3D 4K Exo-Endoscopic Temporal Bone Dissection: A Novel Approach for Sharing the Anatomy.

BACKGROUND: Temporal bone dissection is overwide recognized as an ideal training method for otologic surgeons. The knowledge of temporal bone anatomy and especially of the course of infratemporal facial nerve is pivotal in practice. The 3D exoscope is an innovative and promising tool, that was recently introduced in ear surgery. METHODS: A high-definition 3D exoscope (3D VITOM®) mounted on the VERSACRANETM holding system (Karl Storz) was used to perform two temporal bone dissection, with the aim to study the anatomy of infratemporal facial nerve. The 3D endoscope (TIPCAM®1 S 3D ORL, Karl Storz) was used in combination to provide a close-up high-quality view and to provide a different angle of view on fine anatomical relationships. RESULTS: The high-definition 3D exoscope allowed to conduct the dissection with high quality visualization and to share the same surgical field with trainees. Moreover, it showed a high interchangeability with the 3D endoscope. CONCLUSIONS: 3D 4 K Exo-endoscopic temporal bone dissection seems to have benefits in terms of educational purpose, especially concerning anatomy understanding. The superiority in teaching value of this tool should be further investigated in cohort studies.

The Impact of Piezoelectric Device in Cholesteatoma Endoscopic Surgery: Retrospective Evaluation of Safety and Functional Results.

OBJECTIVE: Atticotomy represents an essential surgical step within the management of attical cholesteatoma during endoscopic ear surgery. The aim of the present study was to evaluate the safety and functional results of an endoscopic atticotomy performed with piezosurgery, in terms of audiological outcomes and tissue's healing. METHODS: This is an observational retrospective study on patients with attical cholesteatoma who underwent endoscopic ear surgery with piezoelectric atticotomy and subsequent scutum reconstruction either with tragal cartilage or temporalis muscle fascia. Scutumplasty's status was evaluated via scheduled outpatient controls through an endoscopic check and classified as stable or unstable at least 10 months after surgery. A pre- and postoperative audiometric examination was performed in each patient. RESULTS: Eighty-four patients were enrolled. In 50 out of 84 patients (59.52%), an exclusive endoscopic procedure was performed, whereas in 34 patients (40.48%) a combined microscopic/endoscopicapproach was adopted. In 72 cases (85.71%), scutum's reconstruction appeared to be normally positioned, whereas 12 patients developed a retraction pocket, which was self-cleaning in 8 of them and non-self-cleaning in the remaining 4. In 17 patients, a slight sensorineural hearing loss (between 5 and 15 dBHL) was observed, and in 2 patients, the loss was greater than 15 dBHL. Overall, no significative differences between pre- and postoperative pure-tone average bone thresholds resulted (p = 0.4983), though a mild significant hearing deterioration was detected by the specific analysis at 4000 Hz (p = 0.0291). CONCLUSION: Piezosurgery represents an extremely useful tool in performing atticotomy during endoscopic tympanoplasties. Our data seem to support the safety of its usage in this specific step, as it did not lead to any significant sensorineural damage on overall pure-tone average. Moreover, satisfactory tissue healing in regard to scutum reconstruction was observed.

Integration of 3D-printed middle ear models and middle ear prostheses in otosurgical training.

BACKGROUND: In otosurgical training, cadaveric temporal bones are primarily used to provide a realistic tactile experience. However, using cadaveric temporal bones is challenging due to their limited availability, high cost, and potential for infection. Utilizing current three-dimensional (3D) technologies could overcome the limitations associated with cadaveric bones. This study focused on how a 3D-printed middle ear model can be used in otosurgical training. METHODS: A cadaveric temporal bone was imaged using microcomputed tomography (micro-CT) to generate a 3D model of the middle ear. The final model was printed from transparent photopolymers using a laser-based 3D printer (vat photopolymerization), yielding a 3D-printed phantom of the external ear canal and middle ear. The feasibility of this phantom for otosurgical training was evaluated through an ossiculoplasty simulation involving ten otosurgeons and ten otolaryngology-head and neck surgery (ORL-HNS) residents. The participants were tasked with drilling, scooping, and placing a 3D-printed partial ossicular replacement prosthesis (PORP). Following the simulation, a questionnaire was used to collect the participants' opinions and feedback. RESULTS: A transparent photopolymer was deemed suitable for both the middle ear phantom and PORP. The printing procedure was precise, and the anatomical landmarks were recognizable. Based on the evaluations, the phantom had realistic maneuverability, although the haptic feedback during drilling and scooping received some criticism from ORL-HNS residents. Both otosurgeons and ORL-HNS residents were optimistic about the application of these 3D-printed models as training tools. CONCLUSIONS: The 3D-printed middle ear phantom and PORP used in this study can be used for low-threshold training in the future. The integration of 3D-printed models in conventional otosurgical training holds significant promise.

