Clinical course of five patients definitively diagnosed with idiopathic perilymphatic fistula treated with transcanal endoscopic ear surgery.

Objectives: An idiopathic perilymphatic fistula (PLF) can be difficult to diagnose because patients present with sudden sensorineural hearing loss (SSHL) and/or vestibular symptoms without any preceding events. In such cases, we currently test for cochlin-tomoprotein (CTP) to confirm the diagnosis of idiopathic PLF because CTP is only detected in the perilymph. In this study, we report the clinical course of five patients definitively diagnosed with idiopathic PLF who underwent PLF repair surgery using transcanal endoscopic ear surgery (TEES). Patients and methods: Five patients were initially treated with intratympanic dexamethasone for SSHL, at which time a CTP test was also performed (preoperative CTP test). Due to refractory hearing loss and/or fluctuating disequilibrium, PLF repair surgery using TEES was performed to seal the oval and round windows using connective tissue and fibrin glue. These patients were diagnosed with definite idiopathic PLF based on pre- or intra-operative CTP test results (negative, < 0.4 ng/mL; intermediate, 0.4-< 0.8 ng/mL; and positive, > 0.8 ng/mL). We evaluated pre- and intra-operative CTP values, intraoperative surgical findings via a magnified endoscopic view, and pre- and post-operative changes in averaged hearing level and vestibular symptoms. Results: Pre- and intra-operative CTP values were positive and intermediate in three patients, positive and negative in one patient, and negative and positive in one patient. None of the patients had intraoperative findings consistent with a fistula between the inner and middle ears or leakage of perilymph. Only two patients showed a slight postoperative recovery in hearing. Four patients complained of disequilibrium preoperatively, of whom two had resolution of disequilibrium postoperatively. Conclusion: A positive CTP test confirms PLF in patients without obvious intraoperative findings. The CTP test is considered more sensitive than endoscopic fistula confirmation. We consider that CTP test results are important indicators to decide the surgical indication for idiopathic PLF repair surgery. In our experience with the five cases, two of them showed improvements in both hearing and vestibular symptoms.

The use of basic fibroblast growth factor to treat intractable Bell's palsy administered via transcanal endoscopic ear surgery.

PURPOSE: Facial nerve decompression surgery is an invasive procedure which has hitherto been the main option for patients with severe intractable Bell's palsy which is resistant to drug treatment. We have developed a new salvage treatment for such patients by using minimally invasive transcanal endoscopic ear surgery (TEES) to deliver the biological regenerative agent, basic fibroblast growth factor (bFGF), to the damaged facial nerve. MATERIALS AND METHODS: An endoscopic salvage treatment group was studied prospectively and was made up of severe intractable Bell's palsy patients who did not respond to high dose steroid treatment and had an ENoG value of 5 % or less. This surgery group was retrospectively compared to a similar control group who had received high dose steroid only. RESULTS: Complete recovery to House-Brackmann (HB) Grade I was achieved by 44.8 % of the endoscopic salvage treatment group which was significantly higher than the 21.2 % of the control group at one-year follow up. Patients with an ENoG value of 1 % to 5 % exhibited a significantly higher complete recovery rate of 71.4 % in the endoscopic salvage treatment group than the 28.6 % of the control group. In addition, no complications were observed including hearing loss. CONCLUSIONS: bFGF delivered via TEES shows considerable promise as a new salvage treatment of severe intractable Bell's palsy that is resistant to high dose steroid treatment without the risks presented by facial nerve decompression surgery.

Benefits of High-Dose Corticosteroid and Antiviral Agent Combination Therapy in the Treatment of House-Brackman Grade VI Ramsay Hunt Syndrome.

