Inferior meatus augmentation procedure (IMAP) normalizes nasal airflow patterns in empty nose syndrome patients via computational fluid dynamics (CFD) modeling

Alterations in nasal airflow and air conditioning after endoscopic nasopharyngectomy for recurrent nasopharyngeal carcinoma: a pilot computational fluid dynamics study

Endoscopic nasopharyngectomy represents a significant intervention for recurrent nasopharyngeal carcinoma (NPC). Various surgical techniques, including transnasal and transoral approaches, are employed. However, the impact of these procedures on nasal airflow dynamics is not well understood. This computational fluid dynamics (CFD) study aimed to investigate alterations in nasal airflow and air conditioning following endoscopic nasopharyngectomy. A 55-year-old male patient with recurrent NPC was selected, whose CT data were utilized for image reconstruction. A preoperative model and two postoperative models, including the transnasal and transoral approach models, were established. The airflow patterns and various CFD parameters were analyzed. In the postoperative models, the high-speed airflow went along the soft palate and into the nasopharyngeal outlet, and there was the low-speed turbulence in the expanded nasopharyngeal cavity. Compared to the preoperative model, the postoperative models exhibited reductions in surface-to-volume ratio, nasal resistance, airflow velocity and proportion of high wall shear stress regions in nasopharynx. The changing trends of nasopharyngeal air temperature and humidity in the preoperative and transoral models were consistent. The heating and humidification efficiency decreased in the transnasal model compared to the transoral model. The endoscopic nasopharyngectomy for recurrent NPC affects the nasal airflow and warming and humidification function. The transoral approach has less influence on aerodynamics of the upper airway compared to the transnasal approach. From a CFD perspective, the endoscopic nasopharyngectomy does not increase the risk of postoperative complications, including the empty nose syndrome and the carotid blowout syndrome.

Application of a Novel 3D-Printed Nasal Plug as a Conservative Treatment for Empty Nose Syndrome

OBJECTIVE

Empty nose syndrome (ENS) is commonly treated by surgery, albeit with limited success. Herein, we introduce our experience of applying a newly developed "3D-printed nasal plug" as an alternative conservative treatment modality.

METHODS

This retrospective study included 20 patients (14 males, 6 females; mean age 46.5 ± 13.5 years) with ENS who underwent the application of the 3D-printed nasal plug at Asan Medical Center between June 2022 and May 2023. Symptom improvement was assessed by Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) before and after applying the nasal plug. Clinical results, such as duration and frequency of plug use, discomfort, and level of satisfaction, were investigated.

RESULTS

The mean follow-up duration was 40.3 ± 24.2 weeks. The average duration of nasal plug usage was 10.8 h per day and 5.3 days a week. The ENS6Q scores improved from 19.6 ± 4.6 to 6.8 ± 5.1 (mean reduction 12.8 ± 5.9) after 30 minutes of wearing. Symptom "nose feelings too open" was improved most by a score of 3.0 ± 1.5 (p < 0.001). Thirteen patients (65.0%) reported that the effectiveness of the plug, initially confirmed at the first wearing, was well maintained during the entire follow-up. Four patients (20.0%) wore the nasal plug uninterruptedly throughout the week, whereas nine patients (45.0%) wore it intermittently as needed. Frequently reported complaints with plug usage were 'displacement of the plug' and 'cosmetic concerns' about the visible hook portion.

CONCLUSION

A 3D-designed nasal plug can be a useful conservative treatment option for ENS patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3935-3940, 2024.

A Systematic Review and Meta-Analysis of Management Options for Empty Nose Syndrome: A Proposed Management Algorithm

OBJECTIVE

Empty nose syndrome (ENS) is an acquired condition characterized by paradoxical nasal obstruction and sensation of nasal dryness often accompanied by psychological disorders such as depression or anxiety, typically occurring after the loss of inferior turbinate tissue or volume in the setting of prior sinonasal surgery. This review aims to identify and evaluate the reported management options.

DATA SOURCES

PubMed, Scopus, and Web of Science.

REVIEW METHODS

The terms "empty nose syndrome" OR "atrophic rhinitis" were used in a systematic search of original articles since the year 1990, yielding 1432 individual studies. These were screened on the Covidence platform for inclusion if any intervention was reported for the treatment of ENS. A pooled analysis of standardized mean differences (SMDs) combined with a random effects model was employed to report outcomes in Empty Nose 6-Item Questionnaire (ENS6Q), Sino-Nasal Outcome Test (SNOT), anxiety, and depression scores.

