Postoperative Pure-tone Average Research Articles

Fundal Fluid as a Predictor of Hearing Preservation in the Middle Cranial Fossa Approach for Vestibular Schwannoma

Determine if the presence of cerebrospinal fluid in the fundal region of the internal auditory canal on preoperative magnetic resonance imaging (MRI) scans is predictive of improved hearing preservation after removal of vestibular schwannoma through the middle cranial fossa approach. Relationships between fundal fluid, tumor nerve of origin, tumor size, and hearing preservation also are examined. Retrospective review. Private practice tertiary neurotology referral center. One hundred one patients with preoperative MRI, complete preoperative and postoperative audiologic data, and histopathologically confirmed vestibular schwannoma treated with a middle cranial fossa approach between January 1, 2006, and June 30, 2009. Primary middle cranial fossa approach for removal of vestibular schwannoma. Fundal fluid status (presence or absence), preoperative and postoperative pure-tone average, and speech discrimination scores and tumor nerve of origin. Fundal fluid was present in 75% of cases. Those with fluid had a higher rate of postoperative measurable hearing (77.6%) compared with those without fundal fluid (52%) (p <or= 0.014). Tumors arising from the superior vestibular nerve also were associated with a higher rate of preserved, serviceable, and measurable hearing, whereas the combination of the presence of fundal fluid and superior nerve tumor had a significantly better chance of hearing preservation than either factor alone. The presence of fundal fluid on preoperative MRI is predictive of hearing outcomes and should be used in counseling patients who are considering hearing preservation surgery via a middle cranial fossa approach for the treatment of isolated vestibular schwannoma.

Ossiculoplasty with Titanium Prosthesis

Objectives: The goal of this study was to make a review of the patients who underwent ossicular chain reconstruction with titanium prosthesis during an 8-year period in our Department. Methods: A retrospective study was made on the ossiculoplasty cases over a period of eight years in a Public Hospital District. The information was extracted by clinical process consultation. Between 1999 and 2008, 124 ossiculoplasties using Kurz ® titanium prosthesis for chronic otitis media were performed (78 partial ossicular chain reconstructions and 46 total ossicular chain reconstructions). The single stage, staged and revision ossicular chain reconstruction were included in the analysis. All patients had a minimum of 6-month postoperative follow-up (mean 3 years and 4 months). Comparisons of preoperative and postoperative pure tone averages were performed. Air-bone gap and implant extrusion rates were measured. The success of the reconstruction was defined as a postoperative air-bone gap (ABG) of 20 dB or better. Results: Successful ossiculoplasty was obtained in 73.1% of partial ossicular chain reconstructions and 30.4% of total ossicular chain reconstructions (P<.05). The postoperative pure-tone average air-bone gaps was 16 dB in partial reconstructions and 26.7 dB in total reconstructions (P<.05). There were five cases of prosthesis extrusion. Conclusions: The majority of the ossiculoplasties improved the hearing status satisfactorily. There was no difference in hearing results in one-stage and two-stage partial ossicular chain reconstruction, but there were better hearing results in the cases of two-stage total ossicular chain reconstruction.

Cochlear implantation in children with enlarged vestibular aqueduct

To determine audiometric outcomes and complications of cochlear implantation in patients with enlarged vestibular aqueduct (EVA). Retrospective review at a tertiary care children's hospital. Twenty-three patients with EVA who underwent cochlear implantation were reviewed using postoperative pure-tone averages (PTA), speech perception thresholds (SPT), Phonetically Balanced Kindergarten test (PBK50) sentence testing scores, and review of complications. Of the 23 patients, the average age at initial cochlear implant referral was 4.7 years, and the average age at implantation was 5.3 years. EVA was diagnosed by computed tomography (nine patients), magnetic resonance imaging (10 patients), or both (four patients). EVA was identified bilaterally in 19 and unilaterally in four patients. Overall, the mean postoperative PTA was 30.5 dB (+/-8.6 dB standard deviation [SD]), and mean SPT was 25.9 dB (+/-8.1 dB SD). A subset of the patients had postoperative PBK50 sentence testing and the average score was 58% (range, 12%-84%). Four children were implanted within 1 month from entrance into our cochlear implant program (early implanted), and three children were implanted more than 10 months after program entrance (late implanted). The mean postoperative PTA was 40.3 dB (+/-7.6 dB SD) for the early group and 26.3 dB (+/-4.2 dB SD) for the late group. Four patients had reported complications, three had intraoperative cerebrospinal fluid (CSF) gushers at the cochleostomy site, and one had postoperative infection requiring implant removal and reimplantation. Children with EVA undergoing cochlear implantation are at greater risk for CSF gushers, but they do well audiometrically and functionally.