OBJECTIVE: Few large-scale investigations have been conducted on treatment of House-Brackmann grade VI (HB grade VI) Ramsay Hunt syndrome (RHS) patients. We compared recovery rates among patients receiving a normal-dose corticosteroid (prednisolone [PSL] 60 mg/d) or high-dose corticosteroid (PSL 200 mg/d), both with or without an antiviral agents. Recovery rates were also examined based on the order of presentation of herpetic vesicles versus facial palsy. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: A total of 128 patients with HB grade VI RHS were treated in our department between 1995 and 2017. These patients were divided into four treatment groups based on corticosteroid dosage and use of an antiviral agent. METHODS: We assessed treatment outcomes for HB grade VI patients together with logistic regression analysis to investigate factors that can impact treatment outcomes, that is, sex, age, days to start of treatment, PSL dosage, and antiviral agent administration. RESULTS: Recovery rates were best in the high-dose corticosteroid group with an antiviral agent (71.1%) in comparison with the normal-dose corticosteroid group with an antiviral agent (60.0%) or high-dose corticosteroid alone (57.1%). Significant factors for treatment outcomes were high-dose corticosteroid administration and early initiation of treatment. A better recovery rate was also found when the herpetic vesicles appeared before facial palsy. CONCLUSION: We showed that a combination of a high-dose corticosteroid and antiviral agent produced the best outcomes for patients with HB grade VI RHS. However, our results were not statistically significant because of small sample size.

The Feasibility and Treatment Results of Transcanal Endoscopic Myringoplasty.

OBJECTIVE: We reported on transcanal endoscopic myringoplasty in 25 cases preliminarily in 2014. Now our number of transcanal endoscopic myringoplasty reached to 209 ears and allowed us to adequately investigate the visibility, necessity of canalplasty, treatment results, and multivariate analysis. STUDY DESIGN: A prospective case series. SETTING: Tertiary referral center. PATIENTS: Transcanal endoscopic myringoplasty was performed on 209 ears in 201 patients between 2011 and 2019 and followed up over 1 year. METHODS: Preoperative endoscopic and microscopic views for the same patient were compared. We examined success rates at 1 year after surgery according to operation type, perforation size, operation side, gender, cause of perforation, and age, and also examined hearing results. Logistic regression analysis was performed to investigate the basic demographic and clinical characteristics of the patients associated with perforation closure. RESULTS: The anterior edge of the preoperative perforation was not visible under microscopy in 14.4% of patients. In contrast, endoscopic views revealed the entire tympanic membrane in one field. However, canalplasty was required in 2.4% of tympanic procedures due to difficulty of manipulation. The overall closure rate for perforations was 90.4%. Logistic regression analysis revealed that age > 11 was the only significant factor associated with perforation closure. The average reduction in air-bone gap was 12.1 dB. CONCLUSION: The endoscopic myringoplasty produced better visualization, the same or better closure rates, and the same or lower complication rates as compared with traditional microscopic techniques.

Detailed clinical features and genotype-phenotype correlation in an OTOF-related hearing loss cohort in Japan.

Mutations in the OTOF gene are a common cause of hereditary hearing loss and the main cause of auditory neuropathy spectrum disorder (ANSD). Although it is reported that most of the patients with OTOF mutations have stable, congenital or prelingual onset severe-to-profound hearing loss, some patients show atypical clinical phenotypes, and the genotype-phenotype correlation in patients with OTOF mutations is not yet fully understood. In this study, we aimed to reveal detailed clinical characteristics of OTOF-related hearing loss patients and the genotype-phenotype correlation. Detailed clinical information was available for 64 patients in our database who were diagnosed with OTOF-related hearing loss. As reported previously, most of the patients (90.6%) showed a "typical" phenotype; prelingual and severe-to-profound hearing loss. Forty-seven patients (73.4%) underwent cochlear implantation surgery and showed successful outcomes; approximately 85-90% of the patients showed a hearing level of 20-39 dB with cochlear implant and a Categories of Auditory Performance (CAP) scale level 6 or better. Although truncating mutations and p.Arg1939Gln were clearly related to severe phenotype, almost half of the patients with one or more non-truncating mutations showed mild-to-moderate hearing loss. Notably, patients with p.His513Arg, p.Ile1573Thr and p.Glu1910Lys showed "true" auditory neuropathy-like clinical characteristics. In this study, we have clarified genotype-phenotype correlation and efficacy of cochlear implantation for OTOF-related hearing loss patients in the biggest cohort studied to date. We believe that the clinical characteristics and genotype-phenotype correlation found in this study will support preoperative counseling and appropriate intervention for OTOF-related hearing loss patients.

Measurement of the Pediatric and Adult Osseous External Auditory Canal: Implications for Transcanal Endoscopic Ear Surgery.

