b'Scientific Session Abstracts SUNDAY APRIL 21, 2024 35: TRANSCAROTID ARTERY REVASCULARIZATION OUTPERFORMS TRANSFEMORAL CAROTID ARTERY STENTING ACROSS AORTIC ARCH TYPES AND DEGREES OF ATHEROSCLEROSISMohammed Hamouda, MD, Shaima Alqrain, MD, Sina Zarrintan, MD,Kevin Yei, MD, Andrew Barleben MD, MPH,Mahmoud B. Malas MD, MHS, RPVI, FACSUniversity of California San Diego, Division of Vascular and Endovascular SurgeryBackground: Transfemoral Carotid Artery Stenting (TFCAS) was currently approved for reimbursement by the Centers for Medicare and Medicaid Services (CMS) for treatment of standard risk patients. TFCAS in patients with complex aortic arch anatomy is known to be challenging with worse outcomes, and Transcarotid Artery Revascularization (TCAR) could be a preferable alternative in patients with complex arch anatomy. We aim to compare outcomes of TCAR versus TFCAS across all aortic arch types and degrees of arch atherosclerosis. Method: All patients undergoing carotid artery stenting between September 2016 and October 2023 were identified in the VQ) database. Patients were stratified into four groups: Group-A (Mild Atherosclerosis and Type I/II Arch), Group-B (Mild Atherosclerosis and Type III Arch), Group-C (Moderate/Severe Atherosclerosis and Type I/II Arch), Group-D (Moderate/SevereAtherosclerosis and Type III Arch). The primary outcome was in-hospital composite stroke or death. ANOVA and 2 tests analyzed differences for baseline characteristics. Logistic regression models were adjusted for potential confounders, and backward stepwise selection was implemented to identify significant variables for inclusion in the final models. Results: A total of 20,114 patients were included [Group-A:12,980 (64.53%); Group-B: 1,175 (5.84%); Group-C: 5,124 (25.47%); Group-D: 835 (4.15%)] (Table I). TCAR was more commonly performed across the four groups (72.21%, 67.06%, 74.94% 69.22%; p0.001). Compared to patients with mild arch atherosclerosis, patients with advanced arch atherosclerosis in Group-C and Group-D were more likely to be female, hypertensive, smokers, and have CKD. Patients with Type-III arch in Group-B and Group-D were more likely to present with stroke preoperatively. On multivariable analysis, TCAR had less than half the risk of stroke/death and one-year mortality compared to TFCAS in the patients with the mildest atherosclerosis and simple arch anatomy (group A) (OR=0.43,95%CI:0.31-0.61,p0.001; HR=0.42,95%CI:0.32-0.57,p0.001) (Table II). Group-B patients with similar atherosclerosis but more complex arch anatomy had 70% lower odds of stroke/death with TCAR compared to TFCAS (OR=0.30,95%CI:0.12-0.75,p=0.01). Similar findings were also evident in patients with more severe atherosclerosis and simple arch anatomy (OR=0.66,95%CI:0.44-0.97,p=0.037). Patients with advanced arch atherosclerosis and complex arch (Group-D) showed the same outcome, but it was not statistically significant (OR=0.91,95%CI:0.39-2.16,p=0.834).88SOUTHERN CALIFORNIA VASCULAR SURGICAL SOCIETY'