Comparison of capabilities and limitations of endoscopes in endoscopic ear surgeries using 3D printed models.

PURPOSE: Endoscopic ear surgery has become a popular operative approach to treat middle ear diseases. Surgeons use either 0° or 30° endoscopes worldwide. The main aim of the work was to compare the properties of these two types of endoscopes. MATERIAL AND METHODS: Since this type of evaluation is hard to perform in vivo during the actual surgery, we designed 3D printed temporal bone models with different levels of complexity. The evaluation of endoscopes was based on image analysis or visibility of anatomical structures. RESULTS: The results show that a 30° endoscope offers a view of lateral walls from 4 mm distance, contrary to a 0° endoscope which cannot see lateral walls from this distance at all. On the other hand, visible area of the anterior wall is up to 40 % larger using 0° endoscope, compared to 30° endoscope. Angled endoscope distorts the picture and leads to the deterioration of the image. At commonly used distances above 5 mm from middle ear structures, resolution and image distortion is comparable between both endoscopes. CONCLUSIONS: Our results do not offer a definitive opinion on which endoscope is better for ear surgery. Both types of endoscopes have advantages and disadvantages, and the choice depends on the surgeon's personal preference and on the type of planned procedure.

Comparison of artefact reduction possibilities with the new active transcutaneous bone conduction implant (Bonebridge).

OBJECTIVE: This study aimed to evaluate the possibilities of artefact reduction using different anatomical implant positions with the Bonebridge bone-conduction hearing implant 602 for a patient with an acoustic neuroma requiring regular diagnostic magnetic resonance imaging of the tumour position. METHOD: Three implant positions and magnetic resonance imaging examinations with and without customised sequences for metal artefact suppression were investigated. The diagnostic usefulness was rated by a radiologist (qualitative evaluation), and the relation between the area of artefact and the total head area was calculated (quantitative evaluation). RESULTS: Following the qualitative analysis, the radiologist rated the superior to middle fossa implant placement significantly better for diagnostic purposes, which is in agreement with the calculated artefact ratio (p < 0.0001). The customised slice-encoding metal artifact correction view-angle tilting metal artifact reduction technique sequences significantly decreased the relative artefact area between 5.13 per cent and 25.02 per cent. The smallest mean artefact diameter was found for the superior to middle fossa position with 6.80 ± 1.30 cm (range: 5.42-9.74 cm; reduction of 18.65 per cent). CONCLUSION: The application of artefact reduction sequencing and special anatomical implant positioning allows regular magnetic resonance imaging in patients with the bone-conduction hearing implant 602 without sacrificing diagnostic imaging quality for tumour diagnosis.

Three-dimensional versus two-dimensional endoscopes in anatomical orientation of the middle ear and in simulated surgical tasks.

BACKGROUND: Three-dimensional endoscopes provide a stereoscopic view of the operating field, facilitating depth perception compared to two-dimensional systems, but are not yet widely accepted. Existing research addresses performance and preference, but there are no studies that quantify anatomical orientation in endoscopic ear surgery. METHODS: Participants (n = 70) were randomised in starting with either the two-dimensional or three-dimensional endoscope system to perform one of two tasks: anatomical orientation using a labelled three-dimensional printed silicone model of the middle ear, or simulated endoscopic skills. Scores and time to task completion were recorded, as well as self-reported difficulty, confidence and preference. RESULTS: Novice surgeons scored significantly higher in a test of anatomical orientation using three-dimensional compared to two-dimensional endoscopy (p < 0.001), with no significant difference in the speed of simulated endoscopic skills task completion. For both tasks, there was lower self-reported difficulty and increased confidence when using the three-dimensional endoscope. Participants preferred three-dimensional over two-dimensional endoscopy for both tasks. CONCLUSION: The findings demonstrate the superiority of three-dimensional endoscopy in anatomical orientation, specific to endoscopic ear surgery, with statistically indistinguishable performance in a skills task using a simulated trainer.

The utility of the exoscope compared to the operating microscope in simulated temporal bone surgery.

