Digital subtraction angiography (DSA) in renal and renovascular hypertension: diagnostic value and application in follow-up studies after PTA.

Diagnosis of renovascular hypertension is of particular interest because it is curable by vascular surgery or percutaneous transluminal angioplasty (PTA). Transvenous digital subtraction angiography (DSA) is a minimally invasive method of importance in detecting renal hypertension of different origins (pre-, intra-, postrenal). This study was carried out to assess the value of transvenous DSA in analyzing the renal arteries and renal parenchyma, in detecting renal artery stenosis, and in controlling PTA results. Our results demonstrate that image quality of transvenous DSA of the renal arteries was excellent (diagnostic in 474 of 510 cases, 93%). A large number (62%) could be analyzed following one injection of contrast medium, in 25% a second, and 6% a third injection was necessary. In follow-up studies after PTA (1 week to 24 months) patients with normalized blood pressure values (16/33) had a completely reopened arterial segment and normal parenchyma of both kidneys. In persistent or recurrent hypertension (17/33) restenosis could be detected by transvenous DSA in 2 cases and renal parenchymal lesions in 8 cases. Reversible intimal dissections observed immediately following PTA had no influence on blood pressure results. Intra-arterial DSA is recommended when renal artery stenosis is to be evaluated for PTA and when the result of balloon catheter dilatation is to be evaluated. Intra-arterial DSA is indicated to exclude stenosis following kidney transplantation and to determine perfusion of the graft (parenchyma and venous return) taking advantage of small volumes and concentrations of contrast material made possible by digital contrast enhancement.