OBJECTIVETo analyze the causes of the vascular crisis and necrosis of free flaps used for reconstruction of defects following head and neck cancer resection and the managements of these issues.

METHODSA total of 850 cases with head and neck tumors who underwent free flap reconstruction from October 2010 to April 2014 were studied retrospectively. The risks for vascular crisis and necrosis were analyzed with one-factor analysis and multivariate analysis.

RESULTSThe total success rate of 95.1% (808/850) for the free flap reconstruction was obtained. Twelve flaps due to poor blood supply indicated during operation were replaced by other free flaps. Among 73 flaps with vascular crisis, 31 flaps were salvaged by surgical exploration and subcutaneous injection of low molecular heparin calcium. Obesity, smoking, preoperative radiotherapy and surgeon's experience, rather than age, hypertension and diabetes, were the risk factors of skin flap necrosis. Two-vein anastomosis had a higher success rate than one-vein anastomosis.

CONCLUSIONSThe necrosis rate of free flaps can be reduced by the choice of suitable flaps, subtly preparation of flaps, carefully vascular anastomosis, and prompt perioperative managements. The two-vein anastomosis is recommended. Diabetes, hypertension and elderly patients are not the contraindications for free flap reconstruction.