Changes of portosystemic collaterals and splenic volume on CT after liver transplantation and factors influencing those changes.

OBJECTIVE The objective of our study was to investigate the changes of portosystemic collaterals and splenic volume after liver transplantation and to determine the factors influencing those changes. MATERIALS AND METHODS Ninety-nine patients underwent liver CT before; immediately after (< 2 weeks); and 2, 6, and 12 months after liver transplantation. Two radiologists retrospectively reviewed the CT images to determine the grade of the portosystemic collaterals and the volume of the spleen. Portosystemic collaterals were categorized as esophageal, paraesophageal, gastric submucosal, gastric adventitial, splenic, mesenteric, or retroperitoneal varices. First, the largest diameter of each varix was determined. Each varix was graded using a 5-point scale according to the number of dilated vessels and the largest diameter. Splenic volume was calculated using a previously reported formula. To determine how varices and splenomegaly develop over time, the grade of varices on each postoperative CT scan was compared with those on the preoperative and immediately prior CT scans. The degree of change of the portosystemic collaterals and change in the splenic volume on CT were correlated with the type of transplantation (deceased-donor-related liver transplantation [DDLT] vs living-donor-related liver transplantation [LDLT]), the transplanted liver weight, and the presence of postoperative adverse events such as rejection and portal or hepatic vein stenosis. RESULTS All varices except splenic and retroperitoneal varices and splenic volume were significantly decreased on CT performed within 2 weeks after liver transplantation (p < 0.05). Approximately 2 months after liver transplantation, all varices except the esophageal varices and splenic volume became stable. The type of transplantation and the presence of postoperative adverse events did not affect the degree of change of varices or change in splenic volume. However, the rate of volume reduction of the spleen in LDLT was weakly but significantly correlated with the weight of the transplanted liver (Pearson's correlation coefficient, r = 0.401; p < 0.0001). CONCLUSION Most varices and splenomegaly significantly decrease during the early postoperative period (< 2 months) after liver transplantation. Patients with large liver transplants undergo a greater decrease in spleen volume than patients with small liver transplants.