Petroclival tumors: a synthesis.

This article focuses on petroclival tumors, which are rare lesions of the posterior fossa-an area that is difficult to access. Because of their location, rarity, insidious growth, and relentless natural progression toward a fatal outcome, petroclival tumors pose major management problems. With improved microsurgical techniques, however, these tumors can be approached and removed with preservation of vital neural and vascular structures.

Digital camera documentation system for facial nerve outcome assessment.

OBJECTIVE: To describe the use of a digital camera to document facial nerve function after skull base surgery. SETTING: Patients undergoing skull base surgery at a tertiary care otologic and neurotologic clinic were used in the study. INTERVENTIONS: None. RESULTS: A digital camera system provided still images and a video strip lasting less than a minute to document facial nerve motion. CONCLUSIONS: An inexpensive digital camera system can be used to capture still and moving images of facial nerve function on a floppy disk. The images can then be transferred to compact disks for storage of many patient files. Such a system allows documentation for research, exchange of data between offices, and patient education, and it can be used for medical-legal purposes among other uses.

Intratympanic steroid injections for intractable Ménière's disease.

OBJECTIVE: To examine whether intratympanic injection of dexamethasone is effective in controlling vertigo in patients with Ménière's disease who have persistent vertigo despite standard medical treatment, including a low-salt/no-caffeine diet and diuretics. STUDY DESIGN: A prospective study. METHODS: From August 1999 to November 2000, 21 patients with intractable Ménière's disease underwent intratympanic injections of 4 mg/mL dexamethasone over a period of 4 weeks as an office procedure. American Academy of Otolaryngology-Head and Neck Surgery guidelines for the definition and reporting of results in Ménière's disease were used. RESULTS: Complete relief of vertigo was maintained in 11 of the 21 patients (52%) at 3 months and in 9 of 21 patients (43%) at 6 months. Repeat injections in 5 patients who had initial control of vertigo, but later failed, yielded control in 3 (60%) patients. The complication rate was low: one patient had a 35-decibel pure tone average decrease in hearing during treatment and one patient had a persistent tympanic membrane perforation. CONCLUSIONS: Intratympanic injections of dexamethasone are a reasonable initial surgical treatment for persistent vertigo in Ménière's disease. The principal benefits are avoidance of systemic administration of steroids, lower cost than endolymphatic sac surgery, and ease of administration as an office procedure. The disadvantages are the need for repeated office visits for injections and the decreasing effectiveness over time.

A review of facial nerve outcome in 100 consecutive cases of acoustic tumor surgery.

OBJECTIVE: To determine the facial nerve outcomes at a tertiary neurotological referral center specializing in acoustic neuroma and skull base surgery. STUDY DESIGN: Retrospective review of 100 consecutive patients in whom acoustic neuromas were removed using all of the standard surgical approaches. METHODS: Functional facial nerve outcomes were independently assessed using the House-Brackmann facial nerve grading system. RESULTS: The tumors were categorized as small, medium, large, and giant. If one excludes the three patients with preoperative facial palsies, 100% of the small tumors, 98.6% of the medium tumors, 100% of the large tumors, and 71% of the giant tumors had facial nerve function grade I-II/VI after surgery. CONCLUSION: Facial nerve results from alternative nonsurgical treatments must be compared with facial nerve outcomes from experienced surgical centers. Based on the facial nerve outcomes from our 100 consecutive patients, microsurgical resection remains the preferred treatment modality for acoustic tumors.

Human studies of a piezoelectric transducer and a microphone for a totally implantable electronic hearing device.