Results of Primary Ossiculoplasty and Prognostic Factors in Canal Wall-Down Tympanoplasty

The ideal goals of chronic middle ear surgery should be the permanent removal of disease and the preservation of good hearing function. The postoperative outcome of hearing and the status of middle ear after canal wall-down tympanoplasty with primary ossiculoplasty were studied in 192 ears with chronic middle ear disease. Cholesteatoma was present in 121 (63.0%) of 192 cases; in the remaining 71 cases (27.0%), there was middle ear mucosa disease without cholesteatoma. The stapes superstructure was present in 142 (73.9%) of 192 cases. The results of preoperative and postoperative pure-tone averages were 55.12 (SD, 4.92) and 35.81 (SD, 4.84) dB, respectively. The preoperative and postoperative air-bone gaps in 192 cases were 32.70 (SD, 5.18) and 21.16 (SD, 5.09) dB, respectively. The mean hearing gain of the 192 ears was 19.17 (SD, 6.09) dB. The presence of stapes superstructure positively affects hearing status. Also, better hearing results were obtained in cholesteatoma cases presented. Recurrences of disease were seen rarely compared with literature. It was revealed that the postoperative outcome of primary canal wall-down tympanoplasty with ossicular chain reconstruction is suitable for safe ear and hearing ear.

Hearing Results Using the SMart Piston Prosthesis

SMart, a newly introduced piston prosthesis for stapedotomy, is a nitinol-based, heat-activated, self-crimping prosthesis. We review our hearing results and postoperative complications using this self-crimped piston prosthesis and compare them with those obtained using stainless steel or platinum piston prostheses. Audiometric results using the SMart piston are identical to those obtained using a conventional piston prosthesis. Retrospective chart review. Private neurotologic tertiary referral center. The 416 ears reviewed included 306 with a SMart prosthesis and 110 conventional prostheses. 61% were women. Mean follow-up time was 5.6 (standard deviation [SD], 6.3 mo) and 6.9 months (SD, 7.0 mo) for the 2 groups, respectively. Stapedotomy using the SMart or a conventional (non-SMart) prosthesis. Audiometric hearing results, including pure-tone average (PTA) and air-bone gap (ABG), and prevalence of postoperative complications. Mean postoperative PTA was 32.6 (SD, 16.8) dB for the SMart group and 29.4 (SD, 13.5) dB for the non-SMart group, with ABGs of 7.6 (SD, 8.9) and 6.0 (SD, 5.2) dB, respectively. Mean change (decrease) in ABG was 18.7 (SD, 13.1) dB for the SMart group and 19.9 (SD, 10.3) dB for the non-SMart group. High-frequency bone PTAs showed overclosure of 2.0 (SD, 7.9) dB for the SMart group and 3.6 (SD, 8.6) dB for the non-SMart group. Postoperative vertigo and tinnitus were infrequent. No significant differences in these audiometric outcomes or complication rates were noted between groups. There was no significant difference in rate of gap closure to within 10 dB (78.3 versus 84.2%, SMart and non-SMart, respectively) or 20 dB (94.2 and 98.0%). Compared with conventional stapes prostheses, the nitinol-based SMart is a safe and reliable stapes prosthesis that eliminates manual crimping without significantly altering the audiometric outcome. Complications are rare, but longer follow-up is needed before establishing long-term stability.

