Objective, real-time, intraoperative assessment of renal perfusion using infrared imaging.

Allograft ischemia induces delayed graft function and is correlated with increasing rates of rejection. There is not currently a way to objectively measure the effects of ischemia in real-time, nor to relate therapies combating reperfusion injury with their intended effects. An infrared (IR) method utilizing a focal plane array detector camera was developed for real-time intraoperative IR imaging of renal allografts, and evaluated in a pilot trial to quantify perfusion in recipients of live (n = 8) and cadaveric donor (n = 5) allografts. Digital images were taken for 3-8 min postreperfusion. Image data were compared to ischemic time and allograft function to assess potential clinical relevance. Cold ischemic time ranged from 0.5 to 29 h and was bimodally distributed between living and cadaveric donors. Renal rewarming time (RT) as determined by IR imaging correlated with cold ischemic time (p < 0.001, R 2 = 0.81), and predicted the subsequent return of renal function with RT negatively correlated to the regression slopes of creatinine (p = 0.02, R 2 = 0.38) and BUN (p = 0.07, R 2 = 0.26). Intraoperative IR imaging noninvasively provides clinically relevant real-time whole kidney assessment of reperfusion. This technology may aide in the objective assessment of therapies designed to limit reperfusion injury, and allow for quantitative assessment of allograft ischemic damage.