Digital vascular imaging and selective renin sampling in post-transplant hypertension. Which kidney is responsible?

Forty-four hypertensive transplant patients were investigated by digital vascular imaging of the graft and simultaneous selective venous sampling for plasma renin activity to attempt to identify those patients whose hypertension may be amenable to surgical treatment. Localization of renin hypersecretion was possible in 12 patients. In ten of these, hypersecretion originated from the native kidney and in two from the graft. Localization was possible in a significantly higher proportion of patients with severe hypertension (8 of 17), and all of these had native kidney hypersecretion. Bilateral nephrectomy may be indicated in these patients. No cases of functionally significant renal artery stenosis were identified. The other major types of abnormal vascular pattern found on digital vascular imaging, diffuse intra-renal arterial attenuation and lower pole hypoperfusion may be secondary to hypertension. This combined technique may be useful in the evaluation of post-transplant hypertension, especially when hypertension is severe.