Size of vascular g
Size of vascular grafts
Prosthetic graft of appropriate size is prepared for insertion , graft size maybe determined by visual estimation or by direct measurement of the aneurysm . Straight tubular graft is used, otherwise a bifurcated or Y shaped graft if necessary (65)
Sizes of vascular grafts
Large – bore prostheses
Large – bore prostheses are used to replace the aorta and the arteries arising from the aortic arch and the iliac arteries . Most large –bore prostheses are crimped as an attempt to resist kinking . The crimps effectively reduce the diameter by about 10% , since the wall of the prostheses is stiff , there will be an impedance at both ends of an insert and in consequence – loss of pulsatile energy .The difficulty is that it is not possible to control or measure accurately all the variables that affect the success of this process , despite all problems, large bore prostheses are very successful when used in appropriate circumstances. There is a reason for this success that is probably the velocity of flow is high and only a very small preparation of the blood flowing through the tube ever comes into contact with the wall
Small bore prostheses
There is no generally accepted small – bore prostheses that works well although there are several prototypes. The process of evaluation small arteries is viscoelastic .
The wall of a small above prostheses should be elastic in addition the wall must be micro porous and resist kinking .