Registration of preoperative temporal bone CT-scan to otoendoscopic video for augmented-reality based on convolutional neural networks

PURPOSE

Patient-to-image registration is a preliminary step required in surgical navigation based on preoperative images. Human intervention and fiducial markers hamper this task as they are time-consuming and introduce potential errors. We aimed to develop a fully automatic 2D registration system for augmented reality in ear surgery.

METHODS

CT-scans and corresponding oto-endoscopic videos were collected from 41 patients (58 ears) undergoing ear examination (vestibular schwannoma before surgery, profound hearing loss requiring cochlear implant, suspicion of perilymphatic fistula, contralateral ears in cases of unilateral chronic otitis media). Two to four images were selected from each case. For the training phase, data from patients (75% of the dataset) and 11 cadaveric specimens were used. Tympanic membranes and malleus handles were contoured on both video images and CT-scans by expert surgeons. The algorithm used a U-Net network for detecting the contours of the tympanic membrane and the malleus on both preoperative CT-scans and endoscopic video frames. Then, contours were processed and registered through an iterative closest point algorithm. Validation was performed on 4 cases and testing on 6 cases. Registration error was measured by overlaying both images and measuring the average and Hausdorff distances.

RESULTS

The proposed registration method yielded a precision compatible with ear surgery with a 2D mean overlay error of 0.65 ± 0.60 mm for the incus and 0.48 ± 0.32 mm for the round window. The average Hausdorff distance for these 2 targets was 0.98 ± 0.60 mm and 0.78 ± 0.34 mm respectively. An outlier case with higher errors (2.3 mm and 1.5 mm average Hausdorff distance for incus and round window respectively) was observed in relation to a high discrepancy between the projection angle of the reconstructed CT-scan and the video image. The maximum duration for the overall process was 18 s.

CONCLUSIONS

A fully automatic 2D registration method based on a convolutional neural network and applied to ear surgery was developed. The method did not rely on any external fiducial markers nor human intervention for landmark recognition. The method was fast and its precision was compatible with ear surgery.

A new 3D-printed temporal bone: 'the SAPIENS'-specific anatomical printed-3D-model in education and new surgical simulations

PURPOSE

Otology and neuro-otology surgeries pose significant challenges due to the intricate and variable anatomy of the temporal bone (TB), requiring extensive training. In the last years 3D-printed temporal bone models for otological dissection are becoming increasingly popular. In this study, we presented a new 3D-printed temporal bone model named 'SAPIENS', tailored for educational and surgical simulation purposes.

METHODS

The 'SAPIENS' model was a collaborative effort involving a multidisciplinary team, including radiologists, software engineers, ENT specialists, and 3D-printing experts. The development process spanned from June 2022 to October 2023 at the Department of Sense Organs, Sapienza University of Rome. Acquisition of human temporal bone images; temporal bone rendering; 3D-printing; post-printing phase; 3D-printed temporal bone model dissection and validation.

RESULTS

The 'SAPIENS' 3D-printed temporal bone model demonstrated a high level of anatomical accuracy, resembling the human temporal bone in both middle and inner ear anatomy. The questionnaire-based assessment by five experienced ENT surgeons yielded an average total score of 49.4 ± 1.8 out of 61, indicating a model highly similar to the human TB for both anatomy and dissection. Specific areas of excellence included external contour, sigmoid sinus contour, cortical mastoidectomy simulation, and its utility as a surgical practice simulator.

CONCLUSION

We have designed and developed a 3D model of the temporal bone that closely resembles the human temporal bone. This model enables the surgical dissection of the middle ear and mastoid with an excellent degree of similarity to the dissection performed on cadaveric temporal bones.

Implantable Hearing Devices in Ontario: A Population-Based Study of Access to Care and Access to Devices

INTRODUCTION

The prevalence of hearing loss in Canada is high, with many patients requiring implantable hearing devices (IHDs) as treatment for their disease severity. Despite this need, many eligible patients do not pursue these interventions. The objective of this study was to examine rates of IHD based on geographic location to understand locoregional variation in access to care.

STUDY DESIGN

This was a retrospective population-based cohort study.

SETTING

All hospitals in the Canadian province of Ontario.

METHODS

Of all patients with IHD between April 1, 1992, and March 31, 2021, cochlear implants (CIs) (4,720) and bone-anchored hearing aids (BAHA) (1,125) cohorts were constructed. Place of residence was categorized based on Local Health Integrated Network (LHIN). Summary statistics for place of surgical institution based on LHIN at first surgery, name of institution of first surgery and "as the crow flies" distance (in km) between place of residence and surgical institution were calculated. Rate of implantations was calculated for LHIN regions based on number of surgeries per 1,000,000 persons/years.

RESULTS

Toronto Central, Central, Central East, and Champlain regions had >10% of patients undergoing BAHA and CI. 1,019 (90.6%) and 4,232 (89.7%) of patients receiving BAHA and CI, respectively, resided in urban/suburban regions and 94 patients (8.4%) and 436 (9.2%) resided in rural regions. The median distance between residential location and the institution was 46.4 km (interquartile range [IQR], 18.9-103.6) and 44.7 km (IQR, 15.7-96.9) for BAHA and CI, respectively. From 1992 to 2021, the number of CI and BAHA performed across Ontario increased by 17 folds and 6 folds, respectively.

CONCLUSION

This large comprehensive population study provides longitudinal insight into the access to care of IHD based on geographic factors. Our findings of the present population-based study indicate an overall increase in access to devices with disproportionate access to care based on geographic locations. Further work is needed to characterize barriers to IHD access to align with demands.

Validation of the Swedish Quality Register for Ear Surgery - SwedEar

BACKGROUND

The Swedish Quality Register for Ear Surgery (SwedEar) is a national register monitoring surgical procedures and outcomes of ear surgery to facilitate quality improvement. The value of the register is dependent on the quality of its data. SwedEar has never been validated regarding data quality or missing entries. Therefor, the purpose of this study was to assess coverage, completeness and response rate in the register and validate the physicians' reported data accuracy.

METHODS

In this validation study, the completeness, response rate and missing registrations were analysed. Data in SwedEar were compared with the yearly collected statistics of otosurgical procedures in The Swedish Otosurgical Society and the comparison of rates between groups was calculated with Fisher's exact test. Validation of registered data accuracy was performed on every 20th registered case during a five-year period. Data were reabstracted from medical records and compared with the original registration. Interrater agreement, reliability measures, Cohen's kappa, Gwet's AC1 and positive predictive value were calculated.

RESULTS

SwedEar has a coverage of 100%. The completeness of registered cases was 84% and the response rate was 74%. The validation of data accuracy assessed 13 530 variables, including audiograms. Less than 3% of incorrect or missing variables were identified. For most of the pre- and postoperative variables the Kappa and Gwet´s AC1 results show an almost perfect agreement (> 0.80). For audiogram data the ICC shows an excellent reliability (> 0.9) for all but one value.

CONCLUSION

This validation shows that SwedEar has excellent coverage, high completeness, and that the data in the register have almost perfect reliability. The data are suitable for both clinical and research purposes. Further efforts to improve completeness are warranted.

Fungal otitis externa and tympanic membrane perforation

Introduction

Otomycosis is a fungus-causing superficial infection of the external auditory canal that is common in otolaryngology practice. Though it is a worldwide infection, but is more prevalent in warm and humid regions. There has been rise in the occurrence of otomycosis in the last few years because of the extensive usage of antibiotic eardrops. Other influencing reasons for the occurrence of otomycosis is swimming, an immunocompromised host (e.g.: DM, AIDs) pregnancy, post-canal wall down mastoidectomy, tympanic membrane perforation, hearing aids and self-inflicted injuries.

