An endovascular catheter for vein ablation comprising: an elongated rod sized for insertion into a vein； at least one irritation element coupled to the distal end portion of the rod, the at least one irritation element having an expanded irritation state for contacting an inner wall segment of the vein to irritate the vein segment to trigger spasm of the vein segment and a non-irritation state, the at least one irritation element arranged for iterative changes between the irritation state and the non-irritation state； and at least one support element coupled to the distal end portion of the rod, the support element arranged to apply a mechanical force from the distal end portion to iteratively return the irritation element to the expanded irritation state in response to dynamic feedback of vein walls pressing against the irritation element to force the irritation element into the non-irritation state.
