The venae comitantes clipping test for the evaluation of the venous drainage of the radial forearm free flap.

Risks of failure of the radial forearm free flap (FRFF) are mainly related to venous congestion. Two different venous drainage system have been described for the FRFF, but the choice of the best one is still controversial. The superficial systems have a larger diameter and a thicker wall veins which makes them easier to anastomose. The deep system provides most part of the venous outflow if the caliber of the venae comitantes (VCs) is adequate. We propose an intra-operative method to evaluate the FRFF venous drainage: the VCs clipping test. The test has been used in the choice of the vein to anastomose in 12 consecutive patients with oral cavity post oncological defects reconstructed with the FRFF. The cephalic vein was included in the flap; the VCs were individually clipped with small liga-clips and divided with the radial artery still patent. The flap was kept with arterial inflow and superficial venous outflow till the recipient site was ready. If there were no signs of venous stasis, the VCs were kept clipped and the cephalic vein anastomosis was made. If clinical signs of venous stasis were revealed, the largest of the VCs was anastomosed to a vein of adequate caliber in the neck. No signs of flap venous congestion were observed in the postoperative period. No flap necrosis occurred. In this small series of patients the venae comitantes clipping test showed to be an easy, reliable and reproducible method to assess intra-operatively which vein to anastomose.