RESULTS

A total of 35 articles were included, comprising 957 individual ENS patients. Surgical interventions mostly in the form of meatus augmentation implants accounted for 26 out of the 36 articles. The remaining ten articles included medical and psychological management options. SMD in SNOT, ENS6Q, anxiety, and depression scores were reported and demonstrated statistically significant improvements in follow-up periods of up to 1 year. All articles reported favorable outcomes following their chosen interventions.

CONCLUSION

There is a paucity of evidence on the management of ENS and an absence of randomized controlled trials. Surgical intervention appears to be the current mainstay of treatment, but there is a potential role for psychological and medical management.

Surgical and Regenerative Treatment Options for Empty Nose Syndrome: A Systematic Review

OBJECTIVES

Patients with empty nose syndrome typically experience paradoxical nasal congestion, nasal dryness, epistaxis, and suffocation. Conservative management is generally preferred for empty nose syndrome. However, some patients continue to experience persistent symptoms. When symptoms do not resolve, surgical options are considered. Therefore, we reviewed the surgical and regenerative treatment options for empty nose syndrome.

METHODS

PubMed, Embase, Scopus, Cochrane Register of Controlled Trials, and Google Scholar were searched from the earliest date provided in the database until December 2022. This review included studies that assessed treatment outcomes using patient symptom scores, including the Sino-Nasal Outcome Test (SNOT-20, -22, and -25) and the Empty Nose Syndrome 6-Item Questionnaire, supplemented by various clinical examinations.

RESULTS

Twenty-eight studies were analyzed. Various materials were utilized, including submucosal injectable materials, allografts/xenografts/cadaveric implants, autologous implants, and synthetic implants. The polyethylene implant was the most commonly used (23.3%), followed by autologous, homologous, or cadaveric costal cartilage (20%). The anterior-inferior lateral nasal wall was the most frequent site of administration. Most studies indicated that surgical intervention led to significant improvements in clinical outcomes, as evidenced by endoscopic exams, acoustic rhinometry, and computed tomography scans, along with patient-reported enhancements in nasal symptoms, psychological well-being, and overall health-related quality of life. However, several studies found no improvement in certain psychological-related questionnaires or saccharin transit times. The average follow-up duration was 12.0 months (range, 2.0-27.6 months). Only two studies reported postoperative adverse effects.

CONCLUSION

Several surgical options and recent tissue regeneration techniques have demonstrated efficacy in treating empty nose syndrome. However, more detailed investigations involving a larger number of participants and a randomized control study are necessary to establish a standardized treatment protocol for patients with empty nose syndrome.

Morphology, Not Only Volume: A Study on Empty Nose Syndrome and Inferior Turbinates

OBJECTIVES

Empty nose syndrome (ENS) is an underdiagnosed but burdensome clinical condition. Studies that have addressed the impact of remnant inferior turbinate volume (ITV) on ENS are scarce. We aimed to evaluate the impact of ITV and phenotyping on the severity and presentation of ENS.

METHODS

All the enrolled patients underwent the following subjective assessments: the ENS 6-Item Questionnaire (ENS6Q), Sino-Nasal Outcome Test-25 (SNOT-25), Beck Depression Inventory-II (BDI-II) and Beck Anxiety Inventory (BAI). The ITV was obtained from finely cut (1-mm-thick slices) sino-nasal computed tomography scan images and analyzed using ImageJ. The correlation between ITV, subjective measurements, and morphology of inferior turbinates was evaluated. ENS was categorized as torpedo type (balanced tissue volume) or pistol type (posterior dominance) based on the morphology.

RESULTS

Overall, 54 patients met the inclusion criteria. The ITV was positively correlated with the ENS6Q score and domain of ENS symptoms in SNOT-25. Neither BDI-II nor BAI scores had a significant correlation with ITV. Based on their morphological classification, the torpedo type exhibited diverse manifestations in the SNOT-25 analysis in response to changes in ITV, while the pistol type demonstrated an elevated rhinologic symptom burden and ENS-specific symptoms as their ITV increased. Nasal resistance did not correlate with the ITV in either type of ENS.

