Aims Common bile duct stones (CBDS) can migrate spontaneously through the duodenal papilla.
ERCP for small CBDS may be thus unnecessary and is likely to carry a significant rate
of complications. We aim at retrospectively evaluating the rate of spontaneous stone
passage in patients with an imaging diagnosis of CBDS.
Methods We conducted a retrospective multi-center analysis of patients undergoing ERCP for
CBDS in a 12-month period. ERCPs with failed biliary cannulation were excluded. Data
regarding patients´ characteristics, imaging findings and ERCP procedure were analysed.
Results 532 patients (69.5±17.5 years, female 55.6%) were included in the analysis. Imaging
revealed presence of sludge in 34 patients (6.4%), single stone in 245 patients (46.1%),
2 or more stones in 253 patients (47.5%). At ERCP, CBDS were not found in 91 patients
(17.1%). Pancreatitis as indication (OR:3.661 C.I.95%:1.441-9.301), imaging finding
of sludge (OR:3.582 C.I.95%:1.439-8.916), < 5 mm stones (OR:2.943 C.I.95%:1.671-5.185)
and interval >7 days between imaging and ERCP (OR:1.982 C.I.95%:1.020-3.849) were
associated to the absence of CBDS at ERCP. Absence of CBDS was observed in 26% of
patients with sludge or ≤5 mm stones and 10.6% of those with > 5mm stones at imaging
(p< 0.001). In patients with imaging finding of ≤ 5 mm stones, the rate of negative
ERCP increased according to the time occurring from the imaging diagnosis and ERCP
(< 7 days:22.8%, 7-30 days:41.4%, >30 days:45.5%; p=0.036). No significant differences
in terms of complications was observed between the two groups
Conclusions Small CBDS may migrate spontaneously in up to 45% of patients. Diagnosis of sludge,
< 5 mm stones and a delay in ERCP >7 days were predictive factors for spontaneous
migration. We suggest that CBDS < 5 mm should not undergo immediate removal. Prospective
studies are needed to confirm these results and demonstrate the safety of a conservative
management in this setting.
