A 2-mm Cutoff Value Is Reasonable and Feasible for Vascular Reconstruction in a Kidney Allograft With Multiple Arteries

Background: Multiple renal arteries are found in approximately 20% of living donor kidneys. We have been using an accessory artery cutoff diameter of 2 mm on preoperative computed tomography angiography to determine whether to sacrifice or reconstruct the artery. In this study, we assessed the validity and feasibility of this cutoff value.

Methods: Living related kidney recipients from 2005 to 2013 were enrolled in this retrospective study. The diameter of the accessory artery and adverse events were evaluated. The lost parenchymal volume (%) due to vascular obstruction or branch ligation was calculated by computed tomography volumetry.

Results: Among 128 kidney transplants, 30 donor kidneys had multiple arteries. Accessory arteries were reconstructed in 18 cases and intentionally ligated in 12 cases (mean diameter of accessory arteries, 3.10 [SD, 0.75] mm and 1.81 [SD, 0.28] mm, respectively). The mean estimated glomerular filtration rate at 1 or 12 months after transplant was not significantly different between the groups. Among reconstructed cases, 14 cases (77.8%) had good patency in the reconstructed arteries whereas the other 4 had vascular complications. The percentage of lost parenchymal volume due to ligation or occlusion of the reconstructed artery (calculated in 16 cases) was predictable with the following formula: lost volume (%) = 9.09 × diameter (mm) - 10.5 (P= .03, r_s= 0.533 by Spearman rank correlation coefficient). This formula indicated that ligation of a 2-mm accessory artery leads to 7.68% loss of the renal parenchyma.

Conclusions: Reconstruction using a cutoff diameter of 2 mm is worth attempting in terms of the success rate and graft function. Sacrifice of a 2-mm accessory artery leads to parenchymal loss of <8%.