Animal study on adjustable pre - fenestration aortic stent - graft

To isolate aortic arch pathologies and keep the branches superior in arch patent, it always need physicians to do in-vivo fenestration or in-situ fenestration when performing the thoracic endovascular aortic repair (TEVAR). However, both of those fenestration techniques need structure modification of the stent-graft, which may affect their long-term stability. We designed an adjustable pre-fenestration aortic stent-graft to treat pathologies in this area and obtained a patent branch arteries. This study used this new designed stent-graft to perform fenestrated-TEVAR (f-TEVAR) in canine aorta. This study aims to identify its feasibility and safety through animal experiments, which might provide preliminary data for potential human implantation.

A total of 8 Labrador Retrievers were underwent f-TEVAR by using the new devices. Digital subtraction angiography was performed before and after f-TEVAR to evaluate the success of the procedures. All the canines were divided into a 4-week group (feeding for 4 weeks after operation) and a 12-week group (feeding for 12 weeks after operation). Computed tomography angiography (CTA) were performed before euthanasia.

The success rate of operation was 100%. During the operation, there was no accident of major bleeding or failure to be released by fenestration. Adjustable fenestration worked well. No stent-graft migration was found in CTA at 4 weeks and 12 weeks after the operation. All branch arteries kept by the adjustable fenestration were patent.

The result of feasibility and safety of the new designed adjustable pre-fenestration aortic stent-graft in f-TEVAR of canine is acceptable. This study provides a reference for further optimization of this stent and human f-TEVAR implantation involving aortic arch lesions.