Purpose: Renal Doppler ultrasonography (DUS) is the gold-standard image test for follow-up after renal transplantation, it is potentially useful to detect renal disease and it could be related with long-term survival. We evaluate whether renal graft survival can be predicted by immediate renal Doppler ultrasonography (IRDUS), defined as ultrasonography carried out in the first 24 h post-surgery.
Materials and methods: Immediate renal DUS findings (resistance index, hydronephrosis, fluid collection, bruises, and vascularization abnormalities) and their association with graft survival were analyzed in a retrospective observational study of 343 renal allografts. Renal transplantation was done using a standard technique, and DUS was performed 24 h post-transplantation. The association of variables with graft survival was evaluated by Cox univariate and multivariate proportional hazards analysis. Kaplan-Meier survival analysis and the log-rank test were used to examine graft survival.
Results: The follow-up median was 85 months. On IRDUS, 137 patients (39.9%) had abnormal findings. The best RI cutpoint for the prediction of graft survival was 0.7; therefore, we defined two different groups: RI ≤ 0.7 (n = 247) versus RI > 0.7 (n = 96). Univariate analysis revealed that graft survival was significantly lower in patients with RI > 0.7 (P ≤ 0.001), vascularization abnormalities (P ≤ 0.001) or bruises (P = 0.026). In multivariate analysis, the only factors independently associated with graft survival were RI (odds ratio 2.4; 95% CI 1.4-4.1) and vascularization abnormalities (odds ratio 2.7; 95% CI 1.1-6.5).
Conclusions: IRDUS can be useful, besides being highly useful in the diagnosis of graft primary dysfunction in the transplanted patient also yields information that can help to predict long-term graft survival.