Evaluation of domestic and Yucatan swine nasal sinus anatomy as models for future sinonasal research of medications delivered by standard instruments used in functional endoscopic sinus surgery

Abstract

There is a need to find an animal model to study new medications to improve mucosal wound healing after functional endoscopic sinus surgery (FESS). Current literature suggests swine as a potential candidate. The lack of information correlating swine computer tomography (CT) and endoscopic sinonasal anatomy prompted us to investigate them in the domestic and Yucatan swine to determine their feasibility as models to test new medications and drug-embedded stents applied using FESS techniques. Two domestic pig heads and 2 Yucatan pig heads were imaged using helical thin slice (1 mm) CT. Two rhinologists analyzed the images and performed endoscopy on the swine. Particular attention was given to accessing the frontal sinus and suturing stents to the nasal septum using standard endoscopic instruments. CT confirmed that swine sinonasal anatomy is largely similar to human, with all major sinuses present. The middle and inferior turbinates of swine arise from a single uniturbinate. The superior turbinates contain large concha bullosa. Unlike human, swine nasal septum is bone anteriorly and cartilage posteriorly. The frontal sinus ostia, regardless of head size, were consistently around 10 cm from the nasal aperture. On endoscopy, domestic swine frontal sinus ostia were easily accessible for topical medication deposition. Silastic splints can be sutured to the domestic swine septum through the posterior cartilaginous portion, allowing for studies involving medication-eluting material. The narrower nasal cavity of Yucatan pigs prohibited endoscopic maneuvers. Domestic swine, but not Yucatan, are a feasible model for future sinonasal research using standard FESS instruments.