An Experimental Study on the Morphological and Functional Changes of the Kidney by Percutaneous Nephrostomy

Chung, Moon Kee

Abstract

To discern the morphological and functional changes of the kidney by percutaneous nephrostomy, unilateral nephrectomy was performed on 9 pigs followed by contralateral percutaneous nephrostomy about 4 weeks later. Renal function was measured every week after removal of nephrostomy tube till the animals were killed at 1, 2, 4 and 6 weeks. Microangiographic and histologic studies were done on the 9 kidneys of percutaneous nephrostomy and another 39 ex-vivo pig kidneys on which nephrostomy tracts were made under direct vision. The results are as follows : 1. Renal vascular injuries were developed mainly at the interlobular vessels in the beginning of dilatation. Interlobular, arcuate and segmental arteries were not torn but pushed away from the nephrostomy tract after dilation. The injured vessels did not heal completely till 2 weeks postoperatively. 2. Rental parenchyma were not removed but splitted away from the nephrostomy tract during dilatation. The nephrostomy tracts started to be replaced with fibrosis from the second week. From the forth week, tubules, vessels and glomeruli were visible in those fibrotic tracts. There were no differences of parenchymal and vascular injuries between the puncture to the calyceal fornix and that to the renal papilla. 3. Renal function decreased slightly at the second week postoperatively but they returned to normal levels thereafter. Beta 2-microglobulins of urine and blood were not detectable by enzyme immunoassay in the experimental subjects. Therefore, the nephrostomy tract constructed by splitting the parenchyme step by step doesn't change renal function.