In Vitro Comparison of Retrograde In Situ Fenestration Using a Re-entry Catheter vs Electrified Guidewire in Thoracic...

Area of Science:

• Vascular Surgery
• Endovascular Interventions
• Biomaterials Engineering

Background:

• In situ fenestration (ISF) is crucial for thoracic endovascular aortic repair (TEVAR) to create access points for visceral and renal arteries.
• Comparing novel ISF techniques is essential for improving procedural safety and efficacy.

Purpose of the Study:

• To evaluate and compare the in vitro feasibility and fenestration characteristics of two ISF techniques: re-entry catheter (REC-ISF) and electrified guidewire (EW-ISF).
• To assess the performance of these techniques in commercially available thoracic stent-grafts.

Main Methods:

• Forty in vitro fenestrations were performed on RelayPro and Valiant stent-grafts using REC-ISF and EW-ISF (10 per graft per technique).
• Grafts were submerged in a 37°C saline bath, and fenestrations were sequentially balloon dilated.
• Outcomes included fenestration geometry, fabric damage, puncture success, and dilatation success, with area measured immediately and after 24 hours to assess recoil.

Main Results:

• EW-ISF achieved 100% puncture success across both grafts, significantly higher than REC-ISF (60-70%).
• Balloon dilatation success was higher with EW-ISF (9/10 in Valiant) compared to REC-ISF (0/10 in Valiant).
• While RelayPro showed similar fenestration areas between techniques, EW-ISF led to more tearing (80%) and less recoil (5.0%) compared to REC-ISF (0% tearing, 23.1% recoil) after 24 hours.

Conclusions:

• EW-ISF demonstrated high technical feasibility, producing consistent, reproducible, and dimensionally stable fenestrations.
• REC-ISF showed material-dependent limitations in this in vitro model.
• EW-ISF is a viable off-the-shelf option for emergency ISF when specialized tools are unavailable, offering improved procedural possibilities.