Methods

Approval from the institutional ethics committee and penned informed agreement from all patients involved in the examination were obtained. 40 patients were included in the study, starting from 1stAugust to 30th September 2021, which emphasized on otomycosis infection with central tympanic membrane perforation. Physical findings such as whitish ear discharge and the presence of hyphae in the EAC, the ear drum, the middle ear mucosa were used to diagnose otomycosis.

Result

20 patients of patched group and 20 patients of non-patched group did not visit for follow up. Data here is for patients who followed-up for 3 weeks. Any significant observation regarding statistical variation in the age, size of perforation, mycological analysis and pure tone audiometry among the two groups were not seen.

Conclusion

To conclude, we state that treatment with clotrimazole solution in patched group is safe in managing otomycosis with tympanic membrane perforation. Otomycosis is a fungus causing surface infection of the external auditory canal that otolaryngologists routinely diagnose by medical examination. In acute otomycosis, overgrowth of the fungus in the external auditory canal is due to increased humidity.

Dr Ahila's Endoscopic Ear Surgery Chisel and Mallet

Endoscopic Ear surgery is evolving day by day and there is need for constant improvement in terms of instrumentation with efficient, quicker, with clear bloodless surgical field and good postoperative outcome and results. The application of Dr Ahila's Endoscopic Ear Surgery Chisel and Mallet are presented. This innovation will provide limited and adequate bone removal in a faster way than drill in endoscopic mastoidectomy and stapedotomy surgeries. Surgical instruments represent a major financial asset to the health care facilities. The use of Dr Ahila's Endoscopic Ear Surgery straight 1 mm or 2 mm Chisel and Mallet is presented. Dr Ahila's Endoscopic Ear Surgery Chisel and Mallet, this innovation will provide faster bone removal than drill or curette without bone dust formation, fogging, irrigation in Endoscopic mastoidectomy and stapedotomy. This instrument is essential to avoid costly replacement, surgeon satisfaction, reduce cost and delays in the operating room and in safe and trained hands enhance patient safety.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03629-0.

Ultra-low-dose CBCT scan: rational map for ear surgery

PURPOSE

This study will evaluate the clinical quality and usability of peripheral image data from the temporal bone area obtained using a sinonasal ultra-low-dose (ULD) cone-beam computed tomography (CBCT) scan and compare them to those obtained using a high-resolution (HR) CBCT.

METHODS

The population consisted of 66 anatomical sites (ears of 33 subjects) imaged using two modalities: an HR CBCT (Scanora 3Dx scanner; Soredex, Tuusula, Finland) and a ULD CBCT (Promax 3D Mid scanner; Plandent, Helsinki, Finland). The image quality (IQ) for every anatomical site in each image was rated using a Likert scale from 0 to 5.

RESULTS

The quality of ULD CBCT scans was clinically sufficient in over 95% of the assessed images of the sigmoid sinus, jugular bulb, epitympanum and mastoid antrum as well as external acoustic meatus (all p > 0.05 compared to HR CBCT). The IQ was clinically sufficient in 75-94% of the assessed images of the scutum, mastoid segment of the facial nerve, cochlea and semicircular canals (all p < 0.05 compared to HR CBCT). The overall IQ of the HR CBCT scans was good or excellent.

CONCLUSION

CBCT imaging and the data at image margins are underutilized. CBCT can produce excellent structural resolution with conventional imaging parameters, even with off-focus images. Using ultra-low doses of radiation, the produced IQ is clinically sufficient. We encourage ear surgeons to check the patients' imaging history and to consider the use of imaging modalities that involve lower radiation doses especially when conducting repetitive investigations and with children.

Effectiveness of endoscopy in cochlear implantation

OBJECTIVE

Determine the effectiveness of endoscopy in cochlear implantation as compared to microscopy.

METHOD

Study comparing microscopy and endoscopy in cochlear implant placement in 34 patients (23 endoscopic implants and 20 implants via microscopy), between 2014 and 2019, at the Centro Medico Naval, Mexico City. The study was performed under informed consent and according to the Council for International Organizations of Medical Sciences (CIOMS).

RESULTS

Of the 34 patients, 12 were children or adolescents and 22 were adults. The visualization of the round window classified via microscopy per St. Thomas Hospital's classification showed that type IIB prevailed in 30.2% of patients, and type III in 41.9%, and when using the endoscope, the round window was observed in full in 82.6% of patients (type I), and type IIA was only observed in 17.4% (four patients). The number of attempts made to place the cochlear implant was greater with the microscope. The time to insertion of the electrode was 1.6 minutes. No differences were observed (p > 0.05) in the number of inpatient days. Cochleostomy was more frequent when using the microscope.

CONCLUSIONS

Endoscopy is an effective resource in cochlear implantation for posterior tympanotomy, with no complications observed, offering greater safety in inserting the electrode through the round window.

Experience of the 'Ear Glove' in children with microtia

INTRODUCTION

Microtia is a congenital condition which can be found in isolation or as part of a syndrome. The key factors to consider when treating a child with microtia are hearing, speech and language development, cosmesis, and the psychological impact on the patient as well as the family. As children age and become more self-aware, the anxiety about transition from primary to secondary school can often be a trigger for carers and child to want a cosmetic solution at a younger age. Any form of cosmetic surgery ideally requires a child with an understanding of what is involved, as well as sufficient growth and anatomy to provide soft tissue resources for surgery. An additional issue for some children with microtia is the concern about adding to their already 'different' appearance by using a bone conduction solution/hearing implant. We present the outcomes of a novel non-surgical prosthesis 'Ear Glove' offered to pediatric patients with microtia.

METHODS

Children with microtia are seen in the multidisciplinary outpatient clinic and reviewed by the team which includes an Otolaryngologist, Audiologist, Plastic surgeon and Maxillofacial prosthetist. When discussing cosmesis, all reconstruction options are explored. These include a 'no treatment' option, both adhesive and implant-retained prosthetic ears, and autologous and/or MedporⓇ ear reconstruction (age appropriate). All children who chose to undergo the adhesive non-surgical prosthetic option 'Ear Glove' for microtia were identified by our prosthetic department (n = 9), and their outcomes reviewed.

RESULTS

Nine children have been fitted with the 'Ear Glove', with all 9 achieving excellent symmetry and aesthetics. Seven patients continue to successfully use their prostheses either daily or for special occasions. Two of these patients also decided to undergo bone anchored hearing implant surgery. One patient opted to change his treatment plans and chose 'no treatment' after feeling he preferred his 'little' ears. Finally, one patient reported the daily use of adhesive to be a deterrent. No skin reactions to the adhesive were reported in any patient.

CONCLUSIONS

The 'Ear Glove' is increasingly being used by microtia patients in our department to good effect. This non-surgical alternative allows young patients to appreciate the cosmetic results of the surgical options before committing to an invasive procedure.

The cutting edge of customized surgery: 3D-printed models for patient-specific interventions in otology and auricular management-a systematic review

PURPOSE

3D-printing (three-dimensional printing) is an emerging technology with promising applications for patient-specific interventions. Nonetheless, knowledge on the clinical applicability of 3D-printing in otology and research on its use remains scattered. Understanding these new treatment options is a prerequisite for clinical implementation, which could improve patient outcomes. This review aims to explore current applications of 3D-printed patient-specific otologic interventions, including state of the evidence, strengths, limitations, and future possibilities.

METHODS

Following the PRISMA statement, relevant studies were identified through Pubmed, EMBASE, the Cochrane Library, and Web of Science. Data on the manufacturing process and interventions were extracted by two reviewers. Study quality was assessed using Joanna Briggs Institute's critical appraisal tools.

RESULTS

Screening yielded 590 studies; 63 were found eligible and included for analysis. 3D-printed models were used as guides, templates, implants, and devices. Outer ear interventions comprised 73% of the studies. Overall, optimistic sentiments on 3D-printed models were reported, including increased surgical precision/confidence, faster manufacturing/operation time, and reduced costs/complications. Nevertheless, study quality was low as most studies failed to use relevant objective outcomes, compare new interventions with conventional treatment, and sufficiently describe manufacturing.

