Supine or non-supine apnea; which can be treated better with expansion sphincter pharyngoplasty?

OBJECTIVES

Expansion sphincter pharyngoplasty is a well-known palatal correction surgery applied for obstructive sleep apnea patients. Even though high success rates are reported, in some patients, the desired outcome cannot be achieved. Therefore, patient selection is crucial to avoid undesirable outcomes. In this study we present our results with expansion sphincter pharyngoplasty, and we aim to show the difference between supine and non-supine apnea in terms of their response to the surgery, in order to utilize position dependency for selection of surgical candidates.

METHODS

Pre- and post-operative polysomnography results of patients who underwent expansion sphincter pharyngoplasty were analyzed retrospectively. Total AHI, supine AHI, non-supine AHI, supine/non-supine AHI ratio and surgical success values are compared.

RESULTS

85 patients were included to the study. Mean AHI significantly decreased from 48.7 ± 27.99 to 26.37 ± 21.16 with the surgery. Surgical success rate was found to be 51.8%. Both supine and non-supine apnea decreased significantly with the surgery, but the decrease was significantly higher in non-supine apnea (20.6% to 39.1% respectively, p = 0.016). There was significant negative correlation between pre-operative supine to non-supine AHI ratio and the change in AHI, showing that supine dominant patients had less improvement with the surgery (r = 0.274, p = 0.01).

CONCLUSION

Expansion sphincter pharyngoplasty is an effective surgery which achieves significant improvement in AHI. Non-supine respiratory events respond better to the surgery than supine events.

Head and neck injuries after leopard attack: Presentation and management

Leopard attacks on humans are reported most often from the Indian subcontinent. The bite wounds are complex injuries infected with polymicrobial inoculum and may present as punctures, abrasions, lacerations or avulsions. The presentation and acceptable treatment of these injuries vary according to the wound. We hereby describe the clinical presentation and treatment of a male victim with leopard bite injuries on the head and neck region. As bite injuries are commonly found on and around the face, maxillofacial surgeons should be familiar with the therapy. Through thorough clinical and radiological examination, it is essential to prevent missing any hidden injuries, which can easily turn lethal. To benefit the rural population, more health facilities need to be established in remote areas.

Oro- and Nasopharyngeal Papillomas with Squamous and Respiratory Features: A Case Series of Schneiderian-Like Papillomas of the Pharynx

There is limited literature detailing the histology of pharyngeal papillomas. Herein, we report our experience with papillomas occurring in the oro-and nasopharynx that have both squamous and respiratory features akin to the sinonasal Schneiderian papilloma. We retrospectively reviewed pharyngeal papillomas that were composed of both squamous and respiratory epithelium received at our institution between 2010 and 2020. Cases of sinonasal papillomas directly extending into the pharynx were excluded. Immunohistochemistry for p16 as well as RNA in situ hybridization to evaluate for 6 low-risk and 18 high-risk HPV genotypes were performed on all cases. Thirteen cases were included. Mean age was 61 with 12 males and 1 female. While often incidentally found, presenting symptoms included globus sensation, hemoptysis, and hoarseness of voice. Histologically, all tumors consisted of squamous and respiratory epithelium with neutrophilic infiltrates arranged in an exophytic/papillary architecture that was reminiscent of the exophytic type of Schneiderian papilloma. Immunohistochemistry for p16 was negative in all papillomas. 85% were positive for low-risk human papillomavirus (HPV) subtypes and all were negative for high-risk HPV subtypes. A well-differentiated, invasive squamous cell carcinoma was associated with two of the cases. Papillomas with squamous and respiratory features similar to the sinonasal exophytic Schneiderian papilloma can arise in the oro- and nasopharynx and like their sinonasal counterparts show an association with HPV. While many in this series were benign, they can be harbingers for invasive squamous cell carcinoma.

Uvulopalatopharyngoplasty for nasal blockage 21 years after total rhinectomy

BACKGROUND

Total rhinectomy is an invasive procedure that significantly impairs the intranasal turbulence, humidification and heating of inspired air. The use of uvulopalatopharyngoplasty for the treatment of sleep-disordered breathing disorders such as primary snoring and obstructive sleep apnoea has diminished over the past years because of the emergence of less invasive procedures and alternative therapeutic options. This clinical record presents the treatment of a long-term side effect of total rhinectomy using uvulopalatopharyngoplasty.

