Purpose: Previous studies have reported that 3% to 8% of patients who have had resection of an infrarenal abdominal aortic aneurysm will subsequently have development of a new aortic aneurysm proximal to the repair. The actual incidence, pathogenesis, and natural history of these aneurysms are unclear. The purpose of this study is to better characterize subsequent proximal aortic aneurysms and to evaluate the outcome of their operative repair.
Method: We retrospectively reviewed our recent experience with surgery for new proximal aortic aneurysms in 123 patients who had had a prior abdominal aortic aneurysmectomy. Seventy-two patients (58.5%) were admitted with chest or abdominal pain, six (4.9%) were admitted with ruptured aneurysms, and 41 (33.3%) were symptom free. Most subsequent aneurysms involved the thoracoabdominal aorta (n = 94; 76.4%); others involved the juxtarenal abdominal aorta, descending thoracic aorta, or transverse aortic arch. The new aneurysm was in continuity with the existing prosthetic graft in 101 cases (82.1%). Resection and graft replacement of the aneurysmal segment was performed on an emergency basis in patients with evidence of impending rupture and electively when aneurysmal diameter exceeded 5.5 cm. The average time interval between the two operations was 8.2 +/- 5.4 years. Mean aortic clamp and visceral ischemic times were 39.7 +/- 14.7 and 33.5 +/- 12.8 minutes, respectively.
Results: The in-hospital mortality rate was 12.2%. Complications included oliguric kidney failure in 11.4% and paraplegia in 4.1%. These results compare favorably with previous studies.
Conclusion: On the basis of the significant prevalence of subsequent proximal aortic aneurysms and the high mortality rate associated with their rupture, we recommend resection of the entire infrarenal aorta during abdominal aortic aneurysm replacement, followed by long-term surveillance with biannual computed tomography or magnetic resonance imaging scanning of the chest and abdomen. Early diagnosis is facilitated by a high index of suspicion and allows surgical intervention to occur before life-threatening rupture. Both emergency and elective proximal aortic surgery in these patients can be performed with acceptable levels of morbidity and mortality.