Payal Mukherjee

Cochlear implants to treat deafness caused by vestibular schwannomas.

Objective Rehabilitation of hearing is complicated in patients with profound bilateral hearing loss in the presence of sporadic vestibular schwannoma (VS) or neurofibromatosis 2 (NF2), especially if the tumor does not need to be removed. We present the outcome of patients who have had a cochlear implant in the tumor affected ear without removal of the primary tumor. Design This is a retrospective multicentre study investigating outcomes of cochlear implantation in profoundly deaf patients with vestibular schwannoma in the implanted ear. Materials and Methods Out of 11 implanted patients, 5 required no treatment for their tumor, whereas 6 had previously undergone radiotherapy. Nine patients experienced NF2, and 2 had unilateral VS in the only hearing ear. Postoperative hearing was assessed with open and closed set speech discrimination, including City University of New York (CUNY) in noise and Bamford, Kowal and Bench (BKB) sentence scores. Results Patients with untreated lesions experienced marked improvement in their BKB and CUNY scores in the implanted ear and were daily cochlear implant users. The improvement was less consistent in the patients who had radiotherapy where only 1 patient attained open set speech discrimination. Conclusion Patients with unilateral VS (sporadic or those affected with NF2) whose tumor status was stable, benefited from cochlear implantation in their tumor-affected ear. Patients who had radiotherapy also benefited from CI, but their outcomes were variable.

Intracranial lipomas affecting the cerebellopontine angle and internal auditory canal: a case series.

Objective: To assess the long-term outcome of lipomas affecting the cerebellopontine angle (CPA) and internal auditory canal (IAC). Patients: This is a retrospective, single-center study of 10 CPA and IAC lipomas that have presented for the last 6 years. There were 8 male and 2 female patients whose age ranged from 22 to 71 years. These lesions were distributed equally between left and right sides. Intervention: The natural progression, audiovestibular signs and symptoms, imaging characteristics, and management options have been evaluated. Main Outcome Measure: Long-term clinical outcome was correlated with serial imaging and audiograms. Results: The most common presenting feature was hearing loss with an average lesion size of 8 mm. Two patients experienced imbalance, with one requiring operative intervention for incapacitating vertigo. The other 9 were managed conservatively. Follow-up imaging was available for 8 cases, and no growth was observed in any of these, with an average follow-up of 3.5 years. Conclusion: Because of the resolution of modern imaging, lipomas of the IAC and CPA are increasingly being recognized and accurately diagnosed. Our data suggest that these lesions are more common than previously thought, representing approximately 1% of all lesions in this location referred to our center. With the absence of growth in 8 cases with follow-up average of 3.5 years as our basis, we recommend that these lesions are managed conservatively by serial imaging. In rare cases, surgery may be required if the lesion is resulting in incapacitating symptoms, such as significant balance disturbance.

Three-dimensional analysis of the vestibular end organs in relation to the stapes footplate and piston placement.

Objective: Measurements of the proximity of the membranous labyrinth to the stapes footplate show considerable variation. Largely, such measurements have been from histologic sections of fixed temporal bones, which may be affected by shrinkage artifact and perspective distortion in the 2-dimensional plane. To overcome these problems, the present study undertook an analysis of the 3-dimensional (3D) architecture of the relationship of the stapes to the membranous labyrinth using high-resolution X-ray micro-computed tomography. Methods: Eleven temporal bones were fixed with Karnovskys fixative (known to minimize shrinkage), soaked in 2% osmium tetroxide, and scanned in a micro-computed tomography scanner. The otic capsule was intact to exclude sectioning artifact, and no alcohol was used to avoid tissue shrinkage. Measurements were taken in a vertical plane to provide distances from the utricle and saccule to the footplate, and 3D reconstruction of the spatial relationship of these structures was carried out. The relationship of these structures to a stapes piston also was studied. Results: The safest area of piston placement was the central and inferior part of the footplate. This was safe up to 0.5 mm depth at all areas except posterosuperiorly where the utricular macula is, on average, only 0.61 mm away from the footplate. The angle of insertion of the piston also influences the end result. Conclusion: Two-dimensional information about vestibular end organ location should serve as a guideline only because the operative field is 3D, and the relationship of the piston to the vestibular labyrinth changes with the angle of placement.

