The predictive accuracy of renal vein renin activity in the surgery of renovascular hypertension.

In a consecutive group of 38 patients undergoing operations for renovascular hypertension, there were 24 arterial reconstructions and 16 nephrectomies. Thirty-two patients were available for late observation, and 25 (78 percent) had a successful result. The renal vein renin ratio (RVRR) correctly predicted successful results in 76 percent of the patients with a RVRR of 1.5 or more but was correct in predicting an unsuccessful result in only one of the six patients with an RVRR less than 1.5. This high incidence of "false-negative" results has appeared in several other reports but has received insufficient emphasis. The presumed causes include inadequate sodium depletion prior to the renal blood vein samplings or, less likely, the effects of renin-suppressing drugs such as alpha methyldopa, propranolol, or reserpine. Because five of the six patients with RVRR less than 1.5 enjoyed a successful result from operation, it is apparent the clinical factors and the aortogram should be determinant when the RVRR, performed under the conditions described, is not diagnostic of renovascular hypertension. Nonetheless, when all diagnostic factors, i.e., the aortogram, the rapid-sequence intravenous pyelogram, and the RVRR, support such a diagnosis, a successful surgical result is nearly certain.