OBJECTIVE: To develop a method for measuring the diameter of the osseous external auditory canal (OEAC) in pediatric and adult patients. STUDY DESIGN: Retrospective analysis of imaging data from patients with a cholesteatoma who underwent transcanal endoscopic ear surgery (TEES) to remove the cholesteatoma by analyzing preoperative sagittal cone beam computed tomography (CBCT) images using ImageJ. METHODS: Pediatric and adult patients were included who underwent TEES for a cholesteatoma between December 2011 and March 2015 and had available preoperative CBCT scans. Sagittal CT imaging data were analyzed by ImageJ to measure the maximum and minimum Feret diameters along the OEAC. The output data were then analyzed to determine the smallest maximum and smallest minimum Feret diameters for each patient. RESULTS: Fifty-one patients ranging in age from 3 to 83 years old were included in this study. The smallest maximum Feret diameter ranged from 6.5 to 10.1 mm (mean: 8.0 mm) for pediatric patients (<16 years of age) and 6.9 to 15.0 mm (mean: 8.9 mm) for adult patients, while the smallest minimum Feret diameter ranged from 3.6 to 5.9 mm (mean: 5.1 mm) for pediatric patients and 3.4 to 6.4 mm (mean: 5.4 mm) for adult patients. Moreover, the smallest maximum Feret diameters of children were significantly smaller than those of adults. CONCLUSION: We have developed a novel method for measuring the diameter along the OEAC and determining its narrowest site. This method can be incorporated into the preoperative evaluation of patients who are candidates for TEES.

Facial nerve and chorda tympani schwannomas: Case series, and advantages of using non-rigid registration of post-enhanced 3D-T1 Turbo Field Echo and CT images (TURFECT) in their diagnosis and surgical treatment.

OBJECTIVE: Facial nerve schwannomas (FNSs) and chorda tympani schwannomas are very rare. Diagnosis of these tumors is sometimes difficult, and treatment consensus has not yet been reached. We report here a series of cases of FNS and chorda tympani schwannoma and highlight the usefulness of our newly developed technique of non-rigid registration of post-enhanced 3D-T1 Turbo Field Echo and CT images (TURFECT) in their diagnosis and treatment. METHODS: MRI images were adjusted with the corresponding CT images in terms of angle and position in order to index the anatomical structures. The well-enhanced T1-Gd+ lesions of tumors having good blood flow show up as bright red after color mapping. RESULTS: Between 2014 and 2018, five patients were diagnosed with schwannomas in the temporal bone: three with FNS and two with chorda tympani schwannoma. Gd-enhanced MRI showed only a high-intensity mass, and we could not detect the relationship between tumor-like mass and bone (including the ossicles) by MRI only. In contrast, TURFECT was very useful for diagnosing the precise location, allowing us to decide on an endoscopic surgical plan in some of our cases. An endoscope enabled visualization of the medial wall of the tympanic cavity and the status of the tumors, thus we could successfully perform transcanal endoscopic biopsy and resections. CONCLUSION: TURFECT can be very useful for diagnosis of FNSs and chorda tympani schwannomas and for deciding surgical treatments such as a transcanal endoscopic approach.

Transcanal Endoscopic Ear Surgery for Congenital Middle Ear Anomalies.

OBJECTIVE: To demonstrate the efficacy of transcanal endoscopic ear surgery (TEES) for congenital middle ear anomalies. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Twenty-one patients ranging in age from 4 to 62 years old (median: 15 yr) who underwent TEES between 2011 and 2017 were compared with 19 patients ranging in age from 3 to 49 years old (median: 11 yr) who underwent microscopic ear surgery (MES) between 2000 and 2011. INTERVENTION: Ossiculoplasty or stapes surgeries were performed with TEES or MES. TEES was performed using a rigid endoscope with an outer diameter of 2.7-mm coupled with a full high-definition video system. MES was performed via a transcanal approach with a retroauricular incision. MAIN OUTCOME MEASURE: Middle ear anomaly classification, operating time, and hearing outcomes based on the American Academy of Otolaryngology and Head and Neck Surgery criteria were evaluated and compared between the TEES and MES groups. RESULTS: For Teunissen and Cremers class III anomalies, defined as ossicular chain malformations with a mobile stapes footplate, postoperative air-bone gap closure to 10 dB or less was achieved in 50% of the TEES group and 47% of the MES group. Postoperative air-bone gap closure to 20 dB or less was achieved in 86% of the TEES group and 100% of the MES group. No significant difference was found in the operating time between the two groups. All MES procedures required a retroauricular incision. CONCLUSION: Our results indicate that TEES has similar auditory outcomes compared with MES while avoiding a retroauricular incision.

