Long-Term Experimental Evaluation of In Situ Laser-Fenestrated Versus Custom-Made Fenestrated Endografts.

OBJECTIVE

This study evaluates the biomechanical performance and long-term durability of in situ laser fenestration (ISLF) compared to custom-made fenestrated endografts (CMD) using a controlled bench-top experimental setup.

METHODS

In situ, laser fenestration was performed in a RelayPro Dacron endograft using a 2.0 mm Turbo Elite OTW Laser Atherectomy catheter. Ten BeGraft Bridging Stent-Grafts (BSG) were implanted in 5 ISLF and 5 CMD Zenith fenestrations and subjected to 50 million fatigue cycles. Fenestrations were evaluated radiographically and microscopically for shape, size, fraying, endograft tearing, and BSG integrity.

RESULTS

Fenestration areas (median 8.1 mm2) and axis lengths (median long axis: 4.03 mm, median short axis: 2.33 mm) in the ISLF group were significantly less than CMD fenestrations (median area: 24 mm2; median long axis: 5.83 mm, median short axis: 5.8 mm) immediately post-manufacturing (p=0.002), but increased significantly after stenting and fatigue (p=0.002). Tearing was observed in 3 of 5 ISLF after ballooning but resolved after BSG implantation. BSG integrity was superior in the ISLF group, with no all-layer defects, while 3 of the 5 tested BeGrafts used in the CMD group revealed fabric defects with partial fracture of the stent in 2 (p=0.007).

CONCLUSION

ISLF fenestrations demonstrated comparable durability to CMD fenestrations after long-term fatigue testing, with distinct advantages in BSG integrity preservation. These findings support ISLF as a viable option for urgent treatment, although further research is warranted to validate these results.Clinical ImpactIn-situ laser fenestration is a feasible technique for urgent complex aortic repair when customized or off-the-shelf devices are unavailable or technically unfeasible. However, long-term mechanical stability and durability under fatigue testing have not been previously evaluated. This study is the first to directly compare the long-term mechanical performance of industry-made custom fenestrations with in-situ laser fenestrations using a fatigue model. Results demonstrate non-inferiority of in-situ laser fenestrations, supporting their use as an effective off-label strategy for emergency or bailout interventions.