Quantification of airflow in the sinuses following functional endoscopic sinus surgery

Surgery for nasal polyposis in cystic fibrosis

BACKGROUND

Cystic fibrosis (CF) is a life-shortening, autosomal recessive disease that leads to abnormal electrolyte concentration in exocrine secretions. Secretion stasis in paranasal sinuses determines chronic rhinosinusitis (CRS) and nasal polyposis. Endoscopic sinus surgery is used to open the sinuses and allow medical treatment to work properly.

OBJECTIVES

To determine the effects of sinus surgery alone or in combination with medical treatment (non-surgical) compared to medical treatment (non-surgical) alone on both nasal and pulmonary function in people with CF diagnosed with CRS with nasal polyposis. Further, to evaluate the impact of sinus surgery (with or without medical treatment) on hospitalization rates, use of antibiotics and pulmonary exacerbation rates.

SEARCH METHODS

We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and hand searching of journals and conference abstract books. Date of last search: 4 July 2022. We also searched other databases (Pubmed, Embase, World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), Virtual Health Library and ClinicalTrials.gov). Date of last search: 18 September 2022.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing groups who underwent endoscopic sinus surgery and groups with medical treatment alone.

DATA COLLECTION AND ANALYSIS

The review authors independently selected studies, extracted data, assessed the risk of bias and evaluated the certainty of the evidence using GRADE. They contacted the authors of the included study for additional information.

MAIN RESULTS

We identified 66 publications relating to 50 studies from electronic searches. Only one study fulfilled the inclusion criteria, and only limited information was available. In this study, 28 participants aged 19 to 28 years were randomized in equal numbers to either nasal irrigation alone or nasal irrigation with surgery (endoscopic polypectomy with extended sinusotomy). The certainty of the evidence was very low according to the GRADE approach. We are uncertain whether, compared to medical treatment alone, the addition of surgical intervention improves nasal symptoms, or reduces bacterial colonization, the use of antibiotics and pulmonary exacerbations. We are also uncertain whether the addition of surgery to medical treatment leads to changes in pulmonary function. There was one episode of bleeding during surgery that was corrected during the procedure with no further consequences. The study did not report on survival.

AUTHORS' CONCLUSIONS

Very low-certainty evidence means we are not certain if endoscopic sinus surgery to treat chronic rhinosinusitis with nasal polyposis in cystic fibrosis is effective. Future research should be multicentric to increase the number of participants and increase statistical power. Adequate randomization and allocation concealment are important to guarantee that the groups are similar. Blinding, however, may not be possible in an ethical trial; even without blinding, results can achieve high-level evidence if the outcomes used are objective parameters. Future research should follow participants of all ages for at least 12 months to evaluate the evolution of nasal polyposis, its recurrence and how symptoms may return. We also consider mortality an important outcome to be assessed. Future clinical research should consider the effects of cystic fibrosis transmembrane conductance regulators, a new group of drugs that may affect the development of nasal polyps.

Value of Opening the Middle Meatus in Patients With Nasal Airway Obstruction

OBJECTIVES

While surgeries to correct the anatomical malformations that cause nasal airway obstruction (NAO) are generally successful, the outcomes of such procedures are often unsatisfactory. The aim of the present study was to assess the value of opening the middle meatus in patients with NAO.

METHODS

Thirty-four patients with nasal obstruction due to nasal septal deviation were included in this study. After randomization, the middle meatus was either opened or not opened during septoplasty. The patients were evaluated through pre- and postoperative rhinomanometry and acoustic rhinometry. The Visual Analog Scale (VAS) scores of subjective symptoms along with responses to the 20-item Sinonasal Outcome Test (SNOT-20) were obtained before surgery and three months after surgery.

RESULTS

The VAS scores and SNOT-20 responses improved significantly in both groups after surgery. The effective treatment rate based on the nasal congestion score (NCS) was 64.7% in the single group (septoplasty alone) and 100% in the combined group (septoplasty in conjunction with opening the middle meatus), and the difference was statistically significant (P = .018). In both groups, surgery significantly improved nasal flow, resistance, minimal cross-sectional area, cross-sectional area 6 cm (CA6) from the anterior nostril and nasal volume. Nasal volume and CA6 after surgery were statistically different between the 2 groups (P = .004 and .019, respectively).

CONCLUSIONS

Opening the middle meatus may further improve the subjective perception of patency on the basis of septoplasty.