Open and endovascular repair of aneurysms affecting the distal extracranial internal carotid artery: case series.

OBJECTIVE Three cases of internal carotid artery aneurysm affecting the distal cervical segment were retrospectively reviewed. METHODS Two patients underwent open surgical repair requiring petrous segment exposure for bypass of the affected segment using a Fisch type A lateral skull base approach. The third patient underwent endovascular stenting. RESULTS There were no cerebrovascular complications post-operatively. Both open repair patients experienced temporary lower cranial nerve palsies. One required facial nerve grafting. All patients had patent grafts at follow up. The stent graft patient had a small endoleak at six months. CONCLUSION Endovascular and open approaches both have advantages and disadvantages. Treatment needs to be tailored to the lesion and the patient. An open surgical approach is difficult but well established. Endovascular treatment of these lesions is a relatively recent technique, and new cases need to be continually reported with a view to attaining long-term data.

Development and use of augmented reality and 3D printing in consulting patient with complex skull base cholesteatoma

ABSTRACT Temporal bone and skull base anatomy is complex and can pose difficulties in patient’s perception of disease and anatomy, perceived risks, and complications of surgery. We wish to demonstrate the development and use of augmented reality (AR) technology and three-dimensional (3D) printing to assist in preoperative patient consultation in the case of a complex skull base cholesteatoma. A series of 3D models were constructed from a patient’s petrous temporal bone computed tomography (CT) scans using CAD (computer-aided design) software to display the cholesteatoma affected temporal bone and related structures. Supplementary labels and titles were also created. A two-dimensional (2D) image was created as an AR recognition marker. Both 3D and 2D assets were uploaded, linked in an AR development platform called Hyperspaces which was then published to the Hyperspaces cloud server to build an AR application for free access using a predefined keyword on an iOS mobile device. Patient’s temporal bone was also fabricated through a fused deposition modelling 3D printer using polylactic acid filament for patient consultation. AR and 3D printing allow patient-specific clinical information and complexities to be made readily available to the patient and doctor at low cost, and aid in understanding complex skull base anatomy and progressive disease such as cholesteatoma. The advancement of AR and 3D printing technologies are making complex and patient-specific 3D medical data visualisation feasible and tangible on a mobile device and in hand. Thus, these technologies can be used as an invaluable patient education and counselling tool offering a powerful medium in specialties where difficult anatomical challenges are encountered.Abbreviations: ABS: acrylonitrile–butadiene–styrene; AM: additive manufacturing; AR: augmented reality; CAD: computer-aided design; CT: computed tomography; DICOM: Digital Imaging and Communication in Medicine; FBX: Filmbox; FDM: fused deposition modelling; JPEG: joint photographic experts group; MRI: magnetic resonance imaging; PLA: polylactic acid; ROI: region of interest; STL: Stereolithography

Utility of 3D printed temporal bones in pre-surgical planning for complex BoneBridge cases

With the advent of single-sided hearing loss increasingly being treated with cochlear implantation, bone conduction implants are reserved for cases of conductive and mixed hearing loss with greater complexity. The BoneBridge (BB, MED-EL, Innsbruck, Austria) is an active fully implantable device with no attenuation of sound energy through soft tissue. However, the floating mass transducer (FMT) part of the device is very bulky, which limits insertion in complicated ears. In this study, 3D printed temporal bones of patients were used to study its utility in preoperative planning on complicated cases. Computed tomography (CT) scans of 16 ears were used to 3D print their temporal bones. Three otologists graded the use of routine preoperative planning provided by MED-EL and that of operating on the 3D printed bone of the patient. Data were collated to assess the advantage and disadvantage of the technology. There was a statistically significant benefit in using 3D printed temporal bones to plan surgery for difficult cases of BoneBridge surgery compared to the current standard. Surgeons preferred to have the printed bones in theatre to plan their drill sites and make the transition of the planning to the patient’s operation more precise. 3D printing is an innovative use of technology in the use of preoperative planning for complex ear surgery. Surgical planning can be done on the patient’s own anatomy which may help to decrease operating time, reduce cost, increase surgical precision and thus reduce complications.