OBJECTIVE: For the surgical treatment of patients with moderate and severe sensorineural hearing loss, the authors have developed a totally implantable hearing device, the totally integrated cochlea amplifier (TICA). To evaluate the effectiveness of transducer and microphone of this device, three separate human studies were conducted. STUDY DESIGN: The first study using transducer prototypes involved self experiments in investigators with normal hearing. The second study used the transducer prototypes in patients with hearing loss, and the third study involved the temporary implantation of the final transducer prototype and microphone in patients undergoing otologic surgery. PATIENTS: In routine middle ear surgery, transducer prototypes were coupled to the ossicular chain of 28 patients. In addition to the transducer, in 5 patients the microphone was placed beneath the skin of the auditory canal, allowing the skin to cover the microphone membrane completely. RESULTS: The piezoelectric transducer reached an equivalent sound pressure level of 145 dB SPL < or =10 kHz. The dynamics for music reached 32 dB, which was identical with the results of the preoperative investigations using high-fidelity headsets (33 dB). The low nonlinear distortions of <0.1% and the frequency range of 10 kHz are reflected in the positive evaluation of the sound quality by 84% of the patients involved. When phonetically balanced speech material and music were presented under free field conditions at a sound level of 65 dB SPL, understanding of the phonetically balanced speech material was 100%. Most patients judged the presentations of music as clear and undistorted with all broadband components. CONCLUSIONS: Data in humans on the performance of the two main components of the TICA implant, the transducer and the microphone, are reported.

Bilateral cochlear implants controlled by a single speech processor.

OBJECTIVE: This study aimed to assess, in one profoundly hearing impaired subject, potential benefits and limitations in placing bilaterally implanted scala tympani electrode arrays under control of a single speech processor. STUDY DESIGN: All available stimulation sites in both ears were compared in studies of pitch discrimination and pitch ranking, identifying three bilateral pairs capable of supporting interaural comparisons with no perceptible difference in pitch. Using those pairs, the subject's ability to lateralize sound was studied as a function of interaural time delay and interaural amplitude difference. Consonant identification scores were obtained for continuous interleaved sampling processors using various unilateral and bilateral combinations of electrodes. RESULTS: For loudness-matched stimuli composed of 50-msec bursts of 80-microsec/phase pulses at 480 pulses/sec, the subject was able to identify the ear receiving the earlier onset for interaural delays at least as brief as 150 microsec for all three matched pairs. For similar simultaneous stimuli, the subject could identify the ear receiving the louder signal for the smallest deviations from loudness-matched amplitudes available from the implanted electronics. The consonant studies found no evidence that bilateral stimulation per se degrades speech processor performance, even for arbitrary divisions of information between the two ears. Additional contralateral as well as ipsilateral channels were observed to improve speech processor performance. CONCLUSIONS: The ability of this subject to lateralize sounds on the basis of interaural delay or loudness difference, combined with the consonant identification results, supports further use of coordinated binaural stimulation to improve cochlear implant users' ability to understand speech, especially in the presence of competing speech noise.

A randomized, blinded study of canal wall up versus canal wall down mastoidectomy determining the differences in viewing middle ear anatomy and pathology.

