Sinus irrigations before and after surgery-Visualization through computational fluid dynamics simulations

Assessing adequacy of surgical extent in CRSwNP: The Completion of Surgery Index

BACKGROUND

Endoscopic sinus surgery (ESS) maximized for topical steroid irrigations is highly effective for polyp disease. As extent and completeness of ESS varies widely by situation and practitioner, it is important to understand when revision surgery is appropriate, particularly in the era of biologic treatments.

METHODS

A Completion of Surgery Index (CoSI) was developed to assess operative changes in polyp patients using pre- and postoperative computed tomography scans. The CoSI was then applied and tested in a cohort of consecutive chronic rhinosinusitis with nasal polyps (CRSwNP) patients, and examined within the context of quality-of-life improvements.

RESULTS

The CoSI assesses surgical extent on a scale of 0-100, with 100 representing the highest possible degree of surgical completeness. Among 100 consecutive CRSwNP patients undergoing ESS in 2021 with postoperative topical steroid irrigations, including 75 revision surgeries, SNOT-22 scores improved at 6 months postoperatively, with durable and consistent improvement at 24 months (p < 0.001). Preoperative CoSI scores in revision surgery patients were 49.4 ± 26.0, improving to 91.0 ± 8.1 postoperatively. SNOT-22 scores for primary ESS patients and patients with a preoperative CoSI score of less than 70 improved by 26.4 and 28.1 points, respectively, in contrast to patients with a preoperative CoSI of 70 or greater (14.1 points, p = 0.029).

CONCLUSIONS

It is important to define extent of surgery in CRSwNP to stratify postsurgical patients based on likelihood to benefit from revision surgery or alternative medications. The CoSI can be utilized to identify patients who are likely to improve significantly with revision surgical intervention.

Optimized gravity-driven intranasal drop administration delivers significant doses to the ostiomeatal complex and maxillary sinus

Chronic and allergic rhinosinusitis impacts approximately 12% of the global population. Challenges in rhinosinusitis treatment include paranasal sinus inaccessibility and variability in delivery efficiency among individuals. This study addresses these challenges of drug delivery by developing a high-efficiency, low-variability protocol for nasal drop delivery to the ostiomeatal complex (OMC) and maxillary sinus. Patient-specific nasal casts were dissected to reveal the configurations of conchae and meatus, providing insights into anatomical features amendable for sinus delivery. Fluorescent dye-enhanced videos visualized the dynamic liquid translocation in transparent nasal casts, allowing real-time assessment and quick adjustment to delivery parameters. Dosimetry to the OMC and maxillary sinus were quantified as drop count and mass using a precision scale. Key delivery factors, including the device type, formulation, and head-chin orientation, were systematically investigated in a cohort of ten nasal casts. Results show that both the squeeze bottle and soft-mist nasal pump yielded notably low doses to the OMC with high variability, and no dose from these two devices was detected within the maxillary sinuses. In contrast, the proposed approach, which included a curved nozzle surpassing the nasal valve and leveraged gravity-driven liquid translocation along the lateral nasal wall, delivered significant doses to the OMC and maxillary sinus. Iterative experimentations identified the optimal head tilt to be 40° and chin tilt to be° from the lateral recumbent position. Statistical analyses established the drop count required for effective OMC/sinus delivery. The proposed delivery protocol holds the potential to enhance chronic rhinosinusitis treatment outcomes with low variability. The dual role of nasal anatomy in posing challenges and offering opportunities highlights the need for future investigations using diverse formulations in a larger cohort of nasal models.

CT analysis of frontal recess air cell and fluid dynamics simulation of frontal sinus in people with different frontal sinus development after Draf1-3 surgery

OBJECTIVE

To explore the effects of Draf1-3 on frontal sinus airflow and frontal sinus irrigation in people with different frontal sinus development METHODS: The development of the frontal sinus and the distribution of the frontal recess cells were evaluated by CT scan in 150 adults (300 sides). The airflow changes into the frontal sinus and frontal recess after Draf were analyzed by Fluent software under a steady state and quiet inspiratory state. Nasal irrigation after Draf in adults with well-developed frontal sinus was simulated using 120 mL saline at a rate of 12 mL/s in a position at 45° to observe the changes in transient flow distribution.

RESULTS

The moderately developed type of the frontal sinus was the most common. The airflow patterns in the frontal sinus and frontal recess in the moderate development group were laminar, while several large vortexes were formed between the frontal sinus and frontal recess in the well-development group. The Draf exerted more significant effects on the patterns, pressure, and velocity of the airflow in the frontal sinus and frontal recess in the well development group than in the moderate development group. The volume fraction of saline in the frontal sinus increased significantly from Draf1 to Draf3, and the time required for a complete infiltration of saline in the frontal sinus mucosa was significantly reduced.

CONCLUSIONS

Draf1-3 has different effects on the airflow field of the frontal sinus with different developmental types; and Draf1-3 can significantly improve the postoperative flushing of the frontal sinus.

[Effects of different surgical methods on the application of topical hormones in the sinus after operation]

Chronic rhinosinusitis （CRS） is a common chronic inflammatory disease in otorhinolaryngology, in which eosinophilic chronic rhinosinusitis with nasal polyps represents the difficult-to-treat chronic rhinosinusitis （DTCRS） with poor prognosis. DTCRS has a poor prognosis, which seriously affects people's physical and mental health, and is treated with various means, including medication, biotherapy and surgery. In recent years, endoscopic sinus surgery and postoperative local administration of nasal hormones as one of its treatment methods have achieved good results. In this paper, we review the relevant literature at home and abroad and give an overview for the treatment means of surgery, focusing on the effect of endoscopic sinus surgery on the distributable range of postoperative nasal glucocorticosteroids in patients with DTCRS, and then on the postoperative efficacy of the treatment, with a view to providing a reference for the clinical treatment of DTCRS.

