Review Question - QID 219946

A 23-year-old minor-league baseball player sustained the injury shown in Figure A seven months ago. Since that time, he has had continued pain, paresthesia, and progressive numbness along the ring and small fingers and has not been able to return to full-time sport. On inspection, he has blanching and mottling over the involved digits with small, painful ulcerations over the tip of the small finger. An angiogram is obtained, which shows the pathology in Figure B. If he undergoes the indicated procedure shown in Figure C with reversed autogenous saphenous vein grafting and returns at 6 months with a recurrence of symptoms and clinical evidence of failure, which of the following would be the most likely explanation?