HYPOTHESIS: Canal wall down and intact canal wall tympanomastoidectomy represent two surgical approaches to middle ear pathology. The authors hypothesize that there is a difference in the ability to view structures in the middle ear between these two methods. BACKGROUND: Depending on the individual, many surgeons have used the two different techniques of intact canal wall and canal wall down tympanomastoidectomy for approaching the middle ear. However, opinions conflict as to which approach provides the best visualization of different locations in the middle ear. This study prospectively evaluated temporal bones to determine the differences in visualizing structures of the middle ear using these two approaches. METHODS: Twelve temporal bones underwent a standardized canal wall down tympanomastoidectomy using a reversible canal wall down technique. All bones were viewed in two dissections: intact canal wall and canal wall down preparations. Four points previously had been marked on each temporal bone in randomly assigned colors. These points include the sinus tympani, posterior crus of stapes, lateral epitympanum, and the Eustachian tube orifice. An observer blinded to the purpose of the study, color, and number of locations recorded the color and location of marks observed within the temporal bones. Randomized bones of two separate settings were viewed such that each bone was viewed in both the canal wall down and the intact canal wall preparations. RESULTS: A significant difference was noted in the ability to observe middle ear pathology between the intact canal wall versus canal wall down tympanomastoidectomy, with the latter showing superiority (p < 0.001). Of the four subsites, the sinus tympani, posterior crus of stapes, and lateral epitympanum were observed more frequently with the canal wall down. There was no significant difference in the ability to observe the Eustachian tube orifice between the two techniques. CONCLUSIONS: Statistical analysis shows good reproducibility and randomization of this study. The canal wall down tympanomastoidectomy allowed for superior viewing of the three locations, sinus tympanic, posterior crus of stapes, and lateral at the tympanum, as they were marked in the study. This study shows the potential for improved visualization via the canal wall down tympanomastoidectomy. A significant amount of literature written by individuals and otology group practices is available retrospectively comparing the advantages and disadvantages of intact canal wall versus canal wall down mastoidectomy procedures for approaching middle ear pathology. In the interest of objectively evaluating the differences between these two approaches, we have studied temporal bones in a prospective randomized, blinded study comparing the two. Twelve bones were used and observed twice, once in each of 2 sessions. All bones were viewed in two dissections: intact canal wall and canal wall down mastoidectomy. Four points were marked on each temporal bone in three different colors applied in a randomized order to eliminate observer expectation. The four points marked include sinus tympani, posterior crus of the stapes footplate, lateral epitympanum, and Eustachian tube orifice. Both intact canal wall and canal wall down bones were provided randomly to the observer at each viewing session. Before the observer was allowed to see the dissections, those requiring replacement of the canal for the first session of the study had this done in a method using native posterior bony canal. Temporal bones were presented to an expert otologist in a randomized fashion with each temporal bone being placed in a temporal bone bowl holder and specialized framework, allowing for rotation and repositioning approximating the experience in an operating room setting. For each temporal bone, the observer filled in a questionnaire describing his or her observations by denoting both location and color of marks observed. (ABSTRACT TRUNCATED)

Reversible canal wall down tympanomastoidectomy. An alternative to intact canal wall and canal wall down mastoidectomy procedures.

OBJECTIVE: To avoid the limitations of canal wall down surgery yet maintain the exposure provided by canal wall down mastoidectomy, the authors have developed a completely "reversible" canal wall down mastoidectomy technique. The purpose of this case report is to determine the feasibility of the "reversible" canal wall down mastoidectomy technique in the treatment of a patient with an aural cholesteatoma. STUDY DESIGN: Having refined the surgical technique using cadaver temporal bones, the "reversible" canal wall down mastoidectomy was performed in a patient with a recurrent aural cholesteatoma. SETTING: The surgical technique was refined in the Carolina Ear Research Institute's temporal bone dissection lab. The patient underwent the surgical procedure by JTM in a standard operating room setting at a private hospital in Raleigh, North Carolina. PATIENTS: The patient was a private patient, referred to the Carolina Ear & Hearing Clinic for treatment of recurrent cholesteatoma. INTERVENTION: A "reversible" canal wall down mastoidectomy was performed in this patient. MAIN OUTCOME MEASURES: The surgeon determined the adequacy of cholesteatoma exposure following temporary removal of the posterior bony canal wall. Intra-operatively, the surgeon assessed the repositioned posterior bony canal segment, looking specifically at its stability and the absence of gaps along the canal cuts. RESULTS: Temporary removal of the posterior bony canal wall improved exposure of the cholesteatoma and facilitated cholesteatoma removal. The repositioned bony canal segment was well stabilized by the bone cement (Oto-cem) and no gaps were noted along the canal cuts. CONCLUSION: Although it is premature to compare the effectiveness of the "reversible" canal wall down technique to other mastoidectomy procedures, this case confirms the feasibility of this approach.

Bone cement reconstruction of the ossicular chain: a preliminary report.

