Renal artery dissection.

Renal artery dissections are stenotic or occlusive lesions most often observed in hypertensive patients with underlying atherosclerosis or fibromuscular disease. Acute dissections may present spontaneously, as a complication of diagnostic or therapeutic angiography or as an agonal event associated with overwhelming systemic illness. Chronic dissections may produce renovascular hypertension or be entirely asymptomatic. Fourteen renal artery dissections have been encountered in nine patients treated at Vanderbilt University Medical Center during the past decade. Eleven dissections have been found in seven patients with renovascular hypertension. Seven of these dissections were chronic (six functional, one silent) and four acute (two spontaneous, two secondary to angiography). Three agonal dissections were found in two additional patients postmortem: one at autopsy and bilateral dissections found at the time of cadaveric donor nephrectomy. Ten bypass procedures, including five complex branch reconstructions of which three were performed ex vivo, have been performed with 100% immediate patency and maintenance or improvement of renal function. Long-term follow-up of these patients has shown sustained patency of the reconstructed renal arteries, excellent blood pressure control, and normal renal function in all. Nephrectomy has not been required and there have been no associated deaths. Seventy-seven additional renal artery dissections in 72 patients collected from previous reports have been analyzed. Patient survival (55/72, 76.4%) and preservation of the involved kidney in surviving patients (26/55, 47.3%) were low in these earlier series. In addition, renal failure was associated with 59% of the deaths. The lethality of renal artery dissections and the ease and success of revascularization, which preserves renal function and ameliorates associated renovascular hypertension, emphasize the need for an aggressive approach to the recognition and treatment of this entity. Therapy should be directed toward arterial reconstructions and the preservation of functioning renal tissue.