Atresia Repair Before Microtia Reconstruction

To compare short-term results of atresia repair when performed before versus after microtia reconstruction. Retrospective case review. Tertiary otologic referral center. Congenital aural atresia with or without microtia: 70 cases over 24 months. Atresia repair before Medpor microtia reconstruction (ARM) versus atresia repair after microtia reconstruction with autogenous rib (ARR) versus atresia reconstruction without microtia (AR). Surgical outcomes, short-term postoperative audiometric results (at least 4 months after surgery but within the first postoperative year), complications. Data from the 3 groups are as follows: ARM, 31 patients with median age 4.2 years (range, 2.5-9.3 yr); ARR, 28 patients with median age 12 years (range, 6.9-61); and AR, 11 patients with median age 5.9 years (range, 5.5-59 yr). Preoperative computed tomographic grading using the Jahrsdoerfer scale demonstrated an average score of 7.4 (range, 6-9) for the ARM group, 7.7 (range, 6-9) for the ARR group, and 8.5 (range, 8-9) for the AR group. For patients scoring 8 to 10 on the Jahrsdoerfer scale, postoperative pure-tone average 2 for each group were as follows: ARM, 28 dB hearing loss (HL); ARR, 32 dB HL; and AR, 29 dB HL. For patients scoring 7 or less, postoperative pure-tone average 2 were as follows: ARM, 42 dB HL; and ARR, 41 dB HL (AR, no patients). Surgical complications of infection and facial nerve injury were not seen in any group. Meatal stenosis was higher in the ARR group. One patient in the ARM group suffered a high-frequency sensorineural HL. No patient receiving Medpor microtia reconstruction suffered a complication due to the presence of the ear canal before microtia reconstruction. Early results of ARM compare favorably with results achieved with atresia repair after microtia reconstruction with autogenous rib cartilage and with atresia repair without microtia repair. Hearing outcome and complications in this study are also comparable with previously reported expert results. Because restoration of binaural hearing has been shown to be advantageous for auditory development and function, timing of atresia repair can be considered before microtia reconstruction on an individual case basis, provided preoperative computed tomographic evaluation shows an adequate chance of surgical success.

Congenital external auditory canal stenosis and partial atretic plate

Objectives To report outcomes of surgery for severe congenital external auditory canal (EAC) stenosis with or without partial atretic plate (PAP). Design Retrospective review. Subjects Thirteen patients (18 ears) had surgery for severe EAC stenosis with ( n = 10, 56%) or without PAP ( n = 8, 44%). Indications included severe stenosis with hearing loss, cerumen impactions, and/or canal cholesteatoma. Mean age = 7.8 years (range 0.4–19.9 years). Mean follow up = 5.2 years (range 0.4–10.0 years). Setting Tertiary care children's hospital. Interventions Nineteen endaural canaloplasties were performed in 17 ears (2 revisions). There was one post-auricular approach. Fifteen tympanoplasties were performed in 13 ears (2 revisions). PAP was reconstructed with drilling to enlarge the bony annulus and fascia grafting to enlarge the tympanic membrane in 10 (56%) ears. Outcome measures Patency of EACs; otologic findings; pure tone averages (PTA); complications. Results All (100%) EACs had improved patency (≥4 mm). Findings included canal cholesteatoma (2/18, 11%), ossicular fixation (4/18, 22%), stapes abnormality (2/18, 11%), and incudostapedial discontinuity from cholesteatoma (1/18, 6%). Mean preoperative PTA = 38.7 dB HL (range 60–20 dB HL). Mean post-operative PTA = 23.6 dB HL (range 50–6.7 dB HL). Audiologic results were significantly better for cases without PAP ( p < .01) and without ossicular fixation ( p < .01). There were seven minor and no major complications. Conclusions Endaural canaloplasty is safe and effective for providing patent EACs and hearing improvement for severe congenital EAC stenosis. However, since hearing outcomes were worse for cases with PAP and ossicular fixation, alternatives such as hearing aids or BAHA ® may be considered.

