Aortic Fenestration: A Why, When, and How-to Guide

Three hundred twenty-five cases of spontaneous aortic dissection seen at two institutions between 1965 and 1986 were reviewed to assess the incidence, morbid sequelae, and specific management of aortic branch compromise. Noncardiac vascular complications occurred in 33% of the study group, and in these patients the overall mortality rate (51%) was significantly (p less than 0.001) higher than in patients without (29%) such complications. Although aortic rupture was the strongest correlate of mortality (90%), death specifically related to vascular occlusion was common when such occlusion occurred in the carotid, mesenteric, and renal circulation. There was a strong correlation between stroke and carotid occlusion (22/26 cases), yet specific carotid revascularization was only used during the chronic phase of the disease. Similarly, peripheral operation was ineffective in reducing the mortality rate in the setting of mesenteric (87%) and renal (50%) ischemia. Fifteen patients required either fenestration or graft replacement of the abdominal aorta for acute obstruction, rupture, or chronic aneurysm development. Thirty-eight patients (12%) demonstrated some degree of lower extremity ischemia, and one third of these required a direct approach on the abdominal aorta or iliofemoral segments to restore circulation. Selected patients with acute aortic dissection may require peripheral vascular operation in accordance with a treatment strategy that directs initial attention to the immediate life-threatening complications.

In an earlier report, we documented the incidence and impact of aortic branch compromise complicating acute aortic dissection (AD) over a 21-year interval (1965-1986). In the current study, management of peripheral vascular complications (PVCs) of AD over the past decade was reviewed. Medical records of patients treated for AD over the interval January 1, 1990, to December 31, 1999, were reviewed. Patients with branch compromise confirmed with radiography or operation and patients with spinal cord ischemia that was based on results of a physical examination defined the study group. Comparisons between subgroups with and without PVC over a 30-year interval were analyzed with the chi(2) test. A total of 187 patients (101 proximal and 86 distal) were treated for AD over the study interval. A total of 53 (28%) of these patients had clinical evidence of organ or limb malperfusion (7 cerebral, 3 upper extremity, 5 spinal cord, 11 mesenteric, 12 renal, and 24 lower extremity [sites inclusive]), and one of three (17 patients) of these underwent specific peripheral vascular intervention. The remaining 65% (36) of the PVC group had complete or partial malperfusion resolution after central aortic therapy (medical or surgical) alone. Open techniques for treating PVC included aortic fenestration (9), femorofemoral grafting (2), and aortofemoral grafting (1). All had favorable outcomes with no mortality. Endovascular procedures in five patients included abdominal aortic fenestration (3) or stenting of the renal (2), mesenteric (2), and iliac (1) arteries with clinical success in three patients and two deaths. The in-hospital mortality rate for the entire group of 187 patients was 18% (15% for proximal aortic operation, 8% in medically treated patients). The presence of aortic branch compromise was not a statistically significant predictor of the patient mortality rate (23% with and 16% without; P =.26). Overall mortality rate in the current study (18% vs 37%; P =.000006) and the mortality rate with PVC (23% vs 51%; P =.001), in particular with mesenteric ischemia (36% vs 87%; P =.026), decreased significantly when compared with prior experience. The overall mortality rate from AD during the past decade has decreased significantly. Similar trends were noted in patients with PVCs, a previously identified high-risk subgroup. Increased awareness and prompt, specific management of PVCs, in particular when visceral ischemia is present, have contributed to improved outcomes in patients with AD.

Aortic fenestration is rarely required for patients with acute or chronic aortic dissection. To better define its role and the indications for its use and to evaluate its success at relieving organ or limb malperfusion, we reviewed our experience with direct fenestration of the aorta. A retrospective analysis of all consecutive aortic fenestrations performed between January 1, 1979, and December 31, 1999, was performed. Fourteen patients, 12 men and two women (mean age, 59.6 years; range, 43-81), underwent fenestration of the aorta. All patients were hypertensive and had a history of tobacco use. By Stanford classification, there were three type A and 11 type B patients. In the acute dissection group (n = 7), indications for surgery were malperfusion in six patients (leg ischemia, 4; renal ischemia, 5; bowel ischemia, 3) and intra-abdominal bleeding from rupture in two. In the chronic dissection group (n = 7), indications for surgery were abdominal aortic aneurysm in 4 patients (infrarenal, 3; pararenal, 1), thoracoabdominal aneurysm in 1, hypertension from coarctation of the thoracic aorta in 1, and aortic occlusion with disabling claudication in 1. Emergency aortic fenestration was performed in seven patients (surgically for 6 and percutaneously for 1). Fenestration level was infrarenal in four and pararenal in three. Concomitant abdominal aortic graft replacement was performed in four patients, combined with ascending aortic replacement (n = 1) and bilateral aortorenal bypasses (n = 1). In two patients, acute fenestration was performed for organ malperfusion after prior proximal aortic replacement (ascending aorta, 1; descending thoracic aorta, 1). Seven elective aortic fenestrations were performed for chronic dissection (descending thoracic aorta, 2; paravisceral aorta, 2; infrarenal aorta, 2 and pararenal aorta, 1). Concomitant aortic replacement was performed in six patients (abdominal aorta, 5; thoracoabdominal aorta, 1). Fenestration was successful at restoring flow in all 10 patients with malperfusion. Operative mortality for emergency fenestration was 43% (3/7). The three deaths that occurred were of patients with anuria or bowel ischemia, or both. There were no postoperative deaths for elective fenestration. At a mean follow-up of 5.1 years, there were no recurrences of malperfusion and no false aneurysm formations at the fenestration site. Fenestration of the aorta can effectively relieve organ or limb ischemia. Bowel ischemia and anuria are indicators of dismal prognosis and emergency fenestration in these patients carries a high mortality. Elective fenestration combined with aortic replacement can be performed safely in chronic dissection. Aortic fenestration is indicated for carefully selected patients with malperfusion and offers durable benefits.