DATE OF OPERATION: MM/DD/YYYY
PREOPERATIVE DIAGNOSIS: Radionecrosis of the temporal bone.
POSTOPERATIVE DIAGNOSIS: Radionecrosis of the temporal bone.
PROCEDURE PERFORMED: Right radical mastoidectomy, petrosectomy, facial nerve exploration, decompression, and split-thickness skin grafting.
SURGEON: John Doe, MD
ANESTHESIA: General.
INDICATION FOR PROCEDURE: The patient is status post radiation therapy for a malignant brain tumor. Several years ago, the patient underwent tympanomastoidectomy for chronic aural suppuration and now presents with deep-seated skull-based pain, aural suppuration, and CT evidence of substantial soft tissue and bony erosion of the temporal bone.
DESCRIPTION OF PROCEDURE: Following satisfactory oral endotracheal anesthesia, the right ear and hemicranium were prepped and draped in the usual fashion. The right lower extremity was prepped out for split-thickness skin graft. A postaural incision was made and carried down through the skin and subcutaneous tissue. A C-shaped incision was made behind the previously created mastoid cavity. Soft tissue was elevated out of the mastoid cavity revealing a huge amount of cholesterol granuloma, granulation tissue, and necrotic bone. The partially-eroded posterior canal wall was identified and the mid vertical segment of the facial nerve, which had been appreciated at prior surgery, was now identified and stimulated with the Prass probe.
Soft tissue was elevated down to the fibrous annulus. The middle ear space was entered. The middle ear was filled with polyp and granulation tissue. The incudostapedial complex was identified. The IS joint was separated. The incus was removed. Circumferentially, the very thickened eardrum was now stripped from the malleus and removed in toto.
Beginning at the protympanum, opening of the eustachian tube, a thick carpet of fibroglandular tissue and thick mucous membranes were evacuated from the tube. It has eroded partially the common party wall with the carotid artery and a small amount of granulation and thickened mucous membrane was left attendant to the artery. Granulation was swept in towards the hypotympanum. All mucous membrane was stripped from the promontory with a small knuckle left attendant to the round window niche. Debris was removed from the sinus tympani.
Cephalically, the cochleariform process was identified and the tympanic segment of the facial nerve was identified. Using suction irrigator and a cutting bur, the mastoid cavity was recontoured. Tegmen was identified superiorly, the sigmoid sinus posteriorly. Retrolabyrinthine and presigmoid space was now decorticated down to the posterior fossa dura, and using a diamond polishing bur, the posterior petrous apex was opened widely with granulation tissue removed. The endolymphatic sac was identified and the infralabyrinthine retrofacial space was now opened widely to the dome of the jugular bulb.
At the level of the horizontal canal, the incus was removed and the posterior canal wall was now removed. The facial nerve was followed from the cochleariform process through the tympanic segment, the facial recess in its vertical segment. The epitympanic area was filled with necrotic debris and very soft mushy bone. Bone was decorticated along the tegmen plate. The perilabyrinthine cells were decorticated. The posterior-superior tract was opened widely. Just anterior to the superior semicircular canal, the facial nerve was now followed to its first genu and then medially to the geniculate ganglion.
Again because of favorable architecture, wide pneumatization and bone destruction, this area was achieved without disturbing the labyrinth. Granulation tissue and hypertrophic swollen mucous membrane was now microdissected as the facial nerve was decompressed from this material. The bony fallopian canal has essentially been eroded completely at the first genua through most of the tympanic segment. In the anterior epitympanic region, granulation tissue and bone was removed.
At this point, the field was copiously irrigated and with the perilabyrinthine and both supra and infralabyrinthine, as well as infracochlear tract opened to the apex, the field was copiously washed out with bacitracin solution. Granulation tissue was now gently elevated off of the superstructure, the staples which appears to have been eroded from the footplate. The footplate itself was mobile and clear. There was no evidence of squame at this point. Gelfoam impregnated with adrenalin filled the cavity. The right lower extremity was prepared, and a split-thickness skin graft was harvested. The wound site was hemostased with a sponge impregnated with adrenalin and then prepared with Adaptic.
A muscle graft was harvested from the temporalis area and a laterally-based conchomeatal flap was created with Lempert I and III incisions being made. The conchal cartilage was removed. Now, split-thickness skin grafts were contoured into the cavity after obliterating the eustachian tube with a muscle graft. The grafts were laid in to cover all bone, including the facial nerve.
The laterally-based conchomeatal flap was loosely tethered to the pericranium posteriorly and Nu Gauze packing impregnated with Polysporin ointment was used to pack the operative field and meatal introitus. Xomed facial nerve monitor NIM 2 unit, which had been employed during the course of surgery with active electrodes to orbicularis oculi and marginal mandibular with ground electrode to the dependent shoulder, was removed. A dry sterile compression dressing was applied after a layered closure was accomplished. The patient was awakened from anesthesia and delivered to the recovery room in satisfactory condition.
