Undersized Versus Conventional Covered Stent Sizing for Hemodialysis Access-Related Central Venous Occlusive Disease: A Retrospective Cohort Study.

Background: This study aimed to compare access and target lesion patency rates between undersized and apposed/oversized lateral-edge covered stents in patients with hemodialysis access-related central venous occlusive disease (CVOD). Methods: A retrospective analysis of 76 hemodialysis patients undergoing endovascular treatment for CVOD was conducted. All of the patients received undersized covered stents at the medial edge. Based on lateral-edge sizing, the patients were divided into undersized (n = 14) and apposed/oversized (n = 62) groups. Patency outcomes were compared using the log-rank test, and multivariable analysis was used to identify risk factors associated with the primary outcome. Results: The 12-month access primary patency rate was significantly higher in the undersized group than in the apposed/oversized group (76.4% vs. 25.9%, p = 0.047). The 12-month target lesion primary patency rate was also higher in the undersized group; however, the difference was not statistically significant (76.4% vs. 52.1%, p = 0.186). Factors associated with the primary outcome included older age (odds ratio [OR] = 1.03, p = 0.011), coronary artery disease (OR = 2.03, p = 0.041), stenting to central veins for access thrombosis (OR = 3.53, p = 0.001), more stents (OR = 3.11, p = 0.002), apposed/oversized lateral stent edge (OR = 2.73, p = 0.044), and higher stent-to-vessel ratio (OR = 1.19, p = 0.022). Conclusions: The 12-month primary patency rate was better in the undersized group than in the apposed/oversized group. Endovascular treatment with undersized covered stents may be a feasible approach for hemodialysis access-related CVOD. Larger randomized studies are required to confirm these findings.