FLUOROSCOPY-FREE DIRECT SOLITARY CHOLANGIOSCOPY VERSUS STANDARD ENDOSCOPIC RETROGRADE CHOLANGIOGRAPHY FOR ENDOSCOPIC CLEARANCE OF NONCOMPLEX BILIARY STONES: A MULTICENTER RANDOMIZED TRIAL

BACKGROUND & AIMS: Removal of bile duct stones is typically accomplished by endoscopic retrograde cholangiography (ERC), which requires fluoroscopy. A fluoroscopy-free technique using direct solitary cholangioscopy (DSC) has been described as an alternative to ERC for biliary stone clearance. This technique offers the advantages of allowing bedside procedures in the intensive care unit, avoiding radiation in pregnant patients and eliminating the need for a fluoroscopy room, which is often a scheduling bottleneck. A direct comparison of ERC versus DSC is needed. We conducted a multicenter noninferiority randomized clinical trial (NCT 03421340) to compare noncomplex biliary stone clearance using ERC versus DSC.

METHODS: Eleven endoscopists at 8 centers in 4 countries performed clearance procedures for noncomplex symptomatic common bile duct (CBD) stones. Eligible patients were aged ≥18, had symptomatic choledocholithiasis, abnormal serum liver enzymes, and ≤5 stones sized ≤10 mm in the CBD on preprocedural imaging. Primary outcome: complete stone clearance by ERC, validated by DSC OR by fluoroscopy-free DSC using a single-operator cholangioscope, validated by ERC. Secondary outcomes: 1) radiation exposure to patient, 2) procedure duration, 3) device- or procedure-related serious adverse events (SAEs) reported by 30 days. Fluoroscopy use during the index DSC procedure, or residual stones detected during the validation procedure in either arm, was a primary endpoint failure.

RESULTS: Of 250 patients enrolled, 126 were randomized to ERC and 124 to DSC. Patient median age was 53.0 (range 19.0–93.0) years, 100 (40.0%) were male. Preprocedural imaging revealed a median of 1.0 (0–5.0) stones and median CBD diameter of 8.5 (0.5–19.0) mm. At the index study procedure, 243 (97.2%) patients underwent biliary sphincterotomy and 68 (27.2%) papillary balloon dilation. Of study patients, 211 (84.4%) had stone removal with a stone extraction balloon, 40 (16.0%) with a cholangioscope-compatible mini-basket, and 3 (1.2%) required lithotripsy. On a modified intention-to-treat basis, complete stone clearance was achieved in 88.9% (112/126) of patients by ERC, and in 87.7% (107/122) of patients by fluoroscopy-free DSC (between-group difference, 1.2%; one-sided upper limit of 95% confidence interval for difference, 8.4%; P=0.022 for noninferiority margin of 10%) (Table 1). For ERC versus DSC respectively, median radiation dose was 26.8 (range 0–296.0) versus 0 (range 0–411.3) milligrays, and median index procedure duration was 11.9 (range 3.8–137.9) versus 22.1 (6.0–67.0) minutes. Procedure-related SAEs occurred in 5 (4.0%) ERC patients and 7 (5.6%) DSC patients (Table 2).

CONCLUSION: Clearance rates of noncomplex biliary stones and rates of SAEs were comparable for ERC versus fluoroscopy-free DSC, with lower exposure to fluoroscopy during DSC.