Retrograde intussusception seven years after a laparoscopic Roux-en-Y gastric bypass.

Intussusception after Roux-en-Y gastric bypass is more common than previously believed. It usually occurs between one and three years post-operatively, though we present a case that presented with a retrograde intussusception necessitating bowel resection seven years after a laparoscpic Roux-en-Y gastric bypass. The diagnosis and etiological theories are discussed based on findings from the literature.

INTRODUCTION

Intussusception following a Roux-en-Y gastrojejunostomy was first described by Agha in 1986.[1] In the last decade, approximately 20 papers have reported intussusception as a post-operative complication of Roux-en-Y gastric bypass (RYGBP). This has correlated with the rapid increase in the rate of bariatric surgery over that time period.[2] Most reported cases present between one and three years post-operatively.[3] We report a rare case of retrograde intussusception seven years after a laparoscopic RYGBP.

CASE REPORT

The patient was a 43-year-old African American female who presented to the emergency room with paroxysmal, severe abdominal pain as well as nausea and vomiting that began soon after a large meal. She denied melena or recent change in bowel habits. She reported losing approximately 100 lbs since her laparoscopic, retrocolic RYGBP. On examination, the patient was well nourished, afebrile, and with normal vital signs. She was in moderate distress with pain out of proportion to the physical examination. Her abdomen was soft, and there were no signs of peritoneal irritation or distension. Laboratory data were unremarkable. Computed tomography scan revealed high-grade small bowel obstruction adjacent to the jejuno-jejunal anastamosis with dilation of the biliopancreatic limb and the gastrojejunal limb [Figure 1]. This obstruction was associated with a loop of small intestine which had telescoped into itself, consistent with intussusception. The patient was immediately taken to the operating room.

Figure 1

CT scan noting bowel within bowel, suggesting intussusception.

Visualization of the abdomen under pneumoperitoneum revealed massively dilated small bowel necessitating conversion to an open procedure. There was an area of intussuscepted bowel just past the small bowel anastomosis of the gastric bypass. Approximately six inches of distal small bowel had telescoped in a retrograde fashion towards the anastomosis [Figure 2]. The intussusception was reduced with great difficulty. The region of telescoped small bowel was non-viable and resected. A leadpoint was not identified. Of note, there was a Petersen defect identified and closed; there was no incarcerated bowel within the defect. Examination of the remaining abdominal cavity was unremarkable. Pathologic analysis of the specimen revealed a segment of small bowel that was focally hemorrhagic and necrotic.

Figure 2

Intussusception of small intestine (small arrow) towards jejuno-jejunal anastamosis (large arrow)

The patient had an unremarkable post-operative course and was discharged on post-operative day five. Follow-up after 24 months has been without complication.

DISCUSSION

Intussusception is an underappreciated complication of RYGBP. In one review of 15 553 gastric bypass surgeries at a single institution, 23 patients developed a retrograde intussusception. Given the rapid increase in the rate of bariatric surgery over the past 20 years, intussusception is becoming an increasingly prevalent entity.[2]

Pathologic lead points such as malignancy or Meckel′s diverticulum have traditionally been thought to be the etiology of small bowel intussusception in adults.[1] Most intussuception occur in an antegrade fashion. With RYGBP, intussusception is more often retrograde.[4] The etiology of intussecption in post RYGBP is largely unknown. Previous literature has hypothesized a iatrogenic lead point created by the suture or staple line at the enteroentero anastamosis, thereby allowing hyperperistalsis of the excluded segment to telescope the biliopancreatic limb into the common limb.[3-6] A post-operative adhesion could do the same.

Others have suggested “Roux stasis syndrome” as another possible etiology in this patient population.[78] Hocking and colleagues described a possible physiologic etiology related to dysmotility of the Roux limb in 1991.[9] Hocking theorized that disorderly peristaltic activity in the Roux limb could create adjacent areas of high and low-pressure thus allowing for an intussusception. This explanation fits in the case presented here as no intraluminal, intramural, or extraluminal cause could be found which may have led to the retrograde jejunojejunal intussusception.

Computer Tomography is the most reliable investigation when suspicion for intussusception presents in a RYGBP patient.[10] When recognized, it can be diagnosed by virtue of its pathognomonic appearance as a complex soft tissue mass consisting of outer and inner portions of the intussusceptions. A crescent shaped piece of mesenteric fat is often appreciated within the intussusception.

In summary, symptomatic intussusception may occur many years after RYGBP and may present with non-specific signs and symptoms. Its incidence may be higher than previously believed, occurring in as many as 1/1000 of patients who undergo RYGBP. Given the enormous popularity of this procedure, intussusception should be on the differential for complaints of post-operative abdominal pain. The etiology of intussusception in the RYGBP population is largely unknown, although dysmotlity associated with the Roux limb may be the etiology in most instances. Computer tomography is the most reliable tool used in its diagnosis.