Comparison of split function ratios with renal vein renin ratios in patients with curable hypertension caused by unilateral renal artery stenosis

Pre- and postoperative studies in 72 hypertensive patients with renal artery stenosis, with special reference to renin activity and aldosterone

Seventy-two patients, aged 6-69 years, were operated on because of presumed renovascular hypertension and subjected to follow-up studies for 4-60 months (mean 28). Unilateral renal artery stenosis was present in 47 patients. Surgery was followed by normalization of blood pressure (BP) in 28 and improvement in 7, whereas 12 showed no response. Sixteen were below the age of 40 and only one failed to respond to surgery. Peripheral venous plasma renin activity (PRA) was increased in 32 and urinary aldosterone elevated in 22 of 35 patients responding favourably to surgery. Renal vein PRA was higher from the kidney with the stenotic renal artery as compared to the contralateral side in all patients responding to surgery. Preoperative peripheral PRA difference was also found in 7 of 12 patients not responding to surgery. Preoperative peripheral PRA was increased in 26 of the patients becoming normotensive after surgery. In 20 of these patients normalization of BP was associated with a fall in peripheral PR. Twenty-five patients had bilateral renal artery stenosis. Four of them had severe hypertension, renal insufficiency and generalized atherosclerosis. They died in immediate connection with operation. Unilateral operation, performed in 11 of the remaining 21 patients, was followed by normalization of BP in 3 and no response in 8. Bilateral reconstructive surgery, performed in 10 patients, resulted in normotension in 2 and improvement in 7. Our studies indicate that determination of peripheral PRA and/or urinary aldosterone can serve as a useful prognostic indicator after surgery in hypertensive patients with renal artery stenosis.

Orthotopic renal autotransplantation in the treatment of renovascular hypertension

Severe hypertension non-responsive to medical therapy was discovered in a 27-year-old woman in the third trimester of pregnancy. Renal arteriography after delivery revealed bilateral renal artery stenosis. The right kidney was smaller than the left one. The differential renal function studies, rather than the renal vein renin measurements, identified which side was causing the hypertension. An attempt at primary repair of the right renal artery failed. Orthotopic renal autotransplantation, using saphenous vein grafts that were interposed between the renal veins and the inferior vena cava, and between the segmental renal arteries and the abdominal aorta, reduced the blood pressure to normal values.

Renal venography: anatomy, technique, applications, analysis of 132 venograms, and a review of the literature

Selective renal venography is a simple but important diagnostic procedure which has few complications. A thorough knowledge of renal venous anatomy is essential for its proper performance and clinical application. This is particularly true because renal venous variations are frequent and may interfere with the successful appraoch to retroperitoneal surgery. The method is widely accepted for the evaluation of the renal venous bed in patients with suspected renal vein thrombosis or hematuria of unknown etiology. It depicts the extent of renal venous involvement in renal carcinoma and clarifies the diagnosis in some patients with avascular tumors, renal pelvic carcinoma, and retroperitoneal tumors. It may also be useful in defining the morphologic abnormality when the kidney fails to visualize on urography, in delineating the extent and nature of renal parenchymal disease, and in enhancing the precision of renal vein renin collection.

Renovascular hypertension: does the renal vein renin ratio predict operative results?

Renal vein renin ratios from 56 hypertensive patients who were operated upon for unilateral stenosis of a main renal artery were compared to blood pressure response to a corrective operation. In patients with renal vein renin ratios greater then 2.0, the upper limits of normal for essential hypertension (95 per cent confidence limits), the cure/improvement rate approximated 90 per cent. However, in patients operated upon despite lesser ratios the cure/improvement rate was also high--83 per cent in our series and 57 per cent in collected reports from the literature. Thus, the test may be falsely negative in a high percentage of patients. Renal vein renin ratios would appear to be most useful in confirming but not necessarily in denying the functional significance of a renal artery stenosis.

Renal perfusion/excretion determination renogram: a new tool in the diagnostic evaluation of renovascular hypertension

Presented herein are initial experiences with the RP/ED renogram, a unique radioisotope differential split function study, which can be performed with a minimum of discomfort to the patient. This test should totally supplant the existing renogram and, with additional experience, may replace the use of split function studies in the evaluation of renovascular hypertension.