Endoscopic Ultrasound Guided Necrosectomy of Walled-Off Pancreatic Necrosis Using a Lumen-Apposing Fully Covered Metal Stent and Hydrogen Peroxide: A Single Center Experience

Abstract

Introduction: A natural sequela of pancreatic necrosis is the development of cystic cavities containing necrotic pancreatic tissue and fluid known as walled-off pancreatic necrosis(WOPN). Historically, surgical necrosectomy has been the mainstay of treatment; however, advances in therapeutic endoscopy have led to increased utilization of less invasive treatment modalities. We studied the use of lumen-apposing fully covered metal stents(LAMS) and hydrogen peroxide(H2O2) lavage in the management of WOPN at our academic medical center. Methods: 10 patients underwent Endoscopic Ultrasound(EUS) guided necrosectomy using LAMS and H2O2 lavage for the management of WOPN from 4/2015-4/2016. EUS was performed using a linear echoendoscope at a frequency of 7.5 MHz with CO2 gas used for insufflation. The cyst cavity was punctured using a 19-gauge needle. After stylet withdrawal in patients 1-6, a 0.035” diameter x 480cm long, straight tip guidewire was used to facilitate the passage of a 10 Fr cystotome into the necrotic cavity. Using EUS and endoscopic guidance, a 15mm x 10mm LAMS was then placed in the necroma, with placement confirmed on fluoroscopy. In patients 7-10, an electrocautery-enhanced LAMS measuring 15mm x 10mm was placed directly into the cyst over the guidewire. In all cases, a balloon was then advanced over the guidewire, through the stent, and into the necroma, followed by inflation to 15mm. The echoendoscope was then withdrawn and a forward-viewing endoscope was utilized to perform direct endoscopic necrosectomy(DEN). Upon completion of DEN, the necroma was lavaged with 100cc of 0.3% H2O2, which was not suctioned out of the cavity. PPIs were held 30 days post initial intervention. Results: The patient cohort had a median age of 52.5±15.5 years and was 60% male. The median size of the WOPN was 10±4.4cm. The technical success rate was 100%, with all patients undergoing successful LAMS placement. Clinical success was achieved in 80% of patients and resolution of WOPN was confirmed via cross-sectional imaging in these patients. Patients had a median of 2 DENs and a median follow-up of 91 days. One patient required escalation to surgical necrosectomy and one patient died 13 days post stent placement due to multisystem organ failure, not related to the procedure. Conclusion: The use of LAMS and H2O2 appears to offer patients a safe, effective and minimally-invasive alternative to surgical necrosectomy, which is associated with significant morbidity and mortality.Table 1Figure 1Figure 2