THE VALUE OF MRCP AND ERCP IN MANAGEMENT OF SUSPECTED COMMON BILE DUCT STONES IN PATIENTS WITH GALLSTONE DISEASE.

Document Type : Original Article

Authors

1 Departments of General Surgery, Faculty of Medicine, Cairo University

2 Radiology, Faculty of Medicine, Cairo University

3 Tropical Medicine, Faculty of Medicine, Cairo University

Abstract

MRCP and ERCP are able to detect CBD stones with high accuracy in patients with suspected stones. With increasing 
availability of MRI, MRCP is becoming the non-invasive extra-hepatic biliary diagnostic investigation of choice. ERCP, 
apart from being a diagnostic procedure, is also applied as a therapeutic tool. The aim of this study is to assess the value of MRCP and ERCP in management of suspected CBD stones in patients with gallstone disease undergoing elective 
cholecystectomy. 
Out of 189 patients with gallstone disease - who underwent elective cholecystectomy - 85, who performed MRCP and/or 
ERCP were statistically analyzed in a retrospective study. 
CBD stones were present in 29/85 patients (34%). 24/29 underwent ERCP with stone clearance followed by open 
cholecystectomy, 4/29 underwent CBD exploration with stone extraction and 1/29 underwent laparoscopic cholecystectomy followed by ERCP with stone extraction. MRCP proved to have a sensitivity of 12/13 (92%) and a specificity of 33/33 (100%) in demonstration of CBD stones. The positive predictive value of MRCP proved to be 12/12 (100%) and the negative predictive value was 33/34 (97%). MRCP detected stones in 12/13 patients with different combination of predictor variables (age >60 years, fever >37.6 oC, raised levels of serum amylase >95u/l, raised levels of alkaline phosphatase >670u/l and bile duct dilatation >8mm or stones on ultrasonography). 
Fifty per cent (27/54) of patients who underwent ERCP were ‘positive’ and this percentage decreased to 41% (16/39) in 
patients who did not undergo MRCP before ERCP. Therapeutic ERCP was performed in 43/54 (80%) patients, in the form of: 22/43 stone extractions, 17/43 sphincterotomies, 2/43 naso-biliary drainage and 2/43 biliary stenting. 
The use of MRCP prior to ERCP, results in maximum effectiveness of ERCP as a therapeutic tool while decreases the 
unnecessary diagnostic attempts in patients with normal findings. Limiting MRCP to gallstone disease patients with two or more variables is optimal as regards cost/benefit by reducing the number of unnecessary MRCPs and minimizing the risk of a missed stone. MRCP is recommended in these patients to confirm the diagnosis, prior to further management by ERCP or CBD exploration. 

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