Necessary Factors for Efficient Frontal Sinus Irrigation After Endoscopic Sinus Surgery: A Systematic Review

OBJECTIVE

The frontal sinus remains a challenging site for irrigation due to its position relative to the nostril and ethmoid sinus. This study aims to summarize the necessary factors for efficient irrigation of the frontal sinus after endoscopic sinus surgery (ESS) among patients with chronic rhinosinusitis (CRS).

METHODS

Using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic literature review was conducted on PubMed, Scopus, and Cochrane databases to identify studies assessing the effect of frontal sinus irrigation in patients with CRS, cadaver models, or 3D-printed models of the sinonasal cavity after ESS.

RESULTS

Of the initial 206 abstracts reviewed, 18 full-text articles were included. The degree of the frontal sinus ostium opening after ESS was found to be associated with the efficacy of frontal sinus irrigation. More extensive frontal sinus surgeries tended to increase frontal sinus penetration. A Draf IIA procedure was identified as the minimum standard to achieve sufficient irrigation in the frontal sinus. Due to decreased backpressure in the nasal passage, increasing septectomy in Draf III did not significantly improve irrigation delivery. Squeeze bottles achieved significantly higher irrigation flow in the frontal sinus than syringes and pulsating devices. Large-volume irrigation devices provided better irrigation for the frontal sinus by entering or flushing the entire frontal sinus. The head position influenced the frontal sinus irrigation by altering the ostia position relative to fluid flow and vertical height of the frontal sinus during irrigation. While the vertex down head position was likely to enhance frontal sinus irrigation, the comfort of the head position and patient compliance should be considered.

CONCLUSION

Elements for optimization of frontal sinus irrigation are a minimum of a Draf IlA procedure for frontal sinus dissection, use of large-volume irrigation, and vertex down head positioning. Developing comfortable head positions with high frontal sinus irrigation efficiency would increase patient compliance and improve outcomes.

LEVEL OF EVIDENCE

NA.

Surgical management of rhinosinusitis for the allergist-immunologist

Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease characterized by inflammation of the sinus, with or without nasal passage inflammation, occurring for more than 12 weeks at a time. CRS has historically been classified in 2 categories: CRS without nasal polyps or CRS with nasal polyps (25%-30% of cases). The mainstay of treatment for CRS with or without nasal polyps is medical management, and options may include a combination of saline irrigation, nasal steroids, allergy medications, antibiotics, oral steroids, and treatment with targeted monoclonal antibodies. Unfortunately, up to 60% of patents report symptoms refractory to maximal medical therapy. As such, a combined approach of surgery and medical therapy may be offered. Endoscopic sinus surgery for CRS is approached in a stepwise fashion, ranging from the simplest technique, such as polyp removal, to more expanded approaches that open the paranasal sinuses and allow gravity-dependent drainage. This review article provides a review and in-depth explanation of various surgical approaches for CRS, including the indications, techniques, and respective outcomes for each one.

Choosing nasal devices: a dilemma in clinical practice

BACKGROUND AND AIM

Upper airway diseases are frequent and recognize different etiopathogenetic mechanisms, including infection, inflammation, and allergy. Therefore, topical treatments are preferable in comparison with systemic medications. Several delivery devices are available on the market, including nasal drops, syringes, sprays, nebulizers, and douches. However, it is clinically relevant to know the better way to use it.

METHODS

The present experience compared five different devices that were tested: i) a nasal dropper, ii) a standard nasal spray device, iii) a mucosal atomization device with a nozzle tip, iv) a nebulizer device, and v) a nasal douche. Saline solution with methylene blue was the marker to evaluate the intranasal distribution.

RESULTS

The findings showed an apparent difference in area distribution among these delivery devices. Conclusion The present experience showed that doctors should choose the most appropriate device for the current disease in clinical practice.

Computational investigation of nasal surface coverage from squeeze bottle and Neti Pot saline irrigation flow

BACKGROUND AND OBJECTIVE

Nasal saline irrigation is a common therapy for inflammatory nasal and paranasal disease or for managing post nasal and sinus surgery recovery. Two common irrigation devices include the netipot and squeeze bottles, where anecdotally, these devices alleviate congestion, facial pain, and pressure. However, a quantitative evaluation of these devices' performance and the fluid dynamics responsible for the irrigation distribution through the nose is lacking. This study tracked the liquid surface coverage and wall shear stresses during nasal saline irrigation produced from a Neti Pot and squeeze bottle.

METHODS

This study used transient computational fluid dynamics (CFD) simulations to investigate the saline irrigation flow field in a subject-specific sinonasal model. The computational nasal cavity model was constructed from a high-resolution computed tomography scan (CT). The irrigation procedure applied a head position tilted at 90° forward using an 80 ml squeeze bottle and 120 ml Neti Pot.

RESULTS

The results from a single sinonasal model demonstrated that the Neti Pot irrigation was more effective in delivering saline solution to the nasal cavity on the contralateral side of irrigation due to typically larger volumes but at the expense of reduced flow and shearing rates, as the flow entered under gravitational forces. The squeeze bottle irrigation provided greater surface coverage on the side of irrigation.

CONCLUSIONS

The results from the single patient model, demonstrated the Neti Pot increased surface coverage in the paranasal sinuses. Reducing the jet diameter may aid the direct targeting of a specific region at the side of irrigation by preventing the impingement of the jet to the nasal passage surface and redirection of the flow. Evaluating this performance across a wider cohort of patients can strengthen the findings.

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.

