Spontaneous renal artery dissection.

Focal lesions in the renal artery caused by fibromuscular dysplasia (FMD) are susceptible to spontaneous intramural dissection, and carry a serious risk of malignant hypertension and loss of renal function. Of four patients with arterial dissection and severe hypertension, nephrectomy was required in two, an aortorenal bypass was constructed in one, and spontaneous re-entry with resolution of malignant hypertension occurred in one man. All except the patient with re-entry became normotensive. Isolated dissections in the renal artery wall in association with FMD apparently occur more often than previously suspected. Since extensive distal dissection may preclude repair, the identification and early surgical treatment of these lesions are important features in managing these patients.