Surgical patterns of venous drainage of the free forearm flap in head and neck reconstruction.

A retrospective review of 40 consecutive free forearm flaps used in head and neck reconstruction in our Head and Neck Service identified five different patterns of venous drainage. In type 1, the cephalic vein and two venae comitantes join into a larger median cubital vein, which itself splits into two sizable branches (n = 8, two anastomoses). In type 2, a median cubital vein drains both the cephalic vein and the two venae comitantes (n = 17, single anastomosis). In type 3, the cephalic vein and the confluence of two venae comitantes are drained separately (n = 7, two anastomoses). In type 4, the cephalic vein and each of two venae comitantes are anastomosed separately (n = 2, three separate anastomoses). In type 5, the cephalic vein and the larger of the two venae comitantes are drained separately (n = 6, two anastomoses). Understanding these possible venous drainage patterns substantially expedites the raising of the free forearm flap. The selection of patterns 1 and 2, when possible, with the large-caliber veins ensures the safety of the flap. Long vascular pedicles permit anastomoses to contralateral neck recipient vessels, obviating vein grafts, and permit safe full head and neck mobility.