CONCLUSION

Several clinical interventions using patient-specific 3D-printing in otology are considered promising. However, it remains unclear whether these interventions actually improve patient outcomes due to lack of comparison with conventional methods and low levels of evidence. Further, the reproducibility of the 3D-printed interventions is compromised by insufficient reporting. Future efforts should focus on objective, comparative outcomes evaluated in large-scale studies.

A Pinch Test to Correct an Unfolded Helix: An Innovative and Predictable Technique

The unfolded helix is an ear deformity more frequent than expected. It might be presented alone or combined with other scapha or concha anomalies, giving the appearance of big and prominent ears. Currently, there are few reports published about its restoration and few modifications have been made to its original surgical approaches since the 1970s. The technique herein described aims to facilitate the helix rim restoration procedure by considering the following preoperative and surgical advices. The preoperative use of the pinch test allows to better understand the patients' expectations, helps to explain the future outcomes to them and simplifies the marking of the tissue to be removed. The additional bilateral only-cartilage resections and the maintenance of the skin excess permit to optimize the cosmetic outcomes. This innovative surgical approach for the helix rim restoration is reliable, has little morbidity associated and presents consistent effective results. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

3D-4K exoscope-assisted temporal bone dissection: a new frontier in surgical training

PURPOSE

To assess if 3D-4K exoscope is a valuable tool for temporal bone dissection and to evaluate its teaching potential.

METHODS

Six consecutive 3D-4K-exoscope-assisted cortical mastoidectomies were performed by a novice, an intermediate and an expert surgeon (two dissections each). All dissections were entirely recorded and later evaluated independently by three other experienced surgeons. The dissection end-product was evaluated according to the Melbourne Mastoidectomy Scale (MMS). Paired t test was used to assess whether novice and intermediate surgeons have a score improvement in the second dissection compared to the first one. Surgeons' interactions, depth effect, and 3D impression were also assessed to perform a subjective analysis.

RESULTS

Mean MMS scores for the novice, intermediate and expert surgeon were 11.3 ± 2.8, 13.8 ± 3.9 and 19 ± 1.3, respectively. Paired t test demonstrated a statically significant improvement between the first and the second dissection both for the novice and the intermediate surgeon (+ 4.7 and + 7 points; p = 0.0002). A high-quality magnification of the temporal bone was obtained, allowing the expert surgeon to identify all the anatomical structures without injuring them. The exoscope was capable of providing a high involvement in the dissections with very effective interactions between the expert surgeon and the trainees, that had access to the same surgical field view.

CONCLUSION

3D-4K-exoscope resulted adequate for a safe and effective mastoidectomy and showed a high potential for training and educational purposes. It can represent a valid option for surgical training of temporal bone dissection and a new interactive tool to understand the complex temporal bone anatomy.

Transmastoid exposure of the labyrinthine segment of the facial nerve: an anatomical study

INTRODUCTION

Compression of the labyrinthine segment of the facial nerve by edema has been considered as an important pathology in the majority of the cases of idiopathic facial nerve paralysis. Hence, it is suggested that total decompression of the facial nerve should also include the labyrinthine segment by a middle fossa approach. However, the middle fossa approach requires craniotomy and temporal lobe retraction, which increases the morbidity. The labyrinthine segment of the facial nerve can also be reached through mastoidectomy. However, many ear surgeons are not familiar with this approach due to the lack of anatomical data on this surgical area.

OBJECTIVE

To study the anatomical limitations of decompression of the labyrinthine segment via transmastoid approach.

METHODS

Complete mastoidectomy was performed in six adult cadavers heads. Dissection was extended in the zygomatic root and posterior bony wall of the external auditory canal to visualize the incudomallear joint completely. The bone between tympanic segment, lateral and superior semicircular canal's ampullas and middle fossa dural plate was removed. Fine dissection was carried out over tympanic segment of the facial nerve in an anterosuperomedial direction the labyrinthine segment was reached.

RESULTS

All the mastoids were well pneumatized. Distances between the labyrinthine segment and middle fossa dura, and between the labyrinthine segment and superior semicircular canal, were 2.5 and 4.5 mm on average, respectively. In addition, distances between the middle fossa dura and dome of the lateral semicircular canal, and between the middle fossa dura and tympanic segment were 4.6 mm and 4.3 mm on average, respectively.

CONCLUSION

It is possible to expose the labyrinthine segment of the facial nerve through mastoidectomy by dissecting the bone in the area between the tympanic segment of the facial nerve, middle fossa dural plate and ampullary ends of the lateral and superior semicircular canals.

Mastoid pressure dressing - Current practice amongst Canadian pediatric cochlear implant surgeons

OBJECTIVES

Mastoid pressure dressing (MPD) has routinely been used following major ear surgery, such as cochlear implant (CI) surgery, to prevent postoperative wound complications. To date, controlled studies have suggested no difference in the incidence of wound complications following MPD use. However, there is a variation in the practice of MPD usage across pediatric CI surgeons. In this study, we aimed to identify the most common type of postoperative dressing management after pediatric cochlear implantation and the factors in the decision-making process for post-surgical care amongst Canadian pediatric CI surgeons.

METHODS

Canadian Otolaryngologists who perform pediatric CI surgery were identified (n = 18) and contacted via email to complete a short online questionnaire regarding current post-operative head dressing practice following CI surgery. Descriptive statistics were used to analyze the response data.

RESULTS

The participants provided an approximate number of CI's they performed in 2016. 100% of the recipients completed the survey. Approximately 376 CI's were completed in 2016 with an average of 21 CI's per surgeon. 61% of participants routinely used MPDs following surgery justified by reasons such as wound protection, institutional standard of care, and physician's original training practice.

CONCLUSION

There is no clear consensus on the use of MPDs amongst Canadian pediatric CI surgeons. Since the current evidence in the literature suggests no difference in wound complication incidence post-surgery with MPD use, a change in postoperative dressing management to non-use in those that employ this practice may be justified. Eliminating the usage of a MPD may also have potential economic benefits. Further prospective controlled studies may be warranted.

Use of simulation-based training of surgical technical skills among ENTs: an international YO-IFOS survey

PURPOSE

The aim of this study was to investigate and compare the use of simulation-based technical skills training (SBTST) in the otolaryngology curriculum in different countries, and to explore the needs and opinions about the use of simulation among young otolaryngologists.

METHODS

An e-survey conducted among Young Otolaryngologists of the International Federation of Oto-rhino-laryngological Societies (Yo-IFOS) members.

RESULTS

139 Yo-IFOS members from 51 countries completed the survey. During residency training, 82.7% of respondents have used SBTST on cadavers, 51.8% on physical simulators, and 43.8% on virtual reality simulators. High costs (65.5%), lack of availability (49.2%) and lack of time (25.5%) were the main barriers limiting the practice of SBTST. These barriers also limited teaching using simulation. Sinonasal surgery (72.7%), temporal bone surgery (67.6%), and head/neck surgery (44.6%) were significantly more frequently taught using SBTST than suspension microlaryngoscopy (25.9%) and pediatric surgery (22.3%) (p < 0.001). The procedures rated as the most important to learn through SBTST were tracheotomy (50.4%), emergency cricothyroidotomy (48.9%), and rigid bronchoscopy (47.5%). On an analogic visual scale (0-100) for the question "how important will simulation be for future ENTs in surgical training?", the mean score was 79.5/100 (± 23.3), highlighting the positive attitude toward the use of SBTST in otorhinolaryngology training.

CONCLUSION

SBTST is an attractive learning and teaching method in otorhinolaryngology, but associated costs, lack of access, and lack of time are the main barriers limiting its use. Emergency procedures are key technical skills to be learned using simulation but in some cases, lack relevant simulators for training.

