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

Abstract

Introduction 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). While 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 dynamic (CFD) model of sinus irrigations to assess the difference in sphenoid sinus delivery of irrigations after irrigating in a nose-to-floor versus nose-to-ceiling head position. Methods 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/s, angle of irrigation 20 degrees to the nasal floor, and either nose-to-floor or nose-to-ceiling head positioning. Results 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 while 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. Conclusion 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.

Evaluation of patient nasal saline irrigation practices following endoscopic sinus surgery

“…There is also the question of quality of irrigation, whereas more experienced and comfortable patients may perform irrigations in a more effective manner than others. This and other variables such has head positioning, which has been shown to affect the penetration of nasal irrigants to certain sinuses, are difficult to ascertain and control for in this particular study design …”

Nasal saline irrigation: a clinical update

“…A wide variety of nasal saline delivery products are commercially available, including low‐volume, high‐volume, powered high‐pressure, and powered nebulized devices. Several studies have evaluated factors (extent of surgery, head position, and type of delivery device) with the potential to impact irrigation penetration into the paranasal sinuses . NSI has minimal sinus penetrance in patients who have not undergone surgery, but is positively correlated with the extent of functional endoscopic sinus surgery (FESS) .…”

“…More recent evidence has expanded our understanding of how head position and extent of surgery influence NSI distribution. A 2017 cadaver study by Craig et al addressed the impact of head position on the penetration of irrigation to the sphenoid sinuses using a computational fluid dynamics model (Table ) . It was determined that the nose‐to‐ceiling position was more effective than the head‐down‐and‐forward position at delivering irrigation to the sphenoid sinuses .…”

“…A 2017 cadaver study by Craig et al addressed the impact of head position on the penetration of irrigation to the sphenoid sinuses using a computational fluid dynamics model (Table ) . It was determined that the nose‐to‐ceiling position was more effective than the head‐down‐and‐forward position at delivering irrigation to the sphenoid sinuses . This position should be considered in cases of recalcitrant sphenoid sinusitis .…”

“…It was determined that the nose‐to‐ceiling position was more effective than the head‐down‐and‐forward position at delivering irrigation to the sphenoid sinuses . This position should be considered in cases of recalcitrant sphenoid sinusitis . A 2017 cadaver study by Halderman et al evaluated the influence of middle turbinate (MT) resection on the penetrance of solution delivered by a powered nasal nebulizer (Table ) .…”