The bovine kidney as an experimental model: Simulated partial nephrectomy of the cranial pole and proportional analysis of the arterial segments.

Previous studies have shown that the pig kidney is not a good model for some procedures. This study aimed to describe the relationship between the collecting system and the intrarenal arteries, the arterial segments, and to evaluate the bovine kidney as an experimental model for partial nephrectomy of the cranial pole. Polyester resin endocasts of the kidney collecting system together with the intrarenal arteries were prepared. Thirty-two kidneys were used to evaluate the relationship between the collecting system and the intrarenal arteries, while 25 kidneys were transversally sectioned at different points to simulate partial nephrectomy of the cranial pole. Polyester resin of different colors was injected into each segmental artery of the 24 kidneys to evaluate the arterial segments proportionally. The renal artery was divided into cranial and caudal primary branches in 75% of the cases. The cranioventral branch curved on the cranial pole and ran toward the ventral mid-zone in 56.3% of the cases, resembling the retropelvic artery of the human kidney. The kidney was divided into two (25%) or three (75%) arterial segments. The caudal arterial segment had the highest proportional volume (62%). The cranioventral branch was damaged in 28.6% of the kidneys sectioned 1 cm inside the hilum. The arterial branching pattern, the arterial segmentation, and the impairment of the arterial supply after the simulated partial nephrectomy of the cranial pole are quite different from those found in humans. Thus, all differences should be taken into account when using the bovine kidney as a model.