Innovative dual-function protective scope mask and filtration system for aerosol generating ENT scope procedures.

Background: Aerosol-generating procedures (AGPs), such as nasoendoscopy, are considered high-risk during the COVID-19 pandemic due to risk of virus aerosol transmission. We aim to evaluate the efficacy of an innovative system in reduction of aerosol contamination. Methods: Pilot study involving 15 healthy volunteers performing aerosol-generating activities with the prototype, compared with and without a standard surgical mask. Results: We found an increased frequency of smaller-sized particle emissions for all four expiratory activities. The particle emission rate with the prototype mask was significantly slower over time for the smallest sized particle (0.3 µm) during breathing, speaking and singing compared with similar activities without the mask (p < .05). We found similar trends for coughing for larger particles but that did not reach statistical significance. Conclusion: The innovation offers good protection against aerosol transmission through the physical barrier of the mask, the negative pressure environment within the mask, and the unit's dual filtration function. Level of evidence: Level 2b.

Sneeze-induced pneumolabyrinth 15 years after stapedotomy.

Pneumolabyrinth refers to the presence of air within the inner ear and is a fairly common occurrence immediately after stapes surgery, but rarely occurs in a delayed manner years after the initial operation. We present a case of a patient with a history of left stapedotomy 15 years prior, who presented with acute onset vertigo, tinnitus and hearing loss in her operated ear. Her symptoms were preceded by an upper respiratory tract infection associated with bouts of sneezing. Examination revealed a spontaneous right beating nystagmus and positive head thrust to the left. Pure tone audiometry demonstrated a left mixed hearing loss which subsequently deteriorated to a profound sensorineural hearing loss. CT showed the presence of air within the left vestibule and semicircular canals. The patient underwent an exploratory tympanotomy and repair of perilymphatic leak with resolution of vestibular symptoms but no improvement in sensorineural hearing thresholds.

Impact of COVID-19 on a Tertiary Otolaryngology Practice in Singapore.

The COVID-19 pandemic has had a major impact in healthcare systems across the world, with many hospitals having to come up with protocols and measures to contain the spread of the virus. This affects various specialties' clinical practices in many ways. Since early 2020 in Singapore, the Department of Otorhinolaryngology at Tan Tock Seng Hospital had to rapidly adapt to this pandemic as we provided services to the main healthcare facility combating the virus in our country. We had to design new workflows and also remain flexible in view of the ever-changing situation. There are 6 important domains for an otolaryngology department or any clinical department in general to consider when making adjustments to their practices in an outbreak: (1) clinical work, (2) education, (3) research, (4) safety of patients and staff, (5) morale of medical staff and (6) pandemic frontline work. We hope that the sharing of our experiences and the lessons learnt will be useful for both our local and international colleagues.

High Resolution Computed Tomography (HRCT) Imaging Findings of Oval Window Atresia with Surgical Correlation.

INTRODUCTION: Isolated oval window atresia (OWA) is a rare cause of congenital conductive middle ear deafness and may be overlooked owing to the normal appearance of the external ear. This anomaly has been previously described, although the published numbers with both imaging and surgical findings are few. Our aim is to correlate the imaging features of OWA with intraoperative findings. MATERIALS AND METHODS: This is a single-centre retrospective evaluation of patients who were diagnosed with OWA and who received surgery from January 1999 to July 2006. No new case was diagnosed after 2006 to the time of preparation of this manuscript. High resolution computed tomography (HRCT) imaging of the temporal bones of the patients were retrospectively evaluated by 2 head and neck radiologists. Images were evaluated for the absence of the oval window, ossicular chain abnormalities, position of the facial nerve canal, and other malformations. Imaging findings were then correlated with surgical findings. RESULTS: A total of 9 ears in 7 patients (two of whom with bilateral lesions) had surgery for OWA. All patients had concomitant findings of absent stapes footplate with normal, deformed or absent stapes superstructure and an inferiorly displaced facial nerve canal. HRCT was sensitive in identifying OWA and associated ossicular chain and facial nerve abnormalities, which were documented surgically. CONCLUSION: OWA is a rare entity that can be diagnosed with certainty on HRCT, best visualised on coronal plane. Imaging findings of associated middle ear abnormalities, position of the facial nerve canal, which is invariably mal-positioned, and associated deformity of the incus are important for presurgical planning and consent.