Cilia Stimulatory and Antibacterial Activities of T2R Bitter Taste Receptor Agonist Diphenhydramine: Insights into Repurposing Bitter Drugs for Nasal Infections

T2R bitter taste receptors in airway motile cilia increase ciliary beat frequency (CBF) and nitric oxide (NO) production. Polymorphisms in some T2Rs are linked to disease outcomes in chronic rhinosinusitis (CRS) and cystic fibrosis (CF). We examined the expression of cilia T2Rs during the differentiation of human nasal epithelial cells grown at air–liquid interface (ALI). The T2R expression increased with differentiation but did not vary between CF and non-CF cultures. Treatment with Pseudomonas aeruginosa flagellin decreased the expression of diphenhydramine-responsive T2R14 and 40, among others. Diphenhydramine increased both NO production, measured by fluorescent dye DAF-FM, and CBF, measured via high-speed imaging. Increases in CBF were disrupted after flagellin treatment. Diphenhydramine impaired the growth of lab and clinical strains of P. aeruginosa, a major pathogen in CF and CF-related CRS. Diphenhydramine impaired biofilm formation of P. aeruginosa, measured via crystal violet staining, as well as the surface attachment of P. aeruginosa to CF airway epithelial cells, measured using colony-forming unit counting. Because the T2R agonist diphenhydramine increases NO production and CBF while also decreasing bacterial growth and biofilm production, diphenhydramine-derived compounds may have potential clinical usefulness in CF-related CRS as a topical therapy. However, utilizing T2R agonists as therapeutics within the context of P. aeruginosa infection may require co-treatment with anti-inflammatories to enhance T2R expression.

Efficacy of Povidone-Iodine Nasal Irrigation Solution After Sinonasal Surgery: A Randomized Controlled Study

OBJECTIVES/HYPOTHESIS

To evaluate the efficacy of postoperative nasal irrigation with povidone-iodine (PVP-I) solution in patients undergoing sinonasal surgery.

STUDY DESIGN

Single-blind, randomized controlled study.

METHODS

This is a prospective, single-blind, randomized controlled study. Patients with chronic rhinosinusitis (CRS) and hypertrophic inferior turbinates who underwent endoscopic sinus surgery (ESS) and inferior turbinate reduction were enrolled in the study. Patients were evaluated using the Taiwanese version of the 22-item Sino-Nasal Outcome Test (TWSNOT-22), rhinomanometry, endoscopic examination, and bacterial cultures. One week after the operation, patients were randomly assigned to either a 0.1% PVP-I nasal irrigation group or a control (normal saline) irrigation group. We then compared the two groups' results to illustrate the effects of nasal irrigation with PVP-I solution following sinonasal surgery.

RESULTS

Of the 55 patients that completed the study, 27 patients were in the PVP-I group and 28 were in the control group. In both groups, the TWSNOT-22 scores, Lund-Kennedy endoscopic scores, and total nasal resistance (TNR) all revealed significant improvements at 3 months postoperatively compared with preoperative measurements (all, P < .05). However, there were no significant differences between the two groups in TWSNOT-22, endoscopic, or TNR scores 3 months after the operation (all, P > .05).

CONCLUSIONS

A dilute 0.1% PVP-I nasal irrigation as a postoperative care modality after sinonasal surgery did not provide additional benefit compared with normal saline irrigation.

LEVEL OF EVIDENCE

2 Laryngoscope, 2021.

Computational fluid dynamic modelling of maxillary sinus irrigation after maxillary antrostomy and modified endoscopic medial maxillectomy

OBJECTIVE

For recalcitrant chronic maxillary sinusitis, modified endoscopic medial maxillectomy has been shown to be clinically beneficial after failed maxillary antrostomy as endoscopic medial maxillectomy may offer improved topical therapy delivery. This study compared irrigation patterns after maxillary antrostomy versus endoscopic medial maxillectomy, using computational fluid dynamic modelling.

CASE REPORT

A 54-year-old female with left chronic maxillary sinusitis underwent maxillary antrostomy, followed by endoscopic medial maxillectomy. Computational fluid dynamic models were created after each surgery and used to simulate irrigations.

RESULTS

After maxillary antrostomy, irrigation penetrated the maxillary sinus at 0.5 seconds, initially contacting the posterior wall. The maxillary sinus was half-filled at 2 seconds, and completely filled at 4 seconds. After endoscopic medial maxillectomy, irrigation penetrated the maxillary sinus at 0.5 seconds and immediately contacted all maxillary sinus walls. The maxillary sinus was completely filled by 2 seconds.

CONCLUSION

Computational fluid dynamic modelling demonstrated that endoscopic medial maxillectomy allowed faster, more forceful irrigation to all maxillary sinus walls compared with maxillary antrostomy.

Effect of surgery, delivery device and head position on sinus irrigant penetration in a cadaver model

OBJECTIVE

The extent of surgery, the type of device used and head position may influence nasal irrigation. The aim of this study was to determine the effectiveness of topical irrigant delivery to the paranasal sinuses according to these factors.

METHOD

Four cadaveric heads underwent four stepwise endoscopic dissections. Irrigations were evaluated after every stage using different delivery devices (squeeze-bottle, gravity-dependent device and syringe) in two head positions (nose-to-sink and vertex down). Irrigant penetration into each sinus was estimated using a four-point scale.

RESULTS

A significant positive effect of surgery was demonstrated for each sinus as well as for the delivery device. High-volume irrigant devices are more effective, and the head position plays a significant role in irrigant distribution to the frontal sinus.

CONCLUSION

This study further confirms the efficacy of high-volume irrigant devices. A vertex down position during the irrigation could improve delivery to the frontal sinus, and the widening of the ostia increases irrigant access to the sinuses.

International consensus statement on allergy and rhinology: rhinosinusitis 2021

I.

EXECUTIVE SUMMARY

BACKGROUND: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR-RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR-RS-2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence-based findings of the document.

METHODS

ICAR-RS presents over 180 topics in the forms of evidence-based reviews with recommendations (EBRRs), evidence-based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary.

RESULTS

ICAR-RS-2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence-based management algorithm is provided.

CONCLUSION

This ICAR-RS-2021 executive summary provides a compilation of the evidence-based recommendations for medical and surgical treatment of the most common forms of RS.

Use of Off-Label Nasal Steroid Irrigations in Long-Term Management of Chronic Rhinosinusitis

OBJECTIVE

Chronic rhinosinusitis (CRS) is an inflammatory disease of the paranasal sinuses and mucosa. Topical nasal corticosteroids are a mainstay treatment for CRS by reducing sinonasal inflammation and improving mucociliary clearance. However, topical corticosteroids have limited paranasal distribution, and patient response to treatment has been variable in randomized controlled trials (RCT). Thus, there is significant interest in evaluating the efficacy of nasal steroids delivered by nasal irrigation in order to improve penetration and absorption of topical steroids into the sinonasal mucosa. In this review, we discuss the use of off-label nasal steroid irrigations in the management of CRS.

