Vein Replacement

Abstract

In extreme cases [i.e., where the subclavian vein is totally fibrotic (Fig. 24.1)] or when the vein segment has been repeatedly treated with multiple endovascular stents and has rethrombosed, it is impossible to operate and to lay a patch on the vein and expect it to function. In extreme cases in which the channel is practically nonexistent, but the inflow from the axillary vein measures at least 10 mm in diameter, it is feasible to remove the entire segment of the fibrotic vein and replace it with an interposition graft. At the present time there are no synthetic grafts that can function adequately in this position, so I have resorted to use of aortic homografts, usually descending thoracic aortic homografts harvested from cadavers of children [1–4]. They usually have a diameter of 10–12 mm roughly the size of the subclavian vein. It is also feasible to use an arterial homograft. Like iliac artery of adults, or even distal small abdominal aorta. The long term results of these homografts have initially been gratifying, however, within a year or 2, the walls of the homograft tend to become calcified and narrowed (Fig. 24.2a, b). If this occurs, it will be necessary to resort to endovascular stent placement in order to maintain a channel of proper caliber. So far this has been one solution to the problem. Fortunately, we have not had to use this approach often: in 25 years of experience treating total obstruction of the vein, we have only implanted 16 homografts (Fig. 24.3a–c). Our patency rates are 75 % up to 7 years of follow-up. Patients treated in this manner should be followed on yearly intervals.