Treatment of large pancreatic radiolucent stone

Previous studies have not clarified the treatment of large pancreatic radiolucent stones (≥ 5 mm). The primary objective of this study was to assess the clinical features and therapeutic efficacy in patients with chronic pancreatitis who have large radiolucent stones, and to propose a treatment strategy.

This analysis examined the data of patients with large pancreatic ductal stones (≥ 5 mm) from March 2011 to June 2018. Patients with radiolucent stones were classified as the radiolucent stones group, while those with pancreatic radiopaque stones presented at the same time were randomly selected as controls in a 1:2 ratio. Data on demographics, disease courses and treatment details were retrieved, and stone clearance and pain relief during the follow-up were compared between the two groups.

A total of 52 patients with large radiolucent stones and 104 patients with large radiopaque stones were included in the study. Pancreatic extracorporeal shock wave lithotripsy (ESWL) was the initial treatment for large radiopaque stone. Endoscopic retrograde cholangiopancreatography (ERCP) was the first-step treatment for all patients in the radiolucent stones group, of which one patient received medication after failed ERCP cannulation, and four who failed stone extraction were treated with ESWL following the placement of a nasopancreatic catheter. There was no significant difference in the complete stone clearance rate (75.0% vs. 78.8%; P = 0.553) between the two groups. Among the 51 patients in the large radiolucent stones group who were followed up for 5.8 years (range 2.1-12.6), complete pain relief was achieved in 42 patients (82.4%), with no significant difference compared with the radiopaque group (82.4% vs. 76.4%; P = 0.409).

ERCP is an effective endotherapy for large radiolucent stone and should be considered the first-step treatment. When stone extraction failed during ERCP, ESWL is recommended following the placement of a nasopancreatic catheter.