Covid-19 and Ear Surgery: Treatment Strategies and Triage during the Post-lockdown Period

The accumulated disease burden during lockdown period, due to postponement of regular surgeries, is expected to put additional pressure on surgeons during the post-lockdown period. Due to the contagious nature of SARS-CoV-2 and its suspected presence in middle ear mucosa and mastoid, Ear surgeons are bound to face a challenging situation in present times as well as in times to come. Through this article we aim to streamline fresh management strategies particularly for the post-lockdown period keeping in mind that immunity after vaccination may take a few months to develop due to various factors discussed in the article. The ENT Cochrane, Pubmed and Web of Science databases were searched extensively using the terms ‘Covid-19 and SARS-CoV-2 in conjunction with Ear surgery and Otology. Data collected from these, put together with our experience helped us in putting forward fresh management strategies to deal with the current situation being experienced worldwide. To reduce the risk of infection to the healthcare staff, we have suggested a new triage strategy for ear surgeries to reduce the accumulated disease burden in the post-lockdown period until immunity by vaccination develops amongst a good number of Ear surgeons. Also we have put forward certain operating guidelines that might prove helpful for the Ear surgeon during these times. Fresh Triage guidelines mentioned in this article are particularly meant to help ear surgeons reduce the accumulated disease burden in the post lockdown-period with ease and efficacy. Since ear surgery poses a risk of infection to the healthcare workers, specific guidelines pertaining to ear surgery during the pandemic are mentioned in detail which in our opinion can be of immense help to all the healthcare professionals involved in ear procedures till the time the vaccine is administered on a large scale.

Prophylactic antiemetic effects of dexamethasone versus 5-HT3 receptor antagonists in ear surgery: a systematic review and meta-analysis

Background The optimal strategy for reducing the high incidence of postoperative nausea and vomiting (PONV) after otologic surgical procedures remains inconclusive. Aim of the review This study compared the prophylactic antiemetic effects of dexamethasone with 5-hydroxytryptamine 3 receptor antagonists (5-HT3-RAs) in ear surgery. Method PubMed, Embase, and Cochrane Library were searched up to October 31, 2020 for randomized controlled trials that used dexamethasone either singly or in combination with 5-HT3-RAs for PONV prophylaxis in adults undergoing ear surgery. Studies in languages other than English and those without a control group of 5-HT3-RAs were excluded. Random effects meta-analyses were performed, and risk of bias was assessed using the version 2 of the Cochrane risk-of-bias tool. Main outcome measures include incidences of early (< 6 h) and overall (0-48 h) PONV, the overall requirement for rescue antiemetics, and the occurrence of adverse events. Results Eight trials of 733 adults were included, and the overall risks of bias were generally low. Pooled risk ratios (RRs) of early and overall PONV of dexamethasone versus 5-HT3-RAs were 2.0 (95% CI 0.8-5.1, I² = 82%), and 1.3 (95% CI 0.6-2.6, I² = 86%). In studies comparing dexamethasone plus 5-HT3-RAs with 5-HT3-RAs alone, pooled RRs of early and overall PONV were 0.8 (95% CI 0.4-1.4, I² = 30%), and 0.5 (95% CI 0.3-0.6, I² = 0%), respectively. Pooled RRs of the overall need for rescue antiemetics comparing 5-HT3-RAs with dexamethasone alone and in combination with 5-HT3-RAs were 1.2 (95% CI 0.4-3.9, I² = 73%) and 0.4 (95% CI 0.1-1.4, I² = 61%), respectively. Common adverse events reported were headache and dizziness, and the incidences range from 0 to 10% without significant differences between the groups. Conclusion The prophylactic antiemetic effects of dexamethasone versus 5-HT3-RAs in ear surgery did not significantly differ in the early and overall postoperative phases. The combination of dexamethasone with 5-HT3-RAs showed superior overall PONV prophylactic effects to 5-HT3-RAs alone in ear surgery, but their differences in the need for rescue antiemetics remained non-significant.

The Long-Term Stability of Fat-Graft Myringoplasty in the Closure of Tympanic Membrane Perforations and Hearing Restoration

BACKGROUND/AIMS

This study was conducted to evaluate the long-term stability of fat-graft myringoplasty (FGM) for chronic tympanic membrane perforations, analyzing the perforation closure rate and re-gained hearing outcome with respect to the size and location of the perforations.

METHODS

Between August 2007 and June 2018, a total of 193 patients who underwent FGM due to chronic tympanic membrane perforation at a tertiary referral center were enrolled and analyzed.

RESULTS

The mean follow-up was 14.6 months (range 6-39). The complete perforation closure rate after FGM was 89.6%, with no statistical difference among the perforation size groups. The mean postoperative air-bone gap (ABG) was 11.0 dB and mean ABG improvement was 4.9 dB.

CONCLUSION

Our FGM technique had a favorable tympanic closure rate for small to large perforations, and yielded relatively good hearing improvement in the mid-size perforation cases over long-term follow-up periods. According to the topographic evaluation of FGM, this procedure resulted in a reliable perforation closure rate and audiological results regardless of the perforation site.

Future of Endoscopic Ear Surgery

Endoscopic ear surgery has gained popularity in recent years, becoming standard practice in otology centers around the world as an adjunct to conventional microscopic surgery and as a sole tool for limited disease. During the last years, technical improvements and growing expertise in the handling of the endoscope allowed introducing an exclusive endoscopic approach to the middle ear, lateral skull base, middle cranial fossa, and posterior fossa/cerebellopontine angle pathologies. Endoscopic instrumentation, techniques, and knowledge have improved during the last few years, and in the future, endoscopic surgical techniques will gain even more importance in otologic surgery.

The Role for Microsurgery of the Ear

Microscopic ear surgery (MES) has been used since the 1950s whereas endoscopic ear surgery (EES) was introduced in the mid-1990s. The advantages of MES should not be forgotten as surgeons turn their attention to new technology. These include depth perception, wide angle view, and the ability to operate with 2 hands. EES affords the ability to look around corners but needs a pristine field and is limited to single-handed surgery in a narrow field. Trainees should be taught both, and technique used should reflect the experience and abilities of the surgeon and the nature of the disease in the particular patient.

Drainage of a petrous apex cholesterol granuloma through an infracochlear approach

The current video presents the surgical management of a cholesterol granuloma of the anterior petrous apex, through the infracochlear approach. The video contains patient's medical history, pre-operative radiological evaluation, surgical approach to the lesion and radiological follow up. Surgery was conducted by an otology and skull base team in a tertiary referral center. The patient is a 49-years-old male, who was referred to our center for a four months history of right tinnitus and fullness. The clinical evaluation was unremarkable and the audiometric testing showed a right sensorineural hearing loss with normal contralateral hearing. A high-resolution CT-scan of the temporal bone was performed showing a lesion occupying the right petrous apex and eroding the cochlea. In a subsequent MRI scan, the lesion appeared hyperintense in both T1- and T2-weighted images. Those radiological features prompted us to the diagnosis of a cholesterol granuloma, and the selected treatment was a drainage via infracochlear approach. The infracochlear approach, firstly described by Giddings et al. [1] in 1991, represents a direct route to the petrous apex, that can be chosen in selected cases with favorable anatomical conditions and that allows respecting of the hearing mechanism. After surgical drainage of the granuloma, no worsening of the pure tone threshold was confirmed by the audiological evaluation. The hospital stay was uneventful and the patient was discharge one day postoperatively. One-year postoperative MRI scan showed signal reduction of the cholesterol granuloma.

Is It Wise to Wait for Ear to Become Dry in Indian Scenario?

