EP605 - Distinguishing Chronic Sigmoid Volvulus From Ogilvie Syndrome: A Case Report

Image or Table (Do Not add text here):

Purpose/Background: Benign etiologies of large bowel obstructions are categorized by mechanical or functional. Mechanical obstructions include volvulus, hernia, adhesions, and stricture. Sigmoid volvulus is the most common benign cause of large bowel obstruction. Functional disorders include colonic pseudo obstruction, paralytic ileus, and chronic constipation. Colonic pseudo obstruction (also known as Ogilvie’s Syndrome) is a functional disorder that causes a large bowel obstruction that can be acute or chronic in nature.

Methods/Interventions: A 62-year-old male with chronic constipation and multiple comorbidities presented with abdominal distention and dyspnea. He was previously treated for Ogilvie's pseudo obstruction through conservative measures. On exam, his abdomen was diffusely distended without percussion tenderness. Initial CT demonstrated pancolonic gaseous distention with an 8 cm cecum, 6 cm transverse colon, and 12 cm rectosigmoid with contrast in the sigmoid colon and rectum. Flexible sigmoidoscopy showed a dilated rectosigmoid colon without physical obstruction. His symptoms improved after decompression, however recurred with imaging showing dilation of the rectosigmoid to 15 cm (Figure). He was given neostigmine with only temporary improvement in symptoms.

Results/Outcomes: Due to recurrent and medically refractory disease, the decision was made to proceed with operative intervention. Operative findings included a dilated and gas filled sigmoid and rectum without obvious transition zones; the rectosigmoid mesentery was broad-based with thickened and scarred peritoneum at the base of the inferior mesenteric artery mesentery. Given the patient’s history and operative findings, we were concerned for chronic intermittent sigmoid volvulus, so a sigmoidectomy with end-colostomy was performed. Postoperatively the patient recovered well without recurrent symptoms and subsequently had an unremarkable recovery after colostomy reversal.

Conclusion/Discussion: Patients with intermittent/chronic sigmoid volvulus present with persistent abdominal distention, pain, and constipation. This can be difficult to distinguish from a functional obstruction as imaging findings are not always pathognomonic. Radiologic findings consistent with volvulus are: a “whirl sign”, a transition point, the “coffee bean” sign, or marked distention of the ahaustral sigmoid colon. Several studies note that dilation of the sigmoid > 9cm on baseline CT increases risk of recurrent sigmoid volvulus. It is generally agreed that dilation > 12cm warrants endoscopic decompression, regardless if dilation is from mechanical or functional etiology. A radiologic finding more consistent with an Ogilvies functional disorder includes a transition in the splenic flexure with proximal dilation. Pathophysiology correlates with the transition of innervation to the distal transverse colon - from the vagal nerve innervating the SMA territory, and pelvic splanchnic nerve innervating the IMA territory. Operative intervention becomes necessary with concerns of bowel ischemia, perforation, or for recurrent volvulus after endoscopic decompression. Chronic volvulus patients typically have operative findings of broad based mesentery that is often thickened and scarred from ongoing rotational insult. This leads to the importance of correlating intraoperative findings with patient presentation. The etiology of a large bowel obstruction can be difficult to determine, however is important in order to appropriately tailor clinical management.