Retrograde jejunojejunal intussusception status following Roux-en-Y gastrojejunostomy.

Reported herein is an experience with retrograde intussusception. The index case was a 25-year-old African American woman who was status post-multiple previous intraperitoneal procedures, including a truncal vagotomy, distal gastrectomy, and Roux-en-Y gastrojejunostomy for the treatment of gastric outlet obstruction secondary to type 2 peptic ulcer disease. The patient presented most recently with symptoms and signs of a high-grade mechanical intestinal obstruction. Preoperatively, computerized axial tomography revealed retrograde intussusception. Urgent exploratory celiotomy confirmed retrograde intussusception of a segment of the common channel just distal to the jejunojejunostomy. The jejunojejunostomy, including the nonreducible intussusceptum and intussuscipiens, was resected. The alimentary tract was reconstituted in conventional fashion. Light microscopic histopathologic analysis revealed acute greater than chronic inflammation, transmural edema, ischemia/necrosis of the intussusceptum, and hypertrophy of the intussuscipiens. Mechanistically, intussusception has been characterized as an internal prolapse. It usually is aboral/antegrade/isoperistaltic in direction with circumferential intraluminal invagination/prolapse/propagation/telescoping of the proximal/cephalad intussusceptum into the distal/caudad intussuscipiens. Retrograde intussusception is the reverse. More specifically, retrograde intussusception is adoral/retrograde/antiperistaltic in direction with circumferential extraluminal exvagination/propagation/telescoping of the proximal/cephalad intussuscipiens over and around the distal/caudad intussusceptum. We speculate that suture lines, staple lines, adhesive disease, and incomplete closure of mesenteric defects are proximate and determinant causes of retrograde intussusception.