In-valve stent graft placement to reduce edge stenosis for recoil venous anastomotic stenosis in arteriovenous graft hemodialysis patients

Purpose: Although stent grafts have demonstrated significant benefits over bare metal stents and conventional venoplasty at maintaining patency of dialysis vascular access, they are far from perfect and are prone to edge stenosis. A new strategy of placing stent graft to reduce the possible occurrence of edge stenosis is therefore proposed in this study. Materials and methods: A retrospective review between 2015 and 2023 identified 21 arteriovenous grafts (AVG) hemodialysis patients who underwent stent graft placement with the medial stent end in an outflow venous valve. The indications for stent graft placement were either due to frequent recoil venous anastomotic stenoses recalcitrant to venoplasty or vascular ruptures after balloon dilation. Stent grafts of 6–7 mm in diameter were deployed crossing the venous anastomosis onto a venous valve. The primary stent-end patency, primary and secondary access patency were calculated with Kaplan-Meier analysis. Results: Technical success was achieved in 100% of the 21 patients. The median primary stent-end patency was 24 months with the patency rates at 12- and 24-month of 65.3% and 43.5% respectively. Six patients had in-stent stenosis and three patients had stent graft downward migration, resulting in edge stenosis. The secondary access patency rates at 1- and 2-year were 100% and 94.7%, respectively. No major complications were encountered in this study. Conclusion: Placing the stent graft end in an outflow venous valve seems to reduce occurrence of the edge stenosis, and therefore prolong the stent graft patency.