OBJECTIVE: To determine the feasibility and efficacy of using a bone cement, Oto-Cem, to reconstruct the ossicular chain. STUDY DESIGN: Prospective clinical trial on nine consecutively chosen adult patients with ossicular chain defects. PATIENTS AND SETTING: Nine patients with ossicular chain defects involving the long process of the incus were treated at the Carolina Ear and Hearing Clinic. The ossicular chain was reconstructed using bone cement by itself or in conjunction with a stapes prosthesis. MAIN OUTCOME MEASURES: Preoperative audiograms were compared with audiograms 3, 6, and 12 months after reconstruction. RESULTS: There was a mean pure-tone average (PTA) improvement of 15 dB in patients undergoing incus to stapes suprastructure reconstruction with the bone cement. The incus to mobile footplate reconstruction (using a stapes prosthesis attached to the newly reconstructed incus) resulted in a 34-dB PTA postoperative improvement. Two of the three patients with incus to oval window repairs experienced a 10-dB improvement in PTA. One of the three patients experienced a loss in speech discrimination and a 2-dB loss in PTA. CONCLUSIONS: Despite the limited number of patients, this preliminary study demonstrates the effectiveness of Oto-Cem in reconstructing a foreshortened incus. There was a substantial hearing improvement in all but one patient in the incus to stapes or the incus to footplate categories.

Cochlear implantation in common cavity malformations using a transmastoid labyrinthotomy approach.

The transmastoid facial recess approach has become the standard technique for cochlear implantation. Although this approach has been used for implantation in patients with common cavity deformities, it is not without increased risk to the facial nerve. Using a direct approach to the common cavity that circumvents the facial recess, we have successfully implanted four patients with common cavity deformities. An aberrant facial nerve in one patient would have precluded placement of the electrode array using standard cochlear implant techniques. As demonstrated in these four patients, the direct approach to the common cavity is an effective approach for placement of the electrode array, minimizes risk to the facial nerve, and may decrease the likelihood of postoperative cerebrospinal fluid leaks. Intraoperative video footage demonstrates the feasibility and facility of this approach in patients with common cavity deformities.

Plasma cell granuloma of the temporal bone.

Plasma cell granulomas are uncommon, benign tumors comprised primarily of mature plasma cells and are a distinct entity, separate from plasmacytomas. They are rarely found in the head and neck, and have never been reported in the temporal bone. This case represents the first report of a plasma cell granuloma originating in the temporal bone. Treatment options include surgical removal and radiation therapy.

Ossiculoplasty with polymaleinate ionomeric prosthesis.

With the continued concern over the possible transmission of viral infections through homologous middle ear implants, there is increasing pressure to develop a truly biocompatible alloplastic middle ear prosthesis. The polymaleinate ionomer, which has been used in dentistry as a filling and luting material for more than 15 years, has recently been used to construct total and partial ossicular replacement prostheses. In an attempt to evaluate these new implants, a multicenter prospective clinical trial was initiated. To date, 92 patients have undergone implantation. The follow-up interval ranged from 3 months to 22 months. Although it is premature to discuss the long-term results, the preliminary surgical experience and audiometric data with these implants are reviewed. From a surgical perspective, the ionomeric prostheses were easily contoured with a diamond burr and were not prone to shattering. Preliminary follow-up audiometric data were available on 80 patients (59 partial ossicular replacement prostheses and 21 total ossicular replacement prostheses). Of the 59 partial ossicular replacement prostheses the air-bone gaps (average of 500 Hz, 1 kHz, 2 kHz and 3 kHz) were as follows: 0 dB to 10 dB, 15 (25%) of 59; 11 dB to 20 dB, 20 (34%) of 59; 21 dB to 30 dB, 11 (19%) of 59; and greater than 30 dB, 13 (22%) of 59. Of the 21 total ossicular replacement prostheses the air-bone gaps were as follows: 0 dB to 10 dB, 6 (29%) of 21; 11 dB to 20 dB, 6 (29%) of 21; 21 dB to 30 dB, 5 (24%) of 21; and greater than 30 dB, 4 (19%) of 21.

Cochlear implant-related osteoneogenesis in an animal model: fluorescent labeling.

