Aortic wall structural strengthening by intraluminal net prosthesis to arrest aneurysm progression and to prevent dissection and rupture

The major limitation implicit in the endovascular procedures for aorticprosthetic substitution is that they cannot be used in those tracts of theaorta where important collateral branches originate (aortic arch,thoraco-abdominal tract, upper abdominal), that would be occluded by theprosthesis. In order to overcome this limitation we hypothesized theendovascular positioning of a prosthesis in the form of a wide mesh networkthat would be gradually and spontaneously covered by new intima andincluded in the aortic wall. The fabric framework linked to the aortic wallwould then condition its significant, regular and uniform mechanicalstrengthening that fractionates and partially absorbs the centrifugepulsatile stress of the bloodstream. The purpose of this paper is to reportthe results of the insertion of a braided Prolene net prosthesis in thefirst 7 cm of the descending aorta of ten swine. The animals were killedafter 6 weeks, the substituted segment removed and aortic wall compliancemeasured under standardized conditions. The prosthesis was found entirelycovered by new intima, well embodied in the aortic wall. The intercostalcollateral included in the substituted segment was patent, as proved bybubble formation during underwater insufflation. Compliance of theprosthesis segment was significantly lower than that of the adjacentdescending aorta. Histology showed a regular net prosthesis inclusion deepin the neo-intima layer. Present results indicate the technical feasibilityof the procedure, achieving significant aortic wall strengthening withoutaffecting the collateral (intercostal) circulation.