Endoscopic Necrosectomy With Self-Expandable Metal Stent (SEMS) Drainage: A Novel Approach in the Treatment of Walled-Off Pancreatic Necrosis (WOPN)

Purpose: Pancreatic necrosis is a feared complication of acute pancreatitis with high morbidity and mortality. Recent literature has suggested the advantages of a minimally-invasive approach.

Methods: Patients that had undergone cyst-gastrostomy with a SEMS prior to endoscopic necrosectomy for WOPN were retrospectively evaluated. Using a therapeutic echoendoscope, a 19-gauge FNA needle was used to puncture the WOPN. A 0.035-inch guide wire was advanced under direct visualization either with the aid of fluoroscopy or EUS. The tract was then dilated using a combination of needle-knife, Sohendra dilators (Wilson-Cook), and/or CRE balloon (Boston Scientific). A fully-covered or uncovered 10mm x 40mm SEMS was then deployed across the tract, and the WOPN was aggressively irrigated. After adequate drainage of the WOPN had occurred, a conventional gastroscope was used to remove the SEMS. A CRE balloon was used to dilate the tract up to 18mm. The gastroscope was then introduced into the necroma and debrided using a combination of irrigation, forceps, Roth nets (US Endoscopy), and stone-retrieval baskets. The goal of each necrosectomy was to debride the walls of the necroma until pink granulation tissue was uncovered. At the conclusion of each necrosectomy, 7 or 10F plastic stents or nasobiliary drain were left in place with repeat necrosectomy performed at the endoscopist's discretion.

Results: 11 total necrosectomies were performed on 4 patients. The mean age of the patients was 55 years. 3 of the 4 patients had sterile necrosis; 1 had infected necrosis. The mean size of the WOPN was 13.9cm prior to cyst-gastrostomy with SEMS. The mean time frame from the onset of acute pancreatitis until cyst-gastrostomy drainage was 108 days (range 24 - 237 days). The first endoscopic necrosectomy was performed a mean of 26 days after initial cyst-gastrostomy SEMS drainage (range 10 - 46 days). Significant improvement in symptoms was seen in all 4 patients, with 2 patients experiencing complete resolution of symptoms, 1 patient with near-complete resolution of symptoms, and 1 patient with partial resolution of symptoms. Complications from endoscopic necrosectomy included fever (1 patient), tachycardia (1 patient), persistent leukocytosis (1 patient), and prolonged procedure time (4 patients). There were no deaths.

Conclusion: In a highly-selective patient population, optimal drainage using SEMS for cyst-gastrostomy may be advantageous to using a smaller diameter plastic stent prior to endoscopic necrosectomy. Prospective, randomized trials must be performed for validation.