Complications and Spontaneous Resolution Rates of Incidentally Detected Choledocholithiasis: A Systematic Review and Meta-Analysis

Introduction: The incidental detection of common bile duct stones (CBDS) often triggers Endoscopic retrograde cholangiopancreatography (ERCP) intervention despite the limited high-quality evidence supporting its efficacy and the potential risks involved. This systematic review and meta-analysis aim to examine the natural history of incidentally diagnosed or asymptomatic CBDS managed conservatively. Methods: We searched PubMed and EMBASE databases from their inception through April 2023 for studies assessing the natural history of conservatively managed CBDS. The biliary complications and spontaneous stone resolution rates were considered primary and secondary outcomes, respectively. We compared complication rates between conservatively managed (wait-and-see approach) patients and those treated with ERCP. Pooled rates and odds ratios (OR) with corresponding 95% confidence intervals (CIs) were calculated. Results: Our analysis included 6 studies (5 observational, 1 RCT). In 5 studies, incidental or asymptomatic CBDS were discovered via Intraoperative Cholangiogram (IOC) in patients scheduled for cholecystectomy. Due to the absence of symptoms and complications, not all underwent ERCP. We analyzed data from 1588 CBDS patients (881 managed conservatively, 707 with ERCP) (Table 1). Complication rates showed no significant difference between conservative management and ERCP approaches (17% vs 22%; OR 0.83, CI 0.2-2.5, I2 82%) (Figure 1 A-C). The spontaneous stone clearance rate was 47.8% (CI 22%-75%, I2 93%) (Figure 1 D). Excluding the only RCT with a notably high clearance rate of 90%, the adjusted clearance rate was 31.3% (95% CI 18-49%, I2 83%) (Figure 1). Conclusion: This meta-analysis revealed significant spontaneous stone clearance and comparable complication rates of CBDS in conservatively managed patients compared to those undergoing ERCP for asymptomatic, incidentally detected CBDS. However, most CBDS were diagnosed via IOC, introducing potential bias as those stones may not have been entirely incidental and could have been symptomatic leading to the cholecystectomy. Our results highlight a clinical gap in understanding the natural history of incidentally found CBDS, necessitating further research, particularly randomized trials taking into consideration the size and number of the CBDS when comparing the “wait and see” to ERCP approaches. At this juncture, due to the lack of high-quality studies, the approach to incidental CBDS remains endoscopic clearance guided by the patient clinical status.Figure 1.: Forest plot summarizing A) Complication rates among conservatively managed patients, B) Complication rates among ERCP-treated patients., C) Comparative complication rates between conservatively managed and ERCP-treated patients, and D) Spontaneous stone clearance rates. Table 1. - Summary of Included Studies Study Study type Duration Country Population Average Follow Up Age (Female %) Complications (Conservative) Complications (ERCP) Need for ERCP (Conservative) Spontaneous Resolution (Conservative) Comment Ammori 2000 Prospective cohort 1990-1997 United Kingdom 22 patients with CBDs < 5 mm detected on IOC 18 months in the intervention group vs 33 months in the conservative management group 54 (22%) 0/8 (0%) 0/14 (0%) 4/14 (29%) NR Collins 2004 Prospective cohort 1990-2001 Ireland 46 patients with positive IOC biliary defects. 12 excluded due to negative IOC at 48 hrs. (false positives). Final population 34 patients 6 weeks follow up NR 0/34 (0%) NA 22/34 (65%) 12/34 (35%) Per authors, there was no relationship between calculus size and bile duct clearance; stones < 5 mm were often retained whereas stones >15 mm passed spontaneously Hakuta 2019 Retrospective cohort study 2010-2018 Japan Asymptomatic bile duct stones were diagnosed by abdominal ultrasound, computed tomography (CT) and/or magnetic resonance cholangiopancreatography (MRCP) 3.2 yrs in wait and see vs 1.9 yrs in ERCP group 75 (59%) 20/114 (18%) 25/77 (32%) NR 22/114 (19%) Maximum stone diameter median in the wait and see group significantly less than the intervention group (5 mm IQR 3-6 vs 6 mm (4–8), P 0.001) Moller 2014 Retrospective cohort study 2005-2009 Sweden Patients found to have CBDs during cholecystectomy on IOC 1 month NR 150/594 (25%) 103/572 (18%) NR NR Used Unfavorable outcome (UQ) as the outcome. Besides, complications this included the development of symptomatic disease Chen 2021 Retrospective cohort study 2014-2018 Australia Incidental asymptomatic CBDS found on IOC during LC. Did not specify the size of the stones 1 month NR NR NR NR 32/75 (43%) Published as conference abstract Abdellatif 2017 RCT NR Egypt Patients with CBDS detected on ICO and CBD < 10 mm were randomized to ERCP vs conservative management preoperatively NR NR NR NR NR 45/50 (90%) Higher risk of pancreatitis (PEP) is in the ERCP group. However, the study did not report other complications. One of the limitations of this study is its publication in an abstract form NR, not reported; RCT, randomized controlled trial.