What is the most common cause of flap failure?

What is the most common cause of flap failure?

• A. Infection
• B. Venous congestion
• C. Necrosis due to pressure
• D. Anastomotic thrombosis

Answer: (D)

The key idea is that flap viability depends on a successful microvascular connection that provides both arterial inflow and venous outflow. When a thrombosis forms at the vascular anastomosis, blood flow to the flap is abruptly blocked. This directly interrupts perfusion and rapidly leads to ischemia and potential flap failure if not addressed immediately. Although venous congestion and other issues can compromise a flap, the most common mechanism that ends up causing complete failure is thrombosis at the anastomosis, because it halts the essential blood supply at the point where the vessels have been connected. Early recognition and prompt re-exploration to revise the anastomosis can sometimes salvage the flap, whereas other problems like infection or external necrosis are less likely to cause immediate, total loss of perfusion.

The key idea is that flap viability depends on a successful microvascular connection that provides both arterial inflow and venous outflow. When a thrombosis forms at the vascular anastomosis, blood flow to the flap is abruptly blocked. This directly interrupts perfusion and rapidly leads to ischemia and potential flap failure if not addressed immediately.

Although venous congestion and other issues can compromise a flap, the most common mechanism that ends up causing complete failure is thrombosis at the anastomosis, because it halts the essential blood supply at the point where the vessels have been connected. Early recognition and prompt re-exploration to revise the anastomosis can sometimes salvage the flap, whereas other problems like infection or external necrosis are less likely to cause immediate, total loss of perfusion.