Otosclerosis in a nonendemic population: Utility of CT scan and correlation with audiometry and surgical outcome.

The incidence of otosclerosis in nonendemic patients is low, and preoperative diagnosis can be challenging. The aim of this study was to evaluate computed tomography (CT) findings in patients with otosclerosis and determine their correlation with audiometric findings and surgical outcome in a nonendemic population. We retrospectively reviewed 17 patients from August 2011 to August 2013 with surgically confirmed otosclerosis who underwent preoperative high-resolution CT scans and pre- and postoperative audiometry. Otosclerotic foci were identified on the scans. The density ratio of these foci was calculated and compared with pre- and postoperative audiometric parameters. One patient with Paget disease was excluded from the study. A total of 19 ears were operated on and included in the data analysis. CT scans were normal in 4 ears (21.1%). Hypodense lesions were detected in the remaining 15 (78.9%) ears and the region of interest mapped out. The density ratio was obtained between the hypodense area and adjacent normal labyrinthine bone. No statistically significant correlation was found between the density ratio and any of the audiometric parameters tested (p > 0.05). The diagnosis of otosclerosis in nonendemic areas is challenging. A preoperative CT scan can be useful when otosclerotic foci are present. However, the density ratio of the otosclerotic foci did not correlate with audiometric parameters or surgical outcome.

Evaluation of cholesteatoma: our experience with DW Propeller imaging.

BACKGROUND: Cholesteatoma management includes early detection and surgical exploration. Due to its tendency to recur, it can be potentially locally aggressive. Magnetic resonance imaging (MRI), and in particular diffusion weighted imaging (DWI), plays an important role in management of these lesions. PURPOSE: To assess the accuracy of Propeller (Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction) DW sequence in detecting middle ear and mastoid cholesteatomas in non-operated ears by surgical correlation. MATERIAL AND METHODS: A retrospective review of 15 patients was done who underwent Propeller DWI with either clinically confirmed or suspected cholesteatomas. Surgical correlation was done in all cases. RESULTS: All patients had hyperintense foci on Propeller DWI. Surgical correlation performed revealed that 13 patients had cholesteatomas while two patients had mastoid abscesses. The location, extent, and size of cholesteatomas on Propeller DWI matched with the operative findings. Of the 13 patients with cholesteatomas, three patients had multiple foci of hyperintensity on Propeller DWI, which corroborated with the surgical finding of multiple cholesteatomas. The average apparent diffusion coefficient value of cholesteatoma was 0.868 × 10(-3) mm(2)/s, found to be higher than that of abscess, which was 0.425 × 10(-3) mm(2)/s. CONCLUSION: Propeller DWI was accurate in assessing the location, extent, and size of cholesteatomas as corroborated with surgical findings. Propeller DWI is useful in detecting number of cholesteatoma foci, a vital finding as it may impact the choice of surgery.

Mucous retention cyst of temporal bone: a mimic of cholesteatoma on DW-MRI.

Non-EPI DW imaging is increasingly being used as a sensitive sequence in detecting cholesteatomas especially if CT findings are not confirmatory. Cholesteatoma appears as a hyperintense focus on DWI. We present two cases of mucous retention cysts in the mastoid temporal bone/middle ear cavity, which present as hyperintense on non-EPI DWI and potentially may mimic cholesteatomas. Differentiating between the two conditions is important, as surgery can be avoided in mucous retention cysts. We have also discussed ways to differentiate between these two conditions on MRI. To our knowledge, this entity is not reported previously.