Tracheal reconstruction: mini-review and anatomical study on the use of antero lateral thigh fascial flap for heterotopical transplantation.

Background: The reconstructive tracheal options for extensive lesions still remain limited and although a valid substitute is required unfortunately, the biomechanical tracheal characteristics do not allow an easy replacement. In this study we reviewed the described options and investigated, in human cadaver model, whether thigh fascia can be used, as an alternative to forearm fascia, as recipient site for trachea graft heterotopical allotransplantation. Anatomical study: In three fresh cadavers, 3 tracheal graft, 6 radial forearm (RF) fascial flaps and 6 antero-lateral thigh (ALT) fascial flaps were harvested. For each flap we simulated the heteretopical transplantation of the trachea in each fascial flap, and the harvesting of the composite graft as a free flap. The composite graft was finally decomposed at bench and the pedicle was injected to confirm fascial vascularization. The main measured outcomes were: flap fascia vascularization after pedicle injection, average time of flap harvesting, number of perforators included in ALT fascial flap and diameter of the vessels for anastomosis. Difficulties were noted, in order to compare RF flap and ALT flap. Results: Fascia vascularization was confirmed in all cases by pedicle injection. The main difficulty with radial flap was to harvest the fascial layer due to its thinness and its strong adherence to palmaris longus tendon, while the main difficulty with ALT flap was to prevent any traction on the perforators. The average time of flap harvesting and graft inset (by a junior plastic surgeon) was 1 h and 30 min for radial forearm flap and 2 h and 10 min for ALT flap. Conclusion: Despite many different techniques proposed in the literature, tracheal heterotopical allotransplantation still seemed the most promising, and ALT flap promised be a feasible alternative for heterotopical transplantation of trachea.