Different from renal artery only clamping, artery and vein clamping causes a significant reduction in number of rat glomeruli during warm ischemia.

PURPOSE: To evaluate glomerular injury in the rat model during renal warm ischemia (WI), comparing artery and vein (AV) clamping with artery only (AO) clamping. MATERIALS AND METHODS: Twenty-four adult male rats underwent 60 minutes of renal WI in the left kidney. The animals were divided into three groups: AV clamping, AO clamping, and Sham surgery. After 30 days, the animals were euthanized, and both kidneys were processed for paraffin embedding and stained with hematoxylin and eosin. Glomerular volume density (Vv[glom]), mean glomerular volume (MGV), and number of glomeruli per mm(3) (Nv[glom]) were evaluated in the renal cortex. RESULTS: The Vv[glom] was reduced in the left kidney (ischemic) when compared with the right kidney in both AV and AO groups by 11.1% and 35.4%, respectively; however, the difference was significant only in the AV group. The Nv[glom] was reduced in the left kidney when compared with the right kidney in both AV and AO groups by 11.6% and 31.4%, respectively; nevertheless, the difference was significant only in the AV group. The MGV of left and right kidneys was the same in both Sham and AO groups and was diminished by 6.7% in the AV group-not significant. CONCLUSION: AV clamping causes a significant decrease in the number of glomeruli in the rat model, while AO clamping reduces the glomerular number, but not significantly. To minimize renal injury, AO clamping may be preferred over AV clamping when WI is necessary in patients with previously compromised renal function.

A proposed new classification for the renal collecting system of cattle.

OBJECTIVE: To evaluate the intrarenal anatomy of kidneys obtained from cattle and to propose a new classification for the renal collecting system of cattle. SAMPLE POPULATION: 37 kidneys from 20 adult male mixed-breed cattle. PROCEDURES: Intrarenal anatomy was evaluated by the use of 3-D endocasts made of the kidneys. The number of renal lobes and minor renal calyces in each kidney and each renal region (cranial pole, caudal pole, and hilus) was quantified. RESULTS: The renal pelvis was evident in all casts and was classified into 2 types (nondilated [28/37 {75.7%}] or dilated [9/37 {24.3%}]). All casts had a major renal calyx associated with the cranial pole and the caudal pole. The number of minor renal calices per kidney ranged from 13 to 64 (mean, 22.7). There was a significant correlation between the number of renal lobes and the number of minor renal calices for the entire kidney, the cranial pole region, and the hilus region; however, there was not a similar significant correlation for the caudal pole region. Major and minor renal calices were extremely narrow, compared with major and minor renal calices in pigs and humans. CONCLUSIONS AND CLINICAL RELEVANCE: The renal collecting system of cattle, with a renal pelvis and 2 major renal calices connected to several minor renal calices by an infundibulum, differed substantially from the renal collecting system of pigs and humans. From a morphological standpoint, the kidneys of cattle were not suitable for use as a model in endourologic research and training.

The bovine kidney as an experimental model in urology: external gross anatomy.

The objective of this work was to obtain and record detailed and accurate measurements of the bovine kidney and to compare these new data with findings in humans. Thirty-eight bovine kidneys were used. The total number of lobes, along with the number of lobes located in the cranial polar, caudal polar and hilar regions, were recorded. Several measurements of the kidneys were made and evaluated. The hilar region presents the greatest length (mean of 76.87 mm) of the 3 renal regions of the kidney. The large area of the bovine renal hilus could make access to hilar structures easier than in the human kidney. The coefficient of variation for renal length was small (8.14%), while the coefficient of variation for the lobar number was high (26.82%). The number of renal lobes ranged from 13 to 35, with a mean of 20.62. The hilar region presents the highest number of lobes, while the cranial pole presents the lowest. The number of lobes in the cranial and caudal poles increases with the width of these regions. This is different from the hilar region, in which the lobar number increases with the length of the hilus. These data indicate that the adult bovine kidney can be used as a model for certain urologic procedures, but researchers must be aware that there are some major differences between the adult bovine kidney and the human kidney, as indicated by the data reported in this paper.

Pig kidney: anatomical relationships between the renal venous arrangement and the kidney collecting system.

PURPOSE: We present a systematic study of the anatomical relationship between the intrarenal veins and the kidney collecting system in pigs. MATERIALS AND METHODS: The intrarenal anatomy (collecting system and veins) was studied in 61, 3-dimensional endocasts of the kidney collecting system together with the intrarenal veins. RESULTS: There are free anastomoses between the intrarenal veins. The interlobar veins unite to produce large venous trunks, which form the renal vein. In our study we observed 2 trunks (cranial and caudal) in 54 of the 61 cases (88.53%) and 3 trunks (cranial, middle and caudal) in 7 (11.47%). Only the ventral surfaces of the cranial and caudal poles were drained by large veins, while the dorsal surfaces emptied by anastomoses into the ventral interlobar veins. There were large veins in a close relationship to the ventral surface (90.16%) and to the dorsal surface (3.28%) of the ureteropelvic junction. In 33 of the 61 cases (54.10%) there was 1 or 2 small dorsal veins. CONCLUSIONS: Although some results of intrarenal venous arrangement in pigs could not be completely transposed to humans, many similarities of pig and human kidneys support its use as the best animal model for urological procedures.