Sa1467 TIME TO RESOLUTION OF WALLED-OFF NECROSIS IN PATIENTS UNDERGOING EUS-GUIDED DRAINAGE (USING 15 MM VS. 20 MM LAMS) WITH PRN NECROSECTOMY: A SINGLE CENTER EXPERIENCE

Abstract

In patients with walled-off necrosis (WON), lumen-apposing metal stents (LAMS) are frequently being used to facilitate EUS-guided drainage. The most commonly used stent types are now typically 15 mm and 20 mm lumen-apposing metal stents. Previous studies have suggested that 15 mm and 20 mm stents have similar safety and efficacy, while 20 mm stents result in less necrosectomy sessions. After the initial drainage of a WON, many advanced endoscopists elect to bring patients back for scheduled, serial necrosectomy sessions. At our institution, we instead only bring patients back for as-needed (or PRN) necrosectomies - typically only if a patient becomes symptomatic. Our patients have good outcomes with this approach, and very little has been written about patients under this philosophy. We thus wished to further explore outcomes using this philosophy, looking specifically at time to WON resolution, using 15 mm or 20 mm LAMS. We conducted a single center retrospective study of patients with walled-off necrosis that underwent a single EUS-guided drainage using a lumen-apposing metal stent, either 15 mm or 20 mm, from December 2016 to September 2019. These were patients that all had eventual resolution of their WON. The primary outcome of the study was time to resolution of walled-off necrosis in days (defined as the dwell time of the LAMS). Controls included WON Size (largest diameter in mm), % Necrosis of WON (measured on EUS imaging), PPI Use (Yes/No), and if the patient received a PRN Necrosectomy (Yes/No). A total of 34 patients were included in this study. The mean age was 58.6 ± 12.6, and there were 10 females and 24 males. The most common etiology of pancreatitis was alcohol (14/34). The most common indications for EUS-guided drainage were abdominal pain (26/34) and suspected infection (6/34). 33 patients underwent EUS –guided cystgastrostomy, and 1 patient underwent EUS-guided cystduodenostomy. 15 patients underwent EUS-guided drainage of WON with 20 mm stents, while 19 patients underwent EUS-guided drainage of WON with 15 mm stents. 2 patients required PRN necrosectomy. Median time to resolution was 72 days for 15 mm stents vs. 61 days for 20 mm stents. An ANCOVA analysis was conducted, and revealed that there was no significant difference regarding time to resolution between the two stent groups (15 mm vs. 20 mm), after controlling for WON Size, % Necrosis, PPI Use, and PRN Necrosectomy (p = .5748). Our study shows that in patients who have undergone EUS-guided WON drainage using 15 mm or 20 mm LAMS with PRN Necrosectomies, there is no statistical difference between the stent types in terms of time to resolution of walled-off necrosis. Using either stent type should be thus still be considered for EUS-guided WON drainage, as they are similar in regards to the ultimate outcome of time to WON resolution.View Large Image Figure ViewerDownload Hi-res image Download (PPT)