Jin Ho Choi1, Joo Seong Kim1, Nam Young Park1, Min Woo Lee1, In Rae Cho1, Woo Hyun Paik1, Sang Hyub Lee1, Ji Kon Ryu1, Yong-Tae Kim1

1Department of Internal Medicine, Liver Research Institute, Seoul National University College of Medicine, Seoul, Korea

Background/Aims: Endoscopic ultrasound-guided ethanol ablation (EUS-EA) is recently introduced for the treatment of pancreatic solid tumors. However, the effect and safeness of this treatment have not been well investigated yet. The aim of this study was to determine the feasibility, effect and complications of EUS-EA for pancreatic solid lesions.

Methods: Between October 2015 and December 2020, 54 patients were performed EUS-EA for suspected to be benign solid pancreatic mass. Of these patients, four diagnosed with malignancy, one diagnosed with tuberculosis, and one without follow-up image were excluded, and finally 48 patients were included in this study. Complete remission was defined as no residual tumor in follow up imaging test.

Results: The median age was 45 years and the median follow-up duration after ablation was 24.83 (4.23 - 62.57) months. Twenty-five patients had pancreatic neuroendocrine tumors, 22 had solid pseudopapillary neoplasm, and one had pancreatic gastrointestinal stromal tumor. The median ablative tumor size was 17 mm. Six cases (12.5%) showed complete remission, 14 cases (29.2%) of size reduction, 24 (50.0%) of no change in size, and 4 (8.3%) of size increment. Clinical remission after EUS-EA were confirmed for two insulinoma and one glucagonoma. Adverse events related to procedure are as follows: One (2.1%) necrotizing pancreatitis, 5 (10.4%) mild acute pancreatitis, and 11 (22.9%) mild abdominal pain.

Conclusion: The effect of EUS-EA for pancreatic solid lesions is limited through this relatively long-term follow-up study. It seems feasible as a local treatment for patients who refuse surgery or poor performance to undergo surgery.

Keywords: endosonography, ethanol ablation, pancreatic neuroendocrine tumor, solid pseudopapillary tumor