[Hypertension in unilateral (non-vascular) nephrosclerosis: renin activity in the venous kidney blood and effect of nephrectomy].

13 patients (9 females, 4 males) with hypertension and unilateral (non-vascular) small kidney underwent nephrectomy. Before surgery, renin activity (PRA) was measured in renal vein blood before and/or 15 and 30 minutes after intravenous stimulation with 40 mg furosemide. From these PRA values renin rations (PRA affected side/PRA unaffected side) were calculated. A ratio of greater than or equal to 1.5 was considered to be significant. After a mean postoperative observation period of 3.9 +/- 1.3 years 6 patients (46%) were cured and 6 were improved. In only 1 patient (8%) did hypertension remain unchanged. No differences could be observed between the renin ratios of cured and improved cases. Furthermore, in no patient was a correlation found between preoperative renin ratios and the degree of postoperative blood pressure reduction. Finally, both patients with renin ratios less than or equal to 1.4 were cured by surgery. Marked differences between cured and improved patients were seen in preoperative blood pressure values, age, duration of hypertension and renal function. Cured patients were younger and had much lower mean systolic and diastolic blood pressure values, shorter duration of hypertension and better renal function than improved patients. These results show that the diagnostic and prognostic validity of renal venous renin ratios is very limited in patients with a unilateral (non-vascular) small kidney. In these patients the effect of nephrectomy can already be predicted by analyzing simple anamnestic, clinical and chemical data.