Morphological assessments on the origin and supplied territory of the artery for the posterior renal segment

In 105 cases the posterior ramus originated from a renal artery bifurcated into anterior and posterior branches and in 78 cases from trifurcated renal artery. In 12 cases, the posterior ramus originated from a renal artery terminated with four branches. From the aorta, as supernumerary renal artery, the posterior branch originated in 7 cases, 3 cases as double and 4 cases as triple renal arteries. In 86 cases the posterior ramus originated from the anterior branch of the renal artery, superior or inferior or both. The arcade aspect was found in only 134 cases. A particular aspect of the arch is the italic “S” (or inverted italic “S”) or double arch, which we found in 24 cases. This type of posterior branch supplied the entire posterior valve, an aspect found in 11 cases. When the posterior branch was not in arcade, it was arranged transversally and ended by bi or trifurcation. The ending by bifurcation was found in 113 cases and by trifurcation in 17 cases. All of these cases, both the right and the left, supplied the entire posterior valve. In all cases, regardless of any aspect of the posterior branch, it supplied the entire posterior valve in 88 cases. The posterior branch supplied the superior pole in 250 cases, the inferior one in 181 and only the posterior mesorenal part, without participating in the supply of the two poles, in 233 cases.