Detecting the recruitment phenomenon in adults using 80-Hz auditory steady-state response.

OBJECTIVES: The ASSR is used widely as an objective measurement of hearing in clinical settings because of its high frequency specificity. The recruitment phenomenon is generally detected using subjective evaluations which require direct communication with the patient. If the recruitment phenomenon can be detected with ASSR, it would facilitate diagnosis in patients with developmental disorders and infants. SUBJECTS AND METHODS: We examined 2 groups of subjects: 10 subjects with unilateral hearing impairment in whom the recruitment phenomenon was detected by the alternate binaural loudness balance test and 12 normal subjects. We compared the relationships between the ASSR response and the stimulus sound pressure level in the 2 groups using the 80-Hz ASSR. RESULTS: The amplitude of ASSR was significantly higher in the impaired ear in hearing-impaired subjects compared to a normal ear in normal subjects. The latency of ASSR was significantly shorter in the impaired ear in hearing-impaired subjects than in the normal ear in the normal subjects. CONCLUSION: This study showed that the recruitment phenomenon caused the higher amplitude and the shorter latency observed in hearing-impaired subjects in the 80-Hz auditory steady-state response (ASSR) in comparison with normal subjects.

Comparison of Postoperative Pain in Patients Following Transcanal Endoscopic Versus Microscopic Ear Surgery.

OBJECTIVE: To compare levels and causes of postoperative pain after cholesteatoma removal by transcanal endoscopic ear surgery (TEES) versus microscopic ear surgery (MES). STUDY DESIGN: Prospective case series. SETTING: Tertiary referral center. PATIENTS: One-hundred-and-sixty-one patients who had undergone middle ear surgery between February 2013 and April 2016. INTERVENTIONS: Comparison of postoperative pain between TEES and MES groups and among TEES and MES subgroups divided by range of bone removal. MAIN OUTCOME MEASURES: Two parameters were used to assess postoperative pain: a pain numeric rating scale (NRS) and number of times a non-steroidal anti-inflammatory drug (NSAID) was taken from postoperative days (PODs) 1 to 7. We also examined the primary factor behind postoperative pain looking at: 1) the surgical incision; 2) bone removal; and 3) number of involved middle ear regions. RESULTS: One-hundred-and-six patients underwent TEES and 55 underwent MES. The mean pain NRS for the 7-day postoperative period was significantly lower for the TEES group (1.1) than the MES group (2.8) (p < 0.001, Mann-Whitney U test). The number of times a NSAID was taken was lower for the TEES group (1.3 pills/wk) than the MES group (5.5 pills/wk) (p < 0.001, Mann-Whitney U test). The mean pain NRS of the TEES and MES subgroups also suggests that extent of bone removal or number of involved middle regions was less important in causing postoperative pain than presence or absence of the retroauricular incision. CONCLUSIONS: TEES is associated with lower postoperative pain and lower use of NSAIDs compared with MES patients.

Benefits of High-dose Steroid + Hespander + Mannitol Administration in the Treatment of Bell's Palsy.

OBJECTIVE: Large-scale investigations have not been recently conducted on the efficacy of high-dose steroid administration of prednisolone (PSL) for Bell's palsy. We compared treatment results between normal-dose steroid (PSL 60 mg/d) and high-dose steroid (PSL 200 mg/d) + Hespander + Mannitol administration. We also investigated the recovery rate for antiviral agents. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: A total of 675 patients with Bell's palsy who had grade V and grade VI on the House-Brackmann (HB) scale were treated in our department between 1995 and 2014. These patients could be divided into a normal-dose group and high-dose group. METHODS: We separately assessed treatment outcomes for HB grade V patients and HB grade VI patients. Logistic regression analysis was also performed to investigate factors that can impact treatment outcomes, i.e., sex, age, days to start of treatment, PSL dosage, and antiviral drug administration. RESULTS: Recovery rates were significantly better in the high-dose steroid + Hespander + Mannitol group in comparison with the normal-dose steroid group for HB grade V (100% versus 77.7%) and HB grade VI (92.5% versus 68.2%). Additional effects of antiviral agents were only shown in the normal-dose group. Significant factors for treatment outcomes were PSL 200 mg/d administration and early initiation of treatment. Insignificant factors were sex, age, and the antiviral agent. CONCLUSION: We showed the high-dose steroid + Hespander + Mannitol administration produced significantly better outcomes than normal-dose steroid administration in the treatment of patients with Bell's palsy.

