Objective computerized determination of the minimum cross-sectional area of the nasal passage on computed tomography

Overview of Nasal Airway and Nasal Breathing Evaluation

Several methods are available for evaluating nasal breathing and nasal airflow, as this evaluation may be made from several different perspectives.Physiologic methods for nasal airway evaluation directly measure nasal airflow or nasal airway resistance, while anatomical methods measure nasal airway dimensions. Subjective methods evaluate nasal breathing through several validated patient-reported scales assessing nasal breathing. Computational fluid dynamics evaluates nasal airflow through the analysis of several physics' variables of the nasal airway.Being familiar to these methods is of utmost importance for the nasal surgeon to be able to understand data provided by the different methods and to be able to choose the combination of evaluation methods that will provide the information most relevant to each clinical situation.

Association of Sinonasal Computed Tomography Scores to Patient-Reported Outcome Measures: A Systematic Review and Meta-analysis

OBJECTIVE

To perform a systematic review of proposed sinus computed tomography (CT) scoring systems and determine their association with patient-reported outcome measures (PROMs).

DATA SOURCES

PubMed, CINAHL, Scopus, and Cochrane Library.

REVIEW METHODS

A systematic search was conducted following the PRISMA guidelines (Preferred Reporting Items for Systematic Reviews and Meta-analyses) for studies describing CT scores and PROMs in patients with chronic rhinosinusitis.

RESULTS

A total of 144 studies were included. Out of 20,741 patients, 53.6% were male and 55.5% had nasal polyposis. A meta-analysis of correlations revealed a moderate correlation between Lund-McKay (LM) and the 22-item Sinonasal Outcome Test (SNOT-22; r = 0.434, P < .001) and a weaker correlation between LM and the 20-item Sinonasal Outcome Test (SNOT-20; r = 0.257, P = .039). Meta-regression also revealed a weak association between LM and SNOT-20 (n = 25 studies) but no significant associations between Zinreich score and SNOT-22 or LM scores and PROMs, including SNOT-22 (n = 94 studies), Rhinosinusitis Disability Index (n = 25), nasal obstruction visual analog scale (n = 15), Chronic Sinusitis Survey (n = 12), Total Nasal Symptom Score (n = 4), Total Symptom Score (n = 3), and 12-Item Short Form Health Survey (n = 3).

CONCLUSION

There is essentially little association between radiologic grade and PROMs. CT grading systems with improved clinical utility are needed.

Which Nasal Airway Dimensions Correlate with Nasal Airflow and with Nasal Breathing Sensation?

Background: Rhinoplasty modifies the nasal pyramid, thereby also modifying the nasal airway. Objectives: To correlate the sensation of nasal breathing, as measured by patient-reported outcome measures, and nasal airflow, as assessed by peak nasal inspiratory flow (PNIF), with nasal airway dimensions, as measured on computed tomography (CT) images. Methods: Fifty Caucasian patients were studied through visual analogue scale (VAS), nasal obstruction symptom evaluation (NOSE) and PNIF. Measurements of the nasal airway were made on CT images: minimal distance between septum and inferior and middle turbinates, nasal valve angle, and nasal valve area. Results: There was a significant association between PNIF and nasal valve area, between VAS and the narrower nasal valve angle and between NOSE and minimal distance between septum and middle turbinate of the narrower side. Conclusions: This study suggests that the dimensions of the nasal valve and of the middle nasal airway have a substantial impact on nasal breathing capacity. It also highlights the importance of unilateral nasal airway obstruction to nasal breathing.

Assessing the Clinical Value of Performing CT Scan before Rhinoplasty Surgery

Introduction

The endonasal mucosal or anatomic pathologies could lead to poor functional results and dissatisfaction after rhinoplasty. Although computed tomography (CT) scan has become an integral part of the diagnostic paradigm for patients with pathologies of the paranasal sinuses, the use of CT scan for preoperative evaluation of patients seeking rhinoplasty is up for debate. Our aim in this study was to compare the efficacy of CT scan in diagnosing nasal pathologies with other evaluating tools in patients undergoing rhinoplasty.

Design

In this randomized controlled trial study, 74 consecutive patients seeking cosmetic rhinoplasty referred to otorhinolaryngology clinic were randomly assigned into three groups based on the perioperative evaluation method: the CT group, the nasal endoscopy group, and the control group (anterior rhinoscopy only). Surgical planning was made according to perioperative findings, and the identified endonasal pathologies were corrected during the surgery. The functional and aesthetic outcomes of the rhinoplasty were assessed by Nasal Obstruction Symptom Evaluation (NOSE), Rhinoplasty Outcome Evaluation (ROE), and the Visual Analogue Scale (VAS) tools before surgery and at 12-month follow-up.