METHODS

A review of clinical trials evaluating the use of nasal steroid irrigations for CRS in the PubMed electronic database was performed.

RESULTS

Of the 12 clinical studies identified, 10 evaluated budesonide irrigations while the remaining 2 focused on mometasone. The overwhelming majority of studies for both budesonide and mometasone supported the use of nasal irrigations with corticosteroids over nasal corticosteroid sprays alone. However, the heterogeneity in study design, patient cohort, and volume of steroid irrigation limit the interpretations of these studies.

CONCLUSIONS

Nasal irrigation with corticosteroids is beneficial and safe for the treatment of CRS. Future RCTs controlling for type of surgical intervention, CRS pheno- and endo-type, as well as dosing and duration of nasal corticosteroid irrigations are warranted.

Neti pot irrigation volume filling simulation using anatomically accurate in-vivo nasal airway geometry

Nasal saline irrigation is frequently utilised in rhinosinusitis management, and after nasal and sinus surgery. Nasal saline irrigation improves mucociliary transport and assists inflammatory mediator and post-surgical debris removal. The aim of this study was to assess the influence different head positions, irrigation inflow nostril, and the nasal cycle have on Neti pot nasal saline volume filling within the nasal passages and maxillary sinuses. Computational fluid dynamics modelling using anatomically correct nasal geometry found only minor difference in nasal cavity volume filling with inflow from either side of the nose however both head position and inflow direction were both found to have a major influence on maxillary sinus volume filling. Computational modelling flow velocity results at the nasopharynx were validated using particle image velocimetry. It was also found that directing irrigation inflow into the patent side of the nose while in the head-back position achieved the highest volume filling of both maxillary sinuses.

Using 3D printed sinonasal models to visualize and optimize personalized sinonasal sinus irrigation strategies

BACKGROUND

Topical sinus irrigations (neti-pot, squeeze bottles) play a critical role in the management of sinonasal disease. However, due to intricate nasal anatomy, penetration of topical irrigations to targeted sinus regions may be highly variable, and difficult to objectively predict. Variables, including head positions, injection angles, flow rates, etc. may vary significantly depending on the individual's anatomy.

OBJECTIVE

The purpose of this study was to propose a novel idea: using a 3D printed model of sinonasal cavities to visualize and develop a patient-specific irrigation strategy.

METHODS

As a proof of concept, 3D replicas of one patient's sinonasal cavities pre- and post-surgery were printed with a Form2 SLA 3D printer based on their CT scans. The setup included rubber/silicon seals attached to the model's nostrils to create a watertight seal with the irrigation device and food color dye added for better visualization of irrigation results.

RESULTS

Irrigations were performed on the 3D models with various head positions, injection angles, and flow rates, and were successful to determine the optimal strategy to targeted sinuses. Significant differences were observed between different targeted sinuses and between pre and post-surgery models.

CONCLUSION

With more affordable 3D printing, this technology may potentially improve patient care and patient education, allowing clinicians and patients to develop a personalized irrigation strategy and have visual confirmation.

Sinus Irrigation Penetration After Proposed Modified Draf IIa Technique in a Side-to-Side Cadaveric Model

BACKGROUND

Endoscopic sinus surgery (ESS) is an effective intervention for patients with medically refractory chronic rhinosinusitis. Frontal sinusotomy is the most challenging part of ESS, with one of the key outcomes being access for topical irrigations.

OBJECTIVE

The purpose of this study is to compare irrigation penetration into the frontal sinus following Draf IIa versus modified Draf IIa frontal sinusotomy.

METHODS

Four fresh cadaver heads were used in this experiment. Draf IIa was performed on one side of each head and a modified Draf IIa on the contralateral side. This proposed modification consists of a Draf IIa combined with an agger nasi punch-out procedure and partial trimming of the vertical lamella of the middle turbinate back to the posterior table of the frontal sinus without drilling the beak. Each head was irrigated with methylene blue-dyed water and recorded by rigid endoscopy through an endonasal view (EV) of the frontal sinus and frontal trephination view (TV). Two blinded rhinologists scored the extent of staining (using an ordinal scale of 0 to 3) for each side. A case report where the modified Draf IIa was performed is also described.

RESULTS

After modified Draf IIa sinuosotomy, the mean score for the EV was 2.125 and for the TV was 2, versus 0.875 and 0.625 for traditional Draf IIa, respectively. There was a statistically significant increase for both EV (p = 0.019) and TV (p = 0.018) after modified Draf IIa.

CONCLUSION

In our cadaveric model, this procedural modification improved penetration of postoperative irrigations into the frontal sinus. This simple technique may be easily adapted into frontal ESS when indicated.

A Scholarly Review of the Safety and Efficacy of Intranasal Corticosteroids Preparations in the Treatment of Chronic Rhinosinusitis

OBJECTIVE

The purpose of this scholarly review is to present an update of the efficacy, safety, and distribution of intranasal corticosteroids (INCS) in the context of treatment for chronic rhinosinusitis (CRS).

MATERIALS AND METHODS

A literature review from 1999 to 2020 of MEDLINE, PubMed, and EMBASE databases was performed, using a comprehensive search strategy. Studies reporting on efficacy, safety, and distribution of all INCS formulations, both Food and Drug Administration (FDA) and non-FDA approved, were reviewed.

RESULTS AND CONCLUSIONS

High-level evidence publications and position papers support the role of INCS in medical treatment for CRS. Significant improvement in disease-specific and general quality of life measures is observed with all formulations of INCS. Overall, the use of both FDA and published non-FDA INCS appears to be safe. Several novel distribution devices might improve penetration to specific areas within the sinuses.

Positional Installation of Intranasal Corticosteroids in the Treatment of Chronic Rhinosinusitis: A Systematic Review of the Literature

OBJECTIVES

First-line treatment of chronic rhinosinusitis includes topical corticosteroids aimed at decreasing inflammation of sinonasal mucosa. No guidelines exist regarding the effect of head position during administration of corticosteroids. We hypothesize certain positions enhance delivery to the paranasal sinuses, with further improvement in delivery after sinus surgery.

