Extensive endovascular repair of thoracic aorta: observational analysis of the results and effects on spinal cord perfusion

Aim : The study aims to analyze retrospective results of extensive endovascular repair of the descending thoracic aorta with special attention to spinal cord malperfusion. Methods : From April 2002 through November 2011, 21 patients underwent stent-graft coverage of the thoracic aorta from the aortic arch at the origin of the left subclavian artery to the celiac trunk, 6 (mean age = 72.3 ± 8.1) for aneurysm disease, 13 ( mean age = 74.3 ± 8.4) for type B aortic dissection and 2 ( mean age = 52.1± 6.5) for aortic rupture. The mean of aortic diameter in cases with aneurysm disease was 7.1 ± 1.6 centimeters and the causes of aortic rupture were post-traumatic and aneurysm pathology respectively. In all cases needing coverage of the left subclavian artery duplex ultrasonography and flowmetry were performed to evaluate patency and flow of both the vertebral arteries. Results : Technical success was 100% with 0% in – hospital mortality. The left subclavian artery was crossed with the uncovered portion of the stent - graft in 11 cases (52.4%) and the covered segment in the other 10 patients (47.6%) without subclavian revascularization because no pre-operative hemodinamic alterations of vertebral arteries were revealed by duplex ultrasonography. The incidence of paraplegia was 9.5% in 2 patients who had prior abdominal aortic aneurysm repair: the first case with preoperative type B aortic dissection presented significant lower extremity paresis within 24 hours after the procedure and in the second patient with a large thoracic aneurysm the signs of paraplegia were evident 3 weeks after discharge from Hospital probably due to delayed occlusion of a major medullary artery. The cumulative survival rate after 1, 3 and 9 years was 91%, 81%, and 71% . Conclusions : The coverage of the entire thoracic aorta is an effective procedure with high probability of success. Spinal cord malperfusion remains a serious complication especially in patients with prior aortic surgery but if collateral blood supply is maintained the occlusion of intercostal arteries do not determine paraplegia or paraparesis. In order to consider acute or chronic occlusion of subclavian, lumbar or hypogastric arteries so preventing spinal cord ischemia, strong preoperative evaluation including analysis of previous surgery for abdominal aortic aneurysm repair and avoidance of T12 aortic segment coverage if feasible is mandatory