CONCLUSIONS

Symptoms were paradoxically worse in ENS patients with greater remnant ITV, and distinct morphological phenotypes in the nasal cavities may result in different presentations. Further investigation into the correlation between remnant inferior turbinates and nerve function is warranted.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:3060-3066, 2024.

Computational Fluid Dynamics and Its Potential Applications for the ENT Clinician

This article is an examination of computational fluid dynamics in the field of otolaryngology, specifically rhinology. The historical development and subsequent application of computational fluid dynamics continues to enhance our understanding of various sinonasal conditions and surgical planning in the field today. This article aims to provide a description of computational fluid dynamics, the methods for its application, and the clinical relevance of its results. Consideration of recent research and data in computational fluid dynamics demonstrates its use in nonhistological disease pathology exploration, accompanied by a large potential for surgical guidance applications. Additionally, this article defines in lay terms the variables analyzed in the computational fluid dynamic process, including velocity, wall shear stress, area, resistance, and heat flux.

Computed Tomographic Evaluations in Patients with Empty Nose Syndrome

OBJECTIVE

We aimed to evaluate computed tomography (CT) images of patients with empty nose syndrome (ENS), investigate the impact of reconstruction surgery on sinus inflammation, and identify the optimal airspace diameter after surgery.

METHODS

We conducted a retrospective case series analysis, identifying and enrolling patients with ENS with perioperative CT findings. The clinical characteristics of the participants were collected, and the modified Lund-Mackay (mLM) CT scores were determined. The anterior airspace diameter was evaluated by measuring the distance between the septum and the lateral nasal wall on the coronal plane at the level of the nasolacrimal duct.

RESULTS

Twenty patients with ENS and perioperative CT images were enrolled. The mean total mLM CT score and all subsite scores showed no significant changes after surgery. The Empty Nose Syndrome 6-item Questionnaire (ENS6Q) score, Sino-nasal Outcome Test-25 (SNOT-25) score, sleep symptoms domain, psychological domain, and empty nose symptoms domain were significantly associated with anterior airspace diameter in the regression analysis.

CONCLUSION

There was no significant difference in sinus inflammation between preoperative and postoperative CT evaluations. The anterior airspace diameters were significantly associated with ENS6Q and SNOT-25 scores.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:2105-2110, 2024.

Evaluation of Post-Intervention Outcomes in Patients with Empty Nose Syndrome

OBJECTIVES

To conduct a systematic review and meta-analysis of published articles to assess the impact of inferior turbinate/meatus augmentation in patients diagnosed with empty nose syndrome (ENS).

DATA SOURCES

PubMed, Cochrane database, Embase, Web of Science, SCOPUS, and Google Scholar.

REVIEW METHODS

Six databases were searched to December 2022. We retrieved studies evaluating improvements in refractory ENS-related symptoms based on various patient-reported outcome measures after inferior turbinate/meatus augmentation.

RESULTS

As a result of meta-analysis, Sinonasal Outcome Test, Empty Nose Syndrome 6-Item Questionnaire (ENS6Q), and depression scores were measured at 1 week; 1, 3, and 6 months; and later than 12 months after intervention for patients with ENS. All scores revealed significant symptom improvement. By reference to the minimal clinically important difference of the ENS6Q (6.25), inferior turbinate/meatus augmentation relieved the nasal symptoms of ENS in the long term. Although the improvements in anxiety scores at 1 week (0.4133 [-0.3366; 1.1633], 0.00, I2 = NA) and 1 month (0.4525 [-0.0529; 0.9579], I2 = 0.0%) were not statistically significant, the scores differed significantly at 3 months (0.7351 [0.4143; 1.0559], I2 = 28.4%), 6 months (0.8297 [0.6256; 1.0337], I2 = 37.2%), and longer than 12 months (0.7969 [0.4768; 1.1170], I2 = 0.0%).

CONCLUSION

These data and analysis suggest that performing inferior turbinate/meatus augmentation on ENS patients may improve not only nasal symptom scores but also accompanying psychological problems such as anxiety and depression. Laryngoscope, 134:2005-2011, 2024.