METHODS

A systematic review of the literature was conducted using Medline Ovid, Embase, Scopus, and Cochrane databases. All studies evaluating intranasal medications administered in 2 or more head positions were included. Study population, head position(s), method/volume of delivery, and outcome metrics were recorded.

RESULTS

Twenty-four studies compared head positions and their role in distribution of intranasal medication. Of 12 papers studying surgically naive subjects, 6 found improvement in delivery to specific sinonasal regions (middle meatus; lateral, superior, or posterior nasal cavity) and/or symptomatic improvement, in the lying head back (LHB) or head down and forward (HDF) positions, but only 3 reached statistical significance. Of 12 papers studying surgically altered patients, 10 found delivery improved in the HDF, LHB, and head forward 45° or 90° positions. Of 5 studies of extended frontal sinus procedures (Draf IIb/III), a majority found distribution to the frontal sinus improved with the head forward 90° position. Patients found the HDF position most uncomfortable.

CONCLUSIONS

Studies found no statistically significant difference in distribution to unoperated sinuses among different head positions. A minority of studies supported the use of the LHB and HDF positions. This suggests that in surgically naive patients, intranasal corticosteroid delivery to sinonasal regions and/or symptomatic improvement may be best achieved with the sinuses positioned inferior to the delivery device. Surgery improved distribution to the paranasal sinuses regardless of head position, although tilting the head forward 90° was particularly effective in delivery to the frontal sinus after extended frontal sinus procedures.

Appropriate extent of surgery for aspirin-exacerbated respiratory disease

The current literature lacks strong guidelines regarding surgical management of patients with aspirin-exacerbated respiratory disease (AERD), who present with the clinical triad of chronic rhinosinusitis with nasal polyposis (CRSwNP), bronchial asthma, and aspirin/nonsteroidal anti-inflammatory drug intolerance. To further define the effectiveness of sinus surgery in treating AERD patients, this review article discusses current evidence regarding outcomes associated with more extensive surgery, the benefits of frontal sinus surgery on polyposis, and the role of Draf III intervention. Numerous studies suggest that Draf III frontal sinusotomy may be an efficacious early intervention due to increased neo-ostial patency and subsequent distribution of topical therapies. Future studies that further investigate the efficacy and safety of extensive surgery in AERD patients are warranted.

Aspirin-exacerbated respiratory disease: A review

OBJECTIVES

Aspirin-exacerbated respiratory disease (AERD) is a chronic respiratory condition characterized by a triad of symptoms: asthma, chronic rhinosinusitis with nasal polyposis, and a respiratory reaction to aspirin and other cyclooxygenase-1 inhibitors, also known as nonsteroidal anti-inflammatory drugs. The objective of this review is to provide otolaryngologists with an overview of the pathophysiology, diagnosis, and treatment of this under-recognized condition.

DATA SOURCES AND METHODS

Foundational papers on AERD were reviewed, focusing on the clinical otolaryngology and allergy/immunology literature and other high impact journals or trials.

RESULTS

AERD results from increased production of pro-inflammatory leukotrienes and a decrease in production of anti-inflammatory prostaglandins associated with the dysregulation of multiple enzymes influencing eicosanoid metabolism. Diagnosis hinges on a high index of suspicion, careful history, and confirmatory testing for all three elements. Treatments include endoscopic sinus surgery; topical, inhaled, or oral corticosteroids; aspirin desensitization; leukotriene modifying drugs; and the new class of biologics such as dupilumab.

CONCLUSION

AERD is an under-recognized disease associated with substantial patient-reported morbidity. We expect rapid progress in the pathophysiological understanding of this disease and available treatments in the coming decades.

LEVEL OF EVIDENCE

5.

Topical corticosteroid irrigations in chronic rhinosinusitis

BACKGROUND

Chronic rhinosinusitis (CRS) has previously been thought to occur secondary to infectious or obstructive etiologies. However, in recent years, primary CRS has been more discretely defined as diffuse airway inflammation, similar to asthma. Adequate medical and surgical therapy are needed to control the inflammation. Our purpose in this study was to evaluate the efficacy and safety of topical corticosteroid treatment.

METHODS

A focused literature review was conducted and we identified 11 original articles from the years 2013-2018 evaluating safety or efficacy of topical corticosteroid irrigations.

RESULTS

Eleven articles were identified. One study found significant benefit between corticosteroid irrigations versus corticosteroid sprays. Two studies found significant benefit between corticosteroid irrigations compared to saline irrigations while two did not. One study found significant improvement in certain patient populations when using corticosteroid irrigations compared to no irrigation. Five studies found no significant increase in risk of adverse side effects with the use of topical corticosteroids.

CONCLUSION

Many factors are associated with efficacious and adequate treatment of primary CRS. The pathology must be correctly diagnosed and be inflammatory in nature. The treatment paradigm should include wide and complete endoscopic sinus surgery for the adequate delivery of topical therapy. Topical therapy should be delivered in large-volume, low-pressure devices with adequate dosing. Although there is some systemic absorption, multiple studies have demonstrated that long-term, daily use of topical corticosteroids does not increase intraocular pressure, suppress the hypothalamic-pituitary-adrenal axis, or increase the risk of subcapsular cataracts. Therefore, topical corticosteroid irrigations should be considered a part of first-line medical treatment in postsurgical CRS patients.

Cadaveric Assessment of the Efficacy of Sinus Irrigation After Staged Clearance of the Medial Maxillary Wall

Background

Nasal irrigation is a significant component of effective medical management in patients with chronic rhinosinusitis (CRS). Irrigations facilitate distribution of topical medical therapies to affected mucosal surfaces and lavage of hypersecretory mucin and inflammatory products.

Objective

To compare the effectiveness of cadaveric nasal irrigation distribution and force following different surgical techniques commonly used to open the maxillary sinus.

