Dataset Information

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

ABSTRACT:

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.

SUBMITTER: Craig JR

PROVIDER: S-EPMC5426973 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

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Publications

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

Craig John R JR Palmer James N JN Zhao Kai K

International forum of allergy & rhinology 20170116 5

<h4>Background</h4>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 irriga ...[more]

PMID: 28092136

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Project description:BackgroundEmpty nose syndrome (ENS) remains highly controversial, with aggressive inferior turbinate reduction (ITR) or mucociliary dysfunction frequently implicated. However, the appropriate degree of ITR is highly debatable.MethodsWe applied individual computed tomography (CT)-based computational fluid dynamics (CFD) to 5 patients receiving relatively aggressive ITR but with no ENS symptoms, and compared them to 27 symptomatic ENS patients who all had histories of aggressive ITRs, and 42 healthy controls. Patients' surgical outcomes were confirmed with 22-item Sino-Nasal Outcome Test (SNOT-22) (ITR: 6.40 ± 4.56; ENS: 58.2 ± 15.9; healthy: 13.2 ± 14.9), Nasal Obstruction Symptom Evaluation (NOSE) scores (ITR: 4.00 ± 2.24; ENS: 69.4 ± 17.1; healthy: 11.9 ± 12.9), and Empty Nose Syndrome 6-Item Questionnaire (ENS6Q) (≥11 for ENS).ResultsBoth aggressive ITR without ENS symptoms and symptomatic ENS patients had significantly lower nasal resistance (ITR: 0.059 ± 0.020 Pa·s/mL; ENS: 0.052 ± 0.015 Pa·s/mL; healthy: 0.070 ± 0.021 Pa·s/mL) and higher cross-sectional areas surrounding the inferior turbinate (ITR: 0.94 ± 0.21 cm2 ; ENS: 1.19 ± 1.05 cm2 ; healthy: 0.42 ± 0.22 cm2 ) than healthy controls. The lack of significant differences among patient groups indicated similar degrees of surgeries between ITR with and without ENS symptom cohorts. However, symptomatic ENS patients have paradoxical significantly less airflow in the inferior meatus (ITR: 47.7% ± 23.6%; ENS: 25.8% ± 17.6%; healthy: 36.5 ± 15.9%; both p < 0.01), but higher airflow around the middle meatus (ITR: 49.7% ± 22.6%; ENS: 66.5% ± 18.3%; healthy: 49.9% ± 15.1%, p < 0.0001) than aggressive ITR without symptoms and controls. Aggressive ITR patients have increased inferior meatus airflow as expected (p < 0.05). This imbalanced airflow produced less inferior wall-shear-stress distribution among symptomatic ENS patients only (ITR: 42.45% ± 11.4%; ENS: 32.2% ± 12.6%; healthy: 49.7% ± 9.9%). ENS patients (n = 12) also had impaired nasal trigeminal function, as measured by menthol lateralization detection thresholds (ITR: 15.2 ± 1.2; ENS: 10.3 ± 3.9; healthy: 13.8 ± 3.09, both p < 0.0001). Surprisingly, aggressive ITR patients without ENS symptoms have better menthol lateralization detection thresholds (LDTs) than healthy controls.ConclusionAlthough turbinate tissue loss is linked with ENS, the degree of ITR that might distinguish postoperative patient satisfaction in their nasal breathing vs development of ENS symptoms is unclear. Our results suggest that a combination of distorted nasal aerodynamics and loss of mucosal sensory function may potentially lead to ENS symptomology.

Project description:ObjectiveThe precise pathogenesis of empty nose syndrome (ENS) remains unclear. Various factors such as nasal aerodynamics and sensorineural dysfunction have been suspected, although evidence is limited. This study reported the first examination of both nasal aerodynamics and trigeminal sensory factors in actual ENS patients.Study designProspective case control.MethodsWe enrolled six patients diagnosed with ENS. Three patients had pre- and post-inferior turbinate (IT) reduction computed tomography scans, which allowed comparison of their nasal aerodynamics changes through computational fluid dynamic (CFD) simulation. Their symptoms were confirmed through Sino-nasal Outcome Test-22, ENS 6-item Questionnaire, acoustic rhinometry, and rhinomanometry findings. Nasal trigeminal sensitivity that potentially mediates their perception of airflow was assessed via menthol lateralization detection thresholds (LDT) and compared with 14 healthy controls.ResultsPost-surgical reductions in nasal resistance were observed and significantly lower than normal (P < 0.05). Computational fluid dynamic analysis showed that, paradoxically for all ENS patients, IT reduction did not draw more airflow to the airway surrounding the ITs, but rather resulted in nasal airflow forming into a narrow jet toward the middle meatus region, leaving the airway surrounding the IT with significantly reduced airflow intensity and air-mucosal interactions (inferior region flow percentage reduced from 35.7% ± 15.9% to post-surgery 17.7% ± 15.7%, P < 0.05; inferior wall-shear-stress reduced from 7.5 ± 4.2 × 10-2 Pa to 3.4 ± 3.1 × 10-2 Pa, P < 0.01). Empty nose syndrome patients also had significantly impaired menthol LDT compared to healthy controls (P < 0.005).ConclusionThe results indicated that a combinatory of factors, including paradoxically distorted nasal aerodynamic, impaired sensorineural sensitivity, and potential predisposing conditions, may contribute to the development of ENS.Level of evidence3b. Laryngoscope, 127:E176-E184, 2017.

Project description:IntroductionSphenoid sinuses, air-filled cavities in the sphenoid bone, develop between the 3rd and 4th year and mature by 12 to 16 years. Understanding their anatomy is vital for safe transsphenoidal surgeries because of nearby vital structures. They exhibit variable pneumatization and often have an intersinus septum. This case emphasizes the importance of understanding sphenoid sinus anatomy, particularly in the context of transsphenoidal surgeries. It also introduces a novel case involving a congenital roof defect, previously unreported in medical literature.Case presentationA 52-year-old male presented with left cheek swelling that progressed to the eyelid, accompanied by low visual acuity, nasal symptoms, and a high temperature. Clinical examination revealed purulent discharge. A CT scan indicated opacity in the left maxillary sinus and a roof defect in the left sphenoid sinus. However, endoscopic surgery revealed the sphenoid sinus to be normal. This indicates that the defect is congenital. A biopsy from the maxillary sinus lesion confirmed lymphoma, and he was sent to the oncology hospital. There was no extension of the maxillary sinus lesion into the sphenoid sinus. This unique case had no history of drainage, taste issues, meningitis, or pituitary surgery.DiscussionThe complete absence of the sphenoid sinus roof is a unique and rare anatomical anomaly with significant implications for surgical procedures. Transsphenoidal surgery, which benefits from endoscopic advancements, provides enhanced visualization but also poses risks due to the proximity to critical structures. Pneumatization of the sphenoid sinus typically reaches maturity during adolescence, with individual variations in extent, Septations, extensions, and asymmetry are common in sphenoid sinus anatomy. This underscores the need for surgeon awareness and adjusted surgical approaches in such rare instances.ConclusionsWe emphasize the importance of a thorough anatomical understanding through precise radiological study before any sinus surgery due to the possibility of unexpected anatomical abnormalities.

Dataset Information

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

Background

Methods

Results

Conclusion

Publications

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

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