Narrative review on endovascular techniques for left subclavian artery revascularization during thoracic endovascular aortic repair and risk factors for postoperative stroke

Abstract

OBJECTIVES The aim of this study was to present a narrative review on endovascular techniques (ET) for revascularization of the left subclavian artery (LSA) during zone 2 thoracic endovascular aortic repair (TEVAR) and on risk factors for postoperative stroke following TEVAR procedures. METHODS Non-systematic search of the literature from the PubMed, Ovid and Scopus databases to identify relevant English-language articles fully published in the period 1 January 2010–1 August 2020. RESULTS Current general agreement is that LSA revascularization should be always attempted in the elective setting. Under urgent circumstances, it can be delayed but might be considered during the same session on a case-by-case basis. Three ET are currently available: (i) chimney/snorkels (also known as parallel grafts), (ii) fenestrations or branches and (iii) proximal scallops. The main issue with ET is the potential for increased peri-operative stroke risk owing to increased manipulation within the aortic arch. Also, they are relatively novel and further assessment of their long-term durability is needed. Intra-operative embolism and loss of left vertebral artery perfusion are hypothesized as the main causes of stroke in patients undergoing TEVAR. CONCLUSIONS The overall risk of stroke seems higher without LSA revascularization during zone 2 TEVAR. As LSA revascularization might have a direct effect in preventing posterior stroke, it should be routinely performed in elective cases, while a case-by-case evaluation can be made under urgent circumstances. While ET can provide effective options for LSA revascularization during zone 2 TEVAR, they are novel and need further durability assessment. Stroke after TEVAR is a multifactorial pathological process and preventing TEVAR-related cerebral injury remains a significant unmet clinical need.

A Single Center Study on the Risks of Peri-Intervention Stroke in Thoracic Endovascular Aortic Repair (TEVAR) and Endovascular Abdominal Aortic Repair (EVAR)

“…The median (IQR) days of ICU admission was 9 days (7, 39) in the PIS patients compared with 0 days (0, 3) in the non-PIS patients (p < 0.001). The median (IQR) days of hospitalization in the PIS patients was 36 days (21, 56) compared with 3 days (3,11) in the non-PIS cases (p < 0.001). For the stroke outcome on discharge, the median (IQR) mRS in the PIS patients was 4 (2, 6).…”

“…Although EVI causes less body tissue injury compared with conventional surgery, its associated vascular complications, particularly strokes, remain a critical concern pending an effective procedure for prevention. Unlike conventional open surgery, in which the variations in the levels of various tissue thrombophilic factors induced by surgical injury during or post-operation are attributed 2 of 11 as a cause of stroke [1,2], a pre-existing atheromatic plaque plus manipulation of the device wire within the vascular lumen can lead to the increased risks of peri-intervention thromboembolism [3]. Dislodgement of an aortic atheroma caused by the intravascular manipulation of the device while performing an aortic EVI, e.g., thoracic endovascular aortic repair (TEVAR) or endovascular abdominal aortic repair (EVAR), can result in an aorto-cerebral embolism, a common etiology of peri-intervention stroke (PIS) [4][5][6].…”

Use of retrograde left subclavian branch portal of Gore TAG thoracic branch endoprosthesis for physician-modified fenestrated branched endovascular repair of thoracoabdominal aortic aneurysm

“… 7 The options for LSA revascularization include conventional cervical debranching such as carotid–subclavian bypass, carotid–axillary bypass, or subclavian artery–carotid artery transposition or the use of endovascular techniques such as parallel grafting, in situ fenestration, and custom-made/physician-modified fenestrated, scalloped, or branched stent grafts. 8 , 9 The Gore TAG TBE was developed for endovascular incorporation of aortic arch branch vessels and is the first device to obtain FDA approval for incorporation of the LSA during zone 2 TEVAR with promising initial and midterm results. 3 , 4 …”

Peri-Operative Management of Patients Undergoing Fenestrated-Branched Endovascular Repair for Juxtarenal, Pararenal and Thoracoabdominal Aortic Aneurysms: Preventing, Recognizing and Treating Complications to Improve Clinical Outcomes

“…Although carotid-subclavian bypass or transposition currently remains the gold standard to revascularize the LSA, newer endovascular alternatives (such as the use of fenestrated or branched endografts for the LSA) have been described recently. Their use is novel, and their actual durability still remains to be assessed [ 75 , 76 , 77 , 78 , 79 , 80 ].…”