Nasal Irrigation Delivery in Three Post-FESS Models From a Squeeze-bottle Using CFD

Purpose

Nasal saline irrigation is highly recommended in patients following functional endoscopic sinus surgery (FESS) to aid the postoperative recovery. Post-FESS patients have significantly altered anatomy leading to markedly different flow dynamics from those found in pre-op or non-diseased airways, resulting in unknown flow dynamics.

Methods

This work investigated how the liquid stream disperses through altered nasal cavities following surgery using Computational Fluid Dynamics (CFD). A realistic squeeze profile was determined from physical experiments with a 27-year-old male using a squeeze bottle with load sensors. The administration technique involved a head tilt of 45-degrees forward to represent a head position over a sink. After the irrigation event that lasted 4.5 s, the simulation continued for an additional 1.5 s, with the head orientation returning to an upright position.

Results

The results demonstrated that a large maxillary sinus ostium on the right side allows saline penetration into this sinus. The increased volume of saline entering the maxillary sinus limits the saline volume available to the rest of the sinonasal cavity and reduces the surface coverage of the other paranasal sinuses. The average wall shear stress was higher on the right side than on the other side for two patients. The results also revealed that head position alters the sinuses’ saline residual, especially the frontal sinuses.

Conclusion

While greater access to sinuses is achieved through FESS surgery, patients without a nasal septum limits posterior sinus penetration due to the liquid crossing over to the contralateral cavity and exiting the nasal cavity early.

Surgery for nasal polyposis in cystic fibrosis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To determine the effects of sinus surgery alone or in combination with medical treatment (non‐surgical) compared to medical treatment (non‐surgical) alone on both nasal and pulmonary function in people with cystic fibrosis diagnosed with CRS with nasal polyposis. Further, to evaluate the impact of sinus surgery (with or without medical treatment) on hospitalization rates, use of antibiotics and pulmonary exacerbation rates.

Xenon-Enhanced Dynamic Dual-Energy CT Is Able to Quantify Sinus Ventilation Using Laminar and Pulsating Air-/Gas Flow Before and After Surgery: A Pilot Study in a Cadaver Model

Background

Chronic rhinosinusitis is a common disease with a significant impact on the quality of life. Topical drug delivery to the paranasal sinuses is not efficient to prevent sinus surgery or expensive biologic treatment in a lot of cases as the affected mucosa is not reached. More efficient approaches for topical drug delivery are, therefore, necessary. In the current study, dual-energy CT (DECT) imaging was used to examine sinus ventilation before and after sinus surgery using a pulsating xenon gas ventilator in a cadaver head.

Methods

Xenon gas was administered to the nasal cavity of a cadaver head with a laminar flow of 7 L/min and with pulsating xenon-flow (45 Hz frequency, 25 mbar amplitude). Nasal cavity and paranasal sinuses were imaged by DECT. This procedure was repeated after functional endoscopic sinus surgery (FESS). Based on the enhancement levels in the different sinuses, regional xenon concentrations were calculated.

Results

Xenon-related enhancement could not be detected in most of the sinuses during laminar gas flow. By superimposing laminar flow with pulsation, DECT imaging revealed a xenon wash-in and wash-out in the sinuses. After FESS, xenon enhancement was immediately seen in all sinuses and reached higher concentrations than before surgery.

Conclusion

Xenon-enhanced DECT can be used to visualize and quantify sinus ventilation. Pulsating air-/gas flow was superior to laminar flow for the administration of xenon to the paranasal sinuses. FESS leads to successful ventilation of all paranasal sinuses.

Comparison of Sinus Deposition from an Aqueous Nasal Spray and Pressurised MDI in a Post-Endoscopic Sinus Surgery Nasal Replica

Background

Optimising intranasal distribution and retention of topical therapy is essential for effectively managing patients with chronic rhinosinusitis, including those that have had functional endoscopic sinus surgery (FESS). This study presents a new technique for quantifying in vitro experiments of fluticasone propionate deposition within the sinuses of a 3D-printed model from a post-FESS patient.

Methods

Circular filter papers were placed on the sinus surfaces of the model. Deposition of fluticasone on the filter paper was quantified using high-performance liquid chromatography (HPLC) assay-based techniques. The deposition patterns of two nasal drug delivery devices, an aqueous nasal spray (Flixonase) and metered dose inhaler (Flixotide), were compared. The effects of airflow (0 L/min vs. 12 L/min) and administration angle (30° vs. and 45°) were evaluated.

Results

Inhaled airflow made little difference to sinus deposition for either device. A 45° administration angle improved frontal sinus deposition with the nasal spray and both ethmoidal and sphenoidal deposition with the inhaler. The inhaler provided significantly better deposition within the ethmoid sinuses (8.5x) and within the maxillary sinuses (3.9x) compared with the nasal spray under the same conditions.

