Peritoneal Encapsulation With Incarcerated Meckel Diverticulum Contributing to Small Bowel Obstruction.

Meckel diverticulum is the most common congenital gastrointestinal malformation, but it is rarely symptomatic. Peritoneal encapsulation is a rare abnormality of embryonic development and may present with obstruction, although it too is usually asymptomatic. We report the case of an 82-year-old male who presented with symptoms and imaging findings consistent with small bowel obstruction. During laparotomy, a peritoneal encapsulation was observed containing the majority of the small bowel. A Meckel diverticulum was discovered tethered to the small bowel mesentery by a mesodiverticular band, preventing egress from the accessory peritoneal membrane and appearing to be the cause of the obstruction. This patient had 3 rare findings-peritoneal encapsulation, Meckel diverticulum, and a mesodiverticular band-contributing to cause an acute small bowel obstruction. The presence of all of these features in one patient is extremely rare, and we believe this is the first description of such a phenomenon.