A Pilot Study of the Safety and Performance of the Otologics Fully Implantable Hearing Device: Transducing Sounds via the Round Window Membrane to the Inner Ear

Objectives: The safety and performance of the Otologics fully implantable hearing device were assessed in adult patients with mixed conductive and sensorineural hearing loss. Methods: The subcutaneous microphone of this fully implantable device picks up ambient sounds, converts them into an electrical signal, amplifies the signal according to the user’s needs, and sends it to an electromechanical transducer. The transducer tip is customized with a prosthesis in order to be in contact with the round window membrane and is protected by fascia; this translates the electrical signal into a mechanical motion that directly stimulates the round window membrane and enables the user to perceive sound. The implanted battery is recharged daily via an external charger and the user can turn the implant on and off as well as adjust the volume with a hand-held remote control. In this pilot study, 6 patients with mixed conductive and sensorineural hearing loss were implanted with the Otologics fully implantable hearing device. Pre- and postoperative air conduction, bone conduction, as well as aided and unaided thresholds and speech scores were measured. Results: No significant differences between preoperative and postoperative pure-tone averages were noted. Average improvement ranged from 19.16 to 35.8 dB of functional gain across audiometric frequencies with a mean of 26.17 ± 5.15 dB. Long-term average functional gain at 12 months was 20.83 ± 6.22 dB. Word recognition scores demonstrated significant differences between unaided and implant-aided conditions. Conclusions: Preliminary results of this trial of the Otologics fully implantable hearing device provide evidence that this fully implantable device is capable of efficiently transferring the sound to the inner ear via the round window membrane in patients with mixed hearing loss.

Bivalve cartilage inlay myringoplasty: An office-based procedure for closing small to medium-sized tympanic membrane perforations

To determine whether bivalve inlay cartilage-perichondrium myringoplasty (BCM) is successful in closing tympanic membrane perforations in an office setting. Retrospective case review. Adult patients with chronic perforations underwent BCM under local and topical anesthesia. Success was defined as complete closure of perforation at follow-up of at least 1 month. Predictors of success were identified by comparing the success and failure groups on pre- and postoperative pure tone average (PTA), patient demographics (age, gender), and characteristics of the perforations (size, location, duration, etiology). A total of 145 procedures were performed and the patients were followed for 1 to 78 months. The success rate for perforations smaller than 4 mm was 75 percent. Size of the perforation, and pre- and postoperative PTAs were significantly different between the two groups. The only significant predictors of success were preoperative PTA and size of perforation. BCM is a viable option for closure of small and medium-sized perforations in an office setting.

Functional outcome of retrosigmoid approach in vestibular schwannoma surgery

Conclusion. The retrosigmoid approach for small vestibular schwannomas (VS) yields a high rate of facial function preservation. Hearing preservation rates depend on tumor size and preoperative hearing. Objectives. To report the results and to investigate the prognostic factors for hearing preservation after removal of small VS by a retrosigmoid approach. Patients and methods. From October 1994 to July 2005, 110 VS removed through a retrosigmoid approach were included in this retrospective study. Preoperative and postoperative clinical, audiometric, videonystagmographic, and imaging data were collected. The mean follow-up period was 23±20.7 months (range 1–110). Results. The preservation of a good facial function (House and Brackmann grade 1–2) was achieved in 91% of patients at 1–2 years after surgery. Among patients with a preoperative class A or B (n=99), a postoperative serviceable hearing (AAO-HNS classes A and B) was preserved in 36% and a useful hearing (classes A, B, and C) in 44%. Hearing preservation appeared to be influenced by tumor size and preoperative hearing. Multiple regression analysis of the preoperative factors influencing the hearing outcome showed that preoperative high frequency pure tone thresholds associated with tumor size were better correlated to postoperative pure tone average (PTA) than preoperative low frequencies.

Hearing Preservation in Patients With a Cochlear Implant

Hearing Preservation in Patients With a Cochlear Implant

Intraoperative Monitoring of Hearing During Cerebellopontine Angle Tumor Surgery Using Transtympanic Electrocochleography

To investigate the use of transtympanic electrocochleography (TT-ECochG) analyzed on-line by a detector strategy software that made possible automatic extraction of TT-ECochG components intraoperatively in real-time domain.Fifteen patients with cerebellopontine angle tumor among 50 patients were included in this study.All subjects were operated on via middle fossa or retrosigmoid approach. Pure-tone average (PTA) was measured at 0.5, 1.0, and 2.0 kHz, and calculations were performed before and after surgery. Auditory function was monitored intraoperatively via TT-ECochG, and analyzed data were displayed on-line.TT-ECochG changes in morphology were described. Postoperative PTA elevation level correlated with TT-ECochG morphology changes occurring intraoperatively.Analyzed on-line, TT-ECochG data were displayed as first negative peak of compound action potential amplitude and latency in time domain every 3 to 5 seconds. A good correlation between postoperative PTA elevation and TT-ECochG morphology changes was showed (Spearman rank test, R = +0.93; t(N-2) = 9.00; p < 0.0001).TT-EcochG seemed to effectively mirror even minimal changes in auditory function during intraoperative monitoring in real-time domain. Developed strategy of on-line analysis makes the intraoperative hearing status assessment faster and easier.

