Branching patterns of the renal artery of the pig

Abstract

Background: The pig kidney is similar in structure and function to the human kideny, thus making it a useful model in understanding the human kidney in health and disease. However, little is known about the branching pattern of the pig renal artery as compared with the human and other animals.

Methods: The right and left kidneys from 11 juvenile pigs were injected with either Mercox compound to form a vascular cast or contrast media to obtain a renal arteriogram. Branching patterns of the renal artery were then examined to the level of the interlobar arteries.

Results: Examination of all 22 kidneys showed the main stem renal artery branching into two predictable patterns, designated I and II. The renal artery in pattern I (17 of 22 kidneys) divides into upper and lower polar arteries that then form anterior and posterior segmental arteries. Pattern I has two variations. Pattern II (5 of 22 kidneys) has a variable blood flow to the upper pole. Not only do anterior and posterior segmental arteries pass to the upper pole, but additional vessels arising from the lower polar artery also supply the upper pole.

Conclusions: The most common branching pattern of the main stem renal artery is pattern I, which divides the blood flow of the entire kidney into two distinct regions. Pattern II is less frequently seen and shows more variability in number and location of branches.