Cochlear osteoneogenesis may result from a variety of pathologic conditions, including cochlear implantation. The etiology of cochlear osteoneogenesis following implantation, however, is not known. Cochlear implant-related osteoneogenesis has been demonstrated in laboratory animals, but the specific cause, extent, or time-course of this process has not been determined. In this preliminary study, fluorescent bone labels were used to assess osteoneogenesis in six chinchillas in three experimental categories: surgical trauma to the cochlea, chronic nonstimulated cochlear implantation, and intrascalar neomycin infusion. Computer image analysis was used to measure the area of labeled bone on representative mid-modiolar histologic sections. The amount of bone deposition was greatest in ears treated with intracochlear neomycin (mean = 2.3835 mm2, SD = 3.7308). Surgical trauma alone (mean = 0.9549 mm2, SD = 1.384) and chronic implantation without stimulation did not produce substantial bone growth when compared to contralateral control ears (mean = 0.0574 mm2, SD = 0.0731). Fluorochrome labeling was also used to differentiate types of bone deposition. The morphology and timing of new bone growth appeared to be related to the type of cochlear injury. These results confirm that intracochlear neomycin may contribute to osteoneogenesis in animal studies of cochlear implantation. This study supports the use of fluorescent bone labeling in the evaluation of cochlear osteoneogenesis.

Ossiculoplasty with polymaleinate ionomeric prostheses.

This article discusses the role of the new Ionomeric middle ear prostheses for ossicular chain reconstruction. Although the prostheses are composed of a rigid alloplastic material, they can be easily sculpted to conform to the middle ear anatomy.

Unusual cerebello-pontine angle tumours.

Fifty-nine unusual cerebello-pontine angle tumours have been studied. These lesions represent 19.3 per cent or 1 in 5 of a series of 305 cerebello-pontine angle tumours of which the rest, 246 (80.7 per cent), were acoustic neuromas. An analysis of the relative incidence, histology and presenting clinical features has been carried out. The various radiographical features and imaging techniques used to diagnose these fascinating tumours have been described and also the otoneurosurgical procedures necessary to excise them.

Hearing preservation using the modified translabyrinthine approach.

Removal of an acoustic neuroma using the translabyrinthine approach has previously been considered "incompatible" with hearing preservation. By modifying the approach and preventing the loss of endolymph, we have successfully removed two intracanalicular acoustic neuromas that originated from the inferior vestibular nerves, and preserved serviceable hearing in the ears operated on. This report represents the preliminary findings using this particular technique in the management of intracanalicular acoustic neuromas.

Cochlear implantation in the congenitally malformed ear.

A child with a congenital hearing loss and auricular malformations was evaluated for cochlear implantation. Preoperative radiologic studies demonstrated a common cavity cochlear malformation and a contralateral narrow internal auditory canal. Intraoperative findings included an aberrantly coursing facial nerve, preventing routine placement of the electrode array. The surgical approach was consequently modified and the cochlea was accessed through a malformed semicircular canal. Cochlear implantation can be performed safely and effectively in children with congenitally malformed ears.

Reconstruction of the radical mastoid.

Open cavity techniques (radical mastoidectomy, canal wall down tympanomastoidectomy, modified radical mastoidectomy) are well established surgical procedures for the treatment of chronic otitis media. Despite their effectiveness in exteriorizing cholesteatoma, they are associated with a 20 to 60 percent incidence of persistent intermittent drainage. In an effort to eliminate this problem, we have employed a Palva flap and medial graft technique to reconstruct the mastoid cavity and middle ear space in those patients with chronically draining ears. Between 1987 and 1990, 28 patients underwent this procedure. Twenty-six of these (93%) had complete obliteration of the mastoid cavity and successful tympanic membrane reconstruction. Two of 28 (7%) had a persistent tympanic membrane perforation and intermittent drainage following their surgery. Based on these results, this procedure is effective in eliminating intermittent drainage associated with the open cavity techniques. The indications for this procedure, the specifics of the surgical technique, and the postoperative results are discussed.