Rectal indometacin to prevent pancreatitis after extracorporeal shock wave lithotripsy (RIPEP): a single-centre, double-blind, randomised, placebo-controlled trial

Abstract

Background: Pancreatitis is the most common complication of pancreatic extracorporeal shock wave lithotripsy (ESWL). There has been little research into effective prevention of post-ESWL pancreatitis. Therefore, we aimed to assess the efficacy of prophylactic rectal indometacin in preventing post-ESWL pancreatitis.

Methods: In this double-blind, randomised, placebo-controlled trial done at Changhai Hospital (Shanghai, China), patients aged 18 years or older with chronic pancreatitis and pancreatic stones (>5 mm in diameter) who were eligible for treatment with ESWL were randomly allocated using a computer-generated randomisation table, in a 1:1 ratio, to receive 100 mg rectal indometacin or identical glycerin (placebo) suppositories 30 min before ESWL. Patients, endoscopists, and outcome assessors were masked to group allocation. The primary outcome was the incidence of post-ESWL pancreatitis within 24 h of ESWL, analysed by the intention-to-treat principle. This study is registered with ClinicalTrials.gov, number NCT02797067.

Findings: Between May 31, 2016, and June 26, 2019, 1370 patients were enrolled, with 685 patients randomly assigned to the rectal indometacin group and 685 patients to the placebo group. All patients received their allocated intervention and completed final follow-up, and were included in the intention-to-treat analysis. Post-ESWL pancreatitis occurred in 60 (9%) patients in the rectal indometacin group and 84 (12%) patients in the placebo group (relative risk 0·71, 95% CI 0·52-0·98; p=0·042). Transient adverse events occurred in 235 (34%) patients in the rectal indometacin group and 252 (37%) patients in the placebo group, with asymptomatic hyperamylasaemia being the most common (189 [28%] patients vs 197 [29%] patients). No difference was noted between groups in the incidence of other complications and transient adverse events.

Interpretation: Pre-procedural administration of rectal indometacin is an efficacious and safe means of reducing the incidence of post-ESWL pancreatitis.

Funding: Programs of Shanghai Municipal Government and the "Ten Thousand Plan"-National High Level Talents Special Support Plan.