CASE REPORT

In 1997, a 62-year-old male underwent total rhinectomy for a nasal schwannoma, followed by rehabilitation with a nasal prosthesis. Twenty-one years later, he presented with severe complaints of nasal blockage and breathing difficulties during both daytime and night-time. Clinical examination revealed no major anomalies besides significant velopharyngeal narrowing. Thus, in 2019, uvulopalatopharyngoplasty was performed to re-establish velopharyngeal patency. Hereafter, the symptoms of nasal blockage disappeared, resulting in an improved quality of life.

CONCLUSION

Uvulopalatopharyngoplasty may prove useful to treat selected patients with daytime breathing difficulties due to velopharyngeal narrowing.

Novel non-invasive assessment of upper airway inflammation in obstructive sleep apnea using positron emission tomography/magnetic resonance imaging

PURPOSE

To develop a novel non-invasive technique to quantify upper airway inflammation using positron emission tomography/magnetic resonance imaging (PET/MRI) in patients with obstructive sleep apnea (OSA).

METHODS

Patients with treatment naïve moderate-to-severe OSA underwent [18F]-fluoro-2-deoxy-D-glucose (FDG) PET/MRI. Three readers independently performed tracings of the pharyngeal soft tissue on MRI. Standardized uptake values (SUV) were generated from region of interest (ROI) tracings on corresponding PET images. Background SUV was measured from the sternocleidomastoid muscle. SUV and target-to-background (TBR) were compared across readers using intraclass correlation coefficient (ICC) analyses. SUV from individual image slices were compared between each reader using Bland-Altman plots and Pearson correlation coefficients. All tracings were repeated by one reader for assessment of intra-reader reliability.

RESULTS

Five participants completed our imaging protocol and analysis. Median age, body mass index, and apnea-hypopnea index were 41 years (IQR 40.5-68.5), 32.7 kg/m² (IQR 28.1-38.1), and 30.7 event per hour (IQR 19.5-48.1), respectively. The highest metabolic activity regions were consistently localized to palatine or lingual tonsil adjacent mucosa. Twenty-five ICC met criteria for excellent agreement. The remaining three were TBR measurements which met criteria for good agreement. Head-to-head comparisons revealed strong correlation between each reader.

CONCLUSIONS

Our novel imaging technique demonstrated reliable quantification of upper airway FDG avidity. This technology has implications for future work exploring local airway inflammation in individuals with OSA and exposure to pollutants. It may also serve as an assessment tool for response to OSA therapies.

Do the dimensions of the hard palate have a relationship with the volumes of the upper airways and maxillary sinuses? A CBCT study

Background

As the hard palate is a central structure of the skull, and its close relationship with the nasal cavity, oral cavity, and maxillary sinuses, it would be of interest to study if there is a relationship between this bone and other structures of the stomatognathic system. Thus, this study aimed to assess the dimensions of the hard palate and associate them with sex, and skeletal and breathing patterns. Also, to investigate if there is a relationship between these dimensions and the volumes of the upper airways and maxillary sinuses.

Methods

Two hundred and ninety-eight CBCT scans of patients were classified according to sex, and skeletal and breathing patterns. Then, the linear dimensions of width and height of the hard palate at the regions of the first premolars and first molars, and the volumes of the upper airways and maxillary sinuses were measured using the CS 3D Imaging and ITK-SNAP software, respectively. Data were submitted to multi-way analysis of variance and linear regression, with a significance level of 5% (α = 0.05).

Results

Sex and facial type influenced the hard palate dimensions (p < 0.05). Males had greater width and height of the hard palate than females (p < 0.0001). It was observed greater width for brachycephalics at the first premolars region (p = 0.0032), and greater height for dolichocephalics at the first premolars (p = 0.0154) and first molars (p = 0.0038) regions. Skeletal malocclusion and breathing pattern did not influence the measurements of the hard palate (p > 0.05). There was a significant relationship between the width and height of the hard palate at the premolar’s region and the total volume of the upper airways (p = 0.018, and p = 0.038), and between both dimensions of the hard palate at the molar’s region and the total volume of the maxillary sinuses (p < 0.0001).