Safety of heat generated by endoscope light sources in simulated transcanal endoscopic ear surgery.

OBJECTIVE: To determine whether heat generated by endoscope light sources during ear surgery is safe. METHODS: Transcanal endoscopic ear surgery (TEES) was simulated using 2.7-mm or 4-mm endoscopes coupled to xenon or LED light sources and a 3D model of human temporal bone. The endoscope tip was fixed at the center of tympanic annulus. Light sources were tested at clinical (30% for xenon and 40% for LED) and 100% settings. Temperatures were measured using thermocouples attached to the endoscope tip and three points within the middle ear cavity: promontory, horizontal portion of the facial nerve and lateral semicircular canal. RESULTS: Maximum temperatures measured within the middle ear cavity were below 31°C at clinical settings, while the temperatures rose to 44.1°C using a 4-mm endoscope with a xenon light source set at 100%. Temperatures measured at the tip were all safe at clinical settings, but rose dramatically to 110.1°C for the 4-mm endoscope with xenon at 100%. CONCLUSION: Endoscopes can be safely used within the middle ear at clinical settings. However, operators should not exceed clinical settings, particularly with 4-mm endoscopes with a xenon light source, to ensure temperatures generated within the middle ear cavity are safe.

Transcanal endoscopic ear surgery for pediatric population with a narrow external auditory canal.

OBJECTIVES: To retrospectively determine the size of the external auditory canal (EAC) in a pediatric population and to describe our experience with transcanal endoscopic ear surgery (TEES) in this pediatric population which had been successfully treated for middle ear disease using TEES. METHODS: We analyzed 31 patients ranging in age from 2 to 13 years old (median: 7.6 years) with middle ear disease who underwent TEES between November 2011 and August 2014. Sixteen of these patients had surgery for cholesteatomas; 11 for chronic otitis media; and 4 for malformation of the middle ear. A preoperative CT scan was performed to evaluate the middle ear disease. Transcanal endoscopic tympanoplasty was performed using a rigid endoscope with a 2.7mm outer diameter. Transcanal endoscopic atticoantrotomy was also performed, as necessary, on some patients to access pathologies in the antrum. The values of anterior-posterior diameters and superior-inferior diameters of the bony parts of EAC were measured retrospectively based on the preoperative CT scan data. RESULTS: TEES was successfully performed in all 31 pediatric patients without resorting to a retroauricular incision. Twenty-seven patients were evaluated for postoperative hearing levels which were found to fall within an acceptable range and for postoperative air-bone gap (ABG) by pure tone audiometry with a resulting mean of 8.6dB. The smallest anterior-posterior diameters of the external ear canal ranged from 3.2 to 7.1mm (5.0±1.0mm) and the smallest superior-inferior diameters ranged from 3.4 to 10.3mm (5.9±1.3mm). CONCLUSION: TEES can be used to safely and effectively treat middle ear disease even in the pediatric population in its narrow EAC.

The Efficacy of Color-Mapped Diffusion-Weighted Images Combined With CT in the Diagnosis and Treatment of Cholesteatoma Using Transcanal Endoscopic Ear Surgery.