OBJECTIVE: To objectively assess the utility of an exoscope during simulated otological surgery. DESIGN: Cohort study. SETTING: Tertiary referral otolaryngology centre. PARTICIPANTS: Seven experienced otologists undertook simulated temporal bone surgery on plastic temporal bones using the Zeiss Kinevo microscope with both a microscope and exoscope facility. OUTCOME MEASURES: The utility of microscope and exoscope was compared using a Likert scale from 1 to 10 with and without PPE. Attributes assessed included image quality, depth perception, adequacy of view, exoscope positioning, surgeon comfort, surgeon safety and adequacy of image and protection for assistants and observers. RESULTS: The exoscope in 3D mode performed as well as or better than the microscope for image quality, field of view and manoeuvrability. It outperformed the microscope for compatibility with PPE, surgeon comfort and assistant/observer experience. It scored almost as highly as the microscope for depth perception. CONCLUSION: There is likely to be a learning curve but this initial assessment of the exoscope shows significant potential as an alternative to the operating microscope in otological surgery but with the advantage of allowing the use of appropriate PPE and better ergonomics for both surgeon and assistant/observer.

Feasibility study of the Vitom 3D exoscope in ENT surgery using an animal model: relevance to coronavirus disease 2019.

OBJECTIVE: The application of a 4K display resolution three-dimensional exoscope system (Vitom 3D) was evaluated to determine the feasibility of adopting the system in ENT surgery in the coronavirus disease 2019 era and beyond. METHODS: Eighteen ENT surgeons performed structured otological tasks on fresh-frozen sheep heads using the Vitom 3D. Structured feedback of the participants' experience was analysed. RESULTS: Seventy-four per cent and 94 per cent of participants reported that the Vitom 3D was ergonomic and comfortable to use respectively. Whilst colour fidelity and image quality were very good, 50 per cent of participants reported image distortion and pixilation at the highest magnification. All participants agreed that there was an increased educational value to exoscope technology. Half the participants preferred the microscope over the Vitom 3D for fine otological work, which may reflect the learning curve. CONCLUSION: The Vitom 3D exoscope is a promising and viable alternative for performing otological surgery when using full personal protective equipment in the coronavirus disease 2019 era.

Piezoelectric canalplasty for exostoses and osteoma.

OBJECTIVE: To evaluate the safety profile and surgical technique for removal of symptomatic exostoses and osteoma of the external auditory canal with a micro-oscillating piezoelectric device. METHOD: A chart review was conducted on patients undergoing piezoelectric canalplasty between 2019 and 2021 at tertiary referral hospital. Surgery was performed by two surgeons with varying experience. Bone removal was achieved using both osteotomy and osteoplasty. Postoperative complications, operative time and hearing outcome were evaluated. RESULTS: The study comprised 16 patients (16 ears). No major complications occurred. The skin of the auditory canal was completely preserved in all patients without injury to the tympanic membrane. Except for one patient with known noise-induced hearing loss, there was no postoperative deterioration of the bone-conduction threshold more than 10 dB HL at any frequency. The difference of the bone-conduction threshold in pure-tone audiometry (average for 0.5, 1, 2 and 4 kHz) three weeks postoperatively had a median of 0.6 dB ± 5.7. One patient complained of temporary new tinnitus. One patient had prolonged wound healing. Mean operative time was comparable with literature data. CONCLUSION: The atraumatic characteristics of the piezoelectric instrument enable low-risk removal of external auditory canal exostoses and osteoma. Through the combination of precise osteotomy and osteoplasty, this novel instrument has the potential to become established in routine canalplasty.

Training in endoscopic ear surgery using the papaya petiole.

BACKGROUND: Endoscopic ear surgery is a game changer in the field of otology. Training in endoscopic skills is essential for ENT residents, and is especially important during the coronavirus disease 2019 lockdown period. In such difficult times, ENT residents and surgeons can undergo hands-on training using a papaya petiole, even within their homes. OBJECTIVE: Endoscopic ear surgery training can be carried out using a papaya petiole, enabling the practice of grommet insertion, tympanomeatal flap elevation and foreign body removal from the external auditory canal. This model does not need any laboratory setup. RESULTS AND CONCLUSION: The hollow structure of the papaya petiole model is very similar to that of the external auditory canal, making training in endoscopic ear surgery easy. Use of the model helps a beginner to train in endoscopic handling and microsurgical instrumentation, and improves depth perception. In addition, it does not require high-end facilities to store equipment or undertake the training at any given point in time.

Using a 4K three-dimensional exoscope system (Vitom 3D) for mastoid surgery during the coronavirus disease 2019 pandemic.