Conclusions

The hard palate dimensions are influenced by sex and facial type, but not by skeletal malocclusion or breathing pattern. Also, there is an association between these dimensions and the volumes of the upper airways and maxillary sinuses.

Association between palliative care referral and burden of illness among cancers of the lip, oral cavity and pharynx

PURPOSE

To evaluate the burden of illness--length of stay (LOS), total charges, and discharge disposition--among cancers of the lip, oral cavity and pharynx (CLOP) patients with and without palliative care (PC) referral.

METHODS

This cross-sectional study utilized the 2017 National inpatient sample database to identify hospitalizations with a primary diagnosis of CLOP. Generalized linear models were used to assess the association between PC referral status and the outcomes-LOS, total charges, and discharge disposition while controlling for patients' characteristics.

RESULTS

There were 4165 PC referral among 52, 524 CLOP patients. The geometric mean of LOS for non-PC referral patients was 3.7 days, and for PC referral was 5.02 days, P < 0.001. In the adjusted analysis, CLOP patients with PC referral were more likely to have a higher LOS (Coefficient: 1.16; 95% CI, 1.01-1.25) compared to those without PC referral. The geometric mean of total charge among non-PC referral group was 48,308 USD, and CLOP-PC referral was 48,983 USD, P = 0.72. After adjusting for covariates, there was still no significant difference between the PC and non-PC referral groups. Discharge disposition were considerably different across the non-PC vs. PC referral groups. Compared to non-PC referral patients, PC referral patients were more likely to be discharge to skilled nursing facility, intermediate care, and another type of facility (aOR = 7.10; CIs, 5.51-9.12), or home health care (aOR = 4.13; CIs, 3.31-5.15).

CONCLUSION

During primary hospitalization, total charges was not different between patient non-PC and PC referral groups; however, the LOS and discharge dispositions were significantly different.

Caution with carotids: A necessary cognizance

Most aberrations in the cervical course of the internal carotid artery are generally encountered as incidental findings due to their asymptomatic nature. However these morphological variations if not identified intra operatively or pre operatively may lead to vascular accidents. It is essential to be aware of the existence of tortuosity, kinking, and coiling of these great vessels while considering patients for surgeries of head and neck cancer, pharyngeal resections, traumatic injury repair, etc. Our paper presents a case series of four patients in whom carotid dolichoarteriopathies were observed during the course of neck dissection. It aims to highlight the precautions required to avoid morbidity in such patients.

Perioperative instrumental swallowing evaluation in adult airway reconstruction: A retrospective observational cohort study

OBJECTIVES

Airway reconstruction for laryngotracheal stenosis (LTS) encompasses several procedures. Dysphagia is a well-recognised sequela of LTS and airway surgery, however studies have employed mostly non-validated assessments post-operatively in small, heterogenous samples, perpetuating uncertainty around the contributions of LTS and its management to impaired deglutition. Consequently, considerable variation in LTS perioperative nutritional management exists. Our objective was to characterise baseline and post-operative dysphagia with instrumental assessment in an LTS cohort undergoing airway reconstruction and provide a gold-standard management framework for its management.

DESIGN, SETTING, PARTICIPANTS AND MAIN OUTCOME MEASURES

We performed a retrospective cohort study of adult airway reconstruction procedures from 2016-2020 at our quaternary centre. Patient background, LTS aetiology, procedure type, tube feeding duration, length of stay and serial Functional Oral Intake Scale (FOIS) and International Dysphagia Diet Standardisation Initiative (IDDSI) scores were noted. Baseline, post-operative day one and post-stent removal Fibreoptic Endoscopic Evaluation of Swallow (FEES) generated Penetration Aspiration Scale (PAS) scores.

RESULTS

Forty-four patients underwent forty-six reconstructions. Baseline incidence of penetration-aspiration was considerably higher than the general population and worsened in the immediate post-operative period, however FOIS and PAS scores generally returned to baseline by discharge. Post-operative FOIS correlated negatively with tracheostomy or airway stent placement. At discharge, 80% tolerated soft or normal diet and 93% were feeding tube independent.

