Site of entry of single main renal artery. Angiographic study

In an effort to determine the frequency of extrahilar entry of the single main renal artery, renal angiographies of 124 left and 124 right kidneys were examined and the findings reviewed. Extrahilar entry of the main renal artery was found in 33 per cent of the kidneys. In 81.7 per cent of the kidneys with extrahilar entry, the artery penetrated the kidney through the upper zones (above the normal hilus). Apical entry of the renal artery was found in 1.6 per cent of the 248 kidneys. There was no entry of the single main renal artery below the hilus of the right kidney. An embryologic explanation of these findings is suggested, and some practical aspects are mentioned.