The Impact of Laser Energy Levels on In Situ Fenestrations of Aortic Stent Grafts: An On-Bench Study.

(1)

Background

Laser in situ fenestration (L-ISF) is an endovascular technique used to preserve target vessel patency in urgent or emergency endovascular aortic repair when fenestrated/branched solutions are unavailable or unsuitable, or as a bailout technique for fenestration or branch misalignment. This on-bench study compared different laser energy levels in five commercially available endografts to assess fabric damage and evaluate fenestration quality, dimensions, and recoil. (2)

Methods

A total of 102 fenestrations were created using a 2.0 mm excimer laser catheter at low (45 mJ/mm2) or high (60 mJ/mm2) energy levels and dilated with a 6 mm plain balloon in five polyester endografts (Zenith Alpha, RelayPro, Endurant IIs, Valiant Captivia, Hercules). High-magnification microscopy assessed morphology and fabric damage after puncture, after dilation, and after 24 h. Quantitative measurements included diameters, area, and recoil under standardized study conditions. (3)

Results

Valiant exhibited clearer puncture margins and no bulging; Hercules showed frequent tearing and more bulging and warp-aligned recoil at high energy. In Endurant IIs, low-energy L-ISF produced larger diameters and area but also greater recoil. RelayPro revealed stronger surface recoil with high energy. (4)

Conclusion

Both low- and high-energy L-ISF were feasible across all tested grafts. A low-energy approach may be preferable for Endurant IIs, potentially reducing the risk of bridging stent graft stenosis.