Contemporary management of isolated chronic infrarenal abdominal aortic dissections.

OBJECTIVE: The purpose of this study was to report the presentation, treatment, and follow-up of isolated infrarenal aortic dissections.

METHODS: A review of 37 patients with isolated infrarenal aortic dissections was performed. Computed tomography scans with intravenous administration of contrast material were examined for all patients; catheter-based angiography, magnetic resonance angiography, and duplex ultrasound were used selectively. In dissections associated with the development of abdominal aortic aneurysm (AAA), the aneurysm growth rate was determined by measuring the change in maximum aneurysm diameter over time and dividing that by the duration of observation.

RESULTS: The majority of infrarenal abdominal aortic dissection patients were male (67.6%). Hypertension (77.1%) and hyperlipidemia (77.1%) were the most common comorbidities among these patients. Aortic atherosclerosis was present in the majority of patients (60.0%); 67.6% of dissections were discovered incidentally and were asymptomatic. The mean dissection length was 5.84 ± 4.23 cm. Concomitant AAAs were present in 48.6% of cases with an average maximum diameter of 4.38 ± 1.41 cm. The aneurysm growth rate was 1.2 mm/y. Aneurysms were significantly larger in men than in women (4.87 ± 1.31 vs 3.12 ± 0.67 cm; P = .001). Endovascular intervention was performed on 14 (37.8%) patients, open surgery was performed on 1 (2.7%) patient, and surveillance with conservative medical treatment was used for 22 (59.5%) patients. Ten patients were treated successfully with endovascular repair for progressive aneurysm expansion. At the time of intervention, the mean AAA diameter was 5.04 ± 1.39 cm. The mean growth rate for aneurysms that were intervened on was 2.3 mm/y. The mean diameter of AAAs that were not intervened on was 3.56 ± 1.04 cm. Type II endoleaks were observed in three (30%) patients who underwent endovascular repair. None of these were associated with aneurysm growth and none required reintervention. The mortality rate for endovascular intervention was 0%. The only open surgical repair performed was on a patient with a ruptured AAA, which the patient did not survive. Angioplasty with stent or stent graft placement was performed in four patients for the treatment of symptomatic arterial insufficiency resulting from aortic dissection. No patients experienced restenosis, and no reinterventions were performed.

CONCLUSIONS: Isolated infrarenal aortic dissection is an uncommon vascular disease that is related to hypertension, hyperlipidemia, and atherosclerosis and may be associated with infrarenal AAA formation. The presence of dissection does not appear to increase the risk of complication or mortality for repair of concomitant aneurysm or for treatment of stenosis.