Anatomic feasibility of a modular Endo-Bentall stent graft system for type A aortic dissection

The implementation of thoracic endovascular aortic repair in patients with type A aortic dissection has been strictly constrained due to the pulsatile movement and distensibility and the insufficient length of landing zones on ascending aorta. The most prevalent anatomical limitation is the insufficient length of proximal and distal landing zones. We propose a modularly designed Endo-Bentall stent graft system to broaden the scope of thoracic endovascular aortic repair in the ascending aorta by covering intimal tears in the aortic root and ascending aorta and reconstructing coronary arteries. This study was conducted to assess the anatomical feasibility of a novel stent graft design.

In this study, we included 152 patients with type A aortic dissection for image measurement and analysis. All computed tomography angiography images were assessed on a 3mensio Workstation version 10.2 (3mensio Medical Imaging B.V.) utilizing the centerline method. We compared the diameters and lengths at various planes in relation to the proposed anatomical criteria for the modular Endo-Bentall stent graft system.

The patients were predominantly male (67.1%), with a median age of 56.5 years (interquartile range, 50.0-65.0 years). Among all aortic dissections, 91.5% extended proximally to the sinotubular junction, whereas only 8.6% were restricted to the tubular ascending aorta. The median perimeter-derived diameter of the aortic annulus was 24.1 mm. The median maximum aortic diameter at the sinotubular junction and brachiocephalic trunk were 44.6 mm and 43.5 mm, respectively. The median height of the left coronary artery, right coronary artery, and sinus of Valsalva were 12.7 mm, 16.7 mm, and 28.4 mm, respectively. After applying exclusion criteria, 66.4% of all patients were anatomically eligible for the modular Endo-Bentall stent graft system. A total of 85.1% of patients were suitable for stent grafts with lengths of 70 mm, 80 mm, or 90 mm. Both antegradely and retrogradely tapered stent grafts were required, according to the diameter differences between the STJ and brachiocephalic trunk.

Utilizing the modular Endo-Bentall stent-graft design, approximately two-thirds of patients with type A aortic dissection are anatomically eligible for endovascular repair. Further animal studies are required to optimize the device design.