The American journal of otology最新文献

Objective: To determine the risk of recurrent tumor in patients after incomplete resection of acoustic neuroma.

Study design: Retrospective case review.

Setting: A tertiary referral center.

Patients: Thirty-nine patients were identified who underwent incomplete resection of acoustic neuroma between January 1988 and December 1993, and had a minimum follow-up of 3.5 years, at a mean of 6.2 years (range 3.5-10.2 years).

Intervention: Regular follow-up. using either computed axial tomography or magnetic resonance imaging yearly.

Main outcome measures: Growth of residual tumor as determined by the increase in its greatest dimension on follow-up imaging studies and the necessity for additional treatment.

Results: Tumor regrowth occurred in 17 patients (44%). Ten patients (26%) required additional treatment during the follow-up period.

Conclusion: This study suggests that incomplete resection of acoustic neuroma is associated with a significant risk of recurrent tumor requiring subsequent intervention.

Objective: To determine spontaneous involution of unilateral acoustic tumors in untreated patients.

Study design: Outcome of a continuous study, 1982 to present.

Setting: Private tertiary otology/neurotology referral center.

Patients: Patients with unilateral acoustic tumors for whom interval imaging was selected rather than surgery or gamma knife radiation, 1982 to the present.

Intervention: Interval imaging with computerized axial tomography and/or magnetic resonance imaging.

Main outcome measure: Spontaneous involution of acoustic tumors.

Results: Forty-seven patients with unilateral acoustic tumors were untreated and followed up with interval imaging for 1 to 12.5 years. Six patients (13%), whose ages ranged from 59 to 74 years and who were followed up for 4.3 to 12.5 years, demonstrated imaging evidence of spontaneous acoustic tumor involution. Involution varied from 3.4 mm to 15 mm.

Conclusions: Spontaneous involution of acoustic tumors does occur. Long-term follow-up is necessary to determine this potential.

Objective: Treatment of idiopathic peripheral facial paralysis has remained controversial in many aspects. The authors report their experience with a protocol based on high-dose prednisolone with intravenous low-molecular-weight dextran and pentoxifylline. For this regimen, the term antiphlogistic-rheologic infusion therapy (ARIT) has been coined.

Study design: Retrospective case-series review.

Setting: University-based hospital of otorhinolaryngology/head and neck surgery.

Patients: 334 patients suffering from sudden facial paralysis of unknown cause.

Intervention: Treatment consisted uniformly of prednisolone in a starting dosage of 250 mg tapering over 18 days and accompanying infusion of dextran and pentoxifylline.

Main outcome measures: Facial nerve function after 6 months, adverse effects of therapy and comorbidity.

Results: From 239 patients with nonrecurrent palsy having received treatment within 12 days after onset, 92% recovered completely (House-Brackmann [HB] Grade I) without sequelae. In incomplete palsy (HB Grade II-V), normal facial function was restored in 97% of cases. Results were significantly better in the group in which therapy had been started within 3 days after the onset of palsy. Other factors such as old age, hypertension, or diabetes did not seem to influence the functional outcome in this series. Serious adverse effects requiring termination of therapy were observed in 1.2% of cases.

Conclusion: ARIT for Bell's palsy is safe and leads to recovery rates superior to the most optimistic observations of the natural course.

Objective: The surgical management of the atelectatic ear is controversial because the natural course toward cholesteatoma development cannot be predicted, and hearing acuity remains normal until later in the disease course. Consequently, surgery is often delayed until there is a clear indication, such as hearing loss or frank cholesteatoma development, but such delay often necessitates more extensive surgery. Because earlier intervention appears to be in the best interest of the patient but is often avoided because of near normal hearing levels at this stage, the author proposes a staging system for classification and management of the atelectatic ear. Hearing results and complications in patients undergoing tympanoplasty with or without ossicular reconstruction are reported for patients with type III and IV retractions.

Study design: A retrospective study using a computerized otologic database to identify patients who meet the inclusion criteria.

Setting: A tertiary referral center.

Patients: A total of 55 patients (63 ears) aged 5 to 78 years underwent cartilage tympanoplasty with or without ossicular reconstruction.

