Frontal sinus surgery and sinus distribution of nasal irrigation.

Background: Effective mucus lavage and delivery of topical pharmaceuticals are central to successful management of chronic rhinosinusitis (CRS). The frontal sinus remains difficult to penetrate with topical therapies. This study evaluates the benefit of Draf III frontal dissection compared to traditional Draf IIa for distribution of topical therapies.

Methods: Fresh human cadaver heads were dissected sequentially with Draf IIa frontal sinusotomy and then Draf III procedures. Each cavity was irrigated with pediatric (120 mL) and adult (240 mL) irrigation bottles with 1/1000 10% fluorescein-labeled free water in 2 fixed positions (vertex and Frankfort horizontal). An endoscope at a fixed position within the frontal sinus recorded frontal sinus and frontal recess penetration. The images then underwent blinded evaluation of fluid distribution scored as 0 to 4 (nasal cavity only, frontal recess, medial one-half, lateral one-half, and lavage). Ordinal distribution score was analyzed with Kendall's tau-b.

Results: Eight specimens (age 76 ± 11.2 years; 50% female) were assessed. Draf III was superior to Draf IIa in ability to achieve frontal sinus distribution of irrigation (90.6% vs 50.1%, p < 0.001). Vertex head position improved distribution (90.6% vs 50.1%, p < 0.001), was synergistic with Draf III (100% with 87.5% lavage, p < 0.001), but was unable to overcome Draf IIa (81.2% with 25% lavage, p < 0.001). Irrigation volume trended toward improved distribution with larger volume irrigations.

Conclusion: Successful treatment of sinonasal disease may require postoperative delivery of topical therapies. Draf III frontal sinusotomy achieves superior topical access, and access to the frontal sinus with Draf IIa appears limited, despite large volumes and positioning.