Isolated renal artery dissection, presentation, evaluation, management, and pathology.

Isolated nontraumatic renal artery dissection is rare. In this communication, 35 cases are presented; 24 cases (group 1) (22 male, 2 female) were diagnosed angiographically, and 11 (group 2) (10 male, 1 female) were observed at autopsy. In group 1, 23 of the patients were hypertensive when they were first seen, and in 17 of them the hypertension was of recent onset. Additional presenting signs and symptoms included flank pain (10 patients), gross hematuria (5), and headaches (6). Renal function was satisfactory. Renal vein renin levels could be lateralized in 8 of 16 patients. Isotope renograms performed in 18 patients, showed unilateral abnormalities in 7, bilateral abnormalities in 6, and normal results in 5. Angiograms showed that the dissection was unilateral in 18 cases and bilateral in 6 cases. Fibromuscular dysplasia was observed radiographically in 22 cases and was bilateral in 12. In group 1, 13 patients were treated with antihypertensive medication only, and 11 underwent operation. At follow-up (mean 52.0 months), the mean blood pressure were 128/88 mm Hg and 139/89 mm Hg for the medical and surgical groups, respectively. Eleven medical and nine surgical patients continued to require antihypertensive drugs at follow-up. Among the 11 patients in group 2, only 4 were hypertensive. In only one case the dissection may have contributed significantly to the patient's death. These studies indicate that isolated nontraumatic renal artery dissection most commonly occurs in young men with coexistent fibromuscular dysplasia. Hypertension is commonly present and therapy should be directed toward its control. In this study, blood pressure control was effectively accomplished with medical therapy.