Interventions: Elevation of the ear drum, followed by cartilage reconstruction of the tympanic membrane, with ossicular reconstruction as indicated.

Main outcome measures: Postoperative pure tone average air-bone gap for four frequencies (500, 1000, 2000, 4000 Hz) compared with preoperative levels.

Results: There was a statistically significant improvement in hearing (p < 0.05).

Conclusions: This staging system offers an effective treatment algorithm for pars tensa retractions and management of type III and IV retractions via cartilage tympanoplasty with or without ossicular reconstruction and is a proven treatment modality.

Hypothesis: To determine the degree to which the fundus of the internal auditory canal (IAC) can be visualized during the middle fossa approach (MFA).

Background: Conventional wisdom states that the MFA provides excellent access to the IAC from the porus acusticus to the fundus. On the basis of observations derived from a substantial surgical experience, it became obvious that a variable fraction of the fundus lies obscure from the surgeon's line of sight during the MFA because of (1) the overhand of the transverse crest and/or (2) the immobility of the facial nerve at its entry into the fallopian canal.

Methods: Intraoperative measurements were performed in ten cases to determine the typical angle of view to the fundus of the IAC in the MFA. This angle of view was projected onto coronal computed tomography scans of 40 temporal bones. Measurements of the IAC were made to determine the amount of fundus that could not be directly visualized during a MF exposure.

Results: On the basis of a surgical line of sight, the fraction of the inferior compartment of the canal that could not be directly visualized because of overhand of the transverse crest ranged from 14% to 34% (median 25%).

Conclusions: Complete resection of IAC tumors involving the fundus via the MFA requires some degree of blind dissection. Specialized tools and techniques are required to minimize the risk of neural injury during this indirect dissection. Inspection of the fundus with either mirror or endoscope is often necessary to exclude the possibility of retained tumor fragments.

Objective: Hearing loss remains the most common symptom associated with acoustic neuroma. This study documents the audiometric findings from 721 acoustic neuroma procedures.

Study design: This was a retrospective study. The preoperative audiometric data were compiled and were analyzed by patient age, gender, tumor size, time of surgery, and neurofibromatosis Type 2 (NF 2). Postoperative audiometric data were arranged and compiled in the same way. The hearing classification proposed by the AAO-HNS was applied to all preoperative and postoperative cases.

Setting: Tertiary referral center.

Patients: Surgically confirmed acoustic neuroma patients who had not previously received surgical or radiosurgical therapy. Patients underwent surgery by the retrosigmoid approach.

Intervention: Surgical removal of an acoustic neuroma. MAIN OUTCOME RESULT: Provision of pure tone and speech data from a group of acoustic neuroma patients, including application of the recently introduced and accepted AAO-HNS hearing classification system.

Results: Preoperative audiometric data were obtained from 694 of 721 patients (96%), of whom 619 had measurable hearing. Postoperative audiometry was performed on 606 patients; 152 had usable data. The combined preoperative audiometric data revealed a high frequency sensorineural hearing loss. Word recognition was servicable. The postoperative pure tones and word recognition scores were worse than preoperative scores. Age, gender, tumor size, and time of surgery had some impact on the preoperative hearing and the postoperative result; NF 2 did not.

Conclusions: The study confirms that hearing alteration is almost universal in acoustic neuroma patients. Hearing preservation is possible in a significant number of cases; however, the postoperative auditory function tends to be worse.

Objective: Patients with benign paroxysmal positional vertigo (BPPV) often experience postural instability as well as brief episodes of vertigo. The purpose of this study was to determine whether successful resolution of the episodic vertigo, through use of the canalith repositioning treatment, would be accompanied by improvement in postural stability.

Study design: Prospective clinical study.

Setting: Outpatient tertiary care facility in a university.

Patients: Thirty-three patients with a diagnosis of the canalithiasis form of BPPV affecting the posterior canal unilaterally. All patients had complete remission of the positional vertigo after treatment. Patients with abnormal caloric or rotary chair test results were excluded from the study.

Intervention: The posterior canal BPPV was treated by the canalith repositioning treatment.

Main outcome measures: Postural stability was assessed by computerized dynamic posturography before and 1 to 2 weeks after treatment. Six different subtests were used.

