P-BN05 Solitary jejunal diverticulum: a rare unexpected cause of chronic pneumoperitoneum

Background Jejunal diverticula are rare acquired herniation of the mucosa and submucosa through the muscularis propria. They are asymptomatic in the majority of cases, however, they can present with non-specific abdominal symptoms and rarely complicate leading to acute abdomen. Perforation usually results in symptoms and signs of acute peritonitis and it is not an identifiable aetiology of chronic pneumoperitoneum. Computed tomography scan may identify intestinal wall oedema, air bubbles travelling through the mesentery, free intra-abdominal air and/or fluid . Radiological diagnosis requires high index of suspicion of such pathology. We report a case of an isolated jejunal diverticulum as a cause for aseptic chronic pneumoperitoneum . Methods A 77-year-old female was referred to the ambulatory emergency surgical unit (AESU) with a 4-month history of nonspecific abdominal pain, considerable weight loss, diarrhea, nausea and a few episodes of vomiting.Physical examination revealed no constitutional signs of sepsis and her abdomen was mildly distended but soft and nontender to palpation. Laboratory investigations were unremarkable. CT scan of her abdomen and pelvis on her first visit showed pneumoperitoneum with associated low volume ascites, which raised the possibility of sealed gastrointestinal perforation. In the absence of any clear signs of sepsis, a strategy of ambulatory, conservative management and follow up was chosen. Four months after her initial presentation our patient presented with ongoing vague abdominal symptoms with weight loss and failure to thrive. A CT colonogram described pneumoperitoneum and larger volume of ascites is in comparison to the previous CT scan. There was an unusual pattern of mural gas in some loops of small bowel in the left side of the abdomen that suggested pneumatosis. MDT decided to proceed with diagnostic laparoscopy. Results Laparoscopy exploration revealed odorless pneumoperitoneum, moderate amount of non-turbid bile stained serous ascites and thin fibrinous covering. We identified a jejunal diverticulum associated with mesenteric air bubbles and moderately enlarged reactive feeling lymph nodes in the diverticular segment . A small bowel resection with a primary side-to-side anastomosis, washout of the abdomen and cholecystectomy were done through a Kocher’s subcostal incision. She made an uneventful post-operative recovery and was discharged home well on day 4. Histopathological examination of the resected specimens confirmed the presence of a ruptured isolated jejunal diverticulum with a breach in muscularis propria and chronic cholecystitis in the gallbladder. Conclusions In summary, our case report highlights the importance of being aware of the possibility of perforated jejunal diverticula as a possible source of chronic pneumoperitoneum causing chronic nonspecific abdominal pain, diarrhea and unexplained weight loss. The surgical option of segmental resection and primary anastomosis was beneficial in this patient. However, calculating the risk benefit ratio remains the mainstay of the management plan, which, as ever, should be tailored to each patient’s general condition and fitness with appropriate counselling and consent.