Computational fluid dynamic modeling of nose-to-ceiling head positioning for sphenoid sinus irrigation

After sinus surgery, patients are commonly instructed to irrigate with saline irrigations with their heads over a sink and noses directed inferiorly (nose-to-floor). Although irrigations can penetrate the sinuses in this head position, no study has assessed whether sphenoid sinus penetration can be improved by irrigating with the nose directed superiorly (nose-to-ceiling). The purpose of this study was to use a validated computational fluid dynamics (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose-to-floor vs nose-to-ceiling head position.

Bilateral maxillary antrostomies, total ethmoidectomies, wide sphenoidotomies, and a Draf III frontal sinusotomy were performed on a single fresh cadaver head. CFD models were created from postoperative computed tomography maxillofacial scans. CFD modeling software was used to simulate a 120-mL irrigation to the left nasal cavity with the following parameters: flow rate 30 mL/second, angle of irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning.

In the postoperative CFD models, the sphenoid sinuses were completely penetrated by the irrigation while in a nose-to-ceiling head position. However, no sphenoid sinus penetration occurred in the nose-to-floor position. Other sinuses were similarly penetrated in both head positions, although the ipsilateral maxillary sinus was less penetrated in the nose-to-ceiling position.

CFD modeling demonstrated that the nose-to-ceiling head position was superior to the nose-to-floor position in delivering a 120-mL irrigation to the sphenoid sinuses.