Two-Year Patency and Reintervention Patterns of Stent Graft Placement for Arteriovenous Graft Outflow Stenosis From a Prospective Multicenter Study

OBJECTIVE: Stent graft placement is an established treatment for arteriovenous graft venous anastomotic stenosis. However, maintaining secondary patency often requires frequent reinterventions, burdening patients, and health care systems. This study evaluated the 2-year outcomes of stent graft placement, focusing specifically on the frequency and anatomical distribution of subsequent reinterventions. METHODS: This 2-year analysis of a prospective, multicenter postmarket surveillance study in Japan involved 103 patients (105 lesions) treated with the GORE VIABAHN Endoprosthesis with Heparin Bioactive Surface for arteriovenous graft venous anastomotic stenosis or thrombosis. Primary endpoints were target-lesion primary patency (TLPP) and access circuit primary patency (ACPP). Reintervention topology across 5 anatomical zones was analyzed. RESULTS: At 2 years, TLPP was 30.5% (95% confidence interval [CI]: 21.0, 40.5), whereas ACPP was lower at 12.4% (95% CI: 6.4, 20.7). Secondary patency was 83.5% (95% CI: 73.6, 90.0) for both measures. A total of 242 reinterventions were performed, with a mean cumulative number of 1.76 per patient at 2 years. Topological analysis revealed that the intra-arteriovenous graft segment was the most frequent site of failure (134 events), followed by stent graft outflow (66 events). Failure at the intra-stent graft was rare (2 events). The median time to first reintervention was shortest for intra-arteriovenous graft lesions (205 days). CONCLUSIONS: Stent graft placement provided durable patency at the target venous anastomosis. However, the primary site of access failure shifted to the intra-arteriovenous graft segment, driving high reintervention rates. These findings highlight the need for therapeutic strategies targeting the graft body to reduce the overall intervention burden.Clinical ImpactThis prospective multicenter study maps, over two years, where reinterventions actually occur after stent graft placement for arteriovenous graft outflow stenosis. Although the treated venous anastomosis remained durable, access circuit primary patency fell to 12.4%, because failure migrated to the graft body, which accounted for 134 reinterventions at a median of 205 days. This reframes success for clinicians: treating the target lesion does not preserve the circuit. Surveillance after stent grafting should anticipate early intra-graft restenosis, and efforts to reduce the intervention burden-cannulation strategy, graft materials, adjunctive devices-should target the graft body rather than the anastomosis.