Restenosis patterns and clinical significance following VIABAHN endoprosthesis placement for refractory arteriovenous graft outflow stenosis.

OBJECTIVE

In this retrospective, single-center, observational study, we classified target lesion restenosis patterns following initial GORE® VIABAHN® endoprosthesis (stent graft) placement, calculated target lesion primary patency (TLPP) stratified by restenosis pattern, and examined their clinical significance.

METHODS

A total of 104 stent graft procedures performed between January 2020 and December 2024 were included in the analysis. Patency from stent graft placement to 1st target lesion revascularization (TLR), from 1st to 2nd TLR, and from 2nd to 3rd TLR was defined as 1st, 2nd, and 3rd TLPP, respectively. We divided target lesion restenosis into two groups: pattern E (edge), which extended up to 5 mm from the downstream edge of stent graft, and pattern D (downstream), which extended beyond 5 mm distal to the downstream edge of stent graft. TLPP was estimated using Kaplan-Meier analysis, and multivariable Cox proportional hazards regression was performed to identify predictors TLPP. The correlation between the elephant trunk (ET) technique (stent graft diameter < outflow vein diameter) and the restenosis pattern was evaluated using Fisher's exact test.

RESULTS

The 1st TLPP, 2nd TLPP, and 3rd TLPP were 81%, 41%, and 17% at 6 months, respectively. There was no significant difference in the TLPP between the groups with and without ET technique. The second TLPP in the Pattern D group was significantly worse than in the Pattern E group (p < 0.005). On multivariable analysis, restenosis pattern (HR = 3.23 (1.59-6.53), p = 0.001) and female sex (HR = 2.33 (1.17-4.68), p = 0.017) were significant predictors of 2nd TLPP. Fisher's exact test revealed a significant positive correlation between the ET technique and pattern E restenosis (p = 0.014, <0.001, and <0.001, for 1st, 2nd, and 3rd target lesion, respectively).

CONCLUSION

Time to loss of TLPP was progressively reduced with each successive balloon angioplasty. Pattern D was associated with poorer TLPP. Restenosis pattern E was significantly correlated with ET technique.