Functional Exercise Capacity and Perceived Exertion in Patients with Empty Nose Syndrome

Empty nose syndrome (ENS) is a complex condition characterized by symptoms such as dyspnea, nasal discomfort, and emotional challenges. This study aimed to evaluate functional exercise capacity and perceived exertion in patients with ENS. Patients with ENS who presented with a range of severe symptoms were prospectively enrolled. Pulmonary function was evaluated using spirometry, and functional exercise capacity was measured via the 6 min walk test (6-MWT). Perceived exertion was quantified using the Borg scale, and cardiopulmonary function was evaluated by monitoring peripheral oxygen saturation (SpO2). These parameters were assessed before and after nasal reconstruction surgery. A total of 44 patients with ENS were enrolled and classified into mild-to-moderate (n = 20) and severe (n = 24) symptom groups. Spirometry results showed no significant differences before and after surgery in the entire cohort. Perceived exertion showed significant postoperative improvement (p = 0.006). The severe ENS symptom group experienced significant improvement in SpO2 (p = 0.013) and perceived exertion (p = 0.002) at the end of the 6-MWT after surgery. Surgical intervention significantly enhanced functional exercise capacity (p = 0.038) in patients with mild-to-moderate ENS symptoms. Surgical reconstruction positively affected perceived exertion and SpO2 at the end of the 6-MWT in patients with ENS. The severity of ENS symptoms, as assessed by SNOT-25 scores, influenced these outcomes. These findings underscore the potential benefits of surgical intervention for enhancing exercise tolerance and respiratory efficiency.

A 3-year follow-up study after nasal reconstruction surgery in patients with empty nose syndrome

KEY POINTS

Empty nose syndrome (ENS) is characterized by a patent nasal airway and a sense of nasal obstruction. ENS and psychological symptoms improved after surgery and remained stable for up to three years. Identifying residual disease is necessary for enhancing therapeutic outcomes in ENS patients.

The Serpentine Sign: A Reliable Endoscopic and Radiographic Finding in Empty Nose Syndrome

OBJECTIVE

Empty nose syndrome (ENS) is a relatively uncommon disease that greatly impacts the quality of life and presents diagnostic challenges. We sought to identify objective clinical findings unique to patients with ENS, and in doing so identified compensatory mucosal hypertrophy in an alternating, undulating swelling on endoscopy and coronal computerized tomography (CT) that we have termed the "Serpentine Sign." Here, we investigated whether this radiographic finding is a reliable manifestation in ENS patients.

METHODS

Retrospective review was undertaken to identify ENS patients with past turbinoplasty, an ENS6Q score of at least 11/30, and symptomatic improvement with the cotton placement test. Control patients without complaints of ENS symptoms (ENS6Q < 11) were identified for comparison. ENS and control patients had coronal CT imaging available to evaluate for the Serpentine Sign, as well as ENS6Q scores, and histologic analysis of nasal tissue.

RESULTS

34 ENS and 74 control patients were evaluated for the presence of the Serpentine Sign. Of the 34 patients with ENS, 18 exhibited this radiographic finding on CT imaging (52.9%) compared to 0 of the 74 control patients (p < 0.0001). Further analysis demonstrated that ENS patients with the Serpentine Sign had lower median scores on ENS6Q than ENS patients without (17.5 vs. 22, p = 0.033). Histology revealed disorganized subepithelium rich in seromucinous glands similar to the nasal septum swell body.

CONCLUSION

The "Serpentine Sign" is a unique presentation of hypertrophic change to the nasal septum soft tissue that is specific to ENS patients and may serve as a reliable radiographic and endoscopic finding in diagnosis.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:1089-1095, 2024.

Facial Pain Triggered by Inferior Turbinate Partial Resection in a Patient with a Previous History of Inferior Meatal Antrostomy: A Case Report

OBJECTIVES

Inferior meatal antrostomy (IMA) is regarded as a safe method, with minimal complications, for managing various lesions in the maxillary sinus. However, in patients with persisting IMA window, resection of the inferior turbinate may result in direct airflow into the antrum, irritating the antral mucosa.

METHODS

Case report and review of literature.

