Tissue pulsatility index: a new parameter to evaluate renal transplant perfusion

Area of Science:

• Nephrology
• Radiology
• Transplant Surgery

Background:

• Chronic allograft nephropathy (CAN) is a significant concern in renal transplantation, characterized by reduced parenchymal perfusion.
• Accurate assessment of transplant perfusion is crucial for long-term surveillance and management of renal allografts.

Purpose of the Study:

• To introduce and evaluate the novel Tissue Pulsatility Index (TPI) as a quantitative parameter for assessing renal transplant perfusion.
• To investigate the utility of TPI in differentiating perfusion between cortical layers and in relation to graft function.

Main Methods:

• Color Doppler sonographic videos of renal transplants from 38 recipients were analyzed.
• Tissue Pulsatility Index (TPI) was calculated as the ratio of the difference between mean systolic and diastolic velocities to the average velocity within the transplant region.

Main Results:

• Significant differences in TPI were observed between proximal and distal cortical layers (1.12 vs. 1.56, P=0.000).
• Elevated creatinine levels correlated with higher distal TPI (1.70) compared to normal creatinine (1.34, P=0.016), indicating compromised function.
• TPI showed significant changes over the post-transplantation period, increasing in the first 9 years and declining thereafter.

Conclusions:

• The novel Tissue Pulsatility Index (TPI) effectively differentiates cortical perfusion in renal transplants.
• TPI serves as a valuable tool for assessing transplant function, distinguishing between compromised and well-functioning grafts.
• TPI provides dynamic insights into transplant perfusion changes across the post-transplantation timeline.