Tympanoplasty is the standard and well-established procedure for closure of tympanic membrane perforations. Tympanoplasty in wet ear is still a topic of debate among ENT surgeons. This study discusses the balance between wait and watch policy and early intervention in wet ear. It also compares the rate of graft uptake and hearing improvement in Type I tympanoplasty in dry and wet ears. This is a hospital based, observational, descriptive and comparative study. Total 246 patients enrolled in the study. Two groups were created with 123 patients in each group. One included dry ears and another included wet ears. All patients had mucosal type of chronic otitis media. They all underwent Type I tympanoplasty. Graft uptake rate and hearing was compared between both groups. The overall success rate (graft uptake) was 91.06% (224). The success rate in dry ear group was 93.50% (115) and in wet ear group it was 88.62% (109). This study concluded that there is no added advantage of drying the ear rather the delay in treatment increases morbidity and drop outs in Indian scenario.

Pain After Ear Surgery: A Prospective Evaluation of Endoscopic and Microscopic Approaches

Objectives/Hypothesis

Assumed advantages of a minimally invasive endoscopic transmeatal approach in ear surgery are less postoperative pain, faster healing, and preservation of functional anatomy. We evaluated pain after ear surgery and compared endoscopic transmeatal, microscopic endaural, and retroauricular approaches.

Study Design

Prospective cohort study.

Methods

A prospective evaluation of pain during 3 weeks after ear surgery was performed. Three groups were defined: endoscopic transmeatal, microscopic endaural, and retroauricular. Data from 20 fully completed questionnaires (Brief Pain Inventory–Short Form) per group were analyzed with Bayesian and frequentist statistics.

Results

For all approaches, low pain scores were found, not exceeding 4 on a scale of 0 to 10. Analysis of the worst, least, and average pain scores documented per 24 hours showed no statistically significant difference nor equality between groups. With Bayesian statistics, a Bayes factor of 1.07, 0.25, and 0.51 was found, respectively. With frequentist statistics a p value of .092, .783, and 0.291 was found, respectively. Small, but statistically significant, differences were found for sleep, natural sleeping position, normal work, and pain medication taken. The location of pain correlates with the incision site.

Conclusions

The results of this study show that the surgical approach has no clinically relevant influence on postoperative pain after ear surgery. The statistically significant differences on natural sleeping position, sleep, normal work, and amount of pain medication taken are small and should be interpreted with caution. Therefore, these should not be decisive factors in the choice of surgical approach in ear surgery.

Level of Evidence

3 Laryngoscope, 131:1127–1131, 2021

[From reconstruction to function : Hands-on training in tympanoplasty using real-time feedback]

Hintergrund

In der Mittelohrchirurgie bedarf es ausgezeichneter feinmotorischer Fertigkeiten. Aufgrund des hohen Komplikationspotenzials im Mittelohr ist die Ausbildung dieser Fertigkeiten am Modell anzustreben.

Fragestellung

Wie gut ist die Ausbildungsmöglichkeit an geeigneten Modellen? Können die am Modell erlernten Fertigkeiten in die intraoperative Situation übertragen werden? Beeinflusst das Modell und die Ausbildung daran die zukünftige Ohrchirurgie?

Material und Methode

Vorliegende Publikationen und eigene Erfahrungen am Dresdener Tympanoplastikmodell (DTM) wurden analysiert und diskutiert.

Ergebnisse

Obwohl die Mittelohrchirurgie hohe Anforderungen an den Ausführenden stellt und am Sinnesorgan Ohr schwerwiegende Komplikationen drohen, gibt es bisher nur wenige Trainingsmöglichkeiten dafür. Das DTM ist ein validiertes Übungsmodell, das diese Lücke schließen kann. Durch eine Real-Time-Feedback-Variante des Modells kann auch das Verständnis für Rekonstruktionsqualität und intraoperative akustische Noxen verbessert werden. Die Übertragung des Real-Time-Feedback-Gedankens in die reale Mittelohrchirurgie kann die Rekonstruktionsqualität zukünftig verbessern.

Schlussfolgerungen

Das Training an geeigneten Modellen ist speziell beim Erlernen der Mittelohrchirurgie anzustreben. Mit dem Real-Time-Feedback kann beim Lernen und Operieren eine weitere Sinneswahrnehmung in die eigene und fremde Qualitätskontrolle der Tympanoplastik sehr wirksam einbezogen werden.

How Long Is Otosclerosis Surgery Effective? Hearing Results after a 22-Year Follow-Up

INTRODUCTION

Stapes surgery is a safe procedure, with favourable hearing outcome. The objective of the study is to assess the long-term hearing results, addressing the bone conduction (BC) decay and the need for hearing aids in otosclerosis patients.

METHODS

We enrolled patients who underwent stapes surgery by means of stapedectomy or stapedotomy between 1991 and 2001. All enrolled patients underwent pure-tone audiometry (PTA) between September 2017 and June 2018. A set of questions was administered to record the prevalence of subjective symptoms and the need for hearing aids.

RESULTS

Seventy patients were enrolled for a long-term evaluation; 37 patients underwent bilateral surgery; therefore, 107 ears were included in the analysis. The average follow-up period was 22 years. No statistically significant difference was found between early and late post-operative air conduction (AC) PTA (41 vs. 49 dB; p > 0.05) nor between early and late post-operative BC-PTA (29 vs. 37 dB; p > 0.05). A significant difference was observed for AC at 8 kHz (65 vs. 78 dB; p < 0.05) and BC at 2 and 4 kHz (28 vs. 40 dB and 45 vs. 58 dB, respectively; p < 0.05).

CONCLUSIONS

This is, to our knowledge, the longest mean follow-up time in the literature. A mild decrease in both AC and BC threshold can be expected and the sensorineural decay is more pronounced on the high frequencies. The subjective hearing symptoms and overall sound perception are satisfactory.

The changes of endotracheal tube intracuff pressures after ear and head and neck surgery-related positions: a prospective observational study

INTRODUCTION

The cuff of an endotracheal tube seals the airway to facilitate positive-pressure ventilation and reduce subglottic secretion aspiration. However, an increase or decrease in endotracheal tube intracuff pressure can lead to many morbidities.

OBJECTIVE

The main purpose of this study is to investigate the effect of different head and neck positions on endotracheal tube intracuff pressure during ear and head and neck surgeries.

METHODS

A total of 90 patients undergoing elective right ear (Group 1: n=30), left ear (Group 2: n=30) or head and neck (Group 3: n=30) surgery were involved in the study. A standardized general anesthetic was given and cuffed endotracheal tubes by the assistance of video laryngoscope were placed in all patients. The pilot balloon of each endotracheal tube was connected to the pressure transducer and standard invasive pressure monitoring was set to measure intracuff pressure values continuously. The first intracuff pressure value was adjusted to 18.4mmHg (25cm H₂O) at supine and neutral neck position. The patients then were given appropriate head and neck positions before related-surgery started. These positions were left rotation, right rotation and extension by under-shoulder pillow with left/right rotation for Groups 1, 2 and 3, respectively. The intracuff pressures were measured and noted after each position, at 15th, 30th, 60th, 90th minutes and before the extubation. If intracuff pressure deviated from the targeted value of 20-30cm H₂O at anytime, it was set to 25cm H₂O again.

RESULTS

The intracuff pressure values were increased from 25 to 26.73 (25-28.61) cm H₂O after left neck rotation (p=0.009) and from 25 to 27.20 (25.52-28.67) cm H₂O after right neck rotation (p=0.012) in Groups 1 and 2, respectively. In Group 3, intracuff pressure values at the neutral position, after extension by under-shoulder pillow and left or right rotation were 25, 29.41 (27.02-36.94) and 34.55 (28.43-37.31) cm H₂O, respectively. There were significant differences between the neutral position and extension by under-shoulder pillow (p<0.001), and also between neutral position and rotation after extension (p<0.001). However, there was no statistically significant increase of intracuff pressure between extension by under-shoulder pillow and neck rotation after extension positions (p=0.033).

CONCLUSION

Accessing the continuous intracuff pressure value measurements before and during ear and head and neck surgeries is beneficial to avoid possible adverse effects/complications of surgical position-related pressure changes.

