernias following gastric bypass operations. 1) When should a patient be explored for an internal hernia? 2) What should be done if necrotic bowel is found at the time of exploration? 3) What should be done for the patient outlined in this presentation?
When should a patient be explored for an internal hernia?
Since the presence of an internal hernia is not consistently diagnosed (and never treated) by radiographic studies, there needs to be a very low threshold for exploration. The classic presentation of left-sided abdominal pain, which is exacerbated by meals, is not always found. Patients who are in obvious extremis need urgent surgical intervention. X-ray studies often delay the procedure and are not necessary. Patients can have recurrent abdominal pains that are intermittent and not severe enough to necessitate emergency room visits but can still be from internal hernias. Certainly, there are other reasons for patients to have intermittent or recurring pains but an internal hernia may be the most serious etiology. I would recommend a diagnostic laparoscopy if the symptoms are recurrent and the etiology is not absolutely known. It is important for the surgeon to look in all possible areas where internal hernias can occur. I would add that if a gastric bypass patient is being explored for another reason, a cholecystectomy for example, the surgeon should consider looking for an internal hernia during the operation.
What should be done if necrotic bowel is found at the time of exploration?
When the bowel becomes incarcerated in an internal hernia, it can cause a closed loop obstruction. Strangulation can occur rather rapidly and, therefore, exploration should be done sooner rather than later. Even with rapid progression to the operating room, some cases end with a compromised bowel. Remember, it is often difficult to reduce the incarceration by addressing it directly. One can more easily reduce the small bowel by starting at the terminal ileum and following the bowel proximally. Since a large amount of bowel may be compromised, the surgeon should consider saving any questionably viable small bowel even to the point of scheduling a second-look operation in 24 to 36 hours. Saving even several inches more may make the difference. It is quite unusual for all three limbs (Roux, bileopancreatic, and common channel) to be strangulated and necrotic. Even if the majority of the common channel is dead, one may consider reconstruction to save absorptive capacity.
What should be done for the patient outlined in this presentation?
The answer to this question starts where the last question finished. One needs to know just what was removed in this 21-year-old woman. Does she have any small bowel that can be placed back into the normal flow? Can the Roux limb be taken down, reversing the gastric bypass and gaining more functional small bowel? Since the original case presentation notes the patient experiencing intolerable symptoms of “dumping” I would surmise the patient still has the Roux limb construction. Reversing the gastric bypass and gaining more small bowel is the primary thought in this situation. If the patient has had all the maneuvers and the simple fact is there is not enough small bowel, then medical treatment is needed. The patient should be given an elemental type of feeding and high doses of pancreatic enzymes, orally. Low fat diets are important to minimize diarrhea. Enzymes can be given in capsule or powered form and should be given liberally.
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