Microvascular transfer of long tracheal autograft segments in the canine model

Objective: The reconstruction of long segment tracheal defects represents an unsolved clinical dilemma. Prior attempts to directly revascularize tracheal segments have been unsuccessful. The objective of this study was to evaluate orthotopic autotransplantation of revascularized long tracheal segments in the canine model. Methods: Ten randomly selected mongrel dogs underwent excision, orthotopic reimplantation, and microvascular revascularization of a long segment (8.0 cm) of cervical trachea. The cranial thyroid artery and the internal jugular vein served as the vascular supply for the tracheal segment. The animals were maintained for a period of 30 days during which time graft viability was measured by routine endoscopic assessment and tracheal biopsies. Ex vivo, tracheal autografts were examined grossly for graft healing and microscopically for histologic architecture. Results: Seven of 10 dogs survived the predetermined 30-day postoperative study period without complications. Postmortem examination demonstrated that 7 dogs had healed tracheal autograft segments with normal histologic architecture, 2 dogs sustained a postoperative wound infection and tracheal dehiscence, and 1 dog sustained a fatal postoperative hematoma. Conclusions: For the first time, we have demonstrated direct revascularization of long segment tracheal autografts in the dog model using the cranial thyroid artery and internal jugular vein as the vascular supply.