1. Low-to-normal renin renovascular hypertension (RVH) and the accuracy of renal vein renin ratios were investigated in 129 consecutive patients referred for suspected RVH. Forty-nine had essential hypertension, 24 unilateral renoparenchymal hypertension and 56 renal artery obstruction. Of the latter, 86% were diagnosed retrospectively as RVH, based on fall in blood pressure with correction of renal ischaemia. We measured baseline, captopril-stimulated and renal vein plasma renin activity (PRA) levels, as well as several other parameters. 2. PRA was low-to-normal in 37% of the RVH patients [low-to-normal renin (LNR-) RVH group] and elevated in the remaining 63% [high-renin (HR-) RVH group]. In the LNR-RVH group, low-to-normal renin levels, by immunoreactive active renin and plasma renin concentration measurements, and a blunted response of PRA to captopril, were seen. As compared with HR-RVH, LNR-RVH patients had a longer duration of hypertension (P < 0.05), higher serum K+ (P = 0.04) and lower diastolic blood pressure (P = 0.02). However, they did not differ for the other variables, including the fall in blood pressure after correction of renal ischaemia. Although the number of bilateral stenoses was similar in the two groups, no patient in the LNR-RVH group had total renal artery occlusion compared with 53% in the HR-RVH group (P = 0.00015). The accuracy of renal vein renin indices were high enough to justify their use only in the patients with total occlusion of a renal artery. 3. Thus LNR-RVH is common in patients with longstanding hypertension without a totally occluded renal artery. Since the sensitivity of renin measurements is low, cure of hypertension would be precluded for more than one third of RVH patients, if these tests were a prerequisite for identifying RVH.

Percutaneous transfemoral renal arteriography.

Renovascular Hypertension with Low-to-Normal Plasma Renin: Clinical and Angiographic Features

Renal tumors are the most common malignancy associated with inferior-vena-caval occlusion. The level of obstruction is usually in the middle third of the vena cava. Middle vena-caval occlusion should be suspected when, in addition to the usual signs of inferior-vena-caval obstruction, the presence of albuminuria, hematuria, nephrotic syndrome, or hepatic dysfunction is demonstrated. Four cases presented here illustrate the clinical syndrome. Intravenous urography and inferior-vena-caval roentgenography are the most useful diagnostic aids. Retrograde pyelography, nephrotomography, and renal arteriography may occasionally be necessary.

Percutaneous transfemoral renal arteriography.

Citations

Renovascular Hypertension with Low-to-Normal Plasma Renin: Clinical and Angiographic Features

Inferior-Vena-Caval Thrombosis in Malignant Renal Lesions

Continuous Preoperative Intra-Arterial Perfusion of Renal Tumors with Cheiyiotherapeutic Agents