OBJECTIVE: To assess the efficacy of a color-mapped diffusion-weighted image combined with a computed tomography scan (CMDWI-CT) in preoperatively evaluating the anatomical location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery (TEES) to reduce intraoperative switching to microscopic ear surgery (MES). STUDY DESIGN: Prospective case study. SETTING: A single university hospital. PATIENTS: Fifty-five patients scheduled for middle ear cholesteatoma surgery. INTERVENTION: The CMDWI-CT is produced in a multistep process. A color-mapped fusion image (CMFI) is created by performing MR cisternography on a 1-mm thin-slice nonecho planar diffusion-weighted imaging (non-EPI DWI) and then by performing color mapping on the resulting image to enhance cholesteatoma visualization. False positives are reduced by taking a T1-weighted image (T1WI), whereas false negatives are further reduced by preoperative endoscopic examination. As cholesteatomas are difficult to locate on a CMFI in the temporal bone region, we stripped out the MR cisternography data from the CMFI and then fused the CMFI to the initial computer tomography (CT) scan to create a CMDWI-CT. This CMDWI-CT better clarifies the cholesteatoma position within temporal bone. MAIN OUTCOME MEASURE(S): CMDWI-CT preoperative findings were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated depending on the cholesteatoma location. RESULTS: CMDWI-CT facilitated accurate detection of the cholesteatoma anatomical location in the temporal bone region which was reflected in positive predictive and negative predictive values of over 90% for all areas of the middle ear. CONCLUSION: CMDWI-CT is a reliable diagnostic modality for evaluating the anatomical location of cholesteatomas that seem as high-signal regions on a CMFI and for determining whether TEES is indicated for treatment in such patients.

The efficacy of color mapped fusion images in the diagnosis and treatment of cholesteatoma using transcanal endoscopic ear surgery.

OBJECTIVE: To assess the efficacy of color mapped fusion images (CMFIs) in preoperatively evaluating the anatomic location of cholesteatomas and determining whether a patient is indicated for transcanal endoscopic ear surgery. STUDY DESIGN: Prospective case study. SETTING: A single university hospital. PATIENTS: Ninety-two patients scheduled for middle ear cholesteatoma surgery. INTERVENTION: Imaging analysis was first performed using echo planar diffusion-weighted imaging (EPI) for the first patient group with mixed results. Imaging analysis was then performed using 1-mm thin-slice non-EPI combined with magnetic resonance cisternography in a second group. The resulting image was then processed using color mapping to create a CMFI that enhanced cholesteatoma visualization. A second non-EPI was also performed on the third group, incorporating a T1-weighted image (T1WI) to reduce false-positives. MAIN OUTCOME MEASURE(S): Preoperative findings from EPI, non-EPI/CMFIs, and non-EPI/T1WI-enhanced CMFIs were compared with intraoperative findings. The positive predictive value and negative predictive value were also evaluated for each group. RESULTS: Both the positive predictive value and negative predictive value obtained from the CMFIs were high in all areas of the middle ear, and CMFI facilitated accurate detection of the anatomic location of cholesteatomas of 3 mm or larger. The incidence of false-positives was further reduced in the final 18 patients by performing T1WI to distinguish between cholesteatomas and cholesterin granulomas. CONCLUSION: CMFI combined with T1WI is a reliable diagnostic modality for evaluating the anatomic location of cholesteatomas 3 mm or larger and determining whether transcanal endoscopic ear surgery is indicated for treatment in such cases.

Feasibility and advantages of transcanal endoscopic myringoplasty.

OBJECTIVE: When performing transcanal myringoplasty under a microscope, the total circumference of the perforation can be difficult to confirm in patients where the external ear canal is narrow and/or protruded. In such patients, a retroauricular incision approach is usually used. However, we have developed a transcanal endoscopic myringoplasty procedure, and the microscopic and endoscopic views are compared herein for the first time. The feasibility and advantages of transcanal endoscopic myringoplasty were examined. STUDY DESIGN: A prospective case series. SETTING: Tertiary referral center. PATIENTS: Transcanal endoscopic myringoplasty was performed on 25 ears in 21 patients with chronic otitis media between September 2011 and December 2012. INTERVENTION: Microscopic and endoscopic views were compared for each patient. The 2 fields of views were both recorded and evaluated to determine the advantages and disadvantages of microscopes and endoscopes. Myringoplasty was performed using an endoscopic technique while comparing views as necessary. RESULTS: Endoscopic views revealed the entire tympanic membrane in a single field with clear visualization of the perforation edges even when the ear canal was curved. This clear visualization facilitated reliable refreshing of the perforation edges and grafting. The anterior edge of the perforation was not visible under microscopy in 5 of 25 ears. Under an endoscopic wide view, the tympanic cavity was observable through the perforation, and the orifice of the tube, ossicular chain, and tympanic isthmus were visible especially with large perforations. Transcanal endoscopic myringoplasty was successfully performed with a simple underlay technique or with an intracanal incision in cases of marginal perforation. CONCLUSION: Comparison of microscopic and endoscopic views revealed superior visualization and operability of the endoscopic approach as opposed to transcanal simple underlay myringoplasty. Transcanal endoscopic myringoplasty does not require surgical exposure such as a retroauricular skin incision to get an anterior view. Our results demonstrated that transcanal endoscopic myringoplasty can be performed, regardless of the perforation size and the narrowness and/or protrusion of external ear canal.

