Comparative Analysis of Spreader Grafts and Spreader Flaps on Intranasal Drug Delivery Efficiency to Posterolateral Nasal Wall

Abstract

Background: This study compared the impact of spreader grafts (SG) and spreader flaps (SF) on the transport of intranasal drug delivery to target the posterolateral nasal wall. Method: SG and SF were each performed in sequence on two cadaveric specimens after soft tissue elevation technique. Computed tomography scans were acquired following each procedure to generate anatomic models for computational fluid dynamics simulation of intranasal sprays under the following conditions: inhalation rate (15 and 30 L/min), spray velocity (1, 5, and 10 m/s), spray released location (center, lateral, medial, top, and bottom), head position (upright, tilted-forward, tilted-backward, and supine), and particle diameter (1-100 µm). Percentage of particles deposited on the posterolateral nasal wall were calculated. Results: For Specimen 1, highest posterolateral wall depositions were Pre-Op: left = 74%, right = 74%; SF: left = 53%, right = 22%; SG: left = 60%, right = 61%. For Specimen 2, highest posterolateral wall depositions were Pre-Op: left = 25%, right = 83%; SF: left = 29%, right = 76%; SG: left = 14%, right = 72%. In general, posterolateral wall deposition was higher at 30 L/min inhalation rate and at 1 m/s spray velocity. Conclusions: Drug delivery targeting the posterolateral nasal wall appears to be dependent on many factors. However, midvault nasal reconstruction does not increase drug delivery to the posterolateral nasal wall.