Zero‐Degree Endoscopic Visualization of the Frontal Sinus Predicts Improved Topical Irrigation Delivery

OBJECTIVE: Management of chronic frontal rhinosinusitis is challenging with high rates of treatment failure, exacerbated by limitations of topical irrigation delivery. We hypothesize that intraoperative zero-degree visualization of the frontal sinus predicts improved postoperative irrigation penetration. Extending a Draf IIa frontal sinusotomy with a limited resection of the middle turbinate axilla-agger nasi complex can allow zero-degree endoscopic visualization of the frontal sinus. This study investigates the change in frontal sinus irrigation delivery after standard Draf IIa frontal sinusotomy versus further resection to achieve zero-degree visualization. STUDY DESIGN: This is a prospective cohort study conducted in a surgical skills laboratory. METHODS: The extent of irrigant penetration into the frontal sinuses was evaluated in 10 cadaveric frontal sinuses following Draf IIa sinusotomy using a standardized trephine visualization model. Irrigant penetration was assessed by three blinded reviewers using the following scale: 0 = irrigation restricted to nasal cavity; 1 = irrigation reaches frontal recess; 2 = irrigation reaches frontal sinus proper; 3 = irrigation fills entire frontal sinus. These results were compared to irrigation after achieving zero-degree endoscopic visualization by performing limited resection of the middle turbinate axilla-agger nasi complex. RESULTS: Irrigant penetration following standard Draf IIa frontal sinusotomy improved after the axilla-agger nasi complex was resected to achieve zero-degree endoscopic visualization (median score 2 [interquartile range: 1-2] vs. 3 [interquartile range: 2-3], P < .01). CONCLUSION: This study demonstrates improved penetration of frontal sinus irrigation following limited resection of the middle turbinate axilla-agger nasi complex to achieve zero-degree endoscopic visualization of the frontal sinus as compared to standard Draf IIa frontal sinusotomy. LEVEL OF EVIDENCE: N/A Laryngoscope, 2020.