Can the Severity of Laboratory Abnormality Predict Presence of Anastomotic Stricture in the Postorthotopic Liver Transplant Population?

Abstract

Introduction: Endoscopic retrograde cholangiopancreatography (ERCP) is an important diagnostic tool in evaluating patients with biliary laboratory abnormalities after orthotopic liver transplant (OLT). Due to the invasiveness of the procedure and risks associated with general anesthesia, ERCP is typically only performed if there is a high pre-test probability of a biliary abnormality, such as an anastomotic stricture. We aimed to determine if the severity of laboratory abnormalities could help predict the presence of an anastomotic stricture. Methods: We performed a retrospective review of 273 patients that underwent OLT at our institution from 1/2012 - 4/2015. 56 patients were analyzed after selecting patients that underwent an ERCP which was either normal or had an anastomotic stricture. Presence of and severity of abnormality was recorded for the following outcomes: temperature, AST, ALT, total bilirubin, alkaline phosphatase, and GGT. Statistical analysis was performed using SPSS with p-value < 0.05 deemed as statistically significant. Results: Mean age of our population was 55.4±10.5 years with a male predominance 41/56 (73%). 19 patients had normal findings on ERCP (normal group), 37 had an anastomotic stricture (stricture group). Mean alkaline phosphatase was higher in the stricture group vs normal group (mean difference 253.6, p=0.048). Severe elevation of alkaline phosphatase (>301) had an odds ratio (OR) of 4.53, CI [1.13-18.24] for anastomotic stricture (p=0.05). Severe elevation in total bilirubin and any abnormal GGT value had a greater odd's ratios for anastomotic stricture, however did not meet statistical significance, OR 2.05 and OR 4.25 respectively (Table 1 and 2).Table 1: Laboratory findings in patients with normal and abnormal ERCP.Table 2: Average values of laboratory findings in patients with normal and abnormal ERCP.Conclusion: Despite increased likelihood for anastomotic stricture with severe elevation of alkaline phosphatase, laboratory abnormalities alone are not reliable enough to predict the presence of an anastomotic stricture. Patients with high suspicion of biliary abnormality should undergo ERCP despite the degree of laboratory value elevations.