CONCLUSIONS

We present the largest adult airway reconstruction cohort with instrumental swallow assessment perioperatively. LTS patients have a higher incidence of underlying dysphagia but swallowing tends to return to baseline with appropriate postoperative rehabilitation. Such practice may avoid the complications, costs and morbidity of prolonged nutritional support.

Automatic segmentation of the pharyngeal airway space with convolutional neural network

OBJECTIVES

This study proposed and investigated the performance of a deep learning based three-dimensional (3D) convolutional neural network (CNN) model for automatic segmentation of the pharyngeal airway space (PAS).

METHODS

A dataset of 103 computed tomography (CT) and cone-beam CT (CBCT) scans was acquired from an orthognathic surgery patients database. The acquisition devices consisted of 1 CT (128-slice multi-slice spiral CT, Siemens Somatom Definition Flash, Siemens AG, Erlangen, Germany) and 2 CBCT devices (Promax 3D Max, Planmeca, Helsinki, Finland and Newtom VGi evo, Cefla, Imola, Italy) with different scanning parameters. A 3D CNN-based model (3D U-Net) was built for automatic segmentation of the PAS. The complete CT/CBCT dataset was split into three sets, training set (n = 48) for training the model based on the ground-truth observer-based manual segmentation, test set (n = 25) for getting the final performance of the model and validation set (n = 30) for evaluating the model's performance versus observer-based segmentation.

RESULTS

The CNN model was able to identify the segmented region with optimal precision (0.97±0.01) and recall (0.96±0.03). The maximal difference between the automatic segmentation and ground truth based on 95% hausdorff distance score was 0.98±0.74mm. The dice score of 0.97±0.02 confirmed the high similarity of the segmented region to the ground truth. The Intersection over union (IoU) metric was also found to be high (0.93±0.03). Based on the acquisition devices, Newtom VGi evo CBCT showed improved performance compared to the Promax 3D Max and CT device.

CONCLUSION

The proposed 3D U-Net model offered an accurate and time-efficient method for the segmentation of PAS from CT/CBCT images.

CLINICAL SIGNIFICANCE

The proposed method can allow clinicians to accurately and efficiently diagnose, plan treatment and follow-up patients with dento-skeletal deformities and obstructive sleep apnea which might influence the upper airway space, thereby further improving patient care.

Microwave ablation for the removal of pharyngeal benign lesions: A prospective pilot case series

OBJECTIVE

We evaluated microwave ablation (MWA) for treatment of isolated pharyngeal benign lesions, in terms of technical feasibility, efficacy, and safety.

METHODS

The patients with pharyngeal benign lesions were treated with endoscopic MWA with a 2450-MHz single cooled-shaft microwave antenna and sent for histological examination. Postoperative pain intensity was measured via visual analogue scale (VAS) on the 12th hour and the third postoperative days.

RESULTS

Of the 137 patients with pharyngeal benign lesions who met the inclusion criteria. The most commonly involved site was the uvula (n = 66, 48.2%), followed by the lateral pharyngeal wall (n = 37, 27.0%), the nasopharyngeal posterior wall (n = 23, 16.8%) and the soft palate (n = 11, 8.0%). All of the procedures were completed using local anesthesia and were well-tolerated by the patients. The ablation time was 5-10 min, with an average duration of 6.3 ± 1.8 min. The most common pathology was papilloma (n = 96, 70.1%), followed by nasopharyngeal cysts (n = 21, 15.3%), polyp (n = 10, 7.3%), epidermoid cysts (n = 8, 5.8%) and Thornwaldt cysts (n = 2, 1.5%). The mean VAS pain score was 2.36 ± 1.08 on postoperative 12th hour and 1.21 ± 0.54 on postoperative third day. At the 6-month follow-up examination, there were no severe complications, such as recurrence, bleeding, or synechiae of the nasal cavity, eustachian tube injury, in any of the patients.

CONCLUSIONS

The MWA for the treatment of isolated pharyngeal benign lesion is feasible and alternative to conventional surgical methods, it allows excision of the lesion while providing hemostasis, involves only a short ablation time and has a very low risk of complications. Most of our patients well-tolerate the procedure, which may be performed under local anesthesia in the outpatient setting.

