Diagnosing nasal obstruction and its common causes using the nasal acoustic device: A pilot study

An adjoint-based approach for the surgical correction of nasal septal deviations

Deviations of the septal wall are widespread anatomic anomalies of the human nose; they vary significantly in shape and location, and often cause the obstruction of the nasal airways. When severe, septal deviations need to be surgically corrected by ear-nose-throat (ENT) specialists. Septoplasty, however, has a low success rate, owing to the lack of suitable standardized clinical tools for assessing type and severity of obstructions, and for surgery planning. Moreover, the restoration of a perfectly straight septal wall is often impossible and possibly unnecessary. This paper introduces a procedure, based on advanced patient-specific Computational Fluid Dynamics (CFD) simulations, to support ENT surgeons in septoplasty planning. The method hinges upon the theory of adjoint-based optimization, and minimizes a cost function that indirectly accounts for viscous losses. A sensitivity map is computed on the mucosal wall to provide the surgeon with a simple quantification of how much tissue removal at each location would contribute to easing the obstruction. The optimization procedure is applied to three representative nasal anatomies, reconstructed from CT scans of patients affected by complex septal deviations. The computed sensitivity consistently identifies all the anomalies correctly. Virtual surgery, i.e. morphing of the anatomies according to the computed sensitivity, confirms that the characteristics of the nasal airflow improve significantly after small anatomy changes derived from adjoint-based optimization.

Litigation in Septorhinoplasty Surgery: A Pan-Specialty Review of National Health Service (the United Kingdom) Data

Success in septorhinoplasty surgery can be difficult to assess due to a lack of objective and measurable outcomes. If patients' expectations are not met, it places surgeons performing septorhinoplasty at risk of litigation which can be stressful and costly. The National Institute of health (NHS) Resolution is a government-funded organization in the United Kingdom that provides expertise to the NHS on resolving patient concerns. Data were requested from NHS Resolution for claims involving septorhinoplasty surgery over a period of 5 years between April 2015 and April 2020. Rhinoplasty claims performed by all specialties were included. Data included the claim status, incident details, alleged injury, damages claimed, and damages paid. A total of 31 claims were identified by the study, equating to a total cost of £1,347,336.10. Of the 31 claims for rhinoplasty or septorhinoplasty, 9 cases were open (29%, £962,361.00) and 22 cases were closed (71%, £384,975.10). The common causes for claims were "intraoperative problems (32%)," "failure to warn-informed consent (19%)," and "foreign body left in situ (13%)." The most common injuries were "cosmetic disfigurement (39%)," "unnecessary pain (29%)," and "additional/ unnecessary operation (29%)." This study highlights the need for improved awareness of clinical negligence claims among surgeons who perform septorhinoplasty. Results are applicable to all specialties who perform the procedure. The study highlights the importance of assessing patients' motives and expectations prior to surgery and emphasizes the need for a well-documented rigorous consent process.

The Nasal Obstruction Balance Index: A Novel Approach to Improving Correlation Between Unilateral Nasal Airway Measurements and Evaluating Nasal Airway Asymmetry

OBJECTIVES/HYPOTHESIS

Demonstrate that the Nasal Obstruction Balance Index (NOBI) model fulfils the unmet need of improving unilateral correlation between subjective and objective nasal obstruction outcome measures and identifying the more obstructed side. Improve correlation between unilateral objective nasal airway measurements (nasal inspiratory peak flow [NIPF] and acoustic rhinometry [AR]) and subjective Visual Analogue Scale for nasal obstruction (VAS-NO) scores. Improve assessment of nasal airway asymmetry by evaluating unilateral measurements both before and after the application of nasal decongestant; which the patient could better understand. NOBI represents a ratio calculated by taking the difference between left and right nasal airway measurements and divided by the maximum unilateral measurement. It is based on Poiseuille's law and aims to reduce the confounding variables which challenge nasal airway measurement.

STUDY DESIGN

Prospective cohort study.

METHODS

Forty-three controls and 34 patients with nasal obstruction underwent both unilateral and bilateral NIPF, AR and VAS-NO measurements; these were repeated after the application of nasal decongestant. The NOBI values for unilateral NIPF, AR, and VAS-NO were calculated both before and after decongestant.

RESULTS

The correlation between unilateral NIPF and AR measurements was enhanced considerably (r = 0.57, P < .01) when NOBI was applied. The NOBI metric significantly increased the correlation between unilateral NIPF, AR, and VAS-NO scores. Postdecongestant NOBI for NIPF and AR measurements correctly identified the more obstructed side in 82.4% and 94.1% of the deviated nasal septum (DNS) cases, respectively.

CONCLUSION

The NOBI model provides a better correlation between unilateral subjective and objective measurements and identifies the more obstructed side.

LEVEL OF EVIDENCE

Prospective cohort study (level III) Laryngoscope, 2021.

Diagnosing nasal obstruction and its common causes using the nasal acoustic device: A pilot study

Objectives

There is a need to develop a medical device which can accurately measure normal and abnormal nasal breathing which the patient can better understand in addition to being able to diagnose the cause for their nasal obstruction.

The aim is to evaluate the accuracy of the nasal acoustic device (NAD) in diagnosing the common causes for nasal obstruction and diagnosing normal and abnormal (nasal obstruction) nasal breathing.

Methods

This pilot study recruited 27 patients with allergic rhinitis (AR), chronic rhinosinusitis (CRS), and a deviated nasal septum (DNS) which represents the common causes for NO and 26 controls (with normal nasal breathing). Nasal breathing sounds were recorded by the NAD akin to two small stethoscopes placed over the left and right nasal ala. The novel outcome metrics for the NAD include inspiratory nasal acoustic score (INA) score, expiratory nasal acoustic (ENA) score and the inspiratory nasal obstruction balance index (NOBI). The change in acoustic score following decongestant is key in this diagnostic process.

Results

Pre‐decongestant ENA score was used to detect the presence of nasal obstruction in patients compared to controls, with a sensitivity of 0.81 (95% CI: 0.66‐0.96) and a specificity of 0.77 (0.54‐1.00). Post‐decongestant percentage change in INA score was used to identify the presence of AR or CRS, with a sensitivity of 0.87 (0.69‐1.00) and specificity of 0.72 (0.55‐0.89) for AR; and a sensitivity of 0.92 (0.75‐1.00) and specificity of 0.69 (0.52‐0.86) for CRS. Post‐decongestant inspiratory NOBI was used to identify DNS, with a sensitivity of 0.77 (0.59‐0.95) and specificity of 0.94 (0.82‐1.00).

Conclusion

We have demonstrated that the NAD can help distinguish between normal and abnormal nasal breathing and help diagnose AR, CRS, and DNS. Such a device has not been invented and could revolutionize COVID‐19 recovery telemedicine.

Level of Evidence

Diagnostic accuracy study—Level III.