To provide a device for releasing from a stenosis of an arterial sclerosis lesion located in a branch part of a coronary blood vessel or including an origin part of a lateral branch, and respective intervention methods for mounting such device.

This device 1 has a stent 4 comprising a scope 4a amounting to two thirds of the total length and adhered to a balloon 3 and a scope 4b corresponding to the remaining one third, not adhered to the balloon 3 before use and being slightly spreading. In case a constrictive arterial sclerosis to be treated is located in a second branch separated from the sclerosed artery or a lesion is located in a branch part of the artery, a proximate end of a metal wire inserted in one of the branches beforehand is passed through the scope 4b. The wire may be mounted with a second balloon or stent for enabling an access to the branch in case of a reduction or complete occlusion of the inner diameter of the entrance part of the branch, and a release from the constriction of the entrance part.