The bypass intervention

1. Coronary Bypass

A cardiac bypass is usually obtained by using a leg vein or an artery from the rear of the chest wall (Arteria mammaria).
The chest wall artery may be used for only one bypass, whereas several bypasses may be obtained from a leg vein. Since in your case more than one coronary vessel might be affected by stenosis or occlusion, the attending surgeon might try to set more than one cardiac bypasses. It may be predictable that material for several bypasses is not obtainable from your own leg veins (too small or varicose veins, condition following thrombosis or previous vein collection). Nevertheless, the necessary number of bypasses may still be created by using artificial vascular grafts. Those grafts will be made of ePTFE or similar material and may undergo postoperative re-occlusion. Several studies have shown that the rate of re-occlusion tends to decline if the inner wall surface of an artificial graft had been lined with endogenous vascular cells. We, therefore, plan to collect a short arm or leg vein segment approximately three weeks prior to the scheduled cardiac bypass operation. Such segment then is used to obtain endogenous vascular cells by which to coat the artificial graft.

2. Peripheral bypass

Peripheral arterial occlusive disease (PAOD) is characterised by impaired blood supply to legs or arms, usually attributable to arteriosclerotic stenosis of peripheral arteries.
There is an alternative between surgical enlargement of the narrowed artery or construction of a bypass around the narrow segment. Such surgical approach is primarily considered for patients who can walk only a short distance without pain or who are even afflicted with tissue defects (necroses). The choice of either balloon dilatation or bypass operation will depend on various factors, such as the extent (severity) of the problem and location of the vascular stenosis. It may be anticipated that no adequate material for a planned bypass may be obtainable from your leg veins (due to too small or varicose veins, condition after thrombosis or previous vein collection). It will, however, be possible to resort to artificial vascular prostheses for bypass construction. Such vascular prostheses made of Goretex or similar material may undergo postoperative re-occlusion. Studies have shown that vascular prostheses which had been lined with endogenous vascular cells tended less frequently to re-occlusion. We, therefore, plan to collect a short vein segment from arm or leg approximately three weeks prior to the scheduled bypass operation. Endogenous vascular cells then are collected from such vein segment and are used to line an artificial vascular prosthesis.