Method of making an endovascular laser treatment device for causing closure of a blood vessel

An endovascular laser treatment device for causing closure of a blood vessel uses an optical fiber adapted to be inserted into a blood vessel. An inner sleeve is arranged around a distal portion of the optical fiber core such that both distal ends of the inner sleeve and the optical fiber core form an enlarged light emitting face. The enlarged emitting face provides substantially lower power density while providing the same amount of total energy during a treatment session. An outer sleeve arranged around the inner sleeve acts as a spacer to position the light emitting face away from an inner wall of the blood vessel. The enlarged light emitting face and the outer sleeve acting as a spacer reduces the possibility of thermal run-away and device damage, and reduce the possibility of vessel perforations, leading to less bruising, post-operative pain and other clinical complications. In yet another aspect of the present invention, a spacer comprises an inner sleeve and an outer sleeve both arranged around a distal portion of the core to prevent the laser light from traveling laterally and to position the light emitting face away from an inner wall of the vessel. The inner sleeve can be a heat resistive material such as ceramic and the outer sleeve can be, for example, a metallic sleeve to provide structural integrity and strength to the distal section of the treatment device.