Identifying patients who may benefit from inferior turbinate reduction using computer simulations

Abstract

Objectives (1) To determine objective criteria to predict which patients may benefit most from inferior turbinate reduction surgery. (2) To test whether the site of turbinate reduction, either along the nasal floor (bottom resection) or along the septal side (medial resection), impacts the extent to which nasal resistance is reduced. Study Design Case series. Methods Three-dimensional reconstructions of the nasal anatomy of five nasal airway obstruction patients were created based on pre-surgical computed tomography scans. Inferior turbinate reduction models were created for each patient using virtual surgery. Airflow, heat transfer, and humidity transport during inspiration were simulated using computational fluid dynamics (CFD). Results Nasal resistance curves revealed little to no difference between bottom resection and medial resection models. In two patients, little change was observed in nasal resistance after virtual inferior turbinate reduction, which was attributed to the narrowest cross-sections being restricted to the anterior nose (i.e., anterior to the inferior turbinate). The three patients whose nasal resistances decreased substantially after virtual inferior turbinate reduction had a narrower airspace in the turbinate region and higher nasal resistance pre-surgery. Nasal air conditioning capacity was more affected by medial resections. Conclusion CFD simulations predicted no significant difference in the decrease in nasal resistance between virtual inferior turbinate reductions performed by bottom vs. medial resection of the turbinate. However, bottom resections better preserved the calculated humidification efficiency. The simulations predicted that the greatest reduction in nasal resistance occurs in patients with highest pre-surgical resistance in the turbinate region.

Impact of Middle versus Inferior Total Turbinectomy on Nasal Aerodynamics

“…This manuscript is part of a larger study aimed at correlating objective and subjective measures of nasal patency. 7,12,16-18,21 Twenty seven patients undergoing NAO surgery (septoplasty, inferior turbinate reduction, and/or rhinoplasty) have been recruited. Ten patients from this cohort were randomly selected for this study.…”

“…6 However, changes in nasal humidification efficiency after nasal surgery have rarely been investigated, 6-8 with most computational studies to date focusing on nasal resistance 9-13 and heat transfer. 14-18 Importantly, the vast majority of previous computational studies were aimed at inferior turbinate reduction, 7,9-11,15 thus the aerodynamic changes after middle turbinate resection remain poorly understood. 19,20 …”

Effects of nasal wall lateralization and pyriform turbinoplasty on nasal air conditioning

“…Nasal air conditioning is more influenced by medial than inferior resection of the turbinate. Yet nasal resistance curves reveal no relevant changes between these in virtual surgery [11]. Partial reduction of hypertrophic turbinates results in improved nasal aerodynamics, which is most evident following resection of the lower third [12].…”

Response to Dr Chung’s Question on Simulating the Nasal Cycle with Computational Fluid Dynamics

“…Many researchers and clinicians are interested in the potential use of virtual surgery in patient-specific digital models to identify patients who are most likely to benefit from nasal surgery and to design surgical approaches that are optimally effective. 1, 2 Since these computational models are based on instantaneous medical images, one key challenge is how to account for the normal physiological fluctuations in nasal patency. 3 Decongestion of the nasal mucosa is an effective strategy to eliminate the confounding effect of the nasal cycle.…”