Transtympanic plugging for chronic patulous eustachian tube
Reviewed by Praneta Kulloo

The authors developed a silicone plug (Kobayashi plug) to manage severe intractable patulous eustachian tube dysfunction (PET). This retrospective study investigates ET function after Kobayashi plug surgery, based on postoperative tympanic membrane (TM) findings and active opening (AO) of the ET. A total of 68 ears of 60 patients had normal TM preoperatively. Among these 68 ears, there were 51 ears in which sonotubometry was performed both before and after surgery to evaluate AO of the ET. Out of the 68 ears with normal preoperative TM, 52 ears (76.5%) were judged successful. Postoperative TM was normal in 41 ears (60.3%) and abnormal in 27 ears (39.7%). Success rate was 75.6% (31/41) in ears with normal postoperative TM and 77.8% (21/27) in ears with abnormal TM. Success rate was 70.6% (36/51) for the 51 ears in which AO was assessed both pre- and postoperatively. It was 66.7% (22/33) in ears with positive AO postoperatively and 77.8% (14/18) in ears without AO postoperatively. Abnormal postoperative TM findings without effectiveness were found in 8.8% (6/68). The authors discussed postoperative obstructive ET dysfunction and residual TM perforation. The incidence of either normal TM or positive AO was 84.3%. They feel that this is because the Kobayashi plug narrows the lumen of the cartilaginous portion of the ET rather than completely obstructing it. Residual perforation rate was 19.1% in this study. Presence of a TM perforation did not necessarily reduce patient satisfaction as it could improve their autophony symptoms. The authors acknowledged that absence of AO does not exclude a normal ear and therefore sonotubometry may not be reliable in judging normal ET function in all cases. PET is a challenging condition. Careful discussion of the options, including the risks and limitations, is paramount before any intervention, including Kobayashi plug surgery.

Tympanic membrane findings and Eustachian tube function after transtympanic plugging for the chronic patulous Eustachian tube.
Kusanoa Y, Ikedaa R, Kawamura Y, et al.
AURIS NASUS LARYNX
2023;50(6):859–65.