Sonography: A useful tool to detect the mechanical causes of renal transplant dysfunction

Purpose. The purpose of th is study was to evaluate the utility of sonograp hy in distinguishing between mechanical and nonmechanical causes for renal transplant dysfunction. Methods. We reviewed all ultrasound examination reports (n = 286) for 63 co nsecutive patients who received 64 renal transplants. We assessed the sensi tivity and specificity of different degrees of hydronephrosis (mild, modera te, or severe) in detecting urinary tract obstruction; different volumes of new or increasing peritransplant fluid in detecting urine leaks; different total volumes of peritransplant fluid in predicting significant compressio n of the transplant; and Doppler vascular criteria for predicting arterial and venous occlusion. Results. All mechanical complications were detected (100% sensitivity) with specificities of 91.9% for ureteral obstruction (criterion, moderate hydro nephrosis), 83.4% for urine leaks (criterion, any new fluid or any increase ), 91.4% for fluid collections that compressed the transplant (criterion, > 100 mi), and 100% for vascular occlusion (criteria, no flow for arterial o cclusion; no venous flow and reversal of arterial flow during diastole for venous occlusion). Conclusions. Sonography is very useful in distinguishing between mechanical and nonmechanical causes for renal transplant dysfunction. It has high sen sitivity and acceptable specificity in this setting. (C) 1999 John Wiley & Sons, Inc.