Impact of endoscopic craniofacial resection on simulated nasal airflow and heat transport

Abstract

Background: Endoscopic craniofacial resections (CFR) are performed for extensive anterior skull base lesions. This surgery involves removal of multiple intranasal structures, potentially leading to empty nose syndrome (ENS). However, many patients remain asymptomatic postoperatively. Our objective was to analyze the impact of CFR on nasal physiology and airflow using computational fluid dynamics (CFD). This is the first CFD analysis of post-CFR patients.Methods: Three-dimensional sinonasal models were constructed from 3 postoperative images using Mimics TM . Hybrid computational meshes were created. Steady inspiratory airflow and heat transport were simulated at patientspecific flow rates using shear stress transport k-omega turbulent flow modeling in Fluent TM . Simulated average heat flux (HF) and surface area where HF exceeded 50 W/m 2 (SAHF50) were compared with laminar simulations in 9 radiographically normal adults.Results: Three adults underwent CFR without developing ENS. Average HF (W/m 2 ) were 132.70, 134.84, and 142.60 in the CFR group, ranging from 156.24 to 234.95 in the nonoperative cohort. SAHF50 (m 2 ) values were 0.0087, 0.0120, and 0.0110 in the CFR group, ranging from 0.0082 to 0.0114 in the radiographically normal cohort. SAHF50 was distributed throughout the CFR cavities, with increased HF at the roof and walls compared with the nonoperative cohort. Conclusion:Average HF was low in the CFR group compared with the nonoperative group. However, absence of ENS in most CFR patients may be due to large stimulated mucosal surface area, commensurate with the nonoperative cohort. Diffuse distribution of stimulated area may result from turbulent mixing a er CFR. To be er understand heat transport post-CFR, a larger cohort is necessary. C 2019 ARS-AAOA, LLC.

Computational technology for nasal cartilage-related clinical research and application

“…84 For example, CFD showed that the magnitude and direction of the airflow pattern in an individual patient's sinonasal anatomy after virtual endoscopic skull base surgery. 10,91 However, the difficulty of sinus reconstruction is that it can only be observed if the sinus is connected to the nasal cavity after model reconstruction, and some small sinus models will cause the modelling process to be extremely complicated. The choice of whether to reconstruct the sinus should be based on the study purpose, but modelling should be as accurate as possible to simulate the real sinuses, so all the potential functional parts should be retained as best as possible.…”

“…Therefore, computational technology, mainly related to surgical modelling and simulation, can assist maxillofacial plastic surgeons in better understanding the nasal cartilage. [8][9][10] Three-dimensional imaging technologies should form the basis for all patient-specific 3D model-related studies and applications. However, imaging of the nasal cartilages is more difficult than imaging of other cartilage types because of its small and complex structural features.…”

“…Therefore, computational technology, mainly related to surgical modelling and simulation, can assist maxillofacial plastic surgeons in better understanding the nasal cartilage. 8 – 10 …”

Comparing nasal physiology after superior ethmoidal and traditional endoscopic anterior cranial base approaches

“…In contrast, airflow in the SEA group was similar to that seen in the control group, but with a small stream of airflow directed to the superior ethmoid space before passing into the choana ( Figure 2). went the TA (6) . Our study yielded similar results to their study.…”

“…Computational fluid dynamics (CFD) is a useful tool to examine nasal physiology and has advantages over conventional methods (4,5) . A recent study has used CFD to demonstrate different airflow, wall shear stress (WSS), heat flux and humidifying efficiencies in patients following the TA compared to controls (6) .…”