Skull Base Reconstruction with ALT Flap: Case Series

Objectives: In some cases, local reconstruction of central skull base defects is not possible when local tissue repair may fail or be unavailable; in such cases free tissue transfer may be necessary. Inset of the flap and management of the pedicle can be challenging. We report seven cases of free tissue transfer for large central skull base defects and approaches applied to address these issues.

Study Design: Case series.

Methods: Patients with central skull base defects underwent reconstruction using a free flap from 2016 to 2020 were analyzed retrospectively in a single institution.

Results: Five patients with recurrent nasopharyngeal carcinoma, one with clival-cervical chordoma, and one with meningioma of the middle cranial fossa were analyzed. All seven patients had prior radiation therapy to the skull base, with or without chemotherapy. Three additionally had skull base osteonecrosis secondary to radiation treatment. Six defects were closed with an anterolateral thigh free flap, and one with a radial forearm free flap. Various approaches to inset and pedicle routing were used. In three patients, the flap was routed through a parapharyngeal approach after the flap was inset into the nasopharynx with an endoscopic assisted approach. In two patients, a retropharyngeal tunnel was created up to the skull base to inset the flap underneath the diseased mucosa. In two others, a Caldwell-Luc was performed to route the pedicle anteriorly toward the facial vessels, and the flap was secured superiorly with endonasal sutures and fibrin glue. There were no flap failures, with an average follow-up time of 18.8 (range: 0.7–47.1) months. All seven patients showed no evidence of flap dehiscence, cerebrospinal fluid (CSF) leak, meningitis, or cancer recurrence. One patient required debulking of the fascial flap 3 days after surgery. Two patients required drainage of a parapharyngeal abscess or seroma, respectively.

Conclusion: Free tissue transfer for reconstruction of the central skull base is a difficult anatomical area to reach and repair, but a variety of approaches are possible to achieve an endoscopically assisted inset closure of the defect and passage of the pedicle.

Fig. 1 Postoperative MRI with contrast revealing ALT flap at the midline skull base.

No conflict of interest has been declared by the author(s).

Publication History

Article published online:
12 February 2021