Maxillofacial reconstruction using in-house virtual surgical planning: Centre-specific virtual surgical planning

Mandibular and maxillary reconstruction using fibula free transfer is common in many tertiary referral centres. Virtual surgical planning (VSP) is a relatively recent adjunct that allows surgeons to plan resection and reconstruction prior to theatre. This has been shown to reduce operative times and decrease surgeon stress intraoperatively. VSP requires technicians with the appropriate skill set and required materials, software and technology, which is accompanied by a cost that may be prohibitive. Usually, this is outsourced to an external company. We present a preliminary case series of VSP in maxillofacial reconstruction done using our own staff without external resources.

Cochlear Implantation in Ménière's Disease With and Without Labyrinthectomy.

OBJECTIVE To investigate outcomes of cochlear implantation (CI) in patients with Ménières disease (MD) with and without surgical labyrinthectomy. STUDY DESIGN Retrospective study. SETTING Multiple tertiary referral centers. SUBJECTS Thirty one ears from 27 patients (17 men, 10 women, aged 42-84) with CI in ipsilateral MD ear. INTERVENTION CI in ears with intact labyrinths (Group 1), CI with simultaneous surgical labyrinthectomy (Group 2), and CI sequential to surgical labyrinthectomy (Group 3). MAIN OUTCOME MEASURE Within-subject improvement on Bamford Kowal Bench test or City University of New York open set sentence tests. RESULTS Majority of ears achieved excellent open-set speech recognition by 12 months post-CI, irrespective of intervention group. Preoperative details including patient age and sex, implant, MD and previous intervention, and audiological test results did not significantly affect outcomes. Patients with MD undergoing CI only may experience vestibular dysfunction which may cause long-term concerns. Incidental finding was noted of eight ears with fluctuating symptoms in ipsilateral ear during 12-month period post-CI, with five of eight ears showing objective fluctuating impedances and mapping. CONCLUSION CI in MD can yield good hearing outcomes in all three groups and this is possible even after a long delay after labyrinthectomy. Bilateral MD patients are complex and prospective quality of life (QoL) measures would be beneficial in being better able to manage the vestibular outcomes as well as the audiological ones.

3D printing and virtual surgical planning in a difficult Bonebridge case

ABSTRACT Virtual surgical planning (VSP) is an applied use of 3D printing showing improvement in patient outcome and health costs though its use in ear surgery has not been reported. VSP was applied to Bonebridge (BB) surgery. A 3D printed temporal bone of a patient requiring revision Modified Radical Mastoidectomy (MRM) was used. MRM was performed on the printed bone and BB site selected by drilling a well to fit the dummy device. Following this, this printed bone was scanned and a surgical cutting guide designed and printed for intraoperative use. The cutting guide was a useful aid to translate the preoperative planning to the operating table. VSP can be a useful tool in BB surgery though its benefit is reserved particularly for difficult cases. More applications allow scalability and having planning and printing facilities based at clinical sites, encourage clinical translation as demonstrated in this case.

Utility of vestibular testing and new technologies in a complex cholesteatoma

Abstract This paper reports a patient with a large recidivist cholesteatoma who underwent audio-vestibular tests and used customized 3D technologies (3D printing, augmented reality, virtual reality) to understand risks of the surgery. The patient was extremely concerned with her clinical findings and it found difficult to understand them. Customized 3D models helped the patient to understand the spatial relations and possible complications of surgery. The benefits of using new technologies in preoperative surgical planning for the surgeon and patient are also explained in a setting when radiological findings indicate high risks for surgery. Computed tomography scan showed a posterior semicircular canal fistula, which would add a significant challenge to the surgery. The fistula was not found in the result of the physiological test (cervical vestibular evoked myogenic potentials) and not found intra-operatively. Application of modern audio-vestibular investigations and use of customized 3D technologies may prove useful aids.