Excessive Weight Loss After Bariatric Surgery Linked to Internal Hernia

Patients who undergo rapid excess weight at various points after bariatric surgery are predisposed to internal hernias, claims a new study.

Researchers at the department of bariatric and minimally invasive surgery at Hillcrest Memorial Hospital (Simpsonville, SC, USA) reviewed 786 patients who underwent laparoscopic gastric bypass between 2002 and 2007; of these, 24 patients developed an internal hernia. The researchers than calculated these patient's weight loss, compared to the standard curve, in which patients who undergo bariatric surgery drop 40% of their excess weight by 3 months, 60% by 6 months, 75% by 9 months, and 85% by 12 months. The study results, however, showed that of the patients who had suffered an internal hernia, 19 had greater than 125% of expected weight loss at one or more follow-up visits. Further analysis showed that individuals with an internal hernia were 5.35 times more likely to have experienced a period of rapid, excessive weight loss than their peers without a hernia have. The study was presented at the clinical congress of the American College of Surgeons (ACS), held during October 2008 in San Francisco (CA, USA).

"Surgeons who perform this kind of procedure should be aware that patients who are rapidly losing weight may be at higher risk for internal hernia, and they should monitor them for signs of the condition,” said lead author Eric Bour, M.D. "This is also the case for general surgeons who see patients in an emergency department. It's our job to educate general surgeons who see patients who have abdominal pain and have lost a tremendous amount of weight in a quicker than expected period of time to be on the lookout for internal hernia as a possible cause of the symptoms.”

An internal hernia is a protrusion of an intraperitoneal viscus into a compartment within the abdominal cavity, and affects between four and 10 percent of patients who have had a laparoscopic gastric bypass procedure. The typical internal hernia occurs when the bowel protrudes through the openings created in the mesentery during the gastric bypass operation to divide the small bowel into parts; one part is surgically moved into the upper part of the abdomen and connected to a newly formed and smaller stomach pouch, and the other part is connected to the small intestine downstream. The internal hernia is corrected by surgically returning the herniated portion of the bowel to its proper position and closing defects with sutures to prevent serious complications, such as strangulation of the small bowel and incarceration or trapping of a segment of bowel within the hernia.

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Department of bariatric and minimally invasive surgery at Hillcrest Memorial Hospital