Comparative Retrospective Cohort Study of Carotid-Subclavian Bypass versus In Situ Fenestration for Left Subclavian Artery Revascularization during Zone 2 Thoracic Endovascular Aortic Repair: A Single-Center Experience

<b>Background:</b> Thoracic endovascular aortic repair (TEVAR) has become the first-line therapy for descending aortic disease. Recent studies have demonstrated that preventive revascularization of the left subclavian artery (LSA) in zone 2 TEVAR cases reduces the risk of neurological complications. However, there is no uniform consensus on the choice of revascularization techniques. Although carotid-subclavian bypass is considered the gold standard method, in situ fenestration techniques have also shown encouraging results. This study aims to compare the carotid-LSA bypass with in situ fenestration (ISF) for LSA revascularization and to discuss our treatment approach. <b>Methods:</b> We conducted a retrospective review of all patients undergoing zone 2 TEVAR with in situ fenestration (ISF) or carotid-subclavian artery bypasses for LSA revascularization at our institution between February 2011 and February 2024. Preoperative patient characteristics and primary outcomes, such as operative mortality, transient ischemic attack, stroke, and spinal cord ischemia, were analyzed between the groups. <b>Results:</b> During the 13-year study period, 185 patients underwent TEVAR procedures. Of these, 51 patients had LSA revascularization with zone 2 TEVAR; 32 patients underwent carotid-subclavian artery bypasses, and 19 underwent in situ fenestration. The technical success rate was 100%. Statistically, there was no significant difference between the groups in terms of primary outcomes such as stroke, transient ischemic attack, spinal cord ischemia, and death (<i>p</i> > 0.05). <b>Conclusions:</b> In situ fenestration (ISF) may be an effective and feasible method for LSA revascularization. With precise patient selection and in experienced hands, ISF appears to be associated with similar perioperative outcomes and mortality rates to the carotid-subclavian bypass.