Modified Postauricular Incision for Preservation of the Lesser Occipital Nerve and the Great Auricular Nerve in Ear Surgery

OBJECTIVE

To describe the feasibility of preserving the lesser occipital nerve (LON) and the great auricular nerve (GAN) in postauricular incision in ear surgery.

METHODS

The distribution of the LON and the GAN was first identified in human cadavers. Then a clinical study was performed in 34 patients who underwent middle ear surgery between September 2016 and January 2017. Patients were divided into the conventional incision group and the modified incision group, according to incision types, and underwent sensory testing and subjective evaluation of auricular numbness after surgery at different times.

RESULTS

Most frequently, the auricular branches of the LON went into the postauricular groove at the same height of inferior crus of antihelix. The vertical dimension from the intersection of the highest auricular branch of the GAN and postauricular groove to intertragic notch ranged from 5.7 to -4.2 mm. Preservation of the LON and the GAN reduced sensory loss in the modified incision group compared to the conventional incision group.

CONCLUSION

Preservation of the LON and the GAN with modified postauricular incision can reduce postoperative auricular numbness.

Association of tympanostomy tubes with future assistive hearing devices-a population based study

Background

Ear (tympanostomy) tube (TT) placement is a common ambulatory surgery in children. Despite the commonality of this treatment, the long-term effects are unknown. The objective of this study was to determine the rate of permanent hearing loss, as measured by use of a rehabilitative hearing device.

Methods

A retrospective comprehensive population-based cohort study was performed, evaluating all hospitals in the Canadian province of Ontario. Three cohorts of children were constructed: TT – at least one ear tube procedure (n = 193,880), No-TT –recurrent visits to a physician for middle ear disease, did not undergo ear tubes (n = 203,283), and Control – an age/sex matched group who had not undergone ear tubes and who didn’t have repeat physician visits for middle ear disease (n = 961,168). The main outcome measures were risk and odds ratio (OR) of rehabilitative hearing devices.

Results

The TT cohort had a higher risk of obtaining a hearing aid (OR 4.53 vs. No-TT, p < 0.001; OR 10.81 vs. Control, p < 0.001), an FM system (OR 3.84 vs. No-TT, p < 0.001; OR 15.13 vs. Control, p < 0.001), and an implanted bone conduction device (OR 5.08 vs. No-TT, p < 0.001; OR 15.67 vs. Control, p < 0.001).

Conclusions

An association between ear tube placement and long-term need for a rehabilitative hearing device was found. This association warrants future prospective research in this area.

Comparison of Different Slice Thicknesses in Computed Tomography for Labyrinthine Fistula Evaluation

OBJECTIVES

The aim of the present study is to assess the impact of different slice thicknesses in computed tomography for labyrinthine fistula evaluation and to determine the appropriate slice thickness.

METHODS

A total of 258 patients who underwent mastoidectomy and tympanoplasty for chronic otitis media with cholesteatoma from 2010 to 2014 were reviewed. The radiological diagnoses were compared with intraoperative findings. Sensitivity and specificity of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick computed tomographic (CT) images for the evaluation of labyrinthine fistulae were calculated. Cohen's κ coefficient was also calculated.

RESULTS

The sensitivities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for the evaluation of labyrinthine fistulae were 76.9, 86.5, 90.4, and 93.3% (observer 1) and 67.3, 76.0, 79.8, and 87.5% (observer 2), respectively. The specificities of 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images for labyrinthine fistula evaluation were 96.1, 94.8, 95.5, and 95.5% (observer 1) and 99.4, 97.4, 95.5, and 94.8% (observer 2), respectively. Cohen's κ coefficients were 0.790, 0.788, 0.876, and 0.911 in 2.0-, 1.5-, 1.0-, and 0.75-mm-thick CT images, respectively.

CONCLUSIONS

The sensitivity of CT for labyrinthine fistula evaluation increases with decreasing slice thickness, while the specificity does not improve.

Endoscopic ear surgery

Objectives

This article reviews the advantages and disadvantages of endoscopic ear surgery (EES).

Method

Pubmed, Google and the Proquest Central Database at Kırıkkale University were queried using the keywords “endoscopic ear surgery”, “ear surgery” and “endoscopy” to identify the literature needed for the review.

Results

Endoscopes allow for enhanced surgical visualisation. The distal part of the apparatus is illuminated and contains lenses angled to allow a wider view of the operative area. Transcanal endoscopic techniques have transformed the external ear canal (EAC) into an operative gateway. The benefits EES can offer include wider views, enhanced imaging capabilities and increased magnification, and ways to see otherwise poorly visualisable portions of the middle ear. EES permits surgeons to operate using minimally invasive otological techniques. When compared with microscope-assisted surgery, endoscopic tympanoplasty has been shown to require a shorter operating time in some instances. There are a number of drawbacks to EES, however, which include the fact that it is a single-handed technique, that the light source may produce thermal injury and that visualisation using the endoscope is severely curtailed if bleeding is profuse.

Conclusion

EES is a safe and effective technique. The current literature supports the idea that the results achieved by endoscopic methods are usually comparably beneficial to results obtained using conventional microscopic methods.

[Secondary surgery of the external ear]

Secondary surgeries of the external ear can be divided into two categories: secondary otoplasties and secondary ear reconstructions. The most frequent causes of secondary otoplasties are a recurrence, an over-corrected ear, an off-center ear, a prominent lobule, and finally chronic ear pain. Recurrence of the prominence can be treated by a new posterior stitch otoplasty, an Earfold clip, or a frame stitch. The over-corrected ear can be projected either by costal cartilage grafts or by hyaluronic acids. Patients who are unsatisfied of the aesthetic result of their prominent ear correction usually complain about an off-centered ear, because the ideal ear axis is parallel to the cheek. A prominent lobule can be corrected with a posterior stitch and a VY flap. Chronic ear pain can be significantly reduced by a protocol of physiotherapy with positive sensory feedback. In ear reconstruction, it is important preserve the retroauricular skin and the superficial temporal fascia, which are the workhorses of ear reconstruction. Secondary ear reconstructions are usually very complex procedures, which should be performed by specialists.

Surgical Outcome of Mastoid Cavity Obliteration Using Postauricular Composite Bone with Periosteum Flap

This study was aimed to evaluate surgical outcome of patients undergoing obliteration of mastoid cavity with postauricular composite osteo-periosteal flap. This interventional study was carried out on 100 patients having unsafe CSOM from Nov. 2012 to Oct. 2014 who underwent canal wall down mastoidectomy with tympanoplasty and obliteration of cavity using composite osteo-periosteal flap. The primary outcome measure was control of suppuration and creation of dry, low-maintenance mastoid cavity, which was assessed using Merchant et al. grading system. At the end of 1 year follow-up, 89% patients had Grade 0 summary score while Grade 3 which was considered as failure of control of infection was not obtained in any patient during the entire follow-up period. Mastoid cavity obliteration using composite osteo-periosteal flap is an effective technique to avoid cavity problems.

The (templar) knight cap: a new and simple way to prevent hair interference during ear surgery

INTRODUCTION

Hair interference is a critical problem in ear surgery. The hair around the surgical area can get stuck unwantedly, making the surgeon habitually struggling with this hair rather than the surgery itself. Hair shaving can cause psychological discomfort, especially for women and data about shaving efficacy are conflicting. With the aim of solving this problem, we developed a new way to clear hair from the operating field named "The (Templar) Knight cap".

TECHNICAL DESCRIPTION

This is a medical elastic stocking open at the ear to be treated and at the face that recalls the typical cap worn by Templar knight. This cap allows good hair retention and marks the surgical site. It is easy to wear does not require additional time for clinical staff.

CONCLUSIONS

The described cap could be a valid instrument during ear surgery with a low cost pricing, making it applicable in very poor settings, such as developing countries.

