Venous valves in the neck: implications for microvascular free flap reconstruction.

Successful microvascular free flap reconstruction requires adequate arterial inflow and venous outflow. We report 4 cases that demonstrate the not uncommon occurrence of locating valves in veins during microvascular head and neck reconstructive procedures. Failure to recognize these valves could have compromised the venous anastomosis. The anatomical literature states that veins in the head and neck lack valves, allowing bidirectional blood flow. As a result, there is potential significant flexibility in the selection of recipient veins for the microvascular anastomosis during free flap reconstruction. The unrecognized presence of a venous valve, however, could cause thrombosis of the venous anastomosis and, ultimately, flap failure. This report of venous valves should speak caution to the head and neck microvascular surgeon when he or she is selecting recipient veins in the neck.