A hierarchical stepwise approach to evaluate nasal patency after virtual surgery for nasal airway obstruction

Abstract

Background: Despite advances in medicine and expenditures associated in treatment of nasal airway obstruction, 25–50% of patients undergoing nasal surgeries complain of persistent obstructive symptoms. Our objective is to develop a “stepwise virtual surgery” method that optimizes surgical outcomes for treatment of nasal airway obstruction. Methods: Pre-surgery radiographic images of two subjects with nasal airway obstruction were imported into Mimics imaging software package for three-dimension reconstruction of the airway. A hierarchical stepwise approach was used to create seven virtual surgery nasal models comprising individual (inferior turbinectomy or septoplasty) procedures and combined inferior turbinectomy and septoplasty procedures via digital modifications of each subject’s pre-surgery nasal model. To evaluate the effects of these procedures on nasal patency, computational fluid dynamics modeling was used to perform steady-state laminar inspiratory airflow and heat transfer simulations in every model, at resting breathing. Airflow-related variables were calculated for virtual surgery models and compared with dataset containing results of healthy subjects with no symptoms of nasal obstruction. Findings: For Subject 1, nasal models with virtual septoplasty only and virtual septoplasty plus inferior turbinectomy on less obstructed side were within the healthy reference thresholds on both sides of the nasal cavity and across all three computed variables. For Subject 2, virtual septoplasty plus inferior turbinectomy on less obstructed side model produced the best result. Interpretation: The hierarchical stepwise approach implemented in this preliminary report demonstrates computational fluid dynamics modeling ability to evaluate the efficiency of different surgical procedures for nasal obstruction in restoring nasal patency to normative level.

Extracting signature responses from respiratory flows: Low‐dimensional analyses on Direct Numerical Simulation‐predicted wakes of a flapping uvula

“…The DMD spatial modes in K2m3 are shown in Figure 11 at different ranks (R = 5, 15,25,35). Even though the size of the red and blue spots of the DMD modes appears to increase with ranks for the 4 ranks considered, no consistent pattern in spot-size variation has been identified when modes at all ranks are considered.…”

“…To facilitate clinical applications, the normative ranges of these variables were identified from 47 healthy adults 14 . Similarly, Frank‐Ito et al 15 developed a stepwise virtual surgery method to optimize surgical outcomes for the treatment of nasal airway obstruction and demonstrated its promising usage in treatment planning in two septoplasty patients. Procedures for snore diagnosis are still limited to specialized sleep laboratories with patients staying overnight, which are costly and time‐consuming.…”

Computational Fluid Dynamics Analysis of Nasal Airway Changes after Treatment with C-Expander

“…The retrospective study includes 9 patients from the ages of 15 to 29 years (8 females, 1 male with a mean age of 18:44 ± 4:28 years), who were treated with a C-expander due to transverse maxillary deficiency from December 2015 to July 2019. All of the patients included were required to meet the following inclusion criteria: The flow chart of the study is as follows: CBCT scan → model reconstruction (mimics) → mesh generation (ICEM CFD) → data acquisition (Fluent) [17,26,27].…”

Nasal airflow of patient with septal deviation and allergy rhinitis

“…Respiratory physiology and pathology significantly depend on the airflow inside the nasal cavity. Because nasal airflow is profoundly affected by the geometry of the flow passage, changes in the shape of the nasal cavity due to diseases or surgical treatments alter the nasal resistance and functions of the nose [32][33][34][35]. Geometric configuration plays a significant role in the flow distribution inside the nasal cavity, especially in disease cases, as the imbalance of the nasal cavity owing to septal deviation is considered to be a common etiology of nasal airway obstruction [4,13,16].…”