Low-Dose Aspirin Reduces the Rate of Renal Allograft Thrombosis in Pediatric Renal Transplant Recipients

OBJECTIVES: Renal allograft thrombosis is an important cause of early renal allograft loss. A previous study from our unit showed thrombosis rates in patients who received heparin that were similar to those who did not receive any thromboprophylaxis. This study evaluated the impact of aspirin prophylaxis on renal allograft thrombosis rates in pediatric renal transplant recipients. MATERIALS AND METHODS: We conducted a retrospective study of 456 consecutive pediatric allografts from deceased and living related donors over age 22 years in a single center. Routine perioperative heparin was introduced in 1994 and was subsequently changed to aspirin prophylaxis in 2000. Group 1 comprised 126 patients who did not receive any thromboprophylaxis, group 2 comprised 128 patients who received heparin, and group 3 comprised 202 patients who received aspirin therapy. Variables associated with increased risk of renal allograft loss were examined using multivariable logistic regression. RESULTS: Thrombosis occurred in 11% (14/126) of grafts in group 1, 9% (11/128) of grafts in group 2, and 1% (2/202) of grafts in group 3 (odds ratio for aspirin group = 0.38, 95% confidence interval, 0.22-0.64; P = .02). In patients who received aspirin (group 3), there was only one renal allograft loss secondary to hemorrhage, and no grafts were lost in patients younger than 5 years of age. CONCLUSIONS: After our center introduced a change from heparin to aspirin prophylaxis, the thrombosis rate in pediatric renal allografts fell from 9% to 1%. Although there are a number of possible confounding variables, the introduction of aspirin has led to a reduced rate of renal allograft thrombosis.