A sheathing (10) for restoring function of venous valves of varicose veins, comprises a planar, flexible piece of material including a nonwoven material. The nonwoven material is configured as a film/sheet. The piece of material preferably has a rectangular shape； a U-shaped cutout (14) on its narrow side (12), where the U-shaped cutout has a width adapted to a diameter of the vein to be enveloped； and two shank-like projections (16). The piece is porous. The sheathing preferably has a reinforcement. The nonwoven material is a polymer that is non-absorbable under physiological conditions. An independent claim is included for a kit useful in extraluminal valvuloplasty, comprising at least one sheathing, and a biocompatible adhesive composition for the sheathing.
