(0530) Radial Forearm Free Flap Reconstruction of a Midline Skull Base Defect Via a Parapharyngeal Corridor

Introduction: The clivus has been a traditionally difficult area to access, both in regards to the removal of tumors as well as reconstruction. The nasoseptal flap is an invaluable reconstructive option for defects of this region. However in the extensively operated patient, other options must be considered when reconstruction of the anterior skull base is necessary.

Methods: Here we present a case of a 54-year-old female with extensive chordoma of the clivus diagnosed in December 2020 and treated with proton beam therapy. Post treatment imaging revealed disease progression. Further treatment necessitated staged endoscopic endonasal resection (July 2023) followed by far lateral transcervical approach to lower clivus (October 2023). She subsequently developed osteomyelitis of the clivus with exposed bone noted on nasal endoscopy.

Due to osteomyelitis, the patient necessitated endonasal debridement and posterior cervical fusion to prevent critical instability of her spine. Prior surgery resulted in a lack of local reconstructive options to bring in vascularized tissue to cover the affected bone, and the decision was made to pursue a radial forearm free flap. The flap was harvested in a fasciocutaneous manner and introduced into the nasopharynx via a parapharyngeal space corridor. The flap was sutured into the inferior aspect of the defect via a transoral approach. The superior portion of the flap inset was performed endoscopically. Staged posterior fusion was performed four days later.

On post operative day 7, the nasal packing was removed and the distal flap pedicle was noted to be exposed and she was returned to the operating room the next day for nasal endoscopy in order to reposition the flap and cover the distal pedicle.

Results: The patient has been seen at one month postoperatively and noted to be healing well. The flap has remained in good position with no exposure of the distal flap pedicle and adequate coverage of the nasopharyngeal defect.

Conclusions: The radial forearm free flap is a viable option for reconstruction of the difficult to reach regions of the anterior skull base when local flap options are not available.