RESULTS/CASE

The present report describes a 29-year-old man who previously underwent unilateral IMA for the excision of a dentigerous cyst. The patient did not report any facial pain following the excision of the cyst. One year later, this patient underwent partial resection of the inferior turbinate for the resolution of nasal stuffiness by another surgeon. Soon after surgery, the patient developed severe facial and ocular pain on the side of the IMA, with the pain being especially aggravated upon inhalation. Endoscopy and computed tomography (CT) revealed a persisting IMA window. The patient's severe discomfort was thought to result from direct airflow into the maxillary sinus, as the resected turbinate may have altered normal nasal airflow. A unilateral inferior meatal augmentation procedure (IMAP) with an autologous ear cartilage implant was performed, resulting in complete relief of pain and discomfort.

CONCLUSIONS

Although IMA alone is a relatively safe surgical procedure, care should be taken when performing inferior turbinoplasty in patients with persistent IMA opening.

Utility of Serum Interleukine-6 Level in Empty Nose Syndrome

Objectives: Empty nose syndrome (ENS), a complication resulting from surgical procedures on turbinate tissue, is characterized by paradoxical nasal obstruction with wide nasal airways. Patients with ENS often also experience psychiatric symptoms, and psychiatric disorder detection remains dependent on subjective evaluation. Objective biomarkers for mental status assessment in patients with ENS are unestablished. This study aimed to evaluate the role of serum interleukin-6 (IL-6) levels in the mental status of patients with ENS. Methods: Overall, 35 patients with ENS who underwent endonasal submucosal implantation surgery were prospectively included in the study. The Sino-Nasal Outcome Test-25 (SNOT-25), Empty Nose Syndrome 6-item Questionnaire (ENS6Q), Beck Anxiety Inventory (BAI), and Beck Depression Inventory-II (BDI-II) were used to assess the physical and psychiatric symptoms of these patients preoperatively, and 3, 6, and 12 months postoperatively. Serum IL-6 levels were analyzed 1 day before surgery. Results: All subjective assessments significantly improved 3 months after surgery and plateaued at 12 months. Patients with higher serum preoperative IL-6 levels tended to experience more severe depression. Regression analysis showed that a preoperative serum IL-6 level > 1.985 pg/mL was significantly correlated with severe depression status in patients with ENS (odds ratio = 9.76, p = 0.020). Conclusions: ENS patients with higher preoperative serum IL-6 levels were more likely to have severe depressive burden. Since more suicidal thoughts or attempts were noted in these patients, timely treatment plan for patients with high levels of serum IL-6 is crucial and may consider psychotherapy after surgical treatment.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Identifying Residual Psychological Symptoms after Nasal Reconstruction Surgery in Patients with Empty Nose Syndrome

Background: Empty nose syndrome (ENS) is a syndrome of paradoxical nasal obstruction that is thought to be mostly caused by inappropriate turbinate procedures. This study aimed to investigate depression- and anxiety-associated psychological symptoms in patients with ENS before and after surgical reconstruction, and to compare them with those of control subjects. Methods: Patients with ENS were prospectively enrolled. The Sino-Nasal Outcome Test-25 (SNOT-25), Empty Nose Syndrome 6-item questionnaire (ENS6Q), Beck Depression Inventory-II (BDI-II), and Beck Anxiety Inventory (BAI) were used to evaluate the participants before and after reconstruction surgery with submucosal Medpor implantation (Stryker, Kalamazoo, MI), as well as control subjects at enrollment. Results: Forty patients with ENS and forty age- and sex-matched controls were recruited. Patients with ENS experienced significant improvement in SNOT-25, ENS6Q, BDI-II, and BAI scores after surgery, but all were significantly greater than those in the control group. Nine patients with ENS (22.5%) had postoperative residual psychological symptoms. Preoperative BDI-II and BAI scores were significant predictors of postoperative residual psychological symptoms. The optimal cut-off value was BDI-II > 28.5 (sensitivity, 77.8%; specificity, 77.4%) in receiver operating characteristic curve analysis. Conclusions: The nasal and psychological evaluations in patients with ENS significantly improved after nasal reconstruction surgery, but both were significantly greater than those in the control group. Identifying individuals who may experience postoperative residual symptoms and providing a multimodal approach, including surgical reconstruction and psychiatric treatment, are suggested.