Methods

Fresh human cadaver heads were dissected sequentially with uncinectomy, maxillary antrostomy, endoscopic maxillary mega-antrostomy, and modified endoscopic medial maxillectomy. After each surgical technique was performed, the corresponding nasal cavity was irrigated with 240 mL irrigation bottles containing 1/1000 10% fluroscein-labeled free water. A nasal endoscope passed through the canine fossa into a fixed position in the maxillary sinus recorded the extent of sinus irrigation. These videos then underwent blinded assessment by 2 observers assessing for irrigation sinus penetration (scored as 0–4) and force (0–2). Ordinal correlation scores were assessed using Kendall’s tau-B.

Results

A total of 17 sinuses (age 53.4 ± 12.6, 36.4% female) were assessed. There was a statistically significant positive correlation between increasing extent of maxillary sinus dissection and both sinus penetration and force as assessed by both observers (Kendall’s tau-B P < .0001).

Conclusion

Increasing the extent of surgical dissection appears to improve penetration and force of the nasal irrigation into the maxillary sinus. This study suggests that while a standard maxillary antrostomy may be sufficient to achieve good topical therapy distribution, more extensive surgery such as a modified medial maxillectomy may be required for sufficient force of sinus lavage.

Impact of Draf III, Draf IIb, and Draf IIa frontal sinus surgery on nasal irrigation distribution

BACKGROUND

Delivery of topical pharmacotherapy to the paranasal sinuses remains integral to the management of chronic rhinosinusitis. The frontal sinus remains a difficult access site for irrigations, often limited by its position relative to the nostril and ethmoid sinus. In view of the previous demonstration of improved frontal sinus irrigation with Draf III vs Draf IIa, in this work we sought to evaluate topical access of Draf IIb relative to Draf IIa and Draf III modification of the frontal sinus outflow tract.

METHODS

Unfixed human cadaver heads were dissected using Draf IIa, Draf IIb, and Draf III frontal sinusotomies. Draf IIa, Draf IIb, and Draf III frontal sinusotomies were performed in progressive sequence on each cadaver head. Nasal irrigation fluid access to the frontal sinus was tested after each successive frontal sinus intervention. Irrigations were performed using Frankfort horizontal and vertex positioning. Blinded reviewers were then asked to evaluate nasal irrigation access based on an ordinal scale.

RESULTS

Eight cadaveric specimens (age, 78 ± 12.3 years; 62.5% female) were assessed. The greatest distribution scores were recorded by Draf III, then IIb, and then IIa (90.7% vs 81.3% vs 50.1%; p < 0.001). Similarly, the rate of lavage was greatest with Draf III (50% vs 12.5% vs 12.5%). Vertex positioning and increasing volume trended toward improved distribution but did not reach statistical significance.

CONCLUSION

Adequate delivery of topical therapy to the paranasal sinuses by nasal irrigation remains critical in the postoperative state. Although increasing the dimensions of the frontal recess improves nasal irrigation delivery, the Draf III procedure provides the optimal delivery of pharmacotherapy in those with frontal sinus disease.

Characterization of nasal irrigation flow from a squeeze bottle using computational fluid dynamics

BACKGROUND

Nasal saline irrigation has become standard of care in various sinonasal conditions, including allergic and nonallergic rhinitis, chronic rhinosinusitis, and in the postoperative patient. Evidence regarding the mechanisms and dynamics of liquid flow through the sinonasal cavity remains limited due to inadequate experimental models (cadaveric, 3-dimensional [3D] printed, imaging of labeled dyes and radioisotopes). We aimed to develop a computational fluid dynamics (CFD) model of nasal irrigation to demonstrate sinonasal surface coverage, residence times across the mucosal surfaces, and shearing force of irrigation.

METHODS

A nasal cavity geometry derived from high-resolution paranasal sinus computed tomography (CT) scans of a healthy, unoperated, 25-year-old patient was created. CFD analysis was performed to assess the distribution of nasal irrigation from a tapered nozzle bottle at a forward head-tilt position of 45 degrees with a 2-second burst at 35 mL/second.

RESULTS

The model demonstrates nasal irrigation from ipsilateral to contralateral with precise measures of velocity, pressure, wall shear stress, and mapping of surface coverage and residence times at specific locations and times. The nasal cavity experiences almost complete coverage of irrigation, while overflow from the nasal cavity facilitates moderate coverage of the ipsilateral maxillary (40%) and anterior ethmoid sinuses (30%). Negligible coverage of the sphenoid and frontal sinuses was noted.

CONCLUSION

Detailed physical mechanisms of liquid irrigation injected from a commonly used squeeze bottle were shown. Ipsilateral maxillary and ethmoid sinus penetration are primarily due to overflow rather than direct jet entry, confirming the recommendation of larger volumes of irrigation to "flood" the sinus ostia.

Nasal saline irrigation - A review of current anatomical, clinical and computational modelling approaches

Nasal saline irrigation is frequently utilised in allergic rhinitis and rhinosinusitis management, and after nasal and sinus surgery. Anatomical modelling, clinical and computational studies guide treatment optimisation. This review offers a comprehensive summary of the modelling methodologies used in previous nasal irrigation studies by undertaking a systematic analysis of anatomical, clinical and computational investigations that assessed nasal saline irrigation using Medline, EMBASE, and Cochrane Review databases. Both procedural and assessment methods were reviewed. It was found that all twenty-four publications reviewed did not discuss the influence of the nasal cycle on internasal geometry and nasal resistance. Cadaver studies misrepresent in vivo nasal geometry. Irrigation pressure and shear forces, which could influence mucociliary transport and postoperative cleaning, were not evaluated. Previous studies focus on irrigation coverage and have not considered the nasal cycle which influences unilateral nasal resistance and thus pressure/ flow relationships and may also increase nasal air-locking. New computational fluid dynamic models could better inform nasal irrigation clinical practice.

