Published online Jan 28, 2021. doi: 10.3748/wjg.v27.i4.358
Peer-review started: November 22, 2020
First decision: November 30, 2020
Revised: December 11, 2020
Accepted: December 28, 2020
Article in press: December 28, 2020
Published online: January 28, 2021
Endoscopic retrograde cholangiopancreatography (ERCP) is an effective and relatively minimally invasive technique for common bile duct (CBD) stones. The recurrence rate of CBD stones after ERCP has increased from 4% to 24%. The incidence of residual stones after mechanical lithotripsy for intractable CBD stones is 24% to 40%. An important reason for the recurrence of CBD stones is the presence of stone debris after lithotripsy.
It has been suggested that saline irrigation of the bile duct after stone removal can increase the cleaning of the bile duct. Complete bile duct clearance is necessary to decrease recurrent bile duct stones. However, the efficacy and dosage of saline are still unclear.
To determine whether saline irrigation can improve CBD clearance after lithotripsy and how much saline solution will remove residual stones/debris.
This prospective self-controlled study enrolled patients receiving mechanical lithotripsy for large (> 1.2 cm) CBD stones. After occlusion cholangiography confirmed CBD stone clearance, peroral cholangioscopy (POC) was performed to determine clearance scores based on the number of residual stones. The number of residual stones spotted via POC was graded on a 5-point scale (score 1, worst; score 5, best). Scores were documented after only stone removal (control) and after irrigation with 50 mL and 100 mL saline, respectively. The stone composition was analyzed using infrared spectroscopy.
Between October 2018 and January, 47 patients had CBD clearance scores of 2.4 ± 1.1 without saline irrigation, 3.5 ± 0.7 with 50 mL irrigation, and 4.6 ± 0.6 with 100 mL irrigation. Multivariate analysis showed that CBD diameter > 15 mm and periampullary diverticula (PAD) were independent risk factors for residual stones. Bilirubin pigment stones constituted the main residual stones found in patients with PAD.
Irrigation with 100 mL of saline may not clear all residual CBD stones after lithotripsy, especially in patients with PAD and/or a dilated (> 15 mm) CBD. Pigment residual stones are soft and commonly found in patients with PAD. Additional saline irrigation may be required to remove retained stones.
In the future, prospective, large sample, multi-center, well-designed studies are needed to validate the amount of saline needed to completely remove the residual stones/debris of different types of CBD stones after mechanical lithotripsy.