Proposal for a new classification of the renal artery in the bovine kidney

摘要

Proper vascularisation is necessary for the correct functioning of all organs. The kidneys of various mammalian species have been examined in order to understand the functioning of this organ. This article presents the first classification of the renal artery division in the kidneys of adult cattle. We collected and analysed specimens of arteries from bovine kidneys with the aim of improving our understanding of their morphology and functioning. The study was conducted on 50 kidneys, 25 right ones and 25 left ones, taken from cattle of both sexes. The examined kidneys were dissected and corrosion casts were made. Division of the renal artery into between two and four primary segmental arteries takes place just before entering the renal hilum. Cranial primary segmental arteries number from one to two (most frequently one), whereas the hilar and caudal ones always occur singly. The mentioned vessels are then divided into between one and four secondary segmental arteries running within the renal sinus. The hilar region (mid-zone) of the kidney exhibits the most variation in terms of vascularisation. The vascularisation of the caudal pole exhibits the lowest degree of variation. Taking into consideration the range of vascularisation of the organ by the particular divisions of the renal artery, three renal branching pattern types were distinguished: type I (84.1% of cases; this type consists of Ia, Ib, Ic and Ic subtypes) - two branches - the renal artery is divided into cranial and caudal primary segmental arteries; type II (11.36% of cases; with IIa and IIb subtypes) -three branches - the renal artery is divided into the cranial, hilar and caudal primary segmental arteries; type III (4.54% of cases) - four branches - the renal artery is divided into two cranial, one hilar and one caudal primary segmental artery. The division of the renal artery takes place along the long axis of the organ. Bovine kidneys are characterised by asymmetry, which may influence the length and diameter of the main arteries. The caudal primary segmental artery has the biggest mean length and mean diameter. The division of the renal artery occurs just before it enters the renal hilum or in the renal sinus.