Early Measurement of Pulsatility and Resistive Indexes: Correlation with Long-term Renal Transplant Function

Purpose: To correlate pulsatility index (PI) and resistive index (RI) measured at early specific intervals after transplantation with 1-year estimated glomerular filtration rate (eGFR) and death-censored transplant survival to assess the long-term prognostic value of these Doppler indexes. Materials and Methods: The local ethics committee was consulted, and no formal approval was required. This retrospective review included 178 consecutive patients (111 male, 67 female; mean age, 43.9 years +/- 13.4 [standard deviation]; age range, 16-72 years) undergoing first deceased-donor renal transplantation between 1997 and 2000. All patients were identified from a prospectively maintained database. Spectral Doppler analysis was performed within 1 week after transplantation in all patients and between 1 week and 3 months after transplantation in 124 patients. Average PI and RI were determined from measurements obtained in the upper, lower, and interpolar regions. For statistical analysis, the x(2) test, analysis of variance, the Student t test, Kaplan-Meier survival plots, and Cox proportional hazards models were used. Results: Within 1 week after transplantation, there was a significant association between PI and 1-year eGFR when analyzed as tertiles (P = .02). Between 1 week and 3 months after transplantation, there was a significant relationship between 1-year eGFR and both PI and RI when comparing the lowest and highest tertiles (47.5 mL/min/1.73 m(2) for PI < 1.26 vs 32.7 mL/min/1.73 m(2) for PI > 1.49 [P = .01], 42.8 mL/min/1.73 m(2) for RI, < 0.69 vs 32.3 mL/min/1.73 m(2) for RI > 0.74 [P = .03]). Both PI and RI were independent predictors of death-censored transplant survival (hazard ratio, 1.68 per unit [P < .001] and 260.4 per unit, respectively [P = .02]). Conclusion: PI and RI in the early posttransplantation period correlate with long-term transplant function and can potentially be used as prognostic markers to aid risk stratification for future transplant dysfunction. (C) RSNA, 2011