Abstract: A temporary intravascular arteriotomy seal for insertion into and retrieval from a blood vessel through an opening in the wall of the vessel. The seal comprises a thin flexible sheet material. According to one embodiment, in an untensioned state, the seal is curved and foldable in the width direction. It is adapted to be folded in the width direction upon exertion for a force on the gripping element directed in the length direction, and upon contacting of the sheet material by the sides of the opening in the vessel wall. By use of the sealing device, arterial by-pass grafting in a briefly-occlusive or non-occlusive end-to-side or side-to-side anastomosis technique is possible with virtually no obstruction to flow, little endothelial denudation and otherwise no wall damage by the intravascular device, and without blocking of side branches.