Intranasal Cross-Sectional Area Changes Following Endoscopic Skull Base Surgery and Their Relation to Postoperative Quality of Life

Objectives: Endoscopic skull base surgery has the potential to significantly alter the intranasal architecture. Sphenoidotomy, nasoseptal flaps, turbinate reduction, and septectomy all may be necessary to achieve adequate visualization and access to the skull base target. The effect of these procedures on postoperative nasal airflow and their corresponding effect on sinonasal quality of life are not well studied. We sought to quantify the changes in nasal architecture following skull base surgery and explore the association of those changes with sinonasal quality of life.

Methods: Acoustic rhinometry was performed on 118 patients preparing to undergo endoscopic skull base surgery. These data were compared with prospective postoperative measurements taken at 6 months or greater following surgery, once postoperative sinonasal changes stabilized. Patients also completed the Sinonasal Outcome Test (SNOT-22) before and after surgery. Beginning 6 weeks postoperatively, patients were followed longitudinally, assessing the evolution of sinonasal architectural and quality-of-life changes.

Results: Each nasal cavity was analyzed independently following topical decongestion with phenylephrine to account for cross-sectional changes in the nasal cycle. Cross-sectional area (CSA) was measured at the anterior portion of the inferior turbinate (CSA1), the anterior portion of the middle turbinate (CSA2), and the midportion of the middle turbinate at the maxillary ostium (CSA3). Results were averaged between nostrils. As expected, CSA1 did not decrease from preoperative values (0.08 cm² change, P = 0.22), reflecting the fact that no surgical manipulation occurs at the internal nasal valve. Postoperative CSA2 increased by mean (SD) 1.23 (0.71) cm² (P = 0.008), and postoperative CSA3 increased by mean (SD) 4.3 (5.1) cm² (P = 0.047), reflecting changes after a mean (SD) follow-up of 16.7 (7.2) months. Postoperative SNOT-22 scores were significantly improved (P = 0.001), with mean (SD) preoperative and postoperative values of 23.0 (19.0) and 17.8 (13.3), respectively. Correlation was present between acoustic rhinometry values and SNOT-22 scores.

Conclusions: Endoscopic skull base surgery may have a beneficial effect on sinonasal quality-of-life. Acoustic rhinometric measurements objectively demonstrate the expected postoperative increases in intranasal volume. Improvements in subjective SNOT-22 data correlate with improved postoperative nasal patency and represent improved sinonasal quality-of-life.