Cerebrospinal Fluid Leakage During Temporal Bone Surgery: Selecting Intra-operative Dural Closure with a Dumbbell-Shaped Muscle Graft as a Surgical Approach

Cerebrospinal fluid (CSF) leakages of the temporal bone may arise during mastoid surgery. The leakages can have multiple potential etiologies, for instance, using a cutting burr near the bony tegmen or monopolar electrocautery on the surface of the dura mater. In this paper, we introduced an effective and simple technique for the management of CSF leakages of the temporal bone. In a prospective case series, 36 patients (16 males and 20 females) who have had an experience of incidental or inevitable CSF otorrhea or otorhinorrhea during temporal bone surgery were selected. All patients were treated using a muscle graft in a dumbbell-shaped design through the dura defect at the Amir-Alam University Hospital between April 2005 and November 2008. The mean size of the defects was 5 mm (a range of 2-10 mm). A dumbbell-shaped autologous muscle graft was immediately successful in sealing the leakage in all patients. Only five patients (13.8%) had some evidence of leakage remaining on the day after the operation, which was subsequently resolved by conservative management in four of them (11.1%). Only one patient (2.7%) was subjected to a second operation for a new defect. Recurrence of CSF leakage or other related complications were not observed during about 7 years of follow up. A free autologous muscle graft, using the dumbbell technique through a small to moderate dura defect is an effective, easily performed, and safe method to seal iatrogenic leakages of the temporal bone.

Endoscopic and minimally-invasive ear surgery: A path to better outcomes

The development of endoscopic ear surgery techniques promises to change the way we approach ear surgery. In this review paper, we explore the current evidence, seek to determine the advantages of endoscopic ear surgery, and see if these advantages are both measureable and meaningful. The wide field of view of the endoscope allows the surgeon to better visualize the various recesses of the middle ear cleft. Endoscopes make it possible to address the target pathology transcanal, while minimizing dissection or normal tissue done purely for exposure, leading to the evolution of minimally-invasive ear surgery and reducing morbidity. When used in chronic ear surgery, endoscopy appears to have the potential to significantly reduce cholesteatoma recidivism rates. Using endoscopes as an adjunct can increase the surgeon's confidence in total cholesteatoma removal. By doing so, endoscopes reduce the need to reopen the mastoid during second-look surgery, help preserve the canal wall, or even change post-cholesteatoma follow-up protocols by channeling more patients away from a planned second-look.

Retrospective study of intranasal dexmedetomidine as a prophylactic against emergence delirium in pediatric patients undergoing ear tube surgery

OBJECTIVES

This study evaluated the effect of intranasal dexmedetomidine on emergence delirium (ED) in pediatric patients who underwent ear tube surgeries. Due to the brief nature of the surgery and low levels of pain experienced, an IV is rarely needed, limiting the medications available to anesthesiologists to manage postoperative delirium that may arise during recovery from inhalational anesthesia. Intravenous dexmedetomidine is an alpha-2 agonist anesthetic that is used in pediatric patients for the management of ED in various surgical procedures. However, intranasal medication has not been evaluated specifically in ear tube surgeries for ED prevention.

METHODS

We conducted a retrospective chart review of pediatric patients at Nemours Children's Hospital who had undergone ear tube insertion or removal surgery between 2013 and 2015, controlling for confounding variables such as age, surgery duration, and anesthesiologist. We used the post anesthesia emergence delirium (PAED) tool, an instrument created to assess ED in the clinical setting. We analyzed the data for significant differences in PAED score and time in the post anesthesia care unit (PACU) between patients treated with intranasal dexmedetomidine and the control group that did not receive the medication.

RESULTS

We found no significant difference between the PAED scores of those patients treated with intranasal dexmedetomidine prior to ear tube surgeries and those who did not receive the medication, and no difference in the duration of PACU stay.

CONCLUSION

These results conflict with other research on intranasal dexmedetomidine and its potential to prevent ED in pediatric patients. This information should prompt further prospective investigation into the most efficacious use of dexmedetomidine for ED prevention, both in terms of timing and dosage required.

Management of labyrinthine fistula: hearing preservation versus prevention of residual disease

The objective of the study was to evaluate postoperative hearing and disease control after cholesteatoma surgery for labyrinthine fistulas. In a retrospective cohort study, we evaluated a consecutive cohort comprising 44 patients (45 ears) with labyrinthine fistulas associated with chronic otitis media with cholesteatoma who underwent surgery between 2002 and 2015. We looked at patient characteristics, pre- and postoperative bone conduction thresholds (BCT), operative approach and findings, extent of disease and the occurrence of residual disease. All deaf ears (24%) presented preoperatively with a large fistula. Opening the membranous labyrinth resulted in significantly worse postoperative BCT (p = 0.01). Neither the present study nor a literature search revealed a significant positive effect of corticosteroids on postoperative hearing preservation. Large fistulas were correlated with poorer preoperative BCTs, but not with poorer postoperative BCTs. Opening the membranous labyrinth during surgery is correlated with poorer postoperative BCTs and can be seen as a predictive parameter. The use of corticosteroids in the perioperative management of labyrinthine fistula was not found to result in any improvement in postoperative BCTs.

Vascular mapping of the retroauricular skin - proposal for a posterior superior surgical incision for transcutaneous bone-conduction hearing implants

BACKGROUND

Passive transcutaneous osseointegrated hearing implant systems have become increasingly popular more recently. The area over the implant is vulnerable due to vibration and pressure from the externally worn sound processor. Good perfusion and neural integrity has the potential to reduce complications. The authors' objective was to determine the ideal surgical exposure to maintain perfusion and neural integrity and decrease surgical time as a result of reduced bleeding.

METHODS

The vascular anatomy of the temporal-parietal soft tissue was examined in a total of 50 subjects. Imaging diagnostics included magnetic resonance angiography in 12 and Doppler ultrasound in 25 healthy subjects to reveal the arterial network. Cadaver dissection of 13 subjects formed the control group. The prevalence of the arteries were statistically analyzed with sector analysis in the surgically relevant area.

RESULTS

The main arterial branches of this region could be well identified with each method. Statistical analysis showed that the arterial pattern was similar in all subjects. The prevalence of major arteries is low in the upper posterior area though large in proximity to the auricle region.

CONCLUSIONS

Diverse methods indicate the advantages of a posterior superior incision because the major arteries and nerves are at less risk of damage and best preserved. Although injury to these structures is rare, when it occurs, the distal flow is compromised and the peri-implant area is left intact. Hand-held Doppler is efficient and cost-effective in finding the best position for incision, if necessary, in subjects with a history of surgical stress to the retroauricular skin.

TRIAL REGISTRATION

This was a non-interventional study.

Hearing Loss after Round Window Surgery in Mice Is due to Middle Ear Effusion

BACKGROUND

Delivery of therapeutic agents directly through the round window (RW) offers promise for treating sensorineural hearing loss. However, hearing loss can result from the surgical approach itself, and the reasons for this are poorly understood. We examined the hearing loss following the 3 major steps involved with the RW approach to access the mouse cochlea: bullostomy, RW puncture, and RW injection.

METHODS

Twenty-one adult CBA/J mice underwent bullostomy alone, 10 underwent RW puncture, and 8 underwent RW injection with PBS with 5% glycerol. Auditory brainstem responses (ABR) and otoscopy were performed preoperatively and up to 6 weeks postoperatively. Hair cells were stained, and survival was assessed using immunofluorescence.

RESULTS

One week postoperatively, mice in all groups showed significant threshold shifts. Otoscopy revealed approximately half of all mice had middle ear effusion (MEE), with a higher incidence of effusion in the RW puncture and RW injection groups. Those with MEE had significant ABR threshold shifts, whereas those without MEE had minimal hearing loss. MEE persisted through 6 weeks in a majority of cases, but in those mice with MEE resolution, there was at least partial improvement in hearing. Immunohistochemistry showed minimal loss of hair cells in all animals.

