Frequent falsely negative renal vein renin tests in unilateral renal parenchymal disease

A retrospective analysis of 12 hypertensive patients with unilateral renal parenchymal disease was done to evaluate the roles of renal vein renin testing and an operation. The patients were considered to have renal parenchymal disease on the basis of radiographic and/or pathologic findings. Only 2 patients had positive renal vein renin studies. Both of these patients were improved after unilateral nephrectomy but 1 had subsequent progression of disease and renal failure. Of the 10 patients with negative studies 5 had unilateral nephrectomy: 4 of them, nevertheless, experienced substantial improvement in the hypertension. It is concluded that hypertensive patients with unilateral renal parenchymal disease often can benefit from an operation and that renal vein renin testing in such patients can be misleading.