Serpentine Sign: evidence of airway compensation in patients with empty nose syndrome

Background: This study aimed to evaluate the presence of Serpentine Signs on computed tomography (CT) images and its impact on the clinical symptoms in patients with empty nose syndrome (ENS). Methods: A retrospective study analysed patients with ENS enrolled in previous studies. The clinical characteristics and results of ENS-specific questionnaire evaluations were reviewed. The ratio of the maximal to minimal thickness (M/m ratio) of the septal mucosa was also calculated to demonstrate the degree of swelling. Mucosal swelling was defined as a thickness greater than twice that of the surrounding mucosa. A Serpentine Sign was identified by the presence of two or more mucosal swellings on one side of the central nasal septum. Results: Seventy-one (74.0%) of the 96 enrolled patients with ENS exhibited Serpentine Signs on CT images. Patients with the Serpentine Sign had significantly lower symptom scores on the ENS 6-item Questionnaire (ENS6Q) and 25-Item Sino-Nasal Outcome Test (SNOT-25). Regression analysis revealed that the ENS6Q, SNOT-25, sleep, psychological, and empty nose symptom domains were significantly associated with the Serpentine Sign. The M/m ratio of the nasal septal mucosa significantly decreased in 39 participants with available postoperative CT images 6 months after nasal reconstruction surgery, along with an improvement in ENS6Q and SNOT-25 scores. Conclusion: The Serpentine Sign was associated with fewer ENS symptoms in patients with ENS. The severity of septal mucosal swelling decreased after surgical reconstruction. These results imply a significant impact of airflow alteration due to over-reduction of the inferior turbinate on the nasal mucosa.