Incidence of anatomical variants in renal vasculature in the presence of normal renal function.

This report defines the incidence of variations in the renal vascular pedicle in a group of patients with normal renal function as determined by standard laboratory criteria. The study group consisted of 166 patients undergoing renal arteriography as potential renal allograft donors. Ninety-seven patients were male and 69 were female. Ages ranged from 18-54 years, median age being 37 years. All patients underwent preliminary screening tests including blood chemistries, creatinine clearance, urinalysis, culture and excretory urography. If these studies were normal, renal arteriography was performed utilizing flush aortogram and, in 20% of cases, selective renal arteriography. The most common anomaly was the presence of multiple renal arteries supplying the same kidney, occurring in 32% of cases. Prehilar segmental branching was the second most common variation, occurring in 17% of patients. Other variations included fetal lobulation (4%), significant stenosis at origin of the renal artery (2%), fibromuscular dysplasia (2%), microaneurysms (0.5%), true aneurysms (1%) and dromedary hump (0.5%). Less than one-half of the patients demonstrated the simplest vascular pedicle, namely, single artery and vein bilaterally. The incidence of anatomical variations in the renal vascular pedicle is greater than attributed to normal subjects in previous reports. Anomalies determine the choice of kidney in renal allografting and may disqualify a potential donor, even in the face of ostensibly normal renal function. Routine arteriography should be considered a standard prerequisite in the evaluation of potential living related renal donors.