ENDOVASCULAR GRAFT FOR REPAIRING ABDOMINAL AORTIC ANEURYSMS

摘要

This is regarding a type of device aimed at a simpler, in relation to alreadyexisting techniques, endovascular positioning of a stent-graft in theabdominalaorta for the therapy of aneurysms up to the point of its bifurcation. Thisdevice is comprised of a system of three cylinders: a "main" centrally placedand two "limbs" peripherally placed. Each of these cylinders has a centraland a peripheral orifice. The cylinders are comprised of a cylindricalmetallicskeleton which is self-expanding and made out of stainless steel or nitinolandwhich is externally covered with a cylinder made out of thin-layered PTFE,Dacron or some other elastic biocompatible material, refolded around theperipheral orifice of the skeleton of the main cylinder. These cylinders canbe compressed into small diameter tubules and enter the vascular lumen. Aftertheir insertion into the desired position, they expand, regaining theiroriginal diameter. The main cylinder is placed inside the aorta becomingmore circular when it comes in contact with the healthy part of the aortacentralto the aneurysm at the center of the orifice. The peripheral orifice of themaincylinder sits upon the expanded aortic bifurcation. The two limbs have acentralorifice with a diameter equal to or approximately about 2 mm smaller thanthe diameter of the peripheral orifice of the main cylinder. The branchingof the main cylinder is accomplished by the entrance of the main ends ofthe two limbs inside the peripheral end of the main cylinder. Both limbs areat the same height in such a manner that they compress each other at thecenterof the cylinder. Each limb exerts equal pressure, whereas equal pressure isalso exerted on the internal surface of the main cylinder from their externalsurface and together they both occupy at the height of their orificesthe entire perimeter of the main cylinder. Alternatively, as limbs (peripheralcylinders), tubes of different diameters and types of skeletons can be used.