Conclusion

In the post-FESS model analysed, the inhaler produced better sinus deposition overall compared with the nasal spray. The techniques described can be used and adapted for in vitro performance testing of different drug formulations and intranasal devices under different experimental conditions. They can also help validate computational fluid dynamics modelling and in vivo studies.

Rhinology in review: from COVID-19 to biologicals

We look back at the end of what soon will be seen as an historic year, from COVID-19 to real-world introduction of biologicals influencing the life of our patients. This review describes the important findings in Rhinology over the past year. A large body of evidence now demonstrates loss of sense of smell to be one of the most common symptoms of COVID-19 infection; a meta-analysis of 3563 patients found the mean prevalence of self-reported loss to be 47%. A number of studies have now shown long-term reduced loss of smell and parosmia. Given the high numbers of people affected by COVID-19, even with the best reported recovery rates, a significant number worldwide will be left with severe olfactory dysfunction. The most prevalent causes for olfactory dysfunction, besides COVID-19 and upper respiratory tract infections in general, are trauma and CRSwNP. For these CRSwNP patients a bright future seems to be starting with the development of treatment with biologics. This year the Nobel prize in Medicine 2021 was awarded jointly to David Julius and Ardem Patapoutian for their discoveries of receptors for temperature and touch which has greatly enhanced our understanding of nasal hyperreactivity and understanding of intranasal trigeminal function. Finally, a new definition of chronic rhinitis has been proposed in the last year and we have seen many papers emphasizing the importance of endotyping patients in chronic rhinitis and rhinosinusitis in order to optimise treatment effect.

Inhalation and deposition of spherical and pollen particles after middle turbinate resection in a human nasal cavity

Middle turbinate resection significantly alters the anatomy and redistributes the inhaled air. The superior half of the main nasal cavity is opened up, increasing accessibility to the region. This is expected to increase inhalation dosimetry to the region during exposure to airborne particles. This study investigated the influence of middle turbinate resection on the deposition of inhaled pollutants that cover spherical and non-spherical particles (e.g. pollen). A computational model of the nasal cavity from CT scans, and its corresponding post-operative model with virtual surgery performed was created. Two constant flow rates of 5 L/min, and 15 L/min were simulated under a laminar flow field. Inhaled particles including pollen (non-spherical), and a spherical particle with reference density of 1000 kg/m³ were introduced in the surrounding atmosphere. The effect of surgery was most prominent in the less patent cavity side, since the change in anatomy was proportionally greater relative to the original airway space. The left cavity produced an increase in particle deposition at a flow rate of 15 L/min. The main particle deposition mechanisms were inertial impaction, and to a lesser degree gravitational sedimentation. The results are expected to provide insight into inhalation efficiency of different aerosol types, and the likelihood of deposition in different nasal cavity surfaces.

Numerical simulation of unsteady airflow in a nasal cavity for various sizes of maxillary sinus opening in a virtual endoscopic surgery

Functional endoscopic sinus surgery (FESS) is performed to treat sinusitis when treatment with medication fails. In the present study, three different virtual maxillary sinus endoscopic surgeries were performed on a realistic 3-D computational model of the nasal cavity of an adult male under the supervision of a specialist. They included only uncinectomy, uncinectomy + 8mm Middle Meatal Antrostomy (MMA) and uncinectomy + 18 mm MMA. Simulations were performed for two human activity respiratory rates, including rest and moderate activities, and effects of different surgeries and respiratory rates on maxillary sinus were investigated. It was found that after endoscopic sinus surgery, the volume of air entering the maxillary sinus increased significantly, and as the size of the MMA increased, or the breathing condition changed from rest to moderate activity, this volume of air increased. For the rest condition, on average for both nasal passages, for uncinectomy +8 mm MMA, around 15 % of the inhaled flow and 7 % of the exhaled flow enter the maxillary sinuses. For uncinectomy +18 mm MMA, these values are 24 % and 14 %, respectively. As human activity increases, a lower portion of inhaled and exhaled air enters the maxillary sinuses. For the moderate activity condition, on average for both nasal passages, for uncinectomy +8 mm MMA, around 11 % of the inhaled flow and 6 % of the exhaled flow rate enters the maxillary sinus. For uncinectomy +18 mm MMA, these values are 16 % and 8%, respectively. Comparing the steady and unsteady simulation results showed that the quasi-steady flow assumption could predict the flow in the maxillary sinus and the volume of air entering the sinuses, almost at any moment of respiration, with acceptable accuracy.