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 x 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%.