The role of computed tomography in the preoperative assessment and follow-up of oromandibular reconstruction with microvascular osteomyocutaneous free flaps

Objective: To investigate the capacity of helical CT in the pre- and post-o perative management of oromandibular reconstruction of patients with oropha ryngeal carcinoma using microvascular composite free flaps. Materials/methods: Thirty-four patients with oropharyngeal cancer were exam ined by helical CT and nine (six men and three women) submitted to oromandi bular reconstruction. The osteomyocutaneous flaps used for reconstruction w ere taken from the iliac crest in six cases and from the fibula in three ca ses. All patients were examined by CT 1-4 days postoperatively and then at 6 monthly intervals. Double helical scans were performed in all cases, with slices of 2-3 mm for primary lesion studies and 5 mm for lymph node stagin g, pitch greater than or equal to 1 and RI=1. Multiplanar (MPR) and 3D reco nstructions were obtained from pre- and postoperative CT examinations. Results: Preoperative CT showed massive bone infiltration in six of the nin e surgical patients and marginal infiltration in three. These findings were confirmed histologically. There were no false negatives. The immediate pos toperative examination showed correct flap positioning in eight of nine cas es. The flap underwent ischemic necrosis in two cases; CT showed very early signs of bone ischemia in both. CT detected two cases of recurrence after about 1 year. Conclusions: Axial CT permitted adequate assessment of the extent of mandib ular infiltration and detected early ischemic complications and distant rec urrences. Integration with MPR and 3D reconstructions simplified the choice of flag type and size and enabled the postoperative assessment of correct flap positioning. This helped the surgeon plan subsequent rehabilitation wi th osseo-integrated implants.