Postoperative course of blood pressure and plasma renin activity in patients with renovascular hypertension.

Thirty patients with renovascular hypertension were treated surgically, and they were divided into two groups according to the kinds of operations they received; nephrectomized group (group A) and revascularized group (group B). Postoperative blood pressure was followed periodically in each patient of two groups. In all patients with an excellent result (diastolic pressure of 90 mmHg or lower without antihypertensive therapy), blood pressure returned to normal within 30 postoperative days. Normal blood pressures were obtained within 3 weeks in eighty-four per cent of them. The normalization of blood pressure following operation was more rapid in group B than in A. The postoperative plasma renin activity (PRA) was determined serially in 10 patients. PRA became normal in 9 within 3 days and in one within 7 postoperative days. The restoration of PRA preceded the normalization of blood pressure. The normalization of PRA was quicker in group A than in B. It is likely that the renal antihypertensive mechanism, suppressed in the ischemic kidney and set again in motion by revascularization, mainly causes this difference in the postoperative changes in PRA and blood pressure between the two groups. It may be concluded that these findings are suggestive of an important role of impaired renal antihypertensive function in the maintenance of high blood pressure in chronic renovascular hypertension in man.