Results: A significant number of patients had abnormal stability, as measured with computerized dynamic posturography, before treatment. After treatment there was a significant increase in the number of subjects with normal results on the different subtests; however, not all patients had normal postural stability. Younger subjects were more likely to show improved stability.

Conclusions: Treatment of BPPV using the canalith repositioning treatment results in improved postural stability in patients with BPPV. Not all patients have normal stability after treatment, however, and assessment and treatment of the balance problems may be necessary.

Background: Temporalis fascia, perichondrium, and cartilage are commonly used for reconstruction of the tympanic membrane in middle ear surgery. Cartilage grafts offer the advantage of higher mechanical stability, particularly in cases of chronic tubal dysfunction, adhesive processes, or total defects of the tympanic membrane, in contrast to fascia and perichondrium, which presumably offer better acoustic quality.

Hypothesis: The purpose of this study was to determine the acoustic transfer characteristics of cartilage of varying thickness and its mechanical deformation when exposed to fluctuations in atmospheric pressure.

Method: Ten pairs of cartilage specimens from the cavum conchae and the tragus were obtained from fresh human cadavers. Young's modulus was determined by mechanical tension tests and statistically evaluated using the t test. The acoustic transfer characteristics of an additional 10 specimens were measured by a laser Doppler Interferometer after stimulation with white noise in an external auditory canal--tympanic membrane model. Mechanical stability was determined by measuring displacement of the cartilage using static pressure loads of < or = 4 kPa.

Results: Young's modulus determinations for conchal and tragal cartilage were 3.4 N/mm2 and 2.8 N/mm2, respectively, but the difference was not significant. Acoustic testing showed a 5-dB higher vibration amplitude in the midfrequency range for conchal compared with tragal cartilage, but the difference was not significant. Reducing cartilage thickness led to an improvement of its acoustic transfer qualities, with a thickness < or = 500 microm resulting in an acceptable acoustic transfer loss compared with the tympanic membrane.

Conclusion: Both conchal and tragal cartilage are useful for reconstruction of the tympanic membrane from the perspective of their acoustic properties. The acoustic transfer loss of cartilage can be reduced by decreasing its thickness. A thickness of 500 microm is regarded as a good compromise between sufficient mechanical stability and low acoustic transfer loss.

Hypothesis: The adhesive octylcyanoacrylate is not associated with significant inner ear toxicity in a guinea pig model.

Background: Many cyanoacrylate adhesives have been investigated for use in otologic surgery, but variable ototoxicity has been reported. Octylcyanoacrylate is a medical-grade adhesive with many properties that make it ideal for use in the ear. It is free of contaminants; it forms a strong, flexible bond; and it inhibits the growth of gram-positive organisms in culture. This is the first study to assess the ototoxicity of this new adhesive.

Methods: Fourteen adult guinea pigs were used. Preoperative auditory brainstem responses (ABRs) were determined. Bilateral antrotomies were performed, and the ears were randomized to adhesive and control (saline) groups. In the adhesive ears. 0.5 or 0.1 mL of octylcyanoacrylate was instilled into the middle ear. Eight weeks later, postoperative ABRs were determined, the animals were killed, and the temporal bones were removed. Middle ear changes were noted, and the ossicular chain was assessed. Cochlear hair cell analyses were performed. Histologic assessment of the middle ear mucosa was performed.

Results: There was a higher incidence of conductive hearing loss in the adhesive group secondary to fixation of the ossicular chain, but there was no significant difference in bone conduction thresholds. The median postoperative bone conduction thresholds (dB peak sound pressure level) was 15.0 in the control group and 17.5 in the adhesive group, p = 0.89. There was also no significant difference in inner hair cell counts (0.4% vs. 0.5% median hair cell loss, p = 0.72) or outer hair cell counts (3.7% vs. 3.0% median hair cell loss, p = 0.23) for the adhesive and control groups, respectively. Histopathologic analysis of the middle ear mucosa demonstrated variable mild to moderate foreign body reaction with no evidence of mucosal ulceration or necrosis.

Conclusions: A large amount of octylcyanoacrylate placed in the middle ear of the guinea pig did not cause any morphologic or functional evidence of inner ear toxicity. This new adhesive is a promising tool for otologic surgery.