Abstract
Suggested several decades ago, the nine-step test is an intuitive test of Eustachian tube function. However, studies employing the nine-step test to assess the results of Eustachian tube balloon dilation (EBD) are limited. We aimed to objectively evaluate the efficacy of EBD in opening failure patients with decreased maximal peak pressure difference (MPD) using the nine-step test. Patients who had MPD values ≤ 13 daPa in the nine-step test were enrolled. The patients were categorized into two groups according to treatment decisions after discussion with a clinician: an EBD group (N = 26) and a medication group (N = 30). One month after treatment, the seven-item Eustachian Tube Dysfunction Questionnaire (ETDQ7) and the nine-step test were administered to all participants and subgroups of symptomatic participants (ETDQ7 > 15). MPD improved (increased) in both the EBD group and the medication group. ETDQ7 values improved (decreased) in the EBD group, but not in the medication group. In subgroup analysis, MPD and ETDQ7 values improved only in the symptomatic EBD group. According to the nine-step test, EBD can normalize 53.8% of decreased MPD. Posttreatment MPD and ETDQ7 scores were significantly better in the EBD group than in the medication group. However, EBD in patients with abnormal nine-step test results seemed less efficacious when the treatment results of the medication group were considered.