The primary use of bleomycin in vascular procedures is for:

Bleomycin is primarily used in vascular procedures for pleurodesis, which is a treatment aimed at causing the pleura, the membranes surrounding the lungs, to adhere together. This process is typically utilized in managing pleural effusions, where fluid accumulates in the pleural space. By using bleomycin, it induces a fibrotic reaction that helps prevent the reaccumulation of fluid by effectively closing off the pleural space.

In contrast, the other options involve procedures where bleomycin is not typically indicated. Angioplasty focuses on widening narrowed or obstructed blood vessels, thrombolysis pertains to the breakdown of blood clots, and embolization involves intentionally blocking a blood vessel, often using materials such as coils or particles, rather than a chemotherapeutic agent like bleomycin. Therefore, the use of bleomycin is distinctly associated with pleurodesis among the choices provided.