IP269 - Comparison of Oral Anticoagulants After Operative Management of Venous Thoracic Outlet Syndrome (vTOS)

Objectives: The purpose of the study is to review the efficacy of Target Specific Oral Anticoagulants (TSOAC) versus vitamin-K antagonist (VKA) for post-surgical anticoagulation in patients with primary subclavian vein thrombosis. Rivaroxaban and Apixaban are newer TSOAC used in DVT treatment and prophylaxis. However, the efficacy and safety of TSOAC for the prevention of recurrent deep vein thrombosis after revascularization of upper extremity compression syndromes is largely unknown.

Methods: Forty-four patients who underwent surgical intervention for axillosubclavian vein thrombosis from 2009 to 2021 from a single institution were retrospectively reviewed. Standard protocol with short-term anticoagulation treatment was given after a combination of surgical intervention including catheter-directed lysis, balloon angioplasty, mechanical thrombectomy, and first rib resection. Primary outcomes measured included vessel patency at 6 months evaluated via ultrasound. Secondary outcomes included bleeding complications, anticoagulation time frame, and follow-up intervals. SPSS was used for statistical analysis.

Results: From our cohort, 17 patients (38.6%) were given Warfarin, 15 (34.1%) were given Rivaroxaban and 12 (27.3%) were given Apixaban for postoperative anticoagulation regimen. The average ages in Warfarin, Rivaroxaban and Apixaban were 33 years (range 16-59), 33 years (range 16-55) and 42.3 years (range 26- 68) respectively. 13 (76.5%) were male and 4 (23.5%) were female on Warfarin, 6 (40%) were male and 9 (60%) were female on Rivaroxaban, and 4 (33.3%) were male and 8 (66.7%) were female on Apixaban. At follow-up ultrasound, 15 patients (88.2%) had success in maintaining patency with Warfarin, 14 (93.3%) with Rivaroxaban and 5 (41.7%) with Apixaban. Additionally, 5 (41.7%) of patients’ veins were stenosed and 2 (16.7%) occluded while on Apixaban, 1 (5.9%) was occluded and 1 (5.9%) stenosed on Warfarin, and 1 (6.67%) was occluded on Rivaroxaban. In the Warfarin group, the mean therapeutic period was 125.5 days (range 61-304 days, S.D = 58.6). The mean therapeutic period in Rivaroxaban was 139.2 days (range 2-365 days, S.D = 83 days) and Apixaban was 113.4 days (range 7 – 243 days, S.D = 73.7 days). Post-operative complications of hemothorax were seen in 1 patient in each of the treatment groups. Additionally, 1 case of hematoma was reported in a patient on Apixaban.

Conclusions: Selective usage of a TSOAC in post-operative patients with axillosubclavian vein thrombosis offers an alternative anticoagulation regimen. These findings highlight a notable difference in post-operative patency of axillosubclavian vein thrombosis treated with different oral anticoagulants. Further investigation is needed to determine superiority of anticoagulation regimen.