Enlargement of the common bile duct in patients with acute graft-versus-host disease: what does it mean?

OBJECTIVE: The aim of the study was to assess variations in the diameter of the common bile duct in patients with gastrointestinal graft-versus-host disease (GVHD) undergoing abdominal CT after allogeneic hematopoietic stem cell transplantation and to correlate the findings with laboratory results on cholestasis. MATERIALS AND METHODS: We performed a retrospective analysis of the caliber of the common bile duct in 27 adult patients with histologically validated gastrointestinal GVHD who underwent two or more follow-up abdominal CT examinations. Another 25 patients who underwent allogeneic hematopoietic stem cell transplantation during the same period at our institution but who did not have GVHD constituted the control group. The diameters of the common bile duct were correlated with cholestasis values. RESULTS: A pathologic diameter of the common bile duct was defined as greater than 7 mm (48 patients) in patients who had not undergone cholecystectomy and greater than 8 mm in those who had (four patients). The median diameter of the common bile duct was 7 mm (range, 4-14.8 mm) in the GVHD group and 5.8 mm (range, 3.9-10.2 mm) in the control group. Pathologic diameters of the common bile duct were found in 67% of the patients in the GVHD group and in 12% of the control group (p < 0.0001). The variation coefficient of the diameter of the common bile duct was 12.4% in the GVHD group (83 examinations) and 6.4% in the control group (92 examinations) (p < 0.0001). Ninety-six percent of the patients in the GVHD group had elevated cholestasis values with a significant positive correlation between bilirubin concentration and diameter of the common bile duct (r = 0.421; p = 0.032). Enhancement of the common bile duct and gallbladder wall was seen in the majority of GVHD patients but no controls (p < 0.0001). CONCLUSION: Temporary dilatation of the common bile duct seems to be a common finding in gastrointestinal GVHD after hematopoietic stem cell transplantation and correlates with bilirubin concentration. This knowledge of fluctuation in bile duct diameter can help to avoid unnecessary tests to evaluate for pathologic causes of biliary dilatation.