Biodegradable extravascular stent

1. A method for preventing or treating vein graft disease, the method comprising:

applying, to a segment or to the whole of a vessel wall of a vein, a dry powder formulation comprising fibrinogen and a fibrinogen activator to prepare an extravascular fibrin polymer stent, wherein the dry powder formulation is applied to an outer surface of the vein, and wherein after 4 weeks, the vessel wall has a thickness less than if the extravascular stent had not been applied to the vein.

2. The method of claim 1 , wherein the fibrinogen or the fibrinogen activator is in a recombinant or a variant form.

3. The method of claim 1 , wherein the dry powder formulation further comprises a carbohydrate selected from the group consisting of trehalose, sucrose, and lactose.

4. The method of claim 1 , wherein the dry powder formulation is obtained by spray-drying.

5. The method of claim 1 , wherein the dry powder formulation comprises the fibrinogen and fibrinogen activator in separate particles or microparticles.

6. The method of claim 1 , wherein the vein is a venous graft.

7. The method of claim 1 , wherein the fibrinogen activator is thrombin or reptilase.

8. The method of claim 7 , wherein the dry powder formulation comprises 10 mg-1 g of fibrinogen and 0.1-10000 IU of thrombin per dose of dry powder formulation.

9. The method of claim 7 , wherein the dry powder formulation comprises 1-30% w/w of fibrinogen and 0.1-1000 IU of thrombin per gram of dry powder formulation.

10. The method of claim 1 , wherein the dry powder formulation of fibrinogen and fibrinogen activator is applied to the vein before implanting the extravascular fibrin polymer stent into the patient.

11. The method of claim 9 , wherein the dry powder formulation comprises 6-30% w/w of fibrinogen and 250-1000 IU of thrombin per gram of dry powder formulation.

12. The method of claim 11 , wherein the dry powder formulation comprises 6% w/w of fibrinogen and 500 IU of thrombin per gram of dry powder formulation.

13. The method of claim 1 , wherein any increase in vessel wall thickness of the extravascular fibrin polymer stent is less than a thickening of the vessel wall in grafts without extravascular support.