Left Subclavian Artery Revascularization May Not Influence the Incidence of Spinal Cord Ischemia in Elective Thoracic Endovascular Aortic Aneurysm Repair

Abstract

To analyze whether left subclavian artery (LSA) revascularization in patients undergoing elective thoracic endovascular aortic repair (TEVAR) for thoracic aortic aneurysm (TAA) is associated with decreased spinal cord ischemia (SCI). The national Vascular Quality Initiative TEVAR module was queried for all procedures performed between 2014 and 2021. Patients presenting with acute aortic dissections or aortic ruptures were excluded from the analysis. Only patients undergoing elective TEVAR for TAA and had their LSA covered during the procedure were included. Patients were divided into two groups according to their LSA revascularization (before or during TEVAR). A descriptive analysis was done to evaluate the change in frequency of LSA revascularization over the study interval. Univariate analysis was done to compare preoperative and intraoperative variables, and primary outcomes of SCI and cerebral stroke between the two groups. Among patients who had elective TEVAR for TAA, 669 patients had the LSA covered. The LSA was revascularized in 67% of these patients (n = 446). The incidence of LSA revascularization increased over the study period (Fig 1) (P < .001). Average age was 69 years, and 65% (n = 433) were male. Demographics and past medical history are summarized in Table I. Spinal cord ischemia developed in 20 patients (3%), and cerebral stroke in 29 patients (4%). No significant difference was seen when comparing postoperative SCI, cerebral stroke, 30-day or 1-year mortality between patients who had LSA revascularization and those who did not (Table II). Long-term survival did not differ between the two groups on Kaplan-Meier analysis (Fig 2). In patients with TAA undergoing elective TEVAR with LSA coverage, an increasing percentage of patients underwent preoperative or concomitant LSA revascularization over the course of the study—81% in 2021. In this study, LSA revascularization, however, did not aff5ct the incidence of postoperative SCI, cerebral stroke, or short or long-term mortality. In conclusion, LSA revascularization did not protect against SCI and may carry its own morbidity in elective TAAs requiring LSA coverage. More detailed studies are needed to help define the role of LSA revascularization in this setting.TableComparison of baseline characteristics, comorbidities, intraoperative variables, and postoperative outcomes between patients who had left subclavian artery (LSA) revascularization and those who did notOverall (n = 669)LSA nonrevascularized (n = 223)LSA revascularized (n = 446)P valueBaseline characteristics Age, years, mean (SD)69 (11)70 (11)69 (11).48 Gender, No. (%).69Male433 (65)142 (64)291 (65)Female236 (35)81 (36)155 (35) Race, No. (%).41African American115 (17)39 (18)76 (17)White474 (71)164 (74)310 (70)Others80 (12)20 (9)60 (14) BMI, mean (SD)28.4 (6.7)28.1 (6.8)28.5 (6.7).45 Smoking status, No. (%).94Never171 (26)59 (27)112 (25)Prior343 (51)113 (51)230 (52)Current154 (23)51 (23)103 (23)Medical History CVD, No. (%)81 (12)31 (14)50 (11).31 CAD, No. (%)111 (17)43 (19)68 (15).19 Congestive heart failure, No. (%)93 (14)33 (15)60 (13).63 COPD, No. (%)193 (29)73 (33)120 (27).12 Hypertension, No. (%)608 (91)199 (89)409 (92).22 Diabetes, No. (%)97 (14)38 (17)59 (13).19 Prior aortic surgery, No. (%)279 (42)103 (46)176 (40).10 Prior aneurysm repair, No. (%)226 (34)82 (36)145 (32).50Intraoperative variables Contrast volume, mL, mean (SD)118 (73)115 (72)120 (73).41 EBL, mL, mean (SD)243 (448)228 (399)251.2 (470).01 Fluoro time, minutes, mean (SD)23.2 (20.3)22.6 (23.0)23.5 (18.9).061 Procedure time, minutes, mean (SD)176 (100)158 (111)186 (94)<.01 Spinal drain placement, No. (%).38None343 (51.4%)111 (49.8%)232 (52.3%)Prophylactic311 (46.6%)106 (47.5%)205 (46.2%)Postoperative11 (1.6%)6 (2.7%)5 (1.1%)Outcomes Spinal cord ischemia, No. (%)20 (3)8 (4)12 (3).52 Cerebral stroke, No. (%)29 (4)9 (4)20 (5).79 30-Day mortality, No. (%)26 (4)5 (2)21 (5).12 1-Year mortality, No. (%)65 (10)21 (9)44 (10).85COPD, Chronic obstructive pulmonary disease; CVD, cerebrovascular disease; EBL, estimated blood loss; PCI, percutaneous coronary interventions; SD, standard deviation. Open table in a new tab Fig 2Kaplan-Meier curves comparing long-term survival between patients who underwent left subclavian artery (LSA) revascularization and those who did not.View Large Image Figure ViewerDownload Hi-res image Download (PPT)