Auditory Results After Vestibular Nerve Section and Intratympanic Gentamicin for Ménière's Disease

Hearing loss is a possible complication of vestibular neurectomy and intratympanic gentamicin administration in Ménière's disease. The aim of this study was to compare the incidence of this complication with the two treatments. Retrospective review. Tertiary referral center. The initial study population reviewed consisted of 24 patients receiving gentamicin injections and 209 patients undergoing vestibular nerve section. Comparison of data was performed among all 24 intratympanic gentamicin patients and the last 24 vestibular neurectomy patients operated on via the retrosigmoid approach. Intratympanic gentamicin administration (26-156 mg) and retrosigmoid vestibular neurectomy. Auditory and vertigo results were evaluated according to the American Academy of Otolaryngology 1995 criteria. The mean preoperative pure-tone average for patients undergoing vestibular nerve section was 48.5 dB, with a speech discrimination score of 85%. In these patients, the postoperative pure-tone average was 50.3 dB, and the speech discrimination score was 82%. Patients undergoing gentamicin injection had a mean pretreatment pure-tone average of 50.1 dB and a speech discrimination score of 87%. The posttreatment pure-tone average and discrimination score for the gentamicin group were 74.7 dB and 65%, respectively. The amount of postprocedure hearing loss was significantly greater in the gentamicin group (p = 0.03). Excellent control of vertigo (classes A and B) was obtained in 95.8% of the patients treated with vestibular nerve section and in 75% of the patients in the gentamicin group. Gentamicin administration and vestibular neurectomy are both effective for relieving vertigo in Ménière's disease. The incidence of hearing loss is significantly higher after gentamicin injection.

Short-term results using Kurz titanium ossicular implants

The efficiency of titanium middle ear prosthesis for ossicular reconstruction in chronic ear disease is investigated in a Scandinavian two-center retrospective study from a Norwegian tertiary otology referral center and a Finnish otology referral center. Retrospective chart reviews were performed for procedures involving 73 titanium prostheses between 1999 and 2004. All patients that underwent surgery including the Kurz Vario titanium prosthesis were included in the study, 38 procedures including the partial ossicular replacement prosthesis (PORP) and 35 procedures including the total ossicular replacement prosthesis (TORP). Mean follow-up was 14 months. The ossiculoplasty was performed alone (29 patients) or in combination with other chronic ear surgery procedures (34 patients). Comparisons of preoperative and postoperative pure tone averages (0.5, 1, 2, and 3 kHz) according to AAO-HNS guidelines are presented, as well as data for different PTA definitions. Otosurgery procedures, complications, revisions, and extrusion rates are reported. A postoperative air-bone gap (ABG) of <or=20 dB was obtained in 77% of the patients, 89% for the Bell (Porp) prosthesis, and 63% for the Arial (Torp) prosthesis. Overall mean pure tone averages improved 20.6 dB with ABG improvement of 19.3 dB. The overall extrusion rate was 5% (4 patients). Titanium prostheses have been easy and fast to handle and effective implants for reconstruction of the ossicular chain. We found no difference between reconstruction with or without cholesteatoma surgery during the same procedure. The combination of CWD and Torp gave significant inferior hearing thresholds as compared to Torp/CWU and Porp/CWD combinations.

