Hybrid approach to thoracoabdominal aortic aneurysms in patients with prior aortic surgery

Objective: The hybrid approach to the repair of thoracoabdominal aortic aneurysm (TAAA), consisting of visceral aortic debranching with retrograde revascularization of the splanchnic and renal arteries and aneurysm exclusion using stent grafts, has been previously described and may be considered particularly appealing in high-risk patients, especially those who have undergone prior aortic surgery. This study analyzed prospectively recorded data of a series of high-risk patients with prior aortic surgery who underwent hybrid TAAA repair at our institute and contrasted the outcomes with those of a similar group of patients who underwent conventional open TAAA repair. Methods: Between 2001 and 2006, 13 patients (12 men) with a median age of 69.6 years (range, 35 to 82 years) underwent one-stage hybrid repair of TAAA (7 type I, 2 type II, 2 type IV, and 2 aneurysms of the visceral aortic patch). These patients, the hybrid group, had a history of aortic surgery (30.7% ascending, 30.7% descending, 46.1% abdominal aortic repair, and 15.4% redo TAAA) and were at high risk for open repair. The criteria used to define these patients as high risk and to indicate the need for hybrid treatment were American Society of Anesthesiologists (ASA) class 3 or 4 associated with a preoperative forced expiratory volume in 1 second (FEV1) <50%. In all cases, we accomplished partial or total visceral aortic debranching through (1) a previous visceral artery retrograde revascularization with synthetic grafts (single bypass, customized Y or bifurcated grafts), and (2) aortic endovascular repair with one of three different commercially produced stent grafts (Cook, W.L. Gore & Assoc, and Medtronic). We analyzed the results and compared the outcomes of the hybrid group with those of a similar group of 29 patients (25 men) with a median age 65.3 years (range, 58 to 79) selected from our overall series of 246 TAAA repairs between 1988 and 2005. These 29 patients, the conventionally treated group, were selected for having had aortic surgery (22% ascending, 38% descending, 42% abdominal aortic repair, and 10.3% redo TAAA), an ASA 3 or 4, a preoperative FEV1 <50%, and a conventional open repair of TAAA (10 type I, 5 type II, 4 type III, 7 type IV, and 3 aneurysms of the visceral aortic patch). Results: In the hybrid group, 32 visceral bypasses were completed and endovascular TAAA repair was successful in all cases. No intraoperative deaths occurred. Perioperative mortality was 23%, and morbidity was 30.8% (renal failure in 2, respiratory failure in 1, and delayed transient paraplegia in 1). At a median follow-up of 14.9 months (range, 11 days to 59.4 months), all grafts were patent at postoperative computed tomography angiography and no aneurysm-related deaths, endoleak, stent graft migration, or morbidity related to visceral revascularization had occurred. No conventionally treated patients died intraoperatively. Perioperative mortality was 17.2% and morbidity was 44.8% (respiratory failure in 7, coagulopathy in 1, renal failure in 2, and paraplegia in 3). At a median follow-up of 5.4 years (range, 1.7 to 7.9 years), no significant complications related to aortic repair occurred, except for three patients (10.3%) with asymptomatic dilatation of the visceral aortic patch <5 cm undergoing radiologic surveillance. Conclusion: Hybrid TAAA repair is technically feasible in selected cases. Perioperative morbidity and mortality were considerable in our subset of high-risk patients with prior aortic surgery, but no aneurysm-related or procedure-related complications were reported at mid-term follow-up. Hybrid TAAA repair did not lead to a significant improvement in outcomes compared with open TAAA repair in a similar group of patients. Larger series are required for valid statistical comparisons and longer follow-ups are necessary to evaluate the durability of hybrid repairs.