To assess the feasibility of a novel functional perfusion model based on enhanced computed tomography (CT) for the evaluation of split renal function and orientation of segmental renal artery clamping during laparoscopic partial nephrectomy (LPN).

From December 2016 to November 2017, functional perfusion model was applied in 91 patients with T1a renal tumors who had undergone LPN with segmental renal artery clamping. Split computed tomographic-glomerular filtration rate (CT-GFR) was calculated using the 2-point Patlak plot technique. Parenchymal perfusion areas of segmental renal arteries were marked, and target segmental arteries were determined by the perfusion areas wherein tumors were confined. LPN with precise segmental renal artery clamping was performed based on the novel model. Correlations between CT-GFR and estimated GFR and radioisotope GFR were analyzed using Pearson's method. Intraoperative ischemic status and surgical outcomes were assessed.

Mean tumor size was 2.9cm. Large tumors were accompanied by more feeding lobar arteries than segmental arteries. CT-GFR was strongly correlated with estimated GFR (r = 0.70) and radioisotope GFR (r = 0.88). All LPNs were successful without converting to main renal artery clamping. Mean operation time was 81.8 minutes; median estimated blood loss was 120mL. The actual parenchymal ischemic region observed during the operation was consistent with the prediction of the perfusion model in all patients. No arterial bleeding or other uncontrollable defect bleeding occurred during tumor resection.

This model is a reliable method for the determination of split renal function and orientation of segmental artery clamping during LPN.