CPT® Code 69955

Total facial nerve decompression and/or repair, as described by CPT® Code 69955, is a surgical procedure aimed at addressing issues related to the facial nerve, which is crucial for facial movement and sensation. The facial nerve is anatomically divided into three distinct regions: the intracranial, intratemporal, and extratemporal segments. This procedure typically begins with a surgical incision made behind the ear, followed by a mastoidectomy, which is the removal of the mastoid bone to gain access to the facial nerve. The surgeon then carefully exposes the nerve along its vertical segment, reaching the stylomastoid foramen, where the nerve exits the skull. To facilitate this exposure, the surgeon removes the bone overlying the nerve using a surgical burr. The procedure also involves accessing the tympanic cavity through the facial recess, necessitating the removal of additional bone over the tympanic segment of the nerve. The labyrinthine portion of the nerve is subsequently exposed. Depending on the surgical approach, the postauricular incision may be extended in a posterosuperior direction, or an additional incision may be made behind and above the ear to enhance visibility and access. During the procedure, the skin is elevated to reveal the temporal muscle fascia, which is then incised and elevated to allow further access. A temporal bone flap is created and elevated, continuing the dissection to the petrous ridge, where critical anatomical landmarks such as the arcuate eminence and greater petrosal nerve are identified. The surgeon meticulously dissects the bone until reaching the previously accessed tympanic cavity. Once the facial nerve is adequately exposed, it is inspected and tested for functionality. If necessary, neurolysis is performed to free the nerve from any surrounding tissue that may be compressing it. In cases where the nerve sheath is compromised, it may be incised to relieve pressure on the nerve. Any injured segments of the nerve are repaired using fine microfilament sutures, employing specialized microinstruments and an operating microscope to ensure precision. If nerve grafting is indicated, grafts are harvested and utilized to replace the damaged sections of the nerve. Upon completion of the nerve repair, the surgeon addresses any surgical defects in the tympanic cavity and internal auditory canal by repositioning the bone flaps to prevent complications such as herniation of the temporal lobe into the middle ear. Additionally, any dural defects are repaired using temporalis fascia grafting. Finally, the temporal bone flap is replaced and secured with sutures, and the overlying tissues are meticulously closed in layers to promote optimal healing.