3D-CT Evaluation of Swallowing: Metrics of the Swallowing Response Using Swallowing CT

Videofluoroscopy and videoendoscopy dramatically changed the evaluation and management of swallowing disorders. Later advancements in techniques for the instrumental evaluation of swallowing were limited by technique and positioning. The advent of 320-row area detector CT solved previous challenges and allowed for the study of swallowing physiology and dysphagia in greater detail. In this summary, we describe the history and evolution of CT technology and describe research and clinical applications for the evaluation of swallowing physiology and pathophysiology.

Synovialosarcoma of the pharynx: A case report and literatture review

•

Synovial sarcoma is a rare malignant neoplasm.

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The location in pharynx is extremely rare.

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The diagnosis of synovial sarcoma is confirmed by surgical biopsy.

•

The objective of this study is to describe the clinical, radiological and histological features of pharyngeal synovial sarcoma and to discuss its therapeutic management.

Introduction

Synovial sarcoma is a rare tumor to be encountered in the head and neck region and is always a challenge in terms of diagnosis, treatment, as our case.

Presentation of case

We present a 23-year old female patient with synovial sarcoma of posterolateral pharyngeal wall. The radiological and clinicopathological features along with various diagnostic tests and treatment options are discussed.

Discussion

The objective of this study is to describe - from a clinical case reported from our institution, and from literature review- the clinical, radiological and histological features of pharyngeal synovial sarcoma and to discuss its therapeutic management.

Conclusion

Synovial sarcoma of pharynx is extremely a rare tumor in current practice.

Diagnostic accuracy of imaging modalities in detection of histopathological extranodal extension: A systematic review and meta-analysis

OBJECTIVE

To present an up to date systematic review and meta-analysis evaluating the diagnostic accuracy of the most used imaging modalities in detection of histopathological extra nodal extension (ENE) in head and neck squamous cell carcinoma.

MATERIALS AND METHODS

Medline, Embase, and Cochrane databases were systematically searched on March 27th 2020. Screening, inclusion, quality assessment, and data extraction were done by two reviewers. Meta-analysis was conducted using the bivariate model approach after pooling the studies according to imaging modality. Heterogeneity was explored by meta-regression. Comparison was done by meta-regression and sub-group analyses.

RESULTS

Out of 476 initial hits, 25 studies were included for analysis. Of these, 14 dealt with CT, nine with PET/CT, four with MRI, two with ultrasound, and none with PET/MRI. Meta-analysis based on a total sample size of 3391 showed that CT had a sensitivity of 76% [67-82%] and specificity of 77% [69-83%], MRI a sensitivity of 72% [64-79%] and specificity of 78% [57-90%], and PET/CT a sensitivity of 80% [76-84%] and specificity of 83% [74-90%] in the ability to predict ENE. No meta-analysis could be done on ultrasound. There were no significant differences between modalities in overall accuracy; however, PET/CT had significantly higher sensitivity than CT and MRI.

CONCLUSION

There was no significant difference in the ability of CT, MRI, and PET/CT to diagnose histopathological ENE, except that PET/CT had a significantly higher sensitivity than CT and MRI.

Prediction of effectiveness of potassium-competitive acid blocker and serotonin noradrenaline reuptake inhibitor on abnormal sensation in the throat: use of patient-reported outcome measures (PROMs)

Purpose

To determine patients with abnormal sensation in the throat (AST) who would respond to potassium-competitive acid blocker (P-CAB) or serotonin noradrenaline reuptake inhibitor (SNRI) treatment.

Methods

AST patients were randomly divided into two groups. Thirty-one and 21 patients received P-CAB and SNRI treatment, respectively. GETS-J, the Japanese version of Glasgow Edinburgh Throat Scales (GETS), consisted of three subscales of throat symptoms (globus sensation, pain/swelling of the throat, and dysphagia) and somatic distress due to the disease, Frequency Scale for the Symptoms of Gastro-esophageal reflux disease (FSSG), and Hospital Anxiety and Depression Scale (HADS) were used before and after treatments. Responders to treatments were defined as those who showed 50% or more decrease in symptom scores or somatic distress.