In silico approaches to respiratory nasal flows: A review

The engineering discipline of in silico fluid dynamics delivers quantitative information on airflow behaviour in the nasal regions with unprecedented detail, often beyond the reach of traditional experiments. The ability to provide visualisation and analysis of flow properties such as velocity and pressure fields, as well as wall shear stress, dynamically during the respiratory cycle may give significant insight to clinicians. Yet, there remains ongoing challenges to advance the state-of-the-art further, including for example the lack of comprehensive CFD modelling on varied cohorts of patients. The present article embodies a review of previous and current in silico approaches to simulating nasal airflows. The review discusses specific modelling techniques required to accommodate physiologically- and clinically-relevant findings. It also provides a critical summary of the reported results in the literature followed by an outlook on the challenges and topics anticipated to drive research into the future.

Computational fluid dynamics simulation to compare large volume irrigation and continuous spraying during nasal irrigation

BACKGROUND

Nasal irrigation is now widely recognized as a treatment for chronic rhinosinusitis and during the postoperative period. However, there are no guidelines for performing irrigation. This study used computational fluid dynamics (CFD) simulation objective physical parameters to optimize and increase the efficiency of nasal irrigation and to compare large-volume, manual, and gravity pressure irrigation vs small-volume continuous spraying.

METHODS

A 3-dimensional (3D) sinonasal model was constructed from a healthy adult high-resolution computed tomography (CT) scan. The 3D nasal model was constructed using a tetrahedral and hex-dominant mesh grid with TGRID™ 16 (ANSYS Inc., Villeurbanne, France) software. A structured hex mesh was created inside the domain using the Hexcore meshing method. The final mesh had a total of 9.6 × 10⁶ cells with an average size of 0.29 mm³ , or an average volume of 2.42 × 10^-2 mm³ . Navier-Stokes equations were resolved with the standard k - ε  model.

RESULTS

Large-volume irrigation (15 mL/s) covered all zones (136 to 310 cm² ) rapidly with strong shear stress and prolonged contact time (310 mPa 3.26 seconds for gravity mode and 280 mPa 3.35 seconds for manual pressure mode). Continuous spraying (3 mL/second) covered all areas (76 to 310 cm² ) but with far less volume, more slowly, with low shear stress (50 mPa), and with shorter contact time (1.84 seconds). The surface wetted by time in contact was 135.4, 113.9, and 46.6 cm² for gravity, manual pressure mode, and continuous spraying, respectively.

CONCLUSION

CFD simulation visualizes the circulation of water during nasal irrigation and makes it possible to determine objective parameters to decide which mode of irrigation may be used.

Effects of sphenoid surgery on nasal irrigation delivery

BACKGROUND

Nasal irrigation is an important component of medical management in chronic rhinosinusitis. Nasal irrigations facilitate topical medication of therapies and lavage of mucin. In this study we aim to compare the influence of increasing surgical sphenoid openings on the distribution, force, and clearance of nasal irrigations.

METHODS

A study was performed on fresh-frozen adult cadaver heads. The surgical ostium was modified on one side via a simple sphenoidotomy, a sphenoid sinusectomy (type 1), and sphenoid sinusectomy (type 3a). The nasal cavity was irrigated using a 240-mL squeeze bottle with 0.1% fluoroscein. An endoscope passed through the contralateral side through the sphenoid septum recorded the irrigation. Videos were recorded and blindly assessed. The distribution was defined as either no irrigation, less than one third of the sinus, less than or equal to two thirds of the sinus, or the complete sinus. The force was defined as minimal, minor, or major. The clearance was defined as no residual, less than one third of volume, less than or equal to two thirds of volume, and more than two thirds volume. Ordinal correlation scores were assessed using the Kendall tau-B test.

RESULTS

Nine specimens (sphenoid sinuses) were assessed (44.4% female; age, 75.0 ± 12.7 years). The use of a sphenoid sinusectomy or larger produced better distribution (percent specimens with more than one third: 100% vs 59%, p < 0.01), more force (percent major: 83% vs 29%, p < 0.01), and better clearance (percent with one third or less remaining: 56% vs 18%, p < 0.01).

CONCLUSION

Increasing sphenoid ostial size improves nasal irrigation penetration. We propose that greater sphenoid sinusectomy size allows for improved lavage and irrigation penetration. Complete removal of the anterior face appears to mitigate pooling of irrigation.

Nasal Delivery Devices: A Comparative Study on Cadaver Model

Nasal nebulization is a more effective method of delivering topical medication than nasal spray. The purpose of this study was to assess the deposition patterns of nebulization in delivering topical agents to the nasal cavities in the human cadaveric model using a color-based method. We have compared these following nasal devices: single-dose vial irrigation, syringe-irrigation, common nasal spray, Spray-sol, MAD nasal, and Rinowash nasal douche. Endoscopic images were recorded at six anatomical regions prior to and following each nasal device application and four reviewers evaluated the amount of surface area staining. At the nasal vestibule, the blue dye distribution achieved with Spray-sol was more extensive than nasal sprays. At inferior turbinate and nasal cavity floor, single dose vial, syringe, MAD nasal, Spray-sol, and Rinowash demonstrated a greater extent of dye distribution than nasal spray. At the middle turbinate, the average score of both Spray-sol and MAD nasal was significantly higher than other nasal investigated devices. At the nasopharynx, Spray-sol nebulization covers a surface significantly greater than other devices. Compared to traditional sprays, Spray-sol and MAD nasal provided a more effective method of delivering topical agents to the deeper and higher portions of the nasal cavities.

Aspirin Exacerbated Respiratory Disease: Epidemiology, Pathophysiology, and Management

The correlation between aspirin sensitivity, asthma, and nasal polyposis was recognized in the early 20th century. Today, this classic triad of symptoms, eponymously named Samter's Triad, is known as aspirin exacerbated respiratory disease (AERD). Aspirin exacerbated respiratory disease affects approximately 0.3⁻0.9% of the general population in the USA and approximately 7% of asthmatic patients. The management of AERD is challenging as no single modality has proven to have high rates of symptom control. Consequently, disease management typically involves a multimodality approach across both medical and surgical disciplines. This review describes the epidemiology of AERD and the current state-of-the-art as it relates to the underlying pathophysiologic mechanisms of this disease process. A significant proportion of the review is focused on the appropriate diagnostic workup for AERD patients including the utility of aspirin provocation testing. The spectrum of medical treatments, including aspirin desensitization and recently introduced immunotherapies, are discussed in detail. Furthermore, surgical approaches to disease control, including advanced endoscopic techniques, are reviewed and treatment outcomes presented.

