Which of the following is a common graft/fistula complication?

• A. Infection (Most Synthetic Grafts)
• B. Aneurysm Formation
• C. Thrombosis/Stenosis
• D. Arterial Steal - Digit Ischemia

Answer: (C)

The main concept here is that the most common problem that causes graft or fistula failure is thrombosis resulting from a narrowing, or stenosis, in the access. Stenosis develops from processes like neointimal hyperplasia at the anastomosis or along the venous outflow tract. As the lumen narrows, flow becomes disturbed and can slow or become turbulent in the narrowed segment. That disrupted flow favors clot formation, so thrombosis often follows stenosis and leads to loss of the access.

This is why thrombosis/stenosis is the best answer: it reflects the typical sequence that ends most accesses in failure. The other options describe real complications but occur less frequently or in more specific contexts. Infection is a concern, especially with synthetic grafts, but thrombosis from stenosis is the more common cause of access loss. Aneurysm formation can happen with repeated cannulation or wall weakness, and steal syndrome (ischemia in the hand) is a known issue but not as common as thrombosis driven by stenosis. In practice, ultrasound surveillance targets detecting stenosis early so we can prevent thrombosis and preserve access.