Results

Pre-treatment GETS-J pain/swelling scores and FSSG acid reflux scores were higher in P-CAB responders and decreased after treatment. Receiver operating characteristic curve for pain/swelling subscale had an area under the curve (AUC) of 0.792 to predict P-CAB responders and a score of 11 provided the best combination of sensitivity (62.5%) and specificity (80%). Somatic distress and HADS anxiety scores, but no other GETS-J symptom scores, decreased after SNRI treatment. Pre-treatment globus scores were lower in SNRI responders. AUC value for globus subscale to predict SNRI responders was 0.741 and a score of 6.5 provided the best combination of sensitivity (70%) and specificity (73%).

Conclusions

Pain/swelling is a characteristic symptom in AST patients who respond to P-CAB treatment. SNRI treatment would be effective for somatic distress in cases with mild symptoms.

Nasopharyngeal airway and subcranial space analysis in Pfeiffer syndrome

Tracheotomy in infancy helps patients with Pfeiffer syndrome to survive by preventing respiratory crisis, but difficulty in decannulation may consequently be a challenge. This study has investigated the regional abnormalities of the nasopharyngeal airway in children with Pfeiffer syndrome to provide an anatomical basis for the surgical treatment and decannulation of the upper airway. Seventy-two preoperative computed tomograms (CT) (Pfeiffer syndrome n=30; control n=42) were included. The airway volume, cross-sectional area, and cephalometrics were measured using Materialise software. Patients with Pfeiffer syndrome developed a 50% (p<0.001) reduction of nasal airway volume, and a 44% (p=0.003) restriction in pharyngeal airway volume. In patients with Pfeiffer syndrome the cross-sectional area at the choana was only half that of the controls (p<0.001). The posterior width of the nasal airway in patients with Pfeiffer syndrome was shortened by 13% (p=0.003), and the height reduced by 21% (p<0.001). The cross-sectional areas at the condylion and gonion levels, which indicate the calibre of the pharyngeal airway at the entrance and midsection, were reduced by 67% (p<0.001) and 47% (p<0.001), respectively, when compared with the controls. The volume of the nasal airway in patients with Pfeiffer syndrome was significantly restricted in length, height, and width, and by choanal stenosis in all cases in this cohort. The reduced anteroposterior length of the nasal airway contributed to the shortened maxilla more than the anteroposterior position. The limited height and width of the nasal pathway was the result of a hypoplastic sphenoid. Restricted mediolateral and anteroposterior dimensions were evident across the entire course of the pharyngeal airway. Mediolateral maxillary expansion in addition to maxillomandibular advancement is therefore likely to benefit these patients.

Recording drug responses from adult Dirofilaria immitis pharyngeal and somatic muscle cells

Despite being considered one of the most pathogenic helminth infections of companion animals, members of macrocyclic lactone class are the only drugs available for the prevention of heartworm disease caused by Dirofilaria immitis. Alarmingly, heartworm prevention is at risk; several studies confirm the existence of macrocyclic lactone resistance in D. immitis populations across the United States. To safeguard the long term prevention and control of this disease, the identification and development of novel anthelmintics is urgently needed. To identify novel, resistance-breaking drugs, it is highly desirable to: Unfortunately, none of the three above statements can be answered sufficiently for D. immitis and most of our hypotheses derive from surrogate species and/or in vitro studies. Therefore, the present study aims to improve our fundamental understanding of the neuromuscular system of the canine heartworm by establishing new methods allowing the investigation of body wall and pharyngeal muscle responses and their modulation by anthelmintics. We found that the pharynx of adult D. immitis responds to both ivermectin and moxidectin with EC₅₀s in the low micromolar range. We also demonstrate that the somatic muscle cells have robust responses to 30 μM acetylcholine, levamisole, pyrantel and nicotine. This is important preliminary data, demonstrating the feasibility of electrophysiological studies in this important parasite.

A multi-centre analysis of a decade of endoscopic pharyngeal pouch surgery in Cheshire and Merseyside

BACKGROUND

There are sparse data on the outcomes of endoscopic stapling of pharyngeal pouches. The Mersey ENT Trainee Collaborative compared regional practice against published benchmarks.

