Plug size selection protocol for the treatment of intractable patulous Eustachian tube with Kobayashi Plug

Background: There have been no useful criteria for initial plug size selection protocol for the treatment of intractable patulous Eustachian tube (PET). Aims/objectives: To establish a method for appropriate plug size selection using tubal function test and subjective symptom severity in PET patients who were treated by Kobayashi Plug insertion. Material and methods: A retrospective survey of medical records identified 39 ears of 35 patients with PET who received insertion of the Kobayashi Plug and whose PET symptoms were thereafter controlled for at least 6 months after surgery. Method: The evaluation scale of PET handicap inventory-10 (PHI-10) was used to indicate PET subjective symptom severity. Tubal function tests (sonotubometry and tubo-tympano-aerodynamic-graphy: TTAG) were performed. Results: There was no correlation between the preoperative PHI 10 score and plug size (p =.157). There was a significant correlation between the preoperative sound attenuation from nostril to EAC measured by sonotubometry and plug size (p <.001). There was no correlation between the preoperative pressure transmission ratio estimated by TTAG and plug size (p =.271). Conclusions and Significance: Sonotubometry which evaluates sound attenuation from nostril to EAC can be a useful tool for selecting plug size.