Externe Stabilisierung von Venenbypässen durch Fibrinkleber führt zu Intimahyperplasie und aneurysmatischen Venengraft- degeneration Extra vascular perivenous fibrin support leads to aneurismal degeneration and intimal hyperplasia in arterialized vein grafts

Background and aims: External support of vein grafts by fibrin glue possibly prevents over-distension, vascular remodelling and neointimal hyperplasia. Previous animal models of neointimal hyperplasia showed conflicting results. Here, long term effects of external fibrin glue support were studied in a new rat model of jugular vein to abdominal aorta transposition. Methods: In male Wistar rats (250–300 g) right jugular vein (1.0–1.5 cm) was transposed to the infrarenal aorta. Fibrin glue (0.25 ml) covered the vein before releasing the vascular clamps (n = 6). Control vein grafts were exposed directly to blood pressure. After 16 weeks vein grafts were pressure fixed for histology. Intima thickness, luminal and intimal area were measured by planimetry and elastic fibres demonstrated by Elastica van Giesson staining. Results: Intimal thickness (74.04 ± 6.7 µm vs. 1245 ± 187 µm*, control vs. fibrin treatment,*: p < 0,001), total wall thickness: 272,8 ± 24,27 vs. 1707,75 ± 210,84, µm ± SEM, p < 0,05, control vs. fibrin treatment, *: p < 0,05) and luminal area (2184755 ± 347314 µm 2 vs. 7231846 ± 1781977 µm 2 *, control vs. fibrin treatment, *: p < 0,05) were significantly increased, elastic fibres in the vessel wall were diminished and the vessel wall infiltrated by mononuclear cells in fibrin glue supported veins. Conclusion: External support of vein grafts by fibrin glue leads to aneurismal degeneration and intimal hyperplasia thereby possibly jeopardizing long term graft patency. Einleitung