Air bubbles are released by thoracic endograft deployment: An in vitro experimental study

Area of Science:

• Biomedical Engineering
• Vascular Surgery
• Cardiovascular Research

Background:

• Embolic stroke is a significant risk associated with thoracic endovascular aortic repair (TEVAR).
• Current understanding attributes TEVAR-related embolic stroke primarily to dislodged atherosclerotic debris.
• An alternative hypothesis suggests air embolism from the endograft delivery system as a potential cause.

Purpose of the Study:

• To experimentally determine if air is released during the deployment of thoracic endografts.
• To investigate air release as a potential alternative source of embolism during TEVAR.

Main Methods:

• Benchtop experimental study involving the deployment of eight thoracic endografts (Medtronic Valiant Thoracic and Gore TAG) in a de-aired, water-filled container.
• Endografts were prepared and deployed following manufacturer instructions.
• Released air volume was collected, measured using a calibrated syringe, and deployment was filmed.

Main Results:

• Air release was observed from all tested thoracic endografts.
• Quantified air volumes ranged from 0.1 to 0.3 mL for Medtronic Valiant Thoracic and <0.025 to 0.04 mL for Gore TAG.
• The largest observed bubbles, approximately 3 mm in diameter, originated from the proximal end of the Medtronic Valiant device.

Conclusions:

• Thoracic endografts release air bubbles upon deployment.
• Air embolism represents a plausible alternative mechanism for stroke occurrence following TEVAR.
• Further investigation into air management during TEVAR is warranted.