Results

All outcome measures improved significantly in either group toward one year after rhinoplasty (all with p value <0.05). Subjects in the CT group demonstrated greater improvement in the NOSE, VAS, and ROE compared to other two groups (NOSE: p value = 0.17; VAS: p value = 0.024; ROE: p value = 0.042).

Conclusions

According to our study, perioperative CT is associated with greater patients' satisfaction and quality of life after rhinoplasty compared to either nasal endoscopy or anterior rhinoscopy. A preoperative CT scan may improve the outcomes of rhinoplasty.

Ultrasound as an Assessment Method in Predicting Difficult Intubation: A Prospective Clinical Study

Objective

Aim of the study is to predict the difficulty in intubation preoperatively using ultrasonography.

Methods

One hundred and thirty-seven patients underwent ultrasound followed by surgery under general anesthesia. A experienced radiologist examined the airway and performed measurements of specific airway parameters: visualization of hyoid bone, visualization of vocal cords through thyroid cartilage, visualization of epiglottis, distance from base of tongue to hyoid bone, distance of hyomental region distance of thyrohyoid region, distance between skin and fat pad thickness to thyroid cartilage, thickness of submental region, distance from epiglottis to skin (above hyoid), and visualization of cricothyroid membrane. After performing ultrasound, patient was presented for surgery. An experienced anesthesiologist who is associated with this study did all the laryngoscopy and intubation.

Results

We were able to visualize all relevant anatomical structures in all the participants using ultrasound. The receiver operating characteristic curve analysis results showed that hyomental is ≤ 1.09 (P value < 0.01) to classify difficult in intubation.

Conclusion

The study shows that ultrasound can reliably image all the airway structures. This study suggests that hyomental distance is a more valid criterion in predicting difficult intubation. Further, case control study is needed for assessing the ease of intubation.

Measurements of nasal airflow and patency: a critical review with emphasis on the use of peak nasal inspiratory flow in daily practice

Objective measures can be used to assist the clinician to diagnose and treat nasal obstruction and also to quantify nasal obstruction in research. Objective measurements of nasal obstruction are as important as objective measurements of lung function. peak nasal inspiratory flow (PNIF), acoustic rhinometry (AR) and rhinomanometry (RM), with their specific peculiarity, assess different aspects of nasal obstruction. From the studies available in the literature, it seems that these methods roughly correlate with each other and that all of them can be alternatively utilized very well in research as well as in clinical practice. This review describes the various methods that can be used to measure nasal patency, airflow and resistance, mainly peak nasal inspiratory flow, rhinomanometry and acoustic rhinometry. PNIF has been demonstrated to be reproducible and as good an indication of objective nasal patency as formal rhinomanometry and has the advantage to be cheap, simple and suitable for serial measurements and for home use even in the paediatric population. PNIF normative data are available for children, adults and elderly subjects, and the availability of unilateral PNIF normal values allows evaluation of nasal sides separately. Just as in the lower airways, objective and subjective evaluation gives different information that together optimizes the diagnosis and the treatment of our patients. We argue that PNIF should be used regularly in every outpatient clinic that treats patients with nasal obstruction.

Computed tomography as an aid to planning intubation in the difficult airway

Patients having oral and maxillofacial operations often require nasal intubation, but limited mouth opening and unfavourable nasal anatomy can make it difficult. We aimed to find out whether there is an association between the prediction of difficult nasal intubation on computed tomography (CT) and actual problems. We retrospectively reviewed the imaging and anaesthetic records of 77 patients who had replacement of the temporomandibular joint (TMJ) as these patients often have limited mouth opening and have had a preoperative CT. There was a positive correlation between a radiographically-assessed difficult nostril and difficulty of intubation (p<0.001). The positive predictive value was 71.4%. As a consequence, our radiologists now routinely report on the nasal cavity in these patients, and their report and the scan are then reviewed by the anaesthetist before intubation. Our results suggest that review of the CT before planned nasal intubation should be part of routine practice.

