Four-channel electromyography of the facial nerve in vestibular schwannoma surgery: sensitivity and prognostic value for short-term facial function outcome.

OBJECTIVE: To evaluate the short-term facial prognostic value of a four-channel facial electromyographic device in vestibular schwannoma surgery. STUDY DESIGN: Eighty-nine vestibular schwannomas operated on and intraoperatively monitored by a four-channel facial electromyographic device between October 2002 and September 2003 were included in this prospective study. Detection was performed in frontal, orbicularis oculi, orbicularis oris, and platysma muscles. MAIN OUTCOME MEASURE: Facial function grading at postoperative Days 1, 8, 30, and 180 (House-Brackmann classification). SETTING: Tertiary referral center. RESULTS: Postoperative facial function at Day 180 was assessed as Grade 1 or 2 in 80%, as Grade 3 or 4 in 16%, and as Grade 5 or 6 in 4% (n=80). The postoperative facial function was related to the intraoperative nerve stimuli thresholds (range, 0.01-3 mA for a response >100 microV) near the brainstem and the proximal-to-distal ratio of the stimulation threshold. A proximal threshold between 0.01 and 0.04 mA had a positive predictive value of 94% for good facial function (Grade 1 or 2). The proximal threshold was lower in patients with improving or stable facial function in comparison with those with a delayed deterioration between Days 8 and 30. The stimulation threshold at the adhesion zone was related to the immediate facial function outcome. The maximal electromyographic response was detected in the frontal muscle or the platysma in 27% of cases and in orbicularis oris and oculi in 73% of cases. CONCLUSION: A four-channel device may enhance electromyographic sensitivity. Determination of stimulation threshold below 0.05 mA yields facial prognostic information.

Long-term functional outcome in facial nerve graft by fibrin glue in the temporal bone and cerebellopontine angle.

The aim of this study was to evaluate the functional outcome of facial nerve repair with fibrin glue in end-to-end anastomosis and intermediate nerve graft. Thirty-six patients undergoing facial nerve repair by end-to-end anastomosis or facial nerve grafting using exclusively fibrin glue between 1986 and 1999 were included in this retrospective study. The population comprised ten vestibular schwannomas (28%), nine temporal bone fractures (25%), seven facial nerve schwannomas (19%), four facial nerve hemangiomas (11%), two iatrogenic facial nerve interruptions (6%) and four miscellaneous facial nerve lesions (11%). Data were reviewed concerning etiology, location of the nerve interruption, type of repair and postoperative facial function according to the repaired facial nerve recovery scale (A: normal; B: independent movements of eyelid and mouth; C: strong closure of eyelids and mouth; D: incomplete eyelid closure; E: minimal movement; F: no movement). Eleven patients (31%) underwent end-to-end nerve anastomosis and 25 (69%) underwent intermediate facial nerve grafting. The mean follow-up period was 50 months (range: 3-95). Among patients followed-up more than 18 months (n = 20), a score of B or C was obtained in 16 patients (80%), a score D in 2 cases (10%) and a score E in 2 cases (10%). The type of repair and the site of interruption did not influence the results. Fibrin glue is a simple, rapid and efficient means of facial nerve repair. In case of intraoperative facial nerve interruption, this type of repair can be attempted in any location at the time of the tumor removal.

Ossiculoplasty with total hydroxylapatite prostheses anatomical and functional outcomes.

OBJECTIVE: To evaluate the results of partial and total ossicular reconstruction prostheses entirely made of hydroxylapatite. STUDY DESIGN: A retrospective review of cases followed-up between 1997 and 2000. SETTING: Tertiary referral center. PATIENTS: One hundred adult patients (60 men and 40 women) were studied. The mean age was 55 years (range, 25 to 65 years). Fifty patients had a previous tympanoplasty. The series included 45 cholesteatomas (45%), 37 chronic otitis media without cholesteatoma (37%), 13 retraction pockets (13%), and 5 posttraumatic ossicular displacements (5%). INTERVENTION: A one-stage ossiculoplasty with a partial ossicular reconstruction prosthesis (n = 65) or a total ossicular reconstruction prosthesis (n = 35) was performed. This was associated with a simple mastoidectomy in 70 cases and a radical mastoidectomy in 10 cases. MAIN OUTCOME MEASURES: All patients were followed-up at 1 year, and 50 were reexamined 2 years after surgery. Clinical and audiometric data were collected in a database at each visit. RESULTS: A prosthetic extrusion was noted in two cases (2%). A prosthetic displacement occurred in 10 cases (10%). A revision surgery was carried out in 10 cases because of an ossiculoplasty failure or a disease recurrence. At 1 year, the residual air-bone gap was lower in cases with a partial ossicular reconstruction prosthesis than those with a total ossicular reconstruction prosthesis (16 +/- 9.3 versus 23 +/- 13.7 dB, p < 0.05). The gain in mean air conduction threshold was 21 +/- 12.8 dB in cases of partial ossicular reconstruction prosthesis and 19 +/- 11.3 dB in cases of total ossicular reconstruction prosthesis (not significant). Revision surgery, canal wall-down mastoidectomy, or cholesteatoma yielded poorer functional results. CONCLUSION: Partial ossicular reconstruction prosthesis and total ossicular reconstruction prosthesis entirely made of dense hydroxylapatite yielded high rates of air-bone gap reduction and high anatomic stability.