A 42-year-old woman who underwent unilateral mastectomy 2 years ago is scheduled to undergo breast reconstruction with a transverse rectus abdominis musculocutaneous (TRAM) flap. She has smoked one pack of cigarettes daily for the past 10 years. To improve survival of this flap, the deep inferior epigastric artery to the flap side is surgically ligated 2 weeks before the reconstruction procedure. Which of the following best represents the mechanism of this intervention?