The Experimental Study Of Domestic Sparating Aortic Stent-graft Implanted In The Canine Thoracic Aorta

Objective:To assess the technical feasibility and the biocompatibility of implanting domesticseparating aortic stent-graft into the canine thoracic aorta.Materials and Methods:Twelve adult dogs were divided randomly and averagely into three groups. The rightfemoral artery was cutdown and then domestic separating aortic stent-graft wastransfemorally deployed in the canine thoracic aorta,furthermore the proximal of thegraft should be at least approached just distal to the left subclavian artery.Thetechnical feasibility of the process was assessed.Angiography was performed toevaluate the position and patency of the stent-graft at 4,8 and 12weeks after stentgraftplacement.Then the dog was sacrificed to obtain specimens.Gross andmicroscope examination were performed to evaluate the fixation between stent-graftand vessel wall,endothelialization of stent-graft surface and pathologic changes ofvessel wall.Results:Ten domestic separating aortic stent-grafts were deployed without the need for thereduction of blood pressure and without migration in the canine thoracic aorta.Onedog was dead because of the rupture of the right femoral artery when the deliverysystem containing the inner bare stent was inserted through the riht femoral artery,andthe reason of another dog'death was that the carine ascending aorta was torn by the migrated outer stent-graft. Angiograms were obtained at 4,8 and 12 weeks after stentgraftplacement. Migration,deformity,rupture and stenosis of stent-graft were notobserved.The bare stent was completely covered by neointima at 4 weeks.Endothelialization of stent-graft started from 4 weeks and the stent-graft was almostcompletely covered by neointima at 12 weeks.ConclusionConclusion:The technology of implanting domestic separating aortic stent-graft into the caninethoracic aorta was feasible.There was good biocompatibility of the domesticseparating aortic stent-graft in the canine thoracic aorta.