OBJECTIVE: Microscopic surgery is currently considered the 'gold standard' for middle-ear, mastoid and lateral skull base surgery. The coronavirus disease 2019 pandemic has made microscopic surgery more challenging to perform. This work aimed to demonstrate the feasibility of the Vitom 3D system, which integrates a high-definition (4K) view and three-dimensional technology for ear surgery, within the context of the pandemic. METHOD: Combined approach tympanoplasty and ossiculoplasty were performed for cholesteatoma using the Vitom 3D system exclusively. RESULTS: Surgery was performed successfully. The patient made a good recovery, with no evidence of residual disease at follow up. The compact system has excellent depth of field, magnification and colour. It enables ergonomic work, improved work flow, and is ideal for teaching and training. CONCLUSION: The Vitom 3D system is considered a revolutionary alternative to microscope-assisted surgery, particularly in light of coronavirus disease 2019. It allows delivery of safe otological surgery, which may aid in continuing elective surgery.

Exoscope-assisted Otologic Surgery During the COVID-19 Pandemic.

OBJECTIVE: The recent COVID-19 pandemic has required careful reconsideration of safe operating room practices. We describe our initial experiences performing otologic surgery with the exoscope during the COVID-19 pandemic. METHOD: The exoscope was used for several semiurgent otologic surgeries in combination with complete eye protection, a "tent" drape, a smoke evacuator with ultra-low particulate air filter, and betadine irrigation. These techniques are demonstrated in the accompanying video. This was compared with our experiences using the microscope. RESULTS: The described modified goggles allowed complete eye protection while providing a fully three-dimensional view of the surgical site. The other safety measures described are simple and efficient techniques which can easily be adopted for otologic surgery using the microscope. CONCLUSION: Use of the exoscope for otologic surgery during the COVID-19 pandemic allows full three-dimensional visualization of the surgical field while simultaneously providing complete eye protection. Use of the "tent" drape, ultra-low particulate air filter, and betadine irrigation are also options that otologic surgeons may consider for additional safety.

Design, prototype development and pre-clinical validation of a novel instrument with a compliant steerable tip to facilitate endoscopic ear surgery.

This work presents the design of a novel compliant steerable tip (CST) instrument to facilitate transcanal (or totally) endoscopic ear surgery (TEES). The evolution of the instrument's design is shown, where prototypes were evaluated by surgeons and their feedback was used to inform the design changes for the next prototype iteration. The final prototype enables the surgeon to articulate the compliant tip to achieve the desired bending curvature while automatically locking in place and providing dissection and suction capabilities. Pre-clinical validation testing was performed in goat and human cadaver models by two surgeons who successfully removed an allograft from the middle ear. Time and the number of blockages while suctioning saline in both cadaver models were measured and compared with current instruments used during TEES. The CST took significantly less time to suction saline within a flooded middle ear compared to the Panetti suction dissector (PSD) for atticus and underwent less blockages than the PSD for atticus, ear drum and sinus tympani instruments, Wilcoxon Method p < .05. Our study demonstrates the development and successful clinical evaluation of a minimally invasive surgical instrument designed to facilitate endoscopic approaches to the ear.

Recommended Personal Protective Equipment for Cochlear Implant and Other Mastoid Surgery During the COVID-19 Era.

OBJECTIVES/HYPOTHESIS: The overall aim of this study was to evaluate personal protective equipment (PPE) that may facilitate the safe recommencement of cochlear implantation in the COVID-19 era, with the broader goal of minimizing the period of auditory deprivation in prelingually deaf children and reducing the risk of cochlear ossification in individuals following meningitis. METHODS: The study design comprised 1) an objective assessment of mastoid drilling-induced droplet spread conducted during simulated cochlear implant (CI) surgery and its mitigation via the use of a protective drape tent and 2) an evaluation of three PPE configurations by otologists while performing mastoid drilling on ex vivo temporal bones. The various PPE solutions were assessed in terms of their impact on communication, vital physiological parameters, visual acuity and fields, and acceptability to surgeons using a systematic risk-based approach. RESULTS: Droplet spread during simulated CI surgery extended over 2 m, a distance greater than previously reported. A drape tent significantly reduced droplet spread. The ensemble of a half-face mask and safety spoggles (foam lined safety goggles) had consistently superior performance across all aspects of clinical usability. All other PPE options were found to substantially restrict the visual field, making them unsafe for microsurgery. CONCLUSIONS: The results of this preclinical study indicate that the most viable solution to enable the safe conduct of CI and other mastoid surgery is a combination of a filtering facepiece (FFP3) mask or half-face respirator with safety spoggles as PPE. Prescription spoggles are an option for surgeons who need to wear corrective glasses to operate. A drape tent reduces droplet spread. A multicenter clinical trial to evaluate the effectiveness of PPE should be the next step toward safely performing CI surgery during the COVID-19 era. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2693-2699, 2020.

