Prior infrarenal aortic surgery is not associated with increased risk of spinal cord ischemia after thoracic endovascular aortic repair and complex endovascular aortic repair.

Objective: Patients with prior infrarenal aortic intervention represent an increasing demographic of patients undergoing thoracic endovascular aortic repair (TEVAR) and/or complex EVAR. Studies have suggested that prior abdominal aortic surgery is a risk factor for spinal cord ischemia (SCI). However, these results were largely based on single-center experiences with limited multi-institutional and national data that had assessed the clinical outcomes for these patients. The objective of the present study was to evaluate the effect of prior infrarenal aortic surgery on the occurrence of SCI.

Methods: The Society for Vascular Surgery Vascular Quality Initiative database was retrospectively reviewed to identify all patients aged ≥18 years who had undergone TEVAR and/or complex EVAR from January 2012 to June 2020. Patients with previous thoracic or suprarenal aortic repair were excluded. The baseline and procedural characteristics and postoperative outcomes were compared between TEVAR and/or complex EVAR with and without previous infrarenal aortic repair. The primary outcome was postoperative SCI. The secondary outcomes included postoperative hospital length of stay, bowel ischemia, renal ischemia, and 30-day mortality. Multivariate regression was used to determine the independent predictors of postoperative SCI. Additional analysis was performed of the patients who had undergone isolated TEVAR.

Results: A total of 9506 patients met the inclusion criteria: 8691 (91.4%) had not undergone prior infrarenal aortic repair and 815 (8.6%) had undergone previous infrarenal aortic repair. Patients with previous infrarenal repair were older with an increased prevalence of chronic kidney disease (P = .001) and cardiovascular risk factors, including hypertension, chronic obstructive pulmonary disease, and positive smoking history (P < .001). These patients also presented with a larger maximal aortic diameter (6.06 ± 1.47 cm vs 5.15 ± 1.76 cm; P < .001) and required more stent-grafts (P < .001) with increased intraoperative blood transfusion requirements (P < .001), and longer procedure times (P < .001). Univariate analysis demonstrated no differences in postoperative SCI, postoperative hospital length of stay, bowel ischemia, or renal ischemia between the two groups. The 30-day mortality was significantly higher in patients with prior infrarenal repair (P = .001). On multivariate regression, prior infrarenal aortic repair was not a predictor of postoperative SCI. In contrast, aortic dissection (odds ratio [OR], 1.65; 95% confidence interval [CI], 1.26-2.16; P < .001), number of stent-grafts deployed (OR, 1.45; 95% CI, 1.30-1.62; P < .001), and units of packed red blood cells transfused intraoperatively (OR, 1.33; 95% CI, 1.03-1.73; P = .032) were independent predictors of postoperative SCI.

Conclusions: Although the patients in the TEVAR and/or complex EVAR group with prior infrarenal aortic repair constituted a sicker cohort with higher 30-day mortality, the rate of SCI was comparable to that of the patients without prior repair. Previous infrarenal repair was not associated with the risk of SCI.