To investigate the management of difficult recipient vessel preparation in microsurgical reconstruction for oral and maxillofacial defects with free flaps and to assess the clinical outcome.

A total number of 739 patients with oral and maxillofacial defects underwent consecutive free flap reconstruction with 761 free flaps from May, 2012 to May, 2015. There were 37 patients who could not find or lack of proper recipient vessels for microvascular anastomosis during operation. Among them, 22 were recurrent oral cancer after tumor ablation, 10 of them undrewent post-operative radiotherapy; 5 were second primary oral cancer, 7 diagnosed with osteoradionecrosis, and 3 suffered from oral and maxillofacial defect and deformity caused by trauma or inflammation. Forty free flaps including 23 anterolateral thigh flaps. (ALT) , 10 fibular flaps and 7 radial forearm flaps were harvested. Methods and techniques used during the operation, instant patency rate after anastomosis, the overall survival rate of free flaps, and post-operative complications were recorded.

Ninety-one anastomoses were performed between 87 pairs of vessels in 37 patients. Fifty recepient vessels were located on ipsilateral side of neck, and the most frequently used recipient vessels were those preserved or not being damaged in former operation and radiation, former transferred free flap vascular pedicles and residual ends of the ligated vessels. Thirty-seven recepient vessels were found on the contralateral side of neck. Thirty-one cases of long-pedicle flap harvesting, 2 cases of vein and artery grafting, 4 cases of vessel transposition, 5 cases of phleboplasties, 9 cases of end-to-side anastomoses, and 1 case of flow-through technique were applied in recipient vessels preparation alone or in combination. The patency rate of anastomosis during operation was 100% and the overall survival rate of free flaps was 97.5%.

Recurrent oral cancer after tumor ablation, second primary oral cancer, osteoradionecrosis and deformity caused by trauma and inflammation are the main reasons of unsuitable recipient vessel conditions in microsurgical reconstruction for oral and maxillofacial defects. Methods including long-pedicle flap harvesting, venous grafting, vessel transposition, phleboplasty, end-to-side anastomosis and flow-through technique applied alone or in combination are still reliable choices for management of neck difficult recipient vessel preparation and anastomosis.

Maxillofacial defects; Surgical flaps; Recipient vessels; Microsurgery