Commentary: Left subclavian artery revascularization during zone 2 thoracic endovascular aortic repair: Bypass versus transposition? Just do it!

The Society of Thoracic Surgeons/American Association for Thoracic Surgery clinical practice guidelines on the management of type B aortic dissection

“…165 Importantly, the LSA represents the primary source of collateral pathways to the AKA outside of the spinal column through the thoracodorsal and internal thoracic arteries, which provides basis for adjunctive LSA revascularization during TEVAR. 166 Other important collateral sources include segmental arteries distal to the segmental artery feeding the AKA, the hypogastric arteries, and the left external iliac artery (Figure 6). 10,167…”

Current state of hybrid solutions for aortic arch aneurysms

“…In certain cases, the left subclavian artery (LSA) may not be readily accessible via a sternotomy approach due to distal takeoff from the arch, in which case type I HAR may involve only debranching of the innominate and left common carotid arteries from the ascending aorta, with the LSA revascularized via a carotid-subclavian bypass (8) (Figure 2) or transposition (9), carotid-axillary bypass (10), or alternatively via a transthoracic aorta to infraclavicular axillary artery bypass (Figure 3, left panel).…”

Permissive Hypertension and Collateral Revascularization May Allow Avoidance of Cerebrospinal Fluid Drainage in Thoracic Endovascular Aortic Repair

“…With regards to the 2 main components of our institutional algorithm, preservation of antegrade LSA flow is of vital importance for several anatomic reasons, including that the anterior spinal artery supplying the anterior two-thirds of the spinal cord is formed from the vertebral artery branches of the subclavian arteries, as well as the fact that the LSA represents the primary source of collateral pathways to the great anterior radicular artery (artery of Adamkiewicz) outside of the spinal column through the thoracodorsal artery and internal thoracic artery. 8 To this point, case reports document spinal cord rescue after zone 2 TEVAR by urgent LSA revascularization when CSFD has failed. 24,25 As for the permissive hypertension component, a recent report by Sandhu and colleagues, 7 from the University of Texas Houston group, of 1059 patients undergoing open descending or TAAA repair during an 11-year period found the mean SBP and MAP at the time of onset of delayed SCI were 107 mm Hg and 68 mm Hg, respectively.…”

“…7 SCI risk after TEVAR is primarily due to decreased SCPP due to systemic hypotension or reduced local perfusion through occlusion of the great anterior radicular artery (artery of Adamkiewicz) as well as important collateral blood supplies via the left subclavian artery (LSA). 8 Historically, cerebrospinal fluid drainage (CSFD) has been used to decrease the intraspinal canal pressure, thereby increasing SCPP. CSFD use in TEVAR was justified primarily using data from open aortic surgery, in which blood pressure lability is more frequent and extreme.…”

“…13 This updated algorithm (Figure 1) recognizes the importance of the LSA to spinal cord blood flow and mandates LSA revascularization in all patients with complete LSA coverage with no preservation of antegrade pulsatile flow. 8 In addition, the updated algorithm uses permissive hypertension in the first month after the operation, with preoperative antihypertensive medications only resumed for persistent SBP exceeding 150 mm Hg. The current report evaluates results with this updated algorithm in a contemporary cohort of patients undergoing isolated descending þ/Àarch TEVAR.…”