Surgery of the external nasal valve: the correlation between subjective and objective measurements

OBJECTIVES/HYPOTHESIS

Minimum cross-sectional area of the nasal passage on CT (CT-MCA) is an objective computerised determination of the minimum cross-sectional area of the nasal passage on CT. CT-MCA was evaluated before and after surgery on the external nasal valve using the 'lateral crus pull-up' procedure (LCPU). The outcomes of CT-MCA were compared with other currently available objective tests for nasal valve patency.

STUDY DESIGN

Prospective cohort study.

METHODS

This study included 34 patients undergoing surgery on the external nasal valve with the use of the LCPU technique. CT-MCA was performed before and after surgery and compared with the subjective perception of nasal passage using the Nasal Obstruction Symptom Evaluation (NOSE) scale and with objective tests such as acoustic rhinometry (A-MCA), rhinomanometry (NAR) and peak nasal inspiratory flow (PNIF).

RESULTS

This study showed a significant correlation between CT-MCA and the NOSE scale, PNIF and NAR. Paired-samples t-tests showed significant improvement after surgery on CT-MCA, PNIF and the NOSE scale. Multiple linear regression analysis showed that PNIF, CT-MCA and NAR were significantly associated with the NOSE scale.

CONCLUSION

CT-MCA and PNIF were both significantly correlated and associated with the patient's subjective perception of nasal passage. The surgical procedure, the 'lateral crus pull-up', showed a significant improvement in the postoperative result both subjectively and objectively.

Computed tomography versus nasal endoscopy for the measurement of the internal nasal valve angle in Asians

CONCLUSIONS

The internal nasal valve (INV) angle in Asians is 21.6 degrees +/-4.5 degrees and it is significantly larger than that of Caucasians. The reconstructed CT method has better reproducibility than the endoscopic method in measuring the INV angle.

OBJECTIVES

The INV is an area of interest for nasal surgeons due to its functional significance in rhinoplasty and septoplasty. This study was designed to evaluate the size of the INV angle in an Asian population by measuring the angle through reconstructed CT scans and nasal endoscopy.

PATIENTS AND METHODS

Thirty-eight ostiomeatal unit CTs and 24 endoscopic photos of patients who had minimal or no sinonasal problems were analyzed. CT images that had been reconstructed perpendicular to the acoustic axis and endoscopic photos were used to measure the INV angle. Each method was verified as to reproducibility and the angles measured by the two methods were compared.

RESULTS

The INV angle of the Asians measured by CT scan was 21.6 degrees +/-4.5 degrees . This value was significantly larger than that of the Caucasians, which has been reported to be 11.4 degrees +/-2.6 degrees (p<0.001). The INV angle measured endoscopically was 19.3 degrees +/-3.6 degrees . Reproducibility of the reconstructed CT method was good (p<0.001), while the reproducibility of the endoscopic method was poor (p=0.093). The correlation between the two methods was also poor (p=0.107).

A Review of the Effects of Expansion of the Nasal Base on Nasal Airflow and Resistance

PURPOSE

The purpose of this article is to inform the reader of the current literature regarding nasal airflow resistance. The anatomy and physiology of nasal airflow resistance will be examined and the known effects of widening of the nasal airway upon airflow will be described.

MATERIALS AND METHODS

This article is a review of the current literature regarding nasal airflow and resistance and the effects of widening of the nasal base. No patient data were collected.

RESULTS

The literature shows that nasal airflow resistance can be changed by surgical manipulation and by rapid palatal expansion, but that the effects on airflow resistance and future growth and development are unpredictable.

CONCLUSION

Patients with a maxilla that is constricted in the transverse dimension and nasal airflow problems may benefit from expansion of the nasal base. The resultant effects upon nasal airflow resistance and subsequent growth and development are unpredictable and therefore airflow issues alone may not be a primary reason to increase the transverse dimension of the nasal base.

Lateral crus pull-up: a method for collapse of the external nasal valve

Collapse of the nasal vestibule during inspiration is a frequently encountered symptom, often caused by weak or medially displaced lateral crura in the lower lateral cartilages. Numerous techniques are available for lateralizing and strengthening the lateral crura using cartilage grafts or suture techniques. In most cases, they involve an external rhinoplasty approach or additional incisions. An elegant endonasal method for widening and strengthening the lateral component of the nasal valve area is described herein. The basis of the procedure is a permanent submucosal spanning suture between the piriform aperture and the distal part of the lower lateral cartilage. The effect of this technique is 2-fold. First, it provides superolateral rotation of the lateral crura, increasing the cross-sectional area, and second, the spanning suture provides additional support for the lateral wall of the nasal vestibule.