[Effect of anatomical changes of frontal recess and frontal sinus on airflow after nasalisation by image...

Objective: To describe the influence of post-operative anatomical structure changes on nasal airflow characteristics by 3D reconstruction and numerical simulation in real cases after nasalisation with Draf Ⅲ so as to explore the correlation between the changes of anatomical structure and subjective symptoms as well as airflow characteristics. Methods: Ten patients underwent nasalization with Draf Ⅲ in Department of Rhinology in Beijing Tongren Hospital from 2006 to 2018 were selected retrospectively. Postoperative follow-up of all patients was more than 1 year. All patients had no abnormalities in their paranasal sinus CT scans and Lund-Kennedy scores were 0 except scar. VAS scores including nasal obstruction, stimulation in frontal sinus, and headache were collected at the same period. The control model was a normal person. Numerical simulation was used for calculating airflow characteristics in deep inspiratory period of both models. Independent sample Mann-Whitney U test and Spearman correlation test were used by software SPSS 22.0. Results: The airflow pressure in frontal sinus ostium was (7.21±1.39)×10(4) Pa (Mean±SD), which was lower than that in normal subjects (8.99×10(4) Pa) under deep inspiratory simulation. But, the velocities in frontal sinus ostium and frontal sinus were (40.10±2.46) m/s and (28.19±1.73) m/s respectively, which were higher than those in normal one (2.70 m/s, 0.73 m/s). The airflow patterns of the two models were basically similar. There was no significant difference in the opening size and volume of frontal sinus between different groups after grouped by three symptoms respectively. No correlation could be found between the opening size and volume of the frontal sinus with the appearance and severity of three subjective symptoms. Conclusions: The airflow pattern and distribution after nasalisation with Draf Ⅲ are like those of normal person. There is no correlation between the changes of anatomy in frontal recess and frontal sinus and nasal airflow characteristics as well as subjective symptoms.