High resolution ultrasound characterization of early allograft hemodynamics in pediatric living related renal transplantation

Purpose: Allograft vascular thrombosis occurs in 5% to 10% of pediatric ren al transplants. The hemodynamics of renal allograft immediately after impla ntation is unclear. High resolution Doppler ultrasound of the renal allogra ft performed in the operating room after incision closure is an effective a nd objective method to advance our understanding of baseline renal allograf t hemodynamics, and identify unsuspected vascular complications early enoug h to ensure prompt surgical repair. Materials and Methods: Between September 1998 and July 2000 high resolution , color power Doppler ultrasound was prospectively performed on 21 living r elated renal transplants in the operating room immediately after incision c losure. Each ultrasound described allograft anastomotic blood flow, directi on of diastolic flow, parenchymal perfusion and resistive indexes. Results: There were 20 (95%) allografts with good power Doppler perfusion t hat had satisfactory immediate function with no vascular complications at 9 to 26-month followup. Initially, anastomotic turbulence was described in 1 5 (71%) allografts, and resistive indexes were abnormal in 8 (38%). Turbule nce and abnormal resistive index normalized in all allografts by 1-month fo llowup. Ultrasound of I allograft identified unsuspected poor perfusion and reversal of diastolic flow in the operating room after incision closure. I n another allograft in which a 4-hour posttransplant ultrasound was compare d with the baseline study in the operating room an unsuspected thrombosis o f the right common iliac vein was confirmed. Conclusions: Good parenchymal perfusion and forward diastolic flow after re nal reperfusion correlated well with immediate graft function. Initial turb ulence and abnormal resistive index in the presence of favorable perfusion are misleading and not independent predictors of graft function. Ultrasound performed in the operating room identified 2 unsuspected major vascular co mplications facilitating prompt surgical correction.