Computational Analyses of Physiologic Effects After Midvault Repair Techniques in Rhinoplasty

Abstract

Background: Midvault reconstruction is an essential element of functional rhinoplasty. An improved understanding of airflow patterns after spreader graft (SG) or spreader flap (SF) techniques can inform surgical techniques based on individual anatomy. Objectives: The objective of this study was to compare the physiologic changes related to nasal function after midvault reconstruction with SF and SG. Methods: Soft tissue elevation (STE), SG, and SF were performed in sequence on 5 cadaveric specimens. Computational modeling was used to simulate airflow, heat transfer, and humidity in three-dimensional nasal airway reconstructions of each specimen. Results: Median bilateral airflow-rates (L/min) were similar for STE (29.4), SF (27.6), and SG (28.9), and were not statistically significant (STE vs SF: P = 1.0, power = 5%; STE vs SG: P = .31, power = 16%; SF vs SG: P = .42, power = 14%). Both SF and SG had increased unilateral airflow volume (L/min) through the more obstructed nasal passage (median: STE 10.3, SF 12.2, SG 12.7), but these differences were not significant (STE vs SF: P = .19, power = 24%; STE vs SG P = .19, power = 30%). Furthermore, SF and SG had decreased unilateral nasal resistance (Pa s/mL) on the more obstructed side (median: STE 0.085, SF 0.072, SG 0.062) (STE vs SF: P = .13, power = 23%; STE vs SG P = .13, power = 24%). For all 3 models, heat flux distribution was greater in the anterior portion of the nasal passage than the posterior portions. Conclusions: Differences in nasal airflow and resistance after SF and SG were not statistically significant, but both procedures resulted in higher airflow rates and decreased nasal resistance through the more obstructed nasal passage.