Anatomical background of ovine kidney for use as animal model: analysis of arterial segmentation, proportional volume of each segment and arterial injury after cranial pole partial nephrectomy

Abstract

Objective: To study the arterial segments of ovine kidney, present a proportional volume analysis of each kidney arterial segment, and analyze arterial injuries caused by simulated partial nephrectomy of cranial pole. Materials and Methods: Forty-eight ovine kidneys injected with polyester resin into the renal arteries and collecting system were used in this study. Eighteen kidneys were used to study the arterial segments and the proportional volume of each renal segment. Other 30 kidneys were submitted to superior pole resection at a distance of 1.0cm, 0.5cm, or exactly at the cranial hilar edge, just before the resin hardening. These endocasts were used to evaluate the arterial injuries caused by these different resection planes. Results: Ovine renal artery divided into two (ventral and dorsal) or three segmental arteries. Dorsal segment presented higher proportional volume than ventral segment. For kidneys with three segments, the third segment was on the caudal region (caudoventral or caudo-dorsal segment) and presented the lowest proportional volume. None of the resected kidneys (at 1.0, 0.5 or at the cranial hilar edge) presented injury of arterial branches that irrigate non-resected region. Conclusion: The segmental distribution of renal artery, the proportional volume of each segment and arterial injuries after cranial pole resection in ovine kidneys are different from what is observed in human kidneys. Meanwhile, ovine kidneys show a primary segmental division on anterior and posterior, as in humans, but different from swine. These anatomical characteristics should be considered when using ovine as animal models for renal experimental and/or training procedures.

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

“…Simulated partial nephrectomy of the cranial pole in humans and pigs demonstrated that transverse sections less than 1 cm cranial to the hilum promoted significant arterial damage, affecting the mid‐zone arterial supply (Favorito et al, 2011; Pereira‐Sampaio et al, 2012), unlike sheep, which had no significant arterial injury after simulated partial nephrectomy of the cranial pole (Zidde et al, 2020). This study showed that the cranioventral branch of the bovine kidney was damaged only in the transverse section performed inside the hilum, 1 cm caudal to the cranial edge of the hilum, impairing the vascular supply of the remaining renal parenchyma (Figure 4).…”

“…Simulated partial nephrectomy of the cranial pole in humans and pigs demonstrated that sections closer to the renal hilum affect the arterial supply of the mid‐zone (Favorito, Brito, & Sampaio, 2011; Pereira‐Sampaio, Henry, Favorito, & Sampaio, 2012). On the other hand, simulated partial nephrectomy of the cranial pole in sheep did not show any significant arterial damage (Zidde, Sampaio, Souza‐Junior, De Souza, & Pereira‐Sampaio, 2020). There is no detailed anatomical study on these topics in a bovine kidney, as well as on the proportional analysis of the arterial segments.…”