Spleen size of live donors for liver transplantation

BACKGROUND: Normal spleen size is not well defined for the adult population. METHODS: Abdominal computed tomography (CT) scans of 238 consecutive living donors for liver transplantation were studied. Two methods for determining splenomegaly were applied. In Method N, a horizontal line was drawn to the left side from the most ventral point of the spleen. A perpendicular line was drawn from the central point of the aorta of the CT slice. The height of the cross point of the two lines was compared with the diameter of the aorta. In Method C, a perpendicular line was drawn from the most ventral point of the spleen. The distance between the posterior and anterior abdominal walls was partitioned in three parts, from dorsal to ventral and defined of Zones 1, 2, and 3, respectively. Donors were divided into two groups, those under age 40 and those over age 40. RESULTS: The mean volume of the spleen was 123 +/- 45 cm(3). Spleen volume was negatively correlated with age (R = -0.32, p < 0.001) and positively correlated with body mass (R = 0.24, p < 0.001). In donors under age 40, the most ventral point of the 96% of the spleens was below four times the diameter of the aorta (Method N). In Method C, 52% of the spleens were located in Zones 1 and 2. In donors over age 40, the most ventral point of the 96% of the spleens was below three times the diameter of the aorta (Method N). Totally 82% of the spleens were located in Zones 1 and 2 (Method C). CONCLUSIONS: Splenomegaly can be evaluated by the simple method on CT although the threshold must be changed by the age of the subject.