[Changes in the dimensions of the remnant kidney after nephrectomy of the pathologic contralateral kidney in adults]. / Cambios en las dimensiones renales del riñón remanente tras la nefrectomía del contralateral patológico en el adulto.

Compensatory renal hypertrophy is a process that has been known since Gustav Simon performed the first nephrectomy procedure in man in 1869. The present study reviews the literature and analyzes the factors relating to this process and its morphologic features. It has been reported that the degree of renal hypertrophy depends, among other factors, on the amount of nephrons lost as well as adaptative capacity of the surviving kidney when the pathologic kidney is removed. The present study also reports the changes in size of the surviving kidney observed at 6, 30, and 90 days after removal of the pathologic kidney in 40 patients. The results show a significant increase 6 days following nephrectomy and a significant decrease at 30 days to mean values higher than those of the preoperative evaluation. Ninety days after nephrectomy, these values significantly increase again but do not reach the same levels as those observed 6 days after nephrectomy. These findings are ascribed to the hemodynamic changes resulting from nephrectomy. These manifest immediately after the procedure and remain unchanged for days and subsequently the structural changes of renal hypertrophy prevail.

[Changes in creatinine clearance and fractional sodium excretion by the remaining kidney after nephrectomy of the contralateral diseased kidney in the adult]. / Cambios en el aclaramiento de creatinina y excreción fraccional de sodio del riñón remanente tras la nefrectomía del contralateral patológico en el adulto.

Unilateral nephrectomy causes immediate changes in renal plasma flow, glomerular filtration, and fractional sodium excretion of the remnant kidney. The present study reviews some aspects of reports published elsewhere relative to renal function adaptation after unilateral nephrectomy and presents the observed changes in creatinine clearance, fractional sodium excretion at 6, 30 and 90 days following removal of kidneys with chronic urologic disease and poor function, in a total of 20 patients. The results obtained show a gradual increase of creatinine clearance in most of the patients, although this increase was not statistically significant. On the other hand, fractional sodium excretion rose significantly at 30 and 90 days after nephrectomy. These findings can be interpreted in the following way: among the regulatory mechanisms, at 6 days postnephrectomy there is a predominance of the effects of increased CINa load to the distal tubule with activation of the renin-angiotensin system, as well as those produced by sympathetic efferents characteristic of the immediate postoperative period. However, at 30 and 90 days, the effects that seem to predominate are due to the expansion of the volume of extracellular fluid. Data obtained at 90 days indicate that balance seems to become stable.

[Calcification of the intervertebral disk in children]. / Calcificación del disco intervertebral en el niño.

Authors present two cases of calcification of the intervertebral disc. They provide an analysis of etiology, symptoms, and roentgenographic clinic course, as well as a review of cases which have been reported in literature.