A Novel Surgery Classification for Endoscopic Approaches to Middle Ear Cholesteatoma.

This study aimed to develop a novel surgery classification for an endoscopic approach to middle ear cholesteatoma. We retrospectively analyzed the surgical approaches and outcomes of patients with middle ear cholesteatoma. Middle ear cholesteatoma surgeries were divided into four types and two special types as follows: type I, attic retraction pocket, which only requires tympanostomy tube placement or retraction pocket resection and cartilage reconstruction; type II, cholesteatoma which is limited to the attic or in which endoscopy can confirm complete removal of mastoid cholesteatoma lesions, including type II a, requiring only use of a curette, and type II b, requiring use of an electric drill or chisel; type III, cholesteatoma not limited to the attic, in which endoscopy cannot confirm complete removal of mastoid cholesteatoma lesions, requiring the combined use of endoscope and microscope to perform endoscopic tympanoplasty and "Canal Wall Up" mastoidectomy; type IV, extensive involvement of mastoid cavity cholesteatoma lesions and/or cases with a potential risk of complications, removal of which can only be performed under a microscope for "Canal Wall Down" mastoidectomy. In addition, there were two special types: "difficult external auditory canal" and congenital cholesteatoma in children. In our system, type I and type II middle ear cholesteatoma surgery was completely performed under an endoscope alone. However, estimating the extent of the lesions, determining the choice of mastoid opening and reestablishing ventilation are the key points for an endoscopic approach to middle ear cholesteatoma. The classification of endoscopic middle ear cholesteatoma surgery may benefit the selection of surgical indications.

The mechanism of balloon Eustachian tuboplasty: a biomechanical study.

Obstructive Eustachian tube dysfunction (OETD) is a common condition resulting from inadequate opening of the Eustachian tube (ET). A new surgical treatment involves high-pressure inflation of a balloon within the ET, with the aim of dilating the soft tissue structure. However, the mechanical effects of this intervention have not been established, nor the impact of changing device size or other technical parameters. A novel experimental technique allowed quantification of plastic and elastic tissue deformation in model materials and then human cadaver ETs during balloon dilation, based on the measured balloon inflation pressure-volume relationship. Plastic tissue deformation was found to be greater using larger balloons and deeper device insertion, but increasing the inflation pressure had a more limited effect, with most deformation occurring well below the clinically used pressures. Histological assessment of ET tissue suggested that mucosal tearing and cartilage cracking were in part responsible for the mechanical changes. Balloon dilation of the ET has huge potential if found to be clinically effective, but currently there is a need to understand and develop the technique further. The novel methods employed in this study will be valuable in future laboratory and in vivo studies of ET balloon dilation. Pressures are reported in Bar as this unit is used for medical balloon dilation procedures in clinical practice. 1 Bar = 100,000 Pa. Graphical abstract caption Dilation of the Eustachian tube for obstructive dysfunction is performed clinically with 3- and 6-mm-diameter balloons of approximately the same overall length. Our data suggest that dilation with a 6-mm balloon causes greater deformation of the soft tissue structure than dilation with a 3-mm balloon. This difference has yet to be demonstrated clinically. Plastic deformation was measured in terms of energy (J) dissipated during balloon inflation.

Efficacy of the mini-meatoplasty.

OBJECTIVES: The lateral meatoplasty is a well-described technique for widening the lateral external auditory meatus. After bony canalplasty, the external auditory meatus may need to be enlarged to accommodate an expanded tympanic ring. In this study, we introduce a novel meatoplasty technique for use during canalplasty and describe its efficacy in widening the external auditory meatus. METHODS: Patients undergoing at least 180-degree bony canalplasty and mini-meatoplasty at a tertiary care facility were enrolled. Meatus diameter was measured before and after mini-meatoplasty using Shea aural speculums and Hegar dilators. RESULTS: Nineteen patients were enrolled. Mean preoperative speculum size was 6.1 mm (range 3.5-7.5 mm). All postoperative speculum sizes were 8 mm (P < .0001). Mean preoperative and postoperative Hegar dilator sizes were 10.6 mm (range 7-14 mm) and 16.2 mm (range 13-19 mm), respectively (P < .0001). The mean increase in aural speculum and Hegar dilator sizes were 1.9 mm (range 0.5-3.5 mm) and 5.7 mm (range 3-10 mm), respectively (P < .0001). CONCLUSIONS: The mini-meatoplasty is a novel and effective technique for widening the external auditory meatus after bony canalplasty. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1294-1298, 2020.