(450) Sinus Drug Delivery Before and After Treatment for Chronic Rhinosinusitis

Introduction: This study uses computational fluid dynamics modeling to determine parameter combinations for maximizing intranasal spray drug delivery into the paranasal sinuses before and after undergoing functional endoscopic sinus surgery (FESS) in a patient with chronic rhinosinusitis (CRS).

Methods: Computed tomography images of an adult male patient with chronic rhinosinusitis (CRS) who was under medical management for 6 years before undergoing FESS were obtained at 3 periods: initial diagnosis (PRE1), 31 months after initial diagnosis (PRE2), and 6 months post FESS (POST); and used for creation of patient-specific three-dimensional sinonasal airway models. Drug particle transport simulations were performed in sinonasal airway models using computational fluid dynamics (CFD) modeling. Simulated drug particles (1-100µm) were released at 1, 5, and 10m/s velocities from 5 release locations (Bottom, Center, Top, Lateral, and Medial) and in 5 head positions (Mygind, Supine, Tilted-Back, Tilted-Forward, and Upright). Highest deposition was quantified for all paranasal sinuses – frontal (FS), maxillary (MS), ethmoid (ES) and sphenoid (SS).

Results: PRE1 had one patent sinus (right ES) with maximum deposition of 0.0006% (Mygind, 5m/s, 1-5µm). PRE2 had no patent sinuses. Maximum depositions for POST sinuses were: Left: ES=7.954%, FS=0.506%, MS=6.994%, SS=0.06575; Right: ES=10.251%, FS=0.148%, MS=17.680%, SS=45.291%. Particles between 1-30 µm had the most sinus deposition at 1 m/s for all left sinuses with varied head positions (Supine: ES and FS, Upright: MS, Mygind: SS). Right sinuses, particles sized 1-20µm (except ES at 51-60µm), had best deposition at 1 m/s (except MS at 5 m/s) at varied head positions (Tilted-Forward: ES, Mygind: FS, Supine: MS and SS).

Conclusions: FESS was very effective in increasing drug delivery.