Left Subclavian Artery Revascularization for Thoracic Aortic Stentgrafting: Single Center Experience in 101 Patients

Abstract

Introduction - Endovascular treatment of thoracic aortic pathology (TEVAR) requires a landing zone of at least 20mm in length, necessitating coverage of the left subclavian artery (LSA) in approximately 40% of the patients.1 Coverage of the LSA may increase the risk of ischaemic stroke, spinal cord ischaemia (SCI) and/or left arm claudication. Besides some endovascular options to preserve LSA flow, in the majority of cases the LSA is surgically revascularized by either a carotid-to-subclavian bypass graft or subclavian-carotid transposition. A relatively safe option, which has been shown to decrease the risk of stroke compared to LSA coverage without revascularization.2,3 Conflicting data and opinions exist in literature on the (additional) risk of surgical LSA revascularization (requiring temporary occlusion of the left common carotid artery (LCCA) for the anastomosis).4,5,6 In this study, we retrospectively analysed the indications, as well as the operative results of LSA revascularization in 97 patients, in our single centre TEVAR experience. Methods - Between 2000 and 2017, a total of 101 consecutive patients underwent surgical revascularization of the LSA prior to, concomitant, or following TEVAR. Data were retrospective collected. Revascularization was performed through a small supraclavicular incision and consisted of a transposition or bypass graft, using perioperative transcranial Doppler. Data regarding the indication for LSA revascularization, procedural details and early and late postoperative results were analysed. Results - A total of 64 carotid-subclavian bypass grafts and 33 subclavian-carotid transpositions were performed in the context of TEVAR. The majority was performed prior to stentgrafting, indicated to reduce the risk of stroke (n=58, incomplete Willis’ circle, dominant left vertebral artery (LVA) and/or exclusion of an arteria lusoria), to reduce the risk of SCI (n=18, in case of previous aortic repair, and/or stenting the entire descending aorta) or to reduce the risk of left arm malperfusion (n=8, small or absent LVA or LVA originating from the aortic arch). In two patients there was a patent left internal mammary artery to coronary artery bypass graft. In fourteen patients LSA revascularization was performed secondary to the stentgraft procedure, either immediately due to acute left arm malperfusion (n=2) or during follow-up due to invalidating left arm claudication (n=12). There was no in-hospital mortality, two ischaemic strokes (2%) were noted and one patient experienced permanent SCI (1%). Both strokes were considered to be related to the stentgraft procedure rather than the preceding LSA bypass. Additional complications observed were sympathetic chain nerve palsy (Horner’s syndrome) (n=6), phrenic nerve palsy (n=5), recurrent nerve palsy (n=4), chyle leakage requiring diet or re-exploration (n=6). In one patient, the LSA bypass occluded during follow-up requiring a redo surgical bypass. Conclusion - Selective surgical revascularization of the left subclavian artery in case of LSA coverage in TEVAR may be indicated to lower the risk of stroke, spinal cord ischaemia, and left arm malperfusion. The procedure can be performed safely when using perioperative monitoring and result in a low risk of stroke and peripheral nerve injury. References1)Kotelis D, Geisbüsch P, Hinz U, Hyhlik-Dürr A, von Tengg-Kobligk H, Allenberg JR, Böckler D. Short and midterm results after left subclavian artery coverage during endovascular repair of the thoracic aorta. J Vasc Surg. 2009 Dec;50(6):1285-1292.2)Patterson BO, Holt PJ, Nienaber C, Fairman RM, Heijmen RH, Thompson MM. Management of the left subclavian artery and neurologic complications after thoracic endovascular aortic repair. J Vasc Surg 2014;60:1491-1497.3)Saouti N, Hindori V, Morshuis WJ, et al. Left subclavian artery revascularization as part of thoracic stent grafting. Eur J Cardiothorac Surg. 2015 Jan;47(1):120-125; discussion 125.4)Maldonado TS, Dexter D, Rockman CB, Veith FJ, Garg K, Arko F, Bertoni H, Ellozy S, Jordan W, Woo E. Left subclavian artery coverage during thoracic endovascular aortic aneurysm repair does not mandate revascularization. J Vasc Surg. 2013 Jan;57(1):116-124.5)Cooper DG, Walsh SR, Sadat U, Noorani A, Hayes PD, Boyle JR. Neurological complications after left subclavian artery coverage during thoracic endovascular aortic repair: a systematic review and meta-analysis. J Vasc Surg. 2009 Jun;49(6):1594-1601.6)Contrella BN, Sabri SS, Tracci MC, Stone JR, Kern JA, Upchurch GR, Matsumoto AH, Angle JF. Outcomes of Coverage of the Left Subclavian Artery during Endovascular Repair of the Thoracic Aorta. J Vasc Interv Radiol. 2015 Nov;26(11):1609-1614.