Autologous Costal Cartilage Augmentation Technique for Treatment of Empty Nose Syndrome

Empty nose syndrome is a rare complication caused by excessive removal of normal tissues after nose surgery. The main symptoms of empty nose syndrome are paradoxical nasal obstruction, dryness, crust and dyspnea. Medical treatments such as irrigation, humidification, and ointment are not very effective, so surgical treatments to reconstruct the normal nasal cavity using implant materials are often considered. If the implant is not properly inserted, the symptoms persist and the implant must be removed again, resulting in the only donor site complications. Therefore, it is essential to treat the implant well and insert it precisely. Here we describe a surgical procedure to manage implant materials using autologous costal cartilage in the form of block, diced, and crushed cartilage for augmentation technique.

Surgical Treatment for Empty Nose Syndrome Using Autologous Dermal Fat: Evaluation of Symptomatic Improvement

Background: Empty nose syndrome (ENS) is caused by nasal turbinate surgery. The standard treatment for ENS is an inferior meatus augmentation procedure (IMAP) in which autologous tissue such as auricular cartilage, rib cartilage, or artificial material is transplanted into the nasal cavity. However, some challenges like a very small auricular cartilage are associated with these autologous tissue types. Moreover, since using rib cartilage is a highly invasive technique, the scar on the chest from where the harvesting is done is easily visible, and the artificial material is susceptible to infection. We used autologous dermal fat (ADF) in IMAPs in our study for the following reasons: the quantity of ADF could be increased or reduced as needed, ADF is considered a safer option than rib cartilage because it is harvested from superficial tissue, it is superior in terms of cosmetic appearance to harvested rib cartilage, and it has a lower risk of infection than any artificial material.Objective: The purpose of our study was to investigate the efficacy and safety of IMAPs using ADF.Methods: We included nine patients with ENS who underwent an IMAP using ADF. The patients' backgrounds and responses to the Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) were recorded. Changes in each item of the ENS6Q before and after surgery (up to 3 months) were analyzed.Results: The postoperative ENS6Q total score and parameters were significantly better than their preoperative counterparts. Nasal dryness improved slightly less than other symptoms. There were no complications.Conclusions: The IMAP using ADF was effective in improving ENS symptoms; however, some physiological functions were difficult to improve, and dryness persisted. Autologous dermal fat is larger than auricular cartilage, less invasive than rib cartilage, and has a lower risk of infection than artificial material.

Clinical perspectives on nasopharyngeal morphology in humans

The nasopharynx is an integral component of the upper aerodigestive tract, whose morphologic features share an intimate relationship with a vast array of clinical, functional, and quality of life conditions related to contemporary humans. Its composite architecture and central location amidst the nasal cavity, pharyngotympanic tube, palate, and skull base bears implications for basic physiologic functions including breathing, vocalization, and alimentation. Over the course of evolution, morphological modifications of nasopharyngeal anatomy have occurred in genus Homo which serve to distinguish the human upper aerodigestive tract from that of other mammals. Understanding of these adaptive changes from both a comparative anatomy and clinical perspective offers insight into the unique blueprint which underpins many clinical pathologies currently encountered by anthropologists, scientists, and otorhinolaryngologists alike. This discussion intends to familiarize readers with the fundamental role that nasopharyngeal morphology plays in upper aerodigestive tract conditions, with consideration of its newfound clinical relevance in the era of the COVID-19 pandemic.

Long-Term Outcomes of Inferior Meatus Augmentation Procedure to Treat Empty Nose Syndrome

OBJECTIVES/HYPOTHESIS

We sought to report the long-term, symptom-focused, prospective outcomes in empty nose syndrome (ENS) patients after undergoing inferior meatus augmentation procedure (IMAP) through use of four validated questionnaires: Empty Nose Syndrome 6-Item Questionnaire (ENS6Q), 22-item Sino-Nasal Outcome Test (SNOT-22), Generalized Anxiety Disorder 7-Item Scale (GAD-7), and Patient Health Questionnaire-9 (PHQ-9).

STUDY DESIGN

Prospective case series.

METHODS

A single-center prospective case series was performed for patients diagnosed with ENS who underwent IMAP between July 2017 and February 2020. Diagnosis of ENS was based on the following criteria: 1) reported discomfort with nasal breathing and/or paradoxical nasal obstruction after inferior turbinate reduction, 2) a positive ENS6Q score of at least 11, and 3) a positive cotton test. Questionnaire responses were recorded prior to surgery as well as 1, 3, 6, and 12 months postoperatively.

