Thoracic aortic parallel stent-graft behaviour when subjected to radial loading.

Area of Science:

• Biomedical Engineering
• Cardiovascular Surgery
• Medical Device Technology

Background:

• Minimally invasive techniques for complex aortic arch disease often involve parallel stent-graft deployment.
• The biomechanical interactions during chimney thoracic endovascular aortic repair (ch-TEVAR) are not fully understood.

Purpose of the Study:

• To characterize the loading and deformation behavior of parallel endografts in representative ch-TEVAR configurations.
• To evaluate device-device and device-artery interactions in parallel endografting.

Main Methods:

• Utilized a radial force testing system to quantify loading profiles of four commercial endografts (Bentley BeGraft, Gore TAG, Gore Viabahn, Medtronic Valiant).
• Tested devices individually and in six parallel combinations.
• Analyzed image data to assess mechanical deformations including gutters, compression, and infolding.

Main Results:

• Parallel endografting significantly increased radial loads compared to standard TEVAR.
• Outward force varied by main endograft manufacturer (TAG combinations > Valiant combinations) but was independent of chimney graft type.
• Endograft deformations differed by chimney graft type (Viabahn resulted in less gutter area and more lumen compression than BeGraft).
• Chimney graft deformations were influenced by deployment arrangement in double ch-TEVAR.

Conclusions:

• Significant variability exists in radial loads and mechanical deformations among clinically relevant ch-TEVAR configurations.
• Device selection and configuration critically influence biomechanical outcomes in ch-TEVAR.
• Further understanding of these interactions is essential for optimizing treatment of complex aortic arch disease.