Severe Acute Pancreatitis with Complicating Colonic Fistula Successfully Closed Using the Over-the-Scope Clip System
A 44-year-old man presented to the emergency room with continuous abdominal pain and met the diagnostic criteria for systemic inflammatory response syndrome (39°C, 130 beats/min, 20 breaths/min). Laboratory tests showed elevation of leukocyte count (WBC) and levels of C-reactive protein (CRP), transaminase, amylase, pancreatic amylase and triglyceride (table ). Two of Ranson's criteria were positive (WBC > 16,000 cells/mm3; blood glucose > 200 mg/dl) []. Contrast-enhanced computed tomography (CT) revealed necrotizing pancreatitis and a diagnosis of hyperlipidemic acute pancreatitis was made. Although extrapancreatic progression of inflammation extended to the anterior pararenal space, there were hypoenhanced lesions in two segments of the pancreas.\nConservative treatment including high-volume infusion, prophylactic antibiotic (meropenem), protease inhibitors and intravenous immune globulin were started immediately. Follow-up CT revealed massive peripancreatic fluid collection and an abscess in the left abdominal cavity (fig. ). CT-guided percutaneous drainage was performed for the pancreatic abscess. No improvement was seen and a 7-Fr pig-tail drainage catheter was placed on hospital day 22. Abscess culture was positive for extended-spectrum β-lactamase (ESBL)-producing Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). The cavity was lavaged of debris and purulent material.\nA 12-Fr silicon catheter was subsequently placed on day 34, 8-Fr and 7-Fr pig-tail catheters were placed on day 48, and the catheter was dilated gradually. Immediately after irrigation of a temporary drain, high fever developed, so we switched to continuous drainage. A 16-Fr drainage catheter inserted on day 69 achieved good drainage. Maroon-colored fluid from the abscess drainage changed to clear fluid on day 78. The volume of fluid drained did not decrease, however, and remained between 200 and 400 ml per day. The fluid was high in amylase and as pancreatic duct disruption was strongly suspected, endoscopic retrograde cholangiopancreatography (ERCP) was performed on day 90. The results showed disruption on the tail of the main pancreatic duct with contrast extravasation. An endoscopic nasopancreatic drainage (ENPD) tube was therefore placed at the tail. With the aim of achieving fistula closure and reduction of output, octreotide (300 μg/day) was used concurrently.\nAs the volume of fluid drained did not decrease below 50 ml/day, octreotide was increased to 600 μg/day on day 105. To increase drainage volume, a 7-Fr pancreatic stent was placed endoscopically on day 111 and dilated to 8.5 Fr on day 133. Fluid volume decreased for around 2 weeks but thereafter increased gradually, so we discontinued octreotide on day 130. We had reached the limit of conservative management at this point and explored the indications for surgical therapy. However, as the abscess culture was still positive for ESBL-producing E. coli and MRSA, surgical treatment was postponed. CRP and WBC were stable and the patient had no abdominal complaint, so a liquid diet was started on day 138. The patient ran a fever ≥38°C the following day, diet was stopped and radiography was performed on day 140 for pyrexia. Drainage tubography showed a small fistula of the colon at the splenic flexure (fig. ); the diagnosis was thus amended to colonic fistula complicated by severe acute pancreatitis. Drainage was effective and therefore the cause of the colonic fistula was suspected to be protraction of the pancreatic fistula.\nTo investigate the communication of fistulas, colonoscopy was performed (CF H-260 AI; working channel of 3.7 mm; Olympus Medical Systems, Tokyo, Japan). After indigo carmine injection, the fistula into the splenic flexure of the colon showed blue staining (fig. ). The fistula was a small erosion and endoscopic treatment appeared feasible. An attempt to seal the perforation endoscopically was performed using the OTSC system (fig. ). Once the colonoscope had been removed, the OTSC applicator was mounted on the tip of the endoscope and reinserted. The tissue edges, including the fistula, were gently pulled inside the cap while continuous suction was applied. The OTSC clip (type T, 10 mm diameter) was released and the fistula was sealed. A Gastrografin enema performed on day 151 showed complete sealing of the leak and improved clinical course.\nA liquid diet was restarted after ENPD tube exchange on day 159 and was smoothly upgraded to a full diet. However, a 7-Fr endoscopic pancreatic stent (EPS) was placed for internal drainage on day 175 because of an increase in the volume of percutaneous drainage. After removing the EPS on day 180, drainage volume immediately decreased. CT on day 189 showed no exacerbation of the abscess and the patient was discharged on day 194.\nFollow-up CT and colonoscopy of the pancreatic and colonic fistulas were performed on day 221. CT showed improvement of the abscess, colonoscopy indicated the clip was in situ and scarred and the perforation site was sealed with no signs of inflammation or ulceration. ERCP performed on day 223 revealed no pancreatic duct disruption. The patient's clinical course was good and he is now receiving outpatient therapy for hyperlipidemia.