Head and Bottle Angles Achieved by Patients During High-Volume Sinonasal Irrigations

BACKGROUND

Certain head positions can optimize topical irrigation distribution to specific sinuses. No studies have assessed whether patients attain these positions when irrigating.

OBJECTIVE

The purpose of this study was to assess head and bottle angles achieved when patients irrigate based on instructions from an irrigation device or from a Rhinologist.

METHODS

Study approval was obtained from Henry Ford Health System's Institutional Review Board (10604). Forty-two patients with various rhinologic conditions were equally divided into groups based on irrigation instruction type: pictoral instructions from an irrigation device or written/verbal instructions from a Rhinologist. Both groups' instructions directed nose-to-floor head positioning. Simulating home irrigations, patients irrigated 120 mL of saline into each naris using 240 mL squeeze bottles. Frontal and lateral views were captured using video cameras. On frontal view, angles were measured between (1) nasal dorsum (ND) and bottle tip (BT; n = 84) and (2) ND and vertical (V; n = 84). On lateral view, angles were measured between (1) line from nasion-to-pogonion (NTP) and horizontal (H) (n = 73) and (2) NTP and BT (n = 73).

RESULTS

On lateral view, average angle between NTP and H was 20.0° (standard deviation [SD] = 13.1, 95% confidence interval [CI] = 17.0-23.0) and between NTP and BT was 59.4° (SD = 15.8, 95% CI = 55.8-63.1). On frontal view, average angle between ND and V was 9.5° (SD = 19.5, 95% CI = 5.3-13.6) and between ND and BT was 24.5° (SD = 12.0, 95% CI = 21.9-27.0). There were no significant angle differences between sides or instruction types.

CONCLUSION

When instructed to irrigate in the nose-to-floor head position, patients achieved a head position uprotated 20° on lateral view and vertex rotated 10° away from the side of irrigation on frontal view.

Diseases of the nasal cavity

Despite garnering minimal attention from the medical community overall, olfaction is indisputably critical in the manner in which we as humans interact with our surrounding environment. As the initial anatomical structure in the olfactory pathway, the nasal airway plays a crucial role in the transmission and perception of olfactory stimuli. The goal of this chapter is to provide a comprehensive overview of olfactory disturbances as it pertains to the sinonasal airway. This comprises an in-depth discussion of clinically relevant nasal olfactory anatomy and physiology, classification systems of olfactory disturbance, as well as the various etiologies and pathophysiologic mechanisms giving rise to this important disease entity. A systematic clinical approach to the diagnosis and clinical workup of olfactory disturbances is also provided in addition to an extensive review of the medical and surgical therapeutic modalities currently available.

How does sinus surgery affect topical irrigation distribution?

PURPOSE OF REVIEW

The current article reviews the literature on the distribution of nasal irrigation in the treatment of chronic sinusitis, especially in how sinus surgery and irrigation techniques affect its delivery to the nasal cavity and paranasal sinuses.

RECENT FINDINGS

Nasal irrigation has become a useful tool in the treatment of chronic sinusitis. Used after endoscopic surgery of the paranasal sinuses, irrigation has shown to be effective in improving edema and removing crusts and secretions in that place. However, some relevant points have been considered in the surgical technique and in the postoperative period to improve irrigation access to the paranasal sinuses such as the amplitude of the sinus ostial opening, irrigation volume and device used, as well as head position during irrigation.

SUMMARY

Postoperative lavage of the paranasal sinus is a recognized adjuvant in the treatment of chronic rhinosinusitis, reducing morbidity and improving local healing, besides allowing the association of topical medications that can be carried to the paranasal sinuses along with the saline increasing the reach of these drugs. Detailed attention to the techniques described in this review improves the distribution of irrigation in the paranasal sinuses after sinus surgery and considerably increases the efficacy of this therapy.

Computational fluid dynamic modeling of nose-to-ceiling head positioning for sphenoid sinus irrigation

BACKGROUND

After sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position.

METHODS

Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning.

RESULTS

In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position.

CONCLUSION

CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL irrigation to the sphenoid sinuses.

Cadaveric validation study of computational fluid dynamics model of sinus irrigations before and after sinus surgery

BACKGROUND

Investigations into the distribution of sinus irrigations have been limited by labor-intensive methodologies that do not capture the full dynamics of irrigation flow. The purpose of this study was to validate the accuracy of a computational fluid dynamics (CFD) model for sinonasal irrigations through a cadaveric experiment.

METHODS

Endoscopic sinus surgery was performed on 2 fresh cadavers to open all 8 sinuses, including a Draf III procedure for cadaver 1, and Draf IIb frontal sinusotomies for cadaver 2. Computed tomography maxillofacial scans were obtained preoperatively and postoperatively, from which CFD models were created. Blue-dyed saline in a 240-mL squeeze bottle was used to irrigate cadaver sinuses at 60 mL/second (120 mL per side, over 2 seconds). These parameters were replicated in CFD simulations. Endoscopes were placed through trephinations drilled through the anterior walls of the maxillary and frontal sinuses, and sphenoid roofs. Irrigation flow into the maxillary, frontal, and sphenoid sinuses was graded both ipsilateral and contralateral to the side of nasal irrigation, and then compared with the CFD simulations.

RESULTS

In both cadavers, preoperative and postoperative irrigation flow into maxillary, frontal, and sphenoid sinuses matched extremely well when comparing the CFD models and cadaver endoscopic videos. For cadaver 1, there was 100% concordance between the CFD model and cadaver videos, and 83% concordance for cadaver 2.

CONCLUSION

This cadaveric experiment provided potential validation of the CFD model for simulating saline irrigation flow into the maxillary, frontal, and sphenoid sinuses before and after sinus surgery.