Incidence of Empty Nose Syndrome Following Endoscopic Endonasal Skull Base Surgery: A Preliminary Trial

Background Empty Nose Syndrome (ENS) is a rare disease that has been predominantly associated with inferior turbinectomies (IT), where it has been reported in about 20% of patients. The association of ENS with middle turbinectomy (MT) has not yet been fully defined. Despite MT being widely used in the preparation of an endoscopic endonasal approach (EEA), these patients seldom report ENS symptoms; thus we attempted to define its incidence in this patient population.

Objective To define the incidence of ENS following skull base surgery through EEA.

Methods Patients with a history of EEA that included MT (MT patients), at least six months after surgery, were presented with open-ended questions asking them to identify nasal symptoms, appearing or worsening after surgery (score: 1–5).  Following this initial survey, they were asked to fill the ENS6Q; a symptom-based questionnaire validated in ENS diagnosis (sensitivity: 86.7%, specificity: 96.6%) with a score greater than or equal to 11. Results were compared to controls with previous sinonasal surgery, but without turbinate resection. Statistical analysis was carried out using Chi-square test and Fisher's exact test.

Results Forty-six subjects (n = 46) were included in the study: thirty-six (n = 36) MT patients and 10 controls. The mean surgery-to-study period was 27.06 months (range: 6–60). The group of MT patients included 25 (69%) without IT (MTsIT) and 11 (31%) with IT (MTwIT). Sixteen of 36 patients (44.44%) reported some nasal complaint (∼score: 2.56), the most common being nasal discharge (62.5%). Of the control group, 9 (90%) denied any symptoms. Overall, the mean ENS6Q score for patients and controls were 5.27 and 5.40, respectively.

Out of the 36 MT patients, 6 (16.66%) had an ENS6Q score compatible with a diagnosis of ENS (∼ENS6Q = 12.33). Of this group (n = 6), only one (16%) initially reported a symptom related to ENS (crusting), while three (50%) mentioned non-ENS symptoms and two (33%) denied suffering from any symptoms at all. On the other hand, two subjects from the control group had a score greater than or equal to 11 (∼ENS6Q = 15), without initially reporting any nasal complaints. There was no significant difference found in ENS diagnosis (according to the ENS6Q score) between the MTwIT and the MTsIT groups. There was no significant difference in ENS diagnosis between patients and controls or in those who did and did not receive radiotherapy (RT) to the sinonasal area.

Conclusion Lack of statistical difference from controls suggests that ENS is not a common sequela after EEA, albeit possible. Interestingly, the incidence of ENS after EEA was similar in patients undergoing isolated MT, to those undergoing combined MT and IT. Similar incidences were also found in the cohorts of patients who received RT compared to those who did not. However, these outcomes could be explained by low statistical power or flaws in the questionnaire. Therefore, it is required to continue the study to better define the nature of the disease in this population.