Comparative study of left vertebral artery revascularization in patients with and without aberrant left vertebral anatomy.

Objective: Left vertebral artery revascularization is indicated in surgery involving zone 2 of the aortic arch and is typically accomplished indirectly via subclavian artery revascularization. For aberrant left vertebral anatomy, direct revascularization is indicated. Our objective was to compare the outcomes of direct vertebral artery revascularization with indirect subclavian artery revascularization for treating aortic arch pathology and to identify predictors of mortality.

Methods: A retrospective cohort study was conducted at a single tertiary hospital, including patients who underwent open or endovascular vertebral artery revascularization from 2005 to 2022. Those who underwent direct vertebral revascularization were compared with those who were indirectly revascularized via subclavian artery revascularization. The outcomes of interest were a composite outcome (any of death, stroke, nerve injury, and thrombosis) and mortality. Univariate logistic regression models were fitted to quantify the strength of differences between the direct and indirect revascularization cohorts. Cox regression was used to identify mortality predictors.

Results: Of 143 patients who underwent vertebral artery revascularization, 21 (14.7%) had a vertebral artery originating from the aortic arch. The median length of stay was 10 days (interquartile range, 6-20 days), and demographics were similar between cohorts. The incidence of composite outcome, bypass thrombosis, and hoarseness was significantly higher in the direct group (42.9% vs 18.0%, P = .019; 33.3% vs 0.8%, P < .0001; 57.1% vs 18.0%, P < .001, respectively). The direct group was approximately three times more likely to experience the composite outcome (odds ratio, 3.41; 95% confidence interval, 1.28, 9.08); similarly, this group was approximately six times more likely to have hoarseness (odds ratio, 5.88; 95% confidence interval, 2.21, 15.62). There was no significant difference in mortality rates at 30 days, 1, 3, 5, and 10 years of follow-up. Age, length of hospital stay, and congestive heart failure were identified as predictors of higher mortality. After adjusting for these covariates, the group itself was not an independent predictor of mortality.

Conclusions: Direct vertebral revascularization was associated with higher rates of composite outcome (death, stroke, nerve injury, and thrombosis), bypass thrombosis and hoarseness. Patients with aberrant vertebral anatomy are at higher risks of these complications compared with patients with standard arch anatomy. However, after adjusting for other factors, mortality rates were not significantly different between the groups.