To Compare the Frequency of Choledocholithiasis in Symptomatic Cholelithiasis using Raised Gamma GT and Alkaline Phosphatase with MRCP

Abstract

Objective: The goal of the present study was to evaluate the validity of GGT and ALP in identifying choledocholithiasis in the symptomatic cholelithiasis patients as compared with MRCP. Study Design: Cross sectional study. Settings: Department of General Surgery, Shaikh Zayed Hospital, Lahore and Allied Hospital, Faisalabad Pakistan. Duration: 12 months from 08-04-2020 to 07-04-2021. Methods: The present study involved 289 patients of both genders aged between 18-70 years diagnosed of cholelithiasis. These patients were assessed by routine liver function tests and choledocholithiasis was suspected on elevated serum alkaline phosphatase level (≥147 IU/L) and gamma glutamyl transferase level (≥48 IU/L). These patients underwent MRCP and diagnosis of CBD stones was confirmed which was considered as gold standard and results of elevated serum ALP and GGT levels were adjudicated accordingly as true or false and positive or negative. An informed written consent was acquired from every patient who was included in the study. Results: The mean age of the patients was 49.2±13.8 years. There was female predominance with male to female ratio of 1:2.8. The diagnosis of CBD stones was established in 56 (19.4%) patients on MRCP. The mean serum levels of ALP (203.84±65.22 vs. 94.07±44.62 IU/L; p-value<0.0001) and GGT (347.84±110.69 vs. 87.15±101.78 IU/L; p-value<0.0001) were significantly higher in patients with choledocholithiasis as compared to those without choledocholithiasis. A cut-off value of 147 IU/L for ALP had a sensitivity of 64.3%, specificity of 67.4% and diagnostic accuracy of 66.8% with positive and negative predictive values of 32.1% and 88.7% respectively. A cut-off value of 48 IU/L for GGT had sensitivity of 91.1%, specificity of 81.6% and diagnostic accuracy of 83.4% with positive and negative predictive values of 54.3% and 97.4% respectively. Conclusion: In the present study, a considerable proportion of patients with cholelithiasis also had choledocholithiasis that was associated with significantly higher mean serum levels of alkaline phosphatase and gamma glutamyl transferase which were found helpful in the diagnosis of CBD stones taking MRCP findings as gold standard and this along with widespread availability, radiation free nature and cheaper cost encourages the favored use of serum alkaline phosphatase and gamma glutamyl transferase in the non-invasive pre-operative diagnosis of choledocholithiasis in future practice.