Effect of head position and surgical dissection on sinus irrigant penetration in cadavers.

Background: Effective treatment for recalcitrant rhinosinusitis requires unobstructed surgical marsupialization of sinus cavities and use of delivery systems that will topically penetrate the sinuses.

Objective: To determine the extent of sinus penetration achieved with nasal irrigation by varying the ostial size and head position.

Methods: Ten thawed fresh-frozen cadaver heads were dissected in a staged manner. After each stage of dissection, sinus squeeze-bottle irrigations were performed in three head positions, and endoscopes placed via external ports into the sinus cavities viewed the sinus ostia. An ordinal scale was developed to grade ostial penetration of irrigations. Three reviewers independently graded the outcomes.

Results: Irrigant entry into sinuses increased with ostial size (P < .001) and the greatest differential of improvement in sinus penetration is obtained at an ostial size of 4.7 mm. Stages 2 and 3 (larger sinus ostia) of maxillary and sphenoid dissections have statistically greater irrigant penetration relative to earlier stages. Frontal sinus irrigation is worse in vertex to ceiling head position. There does not appear to be any significant advantage to head position with maxillary and sphenoid sinuses.

Conclusions: This study shows that the larger the sinus ostium, the better the penetration of irrigant into the sinus, with an ostium of at least 4.7 mm allowing maximal penetration in the maxillary and sphenoid sinuses. The same benefit was not noted in the frontal sinus. Head position was only relevant to the frontal sinus where less penetration was seen with the head neutral (vertex to ceiling) position when compared to forward angled positions.