Hyperplasia In Grafts Research Articles

Kinetics of vein graft hyperplasia: Association with tangential stress

Kinetics of vein graft hyperplasia: Association with tangential stress

A morphometric study of vein graft intimal hyperplasia.

The extent of intimal hyperplasia in veins grafted into arteries is a major determinant of graft survival. The development of intimal hyperplasia in experimental iliolumbar vein grafts in iliac arteries of 36 rats was followed by light microscopy between 2 and 140 days after grafting. The increase in mean thickness of the graft intima was most rapid from 2 to 21 days and then more gradual to reach a maximum at 140 days, when the graft intima was the same thickness as the combined intima and media of the control artery. Grafts aged between 15 and 28 days showed a significant thickening at the anastomosis, but this was not evident in older grafts. Our results quantitate the arterialization of a vein graft and show that there is no significant anastomotic intimal hyperplasia in mature grafts in this model.

Hydraulic and morphologic study of fibrous intimal hyperplasia in autogenous saphenous vein bypass grafts

In certain patients who have had aorto-coronary bypass, the grafts are found to have concentric stenosis at the time of reinvestigation. Subsequent morphologic examination of the excised vein has shown marked intimal fibrous hyperplasia. A simplified aorto-coronary bypass system was simulated by a mathematical computer model, through which the entrance effect of various angles by the anastomosis on the flow in the side branch was studied. By matching the coronary impedance to the aortic pressure wave over a cardiac cycle, the model predicted that the optimal angle to obtain the maximum efficiency is 90 degrees. The pathological findings in a group of 108 patients who underwent aorto-coronary bypass grafting with the saphenous vein were correlated with the clinical course, angiographic findings, and hydraulic features. All four categories of data were available in 8. In all but 1 of the 8 patients who underwent reoperation, there was clinical recurrence of angina an average of 10.6 months after the first operation. Repeat angiography revealed severe narrowing of the vein graft in 6 patients and complete occlusion in 2. The angle 0*** subtended by the vein graft with the aorta was estimated at an average of 45.8 degrees.