The "Lost" Peroneal Vessel - A Rare Anatomical Variation in Free Fibula Flap Harvest.

[INTRODUCTION] Vascularized free fibula flap is one of the commonly used flaps in autologous soft-tissue and osseous reconstructions in the modern era. While there is abundant literature available on the variable branching pattern and course of the popliteal artery, tibial arteries, and dorsalis pedis artery, there is a paucity of text available on the not-so-common peroneal vessels.

[CASE REPORT] A case of a 60-year-old male who was diagnosed with carcinoma of buccal mucosa with involvement of the mandible of the right side was planned for wide local excision with modified radical neck dissection and resurfacing of the resultant defect using a contralateral free fibula osseocutaneous free flap. Intraoperatively, the peroneal vessels were noted to have a premature termination along the lateral border of distal one-third of the fibula, after giving a communicating branch to an anterior tibial artery. The flap was raised based on the same pedicle, without ligating any distal portion of the vessel. Reconstruction of the defect and post-operative recovery was uneventful. Full flap survival was observed.

[CONCLUSION] We report this case as this vascular "anomaly" is one of its kind and has been oblivious to the literature and practicing microsurgeons globally.