1-Year Follow-Up Study of Preemptive TEVAR for Residually Dissected Aortas after Proximal Open Repair of Acute Type A Aortic Dissection in High-Risk Patients for Late Re-Intervention

Abstract

Introduction - Disease progression often occurs in residually dissected aorta after proximal open repair of acute type A aortic dissection (ATAD), requiring distal reoperations, with high mortality and morbidity(1). Unlike type B dissection, the efficacy of preemptive thoracic endovascular aneurysm repair (TEVAR) on the residual disease remains to be seen. We hypothesized that patients who were likely to develop late aneurysmal dilatation of false lumen would benefit from this preemptive approach. Methods - Initially, to analyze risk factors for late aortic events, 108 patients who survived proximal repair for ATAD from 2001 to 2010 were reviewed. During mean follow-up of 40 months, 12 patients required 14 distal re-interventions. On statistic analysis, we identified age < 60 years (p<0.01), aortic diameter > 46mm (p<0.01), and patent false lumen (p<0.05) as factors that predisposed patients who underwent the proximal repair to require late re-interventions. In 2015, we began performing preemptive TEVARs. From April 2015 to January 2016, 11 patients (mean age, 56 years; 72% men) who met the criterion of the aforementioned 3 risk factors underwent preemptive TEVARs. Devices used consisted of a proximal covered stent graft and a distal bare metal stent (Zenith Dissection Endovascular system). Simultaneously, subclavian revascularization was performed in 4 patients and 2 debranching in 2 patients. The interval between proximal repair and TEVAR averaged 122 days (range, 50-297). All patients received 12-month surveillance, including computed tomography (CT). Results - Successful graft deployment and coverage of the primary entry tear was achieved in all patients with no early deaths or intraprocedural conversions. One patient required coil occlusion of the left subclavian artery 5 days post-procedure for retrograde perfusion of the false lumen. No other serious adverse events occurred within 12 months. Survival was 100% at 1 year. Surveillance CT data showed the false lumen was completely (n=8) or partially (n=3) thrombosed in the thoracic aorta at the 12-month visit. Of the 7 patients who underwent the preemptive TEVAR within 3 months, all had complete false lumen thrombosis at the thoracic level. Six of the 7 patients experienced complete shrinkage of false lumen of the thoracic aorta. From pre-treatment to the 12-month visit, the average true lumen area increased by 203 mm2 (p<0.01), and the average false lumen decreased by 276mm2 (p<0.05), at the level of the maximum aortic diameter. Conclusion - TEVAR for residually dissected aortas after proximal open repair of acute type A aortic dissection can be done with a high rate of thoracic aortic remodeling in high-risk patients for late re-intervention. Especially, results of TEVAR within 3 months after open repair are promising. The encouraging results will stimulate further research to define the utility of the preemptive TEVAR. References(1)Geirsson A, Bavaria JE, Swarr D, Keane MG, Woo YJ, Szeto WY, Pochettino A. Fate of the residual distal and proximal aorta after acute type A dissection repair using a contemporary surgical reconstruction algorithm. Ann Thorac Surg 2007:84;1955-64.