Prospective Clinical Study on Cochlear Function after Erbium:Yttrium‐Aluminum‐Garnet Laser Stapedotomy

To assess whether the application of the emitting erbium:yttrium-aluminum-garnet (Er:YAG) laser in stapedotomy has negative effects on vestibular and cochlear functions. Prospective, with 12 to 14 months follow-up. Academic tertiary referral center. Twenty-four patients undergoing stapedotomy (primary surgery) in otosclerosis. All patients underwent Er:YAG laser-assisted stapedotomy for otosclerosis between January 2000 and June 2002. Early (1-3 days after surgery) and late (12-14 months after surgery) postoperative bone-conduction thresholds and the presence of post-operative tinnitus and vertigo were analyzed. In addition, the relation between applied laser energy and postoperative bone-conduction thresholds was calculated. In 22 patients, unchanged preoperative minus early postoperative pure-tone bone-conduction averages at 1, 2, and 4 kHz were observed. In one patient, a slight early deterioration between 10 and 20 dB was seen. In 18 patients, unchanged preoperative minus late postoperative pure-tone bone-conduction averages at 1, 2, and 4 kHz were observed. In two patients, a slight late deterioration between 10 and 20 dB was seen. In two patients, a new postoperative tinnitus was observed. No patient suffered from vertigo at the time of second evaluation. No correlation between applied laser energy and both postoperative bone-conduction thresholds was found. The Er:YAG laser stapedotomy in otosclerosis is a safe technique. Vestibular and cochlear function is not significantly disturbed after Er:YAG laser stapedotomy.

Early Results With Titanium Ossicular Implants

To report the efficacy of titanium middle ear prosthesis for ossicular reconstruction. Retrospective chart reviews were performed for 25 patients who had undergone titanium ossicular implants between January 1, 1999, and June 1, 20001. Tertiary otology referral center. All patients had a minimum of 6 months of postoperative follow-up and no evidence of recurrent otologic disease. All patients had undergone ossiculoplasty using titanium middle ear implants. Comparisons of preoperative and postoperative pure tone averages were performed. Air-bone gap closures and implant extrusion rates were measured. RESULTS Overall mean pure tone averages improved 22.2 dB with air-bone gap improvement at 20.9 dB. Fifty-six percent of patients achieved air-bone gap less than 20 dB postoperatively. The overall extrusion rate was 4%. However, with the placement of cartilage graft interposed between the prosthesis and the tympanic membrane, no extrusion was observed. Titanium implants provide comparable hearing improvement compared with other materials. The extrusion rate seems quite low if cartilage interposition graft is inserted. Its ease of handling, biocompatible properties, and sound conducting properties improve its efficacy as an ossicular implant.

Safety of the erbium:yttrium-aluminum-garnet laser in stapes surgery in otosclerosis.

The purpose of this study was to present early and late bone-conduction hearing thresholds and data about cochlear and vestibular disturbances in patients after erbium:yttrium-aluminum-garnet (Er:YAG) laser stapedotomy in otosclerosis. The study design was a retrospective study. The study was conducted at an academic tertiary referral center. In this study, audiologic data of 117 patients undergoing Er:YAG laser-assisted stapedotomy for otosclerosis between 1993 and 1999 were included. The preoperative minus 2 postoperative (early, 1-3 days; late, at least 6 weeks) average pure-tone bone-conduction thresholds at 1, 2, and 4 kHz and 0.5, 1, 2, and 3 kHz were calculated. The postoperative appearance of nystagmus, vertigo, and tinnitus was analyzed. A total of 91 of 117 patients showed unchanged preoperative minus postoperative pure-tone bone-conduction averages at 1, 2, and 4 kHz in the late postoperative measurement. A slight deterioration was observed in 8 of 117 patients. Regarding the frequencies 0.5, 1, 2, and 3 kHz, 97 of 117 patients showed unchanged preoperative minus postoperative pure-tone bone-conduction averages. A new transient tinnitus appeared in 37 of 117 patients, and a new persistent tinnitus was found in 3 of 117 patients. Most of the patients had no postoperative dizziness (63/117 patients) and no postoperative nystagmus (109/117 patients). The study did not show significant sensorineural hearing loss at or below 3 kHz. Vestibular and cochlear function has no clinically relevant suppression after Er:YAG laser stapedotomy.

Microvascular decompression of the vestibulocochlear nerve for disabling positional vertigo: the House Ear Clinic experience.