METHODS

A 10-year retrospective analysis of endoscopic pharyngeal pouch surgery was conducted and practice was assessed against eight standards. Comparisons were made between results from the tertiary centre and other sites.

RESULTS

A total of 225 procedures were performed (range of 1.2-9.2 cases per centre per year). All centres achieved 90 per cent resumption of oral intake within 2 days. All centres achieved less than 2-day hospital stays. Primary success (84 per cent (i.e. abandonment of endoscopic stapling in 16 per cent)), symptom resolution (83 per cent) and recurrence rates (13 per cent) failed to meet the standard across the non-tertiary centres.

CONCLUSION

Endoscopic pharyngeal pouch stapling is a procedure with a low mortality and brief in-patient stay. There was significant variance in outcomes across the region. This raises the question of whether this service should become centralised and the preserve of either tertiary centres or sub-specialist practitioners.

Extraoral anatomy in CBCT – a literature review. Part 4: Pharyngocervical region

This review about extraoral anatomy depicted in cone beam computed tomography describes the pharyngocervical region. Large (≥ 8 × 8 cm) field of views of the maxilla and/or mandible will inevita-bly depict the pharyngocervical region that com-prises the posterior upper airway, the pharyngeal part of the digestive tract, as well as the cervical segment of the spine. The latter consists of seven cervical vertebrae (C1-C7) with corresponding distinctive features, i.e., the atlas (C1) and the axis (C2). In addition, cervical vertebrae serve as ref-erences for the vertical position of anatomical structures. For instance, C4 is a typical landmark since it generally denotes the level of the chin, of the body of the hyoid bone, of the base of the epiglottis, and of the bifurcation of the common carotid artery, respectively. The pharynx, which is functionally involved in respiration, deglutition, and vocalization, extends from the lower aspect of the skull base to the esophagus. Anatomically, the pharynx is divided into three segments, i.e. the nasopharynx, the oropharynx, and the laryn-gopharynx. All communicate anteriorly with cor-responding cavities, i.e. the nasal cavities, the oral cavity, and the larynx. Although not directly located within the pharyngocervical region, the hyoid bone and the styloid process are also dis-cussed in this review, since both structures are commonly visible on CBCT images of this region.

Cadherin preserves cohesion across involuting tissues during C. elegans neurulation

The internalization of the central nervous system, termed neurulation in vertebrates, is a critical step in embryogenesis. Open questions remain regarding how force propels coordinated tissue movement during the process, and little is known as to how internalization happens in invertebrates. We show that in C. elegans morphogenesis, apical constriction in the retracting pharynx drives involution of the adjacent neuroectoderm. HMR-1/cadherin mediates this process via inter-tissue attachment, as well as cohesion within the neuroectoderm. Our results demonstrate that HMR-1 is capable of mediating embryo-wide reorganization driven by a centrally located force generator, and indicate a non-canonical use of cadherin on the basal side of an epithelium that may apply to vertebrate neurulation. Additionally, we highlight shared morphology and gene expression in tissues driving involution, which suggests that neuroectoderm involution in C. elegans is potentially homologous with vertebrate neurulation and thus may help elucidate the evolutionary origin of the brain.

Imaging of Pharyngocele: An Occupational Overuse Syndrome

Pharyngocele is a rare pathology of the pharynx caused by the laxity of the thyrohyoid membrane. Only about 60 true lateral pharyngocele cases have been reported in the literature over the last 133 years. Laryngocele is a close differential, and the two are difficult to tell apart. Though they have been described well in the literature, they are often misdiagnosed or interchangeably diagnosed. The acquired type of pharyngocele is due to prolonged increased intrapharyngeal pressure and pharyngeal wall weakness, and it is more common than congenital pharyngoceles. Close differential diagnoses include Zenker’s diverticulum, laryngocele, and jugular venous phlebectasia. Acquired lateral pharyngoceles are seen in wind instrument musicians and glassblowers. Hence, these diverticula are described as ‘overuse syndrome’. We present a case of bilateral neck swelling, which occurred doing the Valsalva maneuver with imaging studies.

