Long-term follow-up of pancreatic cysts that resolve radiologically after EUS-guided ethanol ablation

Background: EUS-guided ablation of pancreatic cysts is a minimally invasive technique with reported short-term, CT-defined cyst resolution rates of 33% to 79%. Follow-up results of image-defined, successful pancreatic cyst ablation are not known. Objective: To determine the durability of successful cyst resolution after EUS-guided ethanol lavage. Design: Prospective cohort study. Setting: Two tertiary-care referral hospitals in the United States. Patients: This study involved 12 patients with 1-to-5-cm, unilocular, pancreatic cysts that had previously resolved after ethanol lavage. Interventions: Follow-up CT after cyst resolution. Main Outcome Measurements: The presence or absence of residual pancreatic cysts by CT scanning after previous successful ablation. Results: In a previously reported trial, we found that CT scanning documented pancreatic cyst resolution in 12 patients (33%) after one (n = 6) or two (n = 6) ethanol lavages. These 12 cysts (median diameter 18 mm; range 10-34 mm) were located in the head/uncinate of the pancreas in 6 patients (50%) and in the body of the pancreas in 6 patients (50%). The median cyst fluid carcinoembryonic antigen (CEA) level (available in 11 patients) was 463 ng/mL (range 1.6-64,550 ng/mL; normal, 0-2.5 ng/mL). Clinical diagnoses were mucinous cystic neoplasm (MCN) in 9 patients, intraductal papillary mucinous neoplasm in 1 patient, pseudocyst in 1 patient, and serous cystadenoma (SCA) in 1 patient. Follow-up CT in 3 patients (one each of MCN, SCA, and pseudocyst) after the initial diagnosis of cyst resolution was not available. For the remaining 9 patients (75%), follow-up CT performed in a median of 26 months (range 13-39 months) after initial documentation of cyst resolution demonstrated no evidence of cyst recurrence in any patient. Limitations: Loss to follow-up of some of the cohort. Conclusions: Follow-up after successful EUS-guided ethanol ablation of pancreatic cysts, including suspected mucinous cysts, suggests a durable, image-defined resolution. Longer follow-up in these patients is needed before considering these patients "cured" of their disease.