CONCLUSION

MEE is highly correlated with hearing loss in mice undergoing RW surgery. Otoscopy is an important adjunct to consider after ear surgery in mice, as MEE may contribute to postsurgical hearing loss.

Ultrasound-Guided Greater Auricular Nerve Block as Sole Anesthetic for Ear Surgery

A greater auricular nerve (GAN) block was used as the sole anesthetic for facial surgery in an 80-year-old male patient with multiple comorbidities which would have made general anesthesia challenging. The GAN provides sensation to the ear, mastoid process, parotid gland, and angle of the mandible. In addition to anesthesia for operating room surgery, the GAN block can be used for outpatient or emergency department procedures without the need for a separate anesthesia team. Although this nerve block has been performed using landmark-based techniques, the ultrasound-guided version offers several potential advantages. These advantages include increased reliability of the nerve block, as well as prevention of inadvertent vascular puncture or blockade of the phrenic nerve, brachial plexus, or deep cervical plexus. The increasing access to ultrasound technology for medical care providers outside the operating room makes this ultrasound guided block an increasingly viable alternative.

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.

The image variations in mastoid segment of facial nerve and sinus tympani in congenital aural atresia by HRCT and 3D VR CT

OBJECTIVE

To find the variations of middle ear structures including the spatial pattern of mastoid segment of facial nerve and the shapes of the sinus tympani in patients with congenital aural atresia (CAA) by using the high-resolution (HR) CT and 3D volume rendered (VR) CT images.

METHODS

HRCT was performed in 25 patients with congenital aural atresia including six bilateral atresia patients (n=25, 21 males, 4 females, mean age 13.8 years, range 6-19). Along the long axis of the posterior semicircular canal ampulla, the oblique axial multiplanar reconstruction (MPR) was set to view the depiction of the round window and the mastoid segment of facial nerve. Volumetric rending technique was used to demonstrate the morphologic features. HRCT and 3D VR findings in atresia ears were compared with those in 19 normal ears of the unilateral ears of atresia patients.

RESULTS

On the basic plane, the horizontal line distances between the mastoid segment of the facial nerve and the round window (h-RF) in atresia ears significantly decreased compared to the control ears (P<0.05). There was a significant negative correlation between the sinus tympani area (a-ST) and the distance between the horizontal lines of FN and RW midpoint (h-RF) (P<0.05). The mean area of sinus tympani in atresia group is larger (P<0.05). The shapes of the sinus tympani were classified into three categories: the cup-shaped, the pear-shaped and the boot-shaped. Area measurement indicated that the boot-shaped sinus tympani was a special variation with a large area, which only appears in CAA group. There were a significant difference between the area of the boot-shaped group and the other two groups (P<0.05). The morphologic differences of ST and other middle ear structures can also be observed visually in 3D VR CT images.

CONCLUSION

HRCT and 3D VR CT could help a better understanding of different kinds of variations in mastoid segment of facial nerve and sinus tympani in CAA ears. And it may further help surgeons to make the correct decision for hearing rehabilitation.

The effects of bone pâté on human osteoblasts cell cultures

The aim of the present study was to evaluate the effect of bone pate on human osteoblast differentiation by measuring cell viability, alkaline phosphatase activity and expression of the transcription factors and of the major components of the extracellular matrix. Although bone paté has been used in ear surgery for many years and when placed in contact with mastoid and external auditory canal bone become viable, the cellular mechanisms that lead to its osteointegration have never been described. Bone paté taken from four patients subjected to mastoidectomy and affected by middle ear and mastoid cholesteatoma was placed in contact with osteoblast-like cell cultures. Four experimental conditions were obtained: cell cultures treated with bone patè, with bone paté mixed with fibrin glue, with fibrin glue and untreated. After 24 h, the viability of the cells was evaluated; after 1 week, alkaline phosphatase activity and the expression of transcription factors and bone matrix proteins were assessed by quantitative polymerase chain reaction. After 24 h osteoblasts showed increased viability when treated with bone paté (19 % increase) and bone pate mixed with fibrin glue (34 % increase). After 1 week, the number of alkaline phosphatase positive cells increased by 97 and 94 % in cultures treated with bone paté alone and bone pate mixed with fibrin glue. Treatment with bone patè upregulated transcription factors and components of the extracellular matrix. The present data show that bone paté has a high osteoinductive potential on human osteoblasts, enhancing their activity.

Assessment of skills using a virtual reality temporal bone surgery simulator

Surgery on the temporal bone is technically challenging due to its complex anatomy. Precise anatomical dissection of the human temporal bone is essential and is fundamental for middle ear surgery. We assessed the possible application of a virtual reality temporal bone surgery simulator to the education of ear surgeons. Seventeen ENT physicians with different levels of surgical training and 20 medical students performed an antrotomy with a computer-based virtual temporal bone surgery simulator. The ease, accuracy and timing of the simulated temporal bone surgery were assessed using the automatic assessment software provided by the simulator device and additionally with a modified Final Product Analysis Scale. Trained ENT surgeons, physicians without temporal bone surgical training and medical students were all able to perform the antrotomy. However, the highly trained ENT surgeons were able to complete the surgery in approximately half the time, with better handling and accuracy as assessed by the significant reduction in injury to important middle ear structures. Trained ENT surgeons achieved significantly higher scores using both dissection analysis methods. Surprisingly, there were no significant differences in the results between medical students and physicians without experience in ear surgery. The virtual temporal bone training system can stratify users of known levels of experience. This system can be used not only to improve the surgical skills of trained ENT surgeons for more successful and injury-free surgeries, but also to train inexperienced physicians/medical students in developing their surgical skills for the ear.

Endoscopic middle ear and mastoid surgery for cholesteatoma

INTRODUCTION

To reduce incidence of residual cholesteatoma following ear surgery; and to reduce the need for second look "open" mastoidectomy using endoscopic mastoidotomy. Ten-year retrospective chart review of 249 primary cholesteatoma cases (1994-2004) with a minimum follow-up of two years. The first objective was to evaluate the effectiveness of otoendoscopy in reducing the incidence of "cholesteatoma remnant" at the time of primary surgery. The second investigation was to evaluate the effectiveness of otoendoscopy in reducing the need to open the mastoid cavities during "second look operations".

MATERIALS AND METHODS

Endoscopes were used on all cases as an adjunct to standard microscopic methods. Once all visible cholesteatoma was removed with standard microscopic techniques, endoscopes were utilized in order to identify any "remnants" of cholesteatoma. Endoscopes were also employed during revision second look cases in order to allow the evaluation of intact canal wall mastoid cavities without an open Mastoidectomy approach.

RESULTS

Endoscopy at time of primary operations revealed a 22% incidence of hidden cholesteatoma "remnants" despite apparent total microscopic eradication in closed cavity cases, and 10% in open cavity patients. Endoscopic removal of cholesteatoma remnants reduced the long term cholesteatoma "residual" to 9.7% in closed cavity patients. Furthermore, endoscopic surgery significantly reduced the need to open the mastoids during second look operations.

CONCLUSION

Otoendoscopy is a very effective adjunctive method in ear surgery. It allows significant reduction in cholesteatoma residual rate in both closed cavity and open cavity cases. Furthermore, the great majority of second look mastoids can be evaluated endoscopically and thus avoid an open revision Mastoidectomy.

Endoscopic transcanal middle ear surgery

The advantages and limitations of the microscope have defined postauricular access as the surgical intervention of choice for the treatment of diseases of the middle ear. The wide-angle view provided by the endoscope enables transcanal access to the tympanic cavity, and its otherwise difficult-to-reach extensions: The attic, sinus tympani, facial recess, and hypotympanum. These areas are the primary sites of disease and surgical failure to cure. The endoscope also allows an all encompassing view of the three main elements in tympanoplasty surgery: The ear canal, tympanic membrane, and the tympanic ring. This report is a summary of the author's two 17 years of experience with the use of transcanal operative endoscopy as the primary approach to the management of middle ear disease.