Global burden of disease due to smokeless tobacco consumption in adults: an updated analysis of data from 127 countries

BACKGROUND

Smokeless tobacco (ST) is consumed by more than 300 million people worldwide. The distribution, determinants and health risks of ST differ from that of smoking; hence, there is a need to highlight its distinct health impact. We present the latest estimates of the global burden of disease due to ST use.

METHODS

The ST-related disease burden was estimated for all countries reporting its use among adults. Using systematic searches, we first identified country-specific prevalence of ST use in men and women. We then revised our previously published disease risk estimates for oral, pharyngeal and oesophageal cancers and cardiovascular diseases by updating our systematic reviews and meta-analyses of observational studies. The updated country-specific prevalence of ST and disease risk estimates, including data up to 2019, allowed us to revise the population attributable fraction (PAF) for ST for each country. Finally, we estimated the disease burden attributable to ST for each country as a proportion of the DALYs lost and deaths reported in the 2017 Global Burden of Disease study.

RESULTS

ST use in adults was reported in 127 countries; the highest rates of consumption were in South and Southeast Asia. The risk estimates for cancers were also highest in this region. In 2017, at least 2.5 million DALYs and 90,791 lives were lost across the globe due to oral, pharyngeal and oesophageal cancers that can be attributed to ST. Based on risk estimates obtained from the INTERHEART study, over 6 million DALYs and 258,006 lives were lost from ischaemic heart disease that can be attributed to ST. Three-quarters of the ST-related disease burden was among men. Geographically, > 85% of the ST-related burden was in South and Southeast Asia, India accounting for 70%, Pakistan for 7% and Bangladesh for 5% DALYs lost.

CONCLUSIONS

ST is used across the globe and poses a major public health threat predominantly in South and Southeast Asia. While our disease risk estimates are based on a limited evidence of modest quality, the likely ST-related disease burden is substantial. In high-burden countries, ST use needs to be regulated through comprehensive implementation of the World Health Organization Framework Convention for Tobacco Control.

[Transoral resection of supraglottic laryngeal tumors with the Flex Robotic System]

The Flex Robotic System (Medrobotics, Raynham, MA, USA) allows flexible transoral endoscopic resection of head and neck tumors. The current article presents functional and first oncologic experiences with flexible transoral robot-assisted surgery for resection of supraglottic laryngeal tumors. From July 2014 to February 2020, supraglottic cancers in 32 patients (T1 = 11, T2 = 20, T3 = 1) were resected using the Flex Robotic System in the authors' clinic. Within a prospective clinical study, the feasibility, complications, and oncologic results were assessed. Tumors could be exposed, visualized, and successfully resected in all patients. In difficult-to-reach anatomic regions such as the aryepiglottic fold or petiole, the system provided a very good surgical overview. No serious adverse events occurred. Overall survival and local tumor control after 2 years were 88 and 94%, respectively. In conclusion, supraglottic tumors in difficult-to-reach areas have been successfully resected using the Flex Robotic System, with excellent local tumor control.

How do Caenorhabditis elegans worms survive in highly viscous habitats?

The nematode Caenorhabditis elegans is a filter feeder that lives in various viscous habitats such as soil, the intestines of slugs, and rotting materials such as fruits and stems. Caenorhabditis elegans draws in suspensions of bacteria and separates bacteria from water using the pharyngeal pump. Although these worms often live in highly viscous habitats, it is still unclear how they survive in these environments by eating bacteria. In this study, we investigated the effects of suspension viscosity on the survival rate of malnourished worms by combining live imaging and scaling analyses. We found that survival rate decreased with increases in viscosity because the high viscosity suppressed the amount of food ingested. The same tendency was found in two feeding-defective mutants, eat-6(ad467) and eat-6(ad997). We also found that the high viscosity weakened pump function, but the velocities in the pharynx were not zero, even in the most viscous suspensions. Finally, we estimated the amount of ingested food using scaling analyses, which provided a master curve of the experimental survival rates. These results illustrate that the survival rate of C. elegans worms is strongly dependent on the ingested bacteria per unit time associated with physical environments, such as the viscosity of food suspensions and the cell density of bacteria. The pump function of the C. elegans pharynx is not completely lost even in fluids that have 105 times higher viscosity than water, which may contribute to their ability to survive around the world in highly viscous environments.