Safety of ultrasonic bone curette in ear surgery by measuring skull bone vibrations.

HYPOTHESIS: Mastoidectomy using an ultrasonic bone curette (UBC) is as safe for the inner ear as a mastoidectomy using a high-speed drill. BACKGROUND: Transcanal endoscopic ear surgery (TEES) is a minimally invasive, secure, and functional technique, which has been performed using high-speed drills. We have started to use a UBC instead of the high-speed drill because a UBC allows for simultaneous bone cutting, irrigation, and aspiration. These features of the UBC make it an excellent candidate for use in one-handed TEES, but the safety of the UBC still needs to be confirmed. We thus measured skull vibrations caused by the UBC to estimate the effects of UBC on the inner ear. METHODS: Eight patients with cholesteatoma underwent mastoidectomy using a Sonopet UST-2001 UBC (Stryker, MI, USA) and 2 high-speed drills (drills A and B). Skull vibrations were measured using polyvinylidene difluoride film taped to the forehead as a piezoelectric vibration sensor. The recorded data were transformed to the power spectrum in the frequency domain by fast Fourier transform. The mean and peak values of vibrations were analyzed in four frequency bands: 200 to 500 Hz, 500 to 2,000 Hz, 2,000 to 8,000 Hz, and 8,000 Hz to 20 kHz. RESULTS: Both the mean values and the peak values of skull vibrations caused by the UBC were significantly smaller than those values obtained for drill B between 500 and 8,000 Hz, (p < 0.05). No significant differences were found among the 3 instruments below 500 Hz or above 8,000 Hz. CONCLUSION: Skull vibration levels generated by the UBC were found to be comparable or even lower than those levels associated with conventional high-speed drills. These findings indicated that the UBC can be safely applied to TEES without the risk of harmful effects on the inner ear.

Extension of indications for transcanal endoscopic ear surgery using an ultrasonic bone curette for cholesteatomas.

BACKGROUND: One-handed endoscopic procedures have, up until now, limited the indications for transcanal endoscopic ear surgery (TEES) in cholesteatoma surgery. However, the development of electrically powered instruments has opened the door to such one-handed endoscopic procedures in restricted surgical spaces. OBJECTIVE: We examined the feasibility of using one such powered instrument, the ultrasonic bone curette (UBC) in TEES for cholesteatoma surgery. The UBC offers several advantages, including nonrotational motion and the combination of both suction and irrigation in a single handpiece. STUDY DESIGN: A prospective case series. SETTING: Tertiary referral center. PATIENTS: TEES was performed on 43 cases of primary cholesteatoma between September 2011 and December 2012, including 14 cases extending to the antrum. INTERVENTION: Zero-, 30-, or 70-degree angled rigid endoscopes with an outer diameter of 2.7 mm (Karl Storz) were used together with a high-definition video system. A Sonopet UBC (Stryker) was used to cut bony tissue. The nonrotational motion of the UBC prevents injury to the tympanomeatal flap and other soft tissue, which may result with standard drills. Transcanal endoscopic retrograde mastoidectomy on demand was performed to access the pathologies in the attic and antrum. RESULTS: A minimum attico-antrotomy was performed using the UBC, removing only the bony tissue necessary to visualize the pathology. The cholesteatoma was completely removed from the antral mucosa under clear endoscopic visualization in 13 of 14 cases. After removal of the cholesteatoma, the canal wall was reconstructed using cartilage taken from the tragus. This procedure resulted in greater mastoid preservation. CONCLUSION: The transcanal endoscopic approach to the antrum using the UBC proved to be less invasive and more functional. The UBC contains both a suction and irrigation system in a single handpiece, and this UBC is an appropriate cutting tool that extends the indications for TEES.