BACKGROUND Endoscopic ultrasound-guided ethanol ablation (EUS-EA) for pancreatic cystic lesions (PCLs) has been used in recent years as a feasible treatment modality for low malignant probability PCLs or patients considered high-risk for surgery. The present study aimed to confirm the safety of EUS-EA and to find predictive factors for adverse event (AE).

METHODS A retrospective review was performed from the prospectively maintained database of patients who underwent EUS-EA for PCLs from June 2006 to April 2018 at Seoul National University Hospital. The primary outcomes of the study were the rates of AEs and severe AEs by EUS-EA. The secondary outcome was the predictive factors of AEs including acute pancreatitis and abdominal pain.

RESULTS A total of 214 patients were evaluated and the diagnoses of PCLs according to cystic fluid analysis and clinical features were as follows: serous cystic neoplasm (32.2%), mucinous cystic neoplasm (26.6%), branch duct type intraductal papillary mucinous neoplasm (BD-IPMN) (29.4%), and pseudocyst (11.7%). Three patients (1.4%) experienced severe AEs. Overall, AEs occurred in 71 (33.2%) patients. BD-IPMN (OR: 2.87; 95% CI: 1.05-7.84; P = 0.040), multilocular cysts (OR: 3.59; 95% CI: 1.09-11.85; P = 0.036), suspected ethanol leakage during procedure (OR: 10.68; 95% CI: 1.98-57.53; P = 0.006), and sticky cystic fluid (OR: 3.83; 95% CI: 1.20-12.24; P = 0.024) were predictive factors for post-procedural acute pancreatitis. PCLs of uncinate process (OR: 2.99; 95% CI: 1.22-7.35; P = 0.017) and PCLs with exophytic portion (OR: 3.70; 95% CI: 1.96-7.01; P < 0.001) were predictive factors for post-procedural abdominal pain.

CONCLUSIONS EUS-EA is a safe procedure with a very low rate of severe AEs. It seems possible to predict the AEs according to the features of the procedure and PCLs.