To review characteristics of and outcome in patients undergoing microvascular decompression of the vestibulocochlear nerve. Patients studied had a diagnosis of disabling positional vertigo caused by a vascular loop compressing the VIIIth cranial nerve. Retrospective chart review and telephone interview. Private practice tertiary neurotologic referral center. Twenty patients with disabling positional vertigo underwent 25 retrosigmoid craniotomies for microvascular decompression between November 1990 and June 1999. The 4 men and 16 women ranged in age from 30 to 71 years (mean age, 46 yr). Charts were reviewed and patients were contacted by telephone and asked to rate severity of symptoms (tinnitus and dizziness) on a 4-point scale (none = 1, mild = 2, moderate = 3, and severe = 4) before and after surgery. They were also asked to rate their overall disability from their symptoms on the six-point scale established by the American Academy of Otolaryngology-Head and Neck Surgery. Preoperative and postoperative four-frequency (500 Hz, 1 kHz, 2 kHz, and 4 kHz) pure-tone average and speech discrimination scores were calculated and compared. Complications of surgery are also reported. Postoperative tinnitus score and dizziness score showed significant improvement from preoperative scores (p < or = 0.047 and p < or = 0.001, respectively), with 80% of patients improved in dizziness rating; 85% improved in their overall disability rating, and the difference from preoperative to postoperative was significant (p < or = 0.001). The mean postoperative pure-tone averages (15.4 dB) and speech discrimination scores (99%) did not differ from preoperative scores (11.9 dB and 98%). One patient lost all vestibular function in the operated ear (hearing remained intact) as the only complication of surgery. When asked, 83% of patients responded that they would have the surgery again. Diagnosing disabling positional vertigo secondary to vascular compression of the VIIIth cranial nerve remains the clinical challenge; a clear history plus air-contrast computed tomographic or magnetic resonance imaging make the diagnosis. Microvascular decompression of the vestibulocochlear nerve is a safe and effective operation for these carefully selected patients.

Hearing Preservation after Acoustic Neuroma Surgery

Acoustic neuromas (AN) are benign tumors that arise from the vestibular nerve within the internal auditory canal, where hearing loss is the most common symptom. This retrospective study was done to determine the results of hearing preservation in patients operated for AN at the University of Minnesota, as well as the factors affecting them. One hundred-eighty patients with AN were operated between 1988 and 1998, of whom 91 (50.5%) underwent hearing preservation surgery by either the middle fossa (MF) or the suboccipital (SO) approach. Preoperative and postoperative pure-tone averages (1, 2, and 4 K), speech discrimination scores (SDS), and acoustic reflex thresholds (ART) were noted and classified according to the Shelton's and the Gardner's classifications. The overall rate of hearing preservation was 23.1%. The outcome of hearing results was better with the MF approach compared with the SO approach. Small tumor size and better preoperative hearing levels favored a better postoperative hearing result. The rate of hearing improvement over time was better for the MF patients. Patients for whom intraoperative auditory monitoring was performed seemed to have better hearing outcomes.

Hearing results in pediatric patients after canal-wall-up and canal-wall-down mastoid surgery

Hearing results were studied in pediatric patients after canal-wall-up and canal-wall-down mastoid surgery in a private practice setting. A retrospective chart review was performed on 69 patients who underwent surgery from 1991-1995. Twenty-six patients underwent canal-wall-up mastoidectomies, and 43 patients underwent canal-wall-down mastoidectomies. Various types of ossicular reconstruction were performed in patients in both groups. Hearing was evaluated for preoperative and postoperative pure-tone averages, speech-reception thresholds, and air-bone gaps for the various types of ossicular reconstruction. Patients with canal-wall-up mastoidectomies and an intact ossicular chain had an average postoperative air-bone gap of 15 dB, whereas reconstruction of the ossicular chain (regardless of technique) resulted in an average postoperative air-bone gap of 19 dB. Patients with canal-wall-down mastoidectomies and an intact ossicular chain had an average air-bone gap of 15 dB, while all techniques of ossicular reconstruction had an average air-bone gap of 29 dB. Canal-wall-up and canal-wall-down mastoid surgeries in pediatric patients have similar hearing results. Variables other than hearing should be used to make treatment decisions regarding the canal wall in pediatric candidates for mastoid surgery. (Otolaryngol Head Neck Surg 1998;119:439-43.)