Shrinkage of renal tissue after impregnation via the cold Biodur plastination technique.

Thorough dehydration is a key for good plastination and invariably it leads to shrinkage. Shrinkage during plastination has been studied to lesser extent. Shrinkage was studied in 10 pig kidneys including regional shrinkage (cortex, medulla, sinus) and at which stages of the process (dehydration, impregnation, curing) shrinkage occurred. Kidneys were fixation by perfusion of 10% neutral buffered formalin solution via the renal artery. The vessels and ureter were filled with colored silicone (Dow Corning, Silastic E RTV Silicone Rubber) and the kidneys were cut into one centimeter transverse slices. Two slices of each kidney were plastinated via the classic von Hagens' method. Slices were photographed at the same focal length after preparation and at the end of each stage of plastination. Slice surface area was determined by a point-counting planimetry method. Post dehydration shrinkage of the kidney was 10.21% while post impregnation 10.11%. After completion of plastination, total area of kidney slice shrinkage was 19.72%. Cortical area shrunk 12.81% after dehydration and 13.16% after impregnation. After plastination, cortical area had shrunk 24.28%. No significant shrinkage occurred in the medulla and sinus. Results demonstrate that kidney shrinkage during impregnation is as intense as during dehydration. Significant shrinkage occurred in the renal cortex but not in the medulla and sinus. This demonstrates that different tissue types, even in the same specimen, have different rates of shrinkage during dehydration and impregnation. Therefore, plastinated specimens should be used carefully in research where obtaining measures is important.

The dog kidney as experimental model in endourology: anatomic contribution.

Abstract A systematic study of the morphometry and the collecting system of the canine kidney is presented and compared with previous findings in humans. Renal measurements (kidney length, width, and thickness) were recorded. In addition, 110 three-dimensional endocasts of the kidney collecting system were produced and studied. Anatomic details, important to research and surgical training in endourology, were observed and recorded in canine kidneys. Dogs whose height was more than 70 cm at the withers presented similar kidney measurements to those found in the adult human. The collecting system consisted only of a renal pelvis with a variable number of recesses around its perimeter. The dog kidney is not a good model for experimental studies that consider the morphology of the collecting system. Kidneys from dogs taller than 70 cm, however, might be useful as a model in experimental studies in which renal volume is an important aspect, such as shockwave lithotripsy and endourology.

Dog kidney: anatomical relationships between intrarenal arteries and kidney collecting system.

The detailed findings of canine intrarenal anatomy (collecting system and arteries) are presented. Ninety-five three-dimensional endocasts of the kidney collecting system together with the intrarenal arteries were prepared using standard injection-corrosion techniques and were studied. A single renal artery was observed in 88.4% of the casts. The renal artery divided into a dorsal and a ventral branch. Using the branching pattern of the ventral and dorsal divisions of the renal artery, the vessels were classified in type I or type II. Type I presented a cranial and a caudal artery, whereas type II presented a mesorenal and a caudal artery. Cranial branches of dorsal and ventral arteries supplied the cranial pole in 90.5% of the specimens. Caudal branches of the dorsal and the ventral divisions of the renal artery irrigated both the caudal pole and the mid-zone of the kidney in 95.8% and 98.9% of the cases, respectively. In all casts, caudal branches of both dorsal and ventral arteries supplied the caudal pole. Therefore, the caudal branches of the ventral and dorsal divisions of the renal artery are of utmost importance in the kidney arterial supply. Although many results of renal and intrarenal anatomy in dogs may not be completely transposed to humans, the anatomical relationship between arteries and the collecting system in the cranial pole of the dog kidney is similar to those in man. This fact supports the use of the dog as an animal model for urologic procedures at the cranial pole.