RESULTS

Seventeen eligible patients were included. Mean ENS6Q scores were significantly reduced at all postoperative time points (p < .0001, p < .0001, p < .0001, p = .0003). Of the six ENS6Q subdomains, five (suffocation, dryness, sense of diminished airflow, nasal crusting, and nasal burning) were significantly reduced 1-year postoperatively (p < .0001, p = .0004, p = .0136, p = .0114, p = .0080, respectively). SNOT-22 scores were significantly reduced at all time points (p = .0021, p = .0227, p = .0004, and p = .0025). Of the SNOT-22 subdomains, the sleep subdomain was significantly reduced 1-year postoperatively (p = .0432). Low baseline GAD-7 and PHQ-9 scores were recorded at 7 and 9.4, respectively, and although scores at all postoperative time points were reduced, there was no statistical significance.

CONCLUSION

IMAP via implant of cadaveric rib cartilage provides significant, long-term improvements in ENS-specific and general sinonasal symptoms.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E2736-E2741, 2021.

Empty Nose Syndrome Pathophysiology: A Systematic Review

OBJECTIVE

The pathophysiology of empty nose syndrome (ENS) remains unclear despite significant research. The pathophysiologic mechanism of ENS was systematically reviewed.

DATA SOURCES

MEDLINE and Embase.

REVIEW METHODS

Data were systematically reviewed for studies that provided original data on pathophysiology.

RESULTS

A total of 2476 studies were screened, and 19 met the inclusion criteria: 13 case-control and 6 cross-sectional. Nine pathophysiologic themes were identified.• Demographics: ENS symptoms had no relationship with climatic factors.• Symptomatology: ENS patients demonstrated high symptom severity.• Mental health: Anxiety and depression including hyperventilation were reported in >50% of ENS patients and correlated with ENS symptom severity.• Anatomic features: Structural changes in response to turbinate surgery were similar between ENS and non-ENS patients.• Airflow analysis: Airflow parameters were similar between ENS and non-ENS patients after turbinate surgery. On computational fluid dynamic analysis, differences were found on multiple outcomes.• Diagnostic testing: The menthol detection test was impaired in ENS, and cotton placement in the airway improved ENS symptoms.• Cognitive function: Functional magnetic resonance imaging showed activation in emotional processing area during breathing.• Olfactory function: Subjective impairment was reported in ENS, but quantitative measures were similar to non-ENS patients.• Mucosal physiology/innate immunity: Turbinate histopathology in ENS showed a tissue-remodeling pattern. Nasal nitric oxide level was lower in ENS patients.

CONCLUSION

There is evidence of high comorbid mental health disorders in ENS patients. An abnormal trigeminal-thermoreceptor response may be present in some patients. The influence of altered airflow and the evidence of surgery as the cause for ENS are unclear.

An Introduction to Biomedical Computational Fluid Dynamics

Computational fluid dynamics (CFD) is a tool that has been used by engineers for over 50 years to analyse heat transfer and fluid flow phenomena. In recent years, there have been rapid developments in biomedical and health research applications of CFD. It has been used to evaluate drug delivery systems, analyse physiological flows (e.g. laryngeal jet flow), facilitate surgical planning (e.g. management of intracranial aneurysms), and develop medical devices (e.g. vascular stents and valve prostheses). Due to the complexity of these fluid flows, it demands an interdisciplinary approach consisting of engineers, computer scientists, and mathematicians to develop the computer programs and software used to solve the mathematical equations. Advances in technology and decreases in computational cost are allowing CFD to be more widely accessible and therefore used in more varied contexts. Cardiovascular medicine is the most common area of biomedical research in which CFD is currently being used, followed closely by upper and lower respiratory tract medicine. CFD is also being used in research investigating cerebrospinal fluid, synovial joints, and intracellular fluid. Although CFD can provide meaningful and aesthetically pleasing outputs, interpretation of the data can be challenging for those without a strong understanding of mathematical and engineering principles. Future development and evolution of computational medicine will therefore require close collaboration between experts in engineering, computer science, and biomedical research. This chapter aims to introduce computational fluid dynamics and present the reader with the basics of biological fluid properties, the CFD method, and its applications within biomedical research through published examples, in hope of bridging knowledge gaps in this rapidly emerging method of biomedical analysis.