Intranasal Spray Characteristics For Targeting the Sinuses Before And After Functional Endoscopic Sinus Surgery

Submitted by:

Amanda Balash BS
Florida Atlantic University Charles E. Schmidt College of Medicine

Presenter(s):

Amanda Balash, BS
Dennis O. Frank-Ito, PhD

Abstract

Computed tomography scans of an adult male patient with CRS who was under medical management for 6 years before undergoing FESS were obtained at 3 time points: initial diagnosis (PRE1), 31 months after initial diagnosis (PRE2), and 6 months post FESS (POST; 77 months after initial diagnosis). The patient had bilateral disease with the right side being more obstructed. The patient’s images (PRE1, PRE2, and POST) from computed tomography were read into an imaging analysis software for creation of anatomically realistic and patient-specific three-dimensional sinonasal airway models. Sinonasal airflow and drug particle transport simulations were performed in each of the three airway models using computational fluid dynamics (CFD) modeling. Intranasal spray particles of 1-100 µm were simulated at release speeds of 1, 5, and 10 m/s from 5 release locations (Bottom, Center, Top, Lateral, and Medial) at a nozzle insertion depth of 15 mm. Drug delivery simulations were performed in the head tilted forward position. Particle deposition was quantified for each paranasal sinus. PRE1 and PRE2 showed no patent sinuses due to opacification. Maximal deposition for the POST paranasal sinuses was: left ES=0.277%, left FS=0.022%, left MS=0.753%, left SS=0.003%, right ES=3.255%, right MS=1.284%, right SS=3.751%. The right FS had no deposition due to opacification. Particles between 1 and 20 µm at the top release location had the best deposition for all the left sinuses while the optimal velocity varied (5 m/s for ES and FS, 1 m/s for MS, 10 m/s for SS). For the right side, except for the sphenoid sinus, larger particles (ES= 51-60 µm , MS= 31-40 µm, no FS deposition) all released at a velocity of 1 m/s had the greatest deposition. For the right sphenoid sinus, maximal deposition occurred with particles 6 to 10 µm released at 1 m/s. For the right side, particles released at the center (ES) and medial (MS and SS) spray release locations had superior deposition. Overall, FESS was very effective in increasing drug delivery.

Objectives

To investigate intranasal spray drug delivery into the paranasal sinuses in an adult male patient with chronic rhinosinusitis (CRS) before and after undergoing functional endoscopic sinus surgery (FESS).

To determine intranasal spray parameter combinations for maximizing sinus drug delivery before and after FESS.

To determine optimal particle size range(s) for best intranasal spray drug delivery into each paranasal sinus before and after FESS.