Iliac Vein Stenting for Chronic Proximal Venous Outflow Obstruction in a Predominantly Asian-American Cohort

Background: We investigated the outcome of vein stenting placement for chronic proximal venous outflow obstruction (PVOO) in a predominantly Asian-American cohort to improve patient selection, enhance technical approach, and better define quality measurements of this emerging vascular intervention. Methods: A total of 462 consecutive patients, 73% Asian American (n = 336), who underwent iliac vein stenting for chronic PVOO from October 2013 to July 2016 were reviewed. Postoperative outcomes at five follow-up visits were assessed. Wilcoxon–Mann–Whitney and Kruskal–Wallis tests were run for demographic and operative variables. Ordered logistic regressions were run for the outcome at each time point, and Chi-squared tests as well as Fisher's exact tests were used for categorical variables. Results: Follow-up was maintained in 90% of patients, with a mean follow-up time of 695 days. Asian-American patients were more likely to present with varicose veins (77.4% vs. 54.8%, P < 0.001), and non-Asian patients were more likely to present with active ulceration (26.2% vs. 5.1%, P < 0.001). Asian-American patients were more likely to have bilateral stents placed (61.6% vs. 50%, P = 0.026) and were less likely to have reinterventions (11.3% vs. 27.8%, P < 0.001), a history of deep vein thrombosis (8.3% vs. 29.4%, P < 0.001), or intraoperative findings of chronic postphlebitic changes (17.6% vs. 33.3%, P < 0.001). Kruskal–Wallis tests were significant for improvement in patients of all the Clinical, Etiology, Anatomy, Pathophysiology classes at 30 days (P = 0.041), 90 days (P = 0.045), 6 months (P = 0.041), and 1 year (P < 0.01). The Asian-American population had improved but comparatively lower follow-up scores at the 30-day mark (48% significantly improved or better vs. 63%, P = 0.008) but higher follow-up scores at the >1 year mark (80% significantly improved or better vs. 59%, P < 0.001). Conclusions: Asian-American patients undergoing vein stent placement for chronic PVOO had comparatively worse outcomes than non-Asian patients at 30 days and better outcomes after one year. These patient groups had different outcomes postoperatively and outcomes which evolve differently over time.