Intraoperative symptom-guided plug size selection in sitting position Kobayashi plug surgery for patulous eustachian...

To evaluate the efficacy and safety of Kobayashi Plug Surgery (KPS) for patulous Eustachian tube (PET) performed under local anesthesia in the sitting position, using intraoperative subjective symptoms to guide plug size selection, and to investigate its effect on revision surgery rates.

This retrospective study included 61 patients (73 ears) with refractory PET who underwent KPS between December 2023 and June 2025. All procedures were performed under local anesthesia with patients in the sitting position, allowing for real-time assessment of subjective symptoms immediately after plug placement. If symptoms persisted, the plug size was increased intraoperatively. Clinical data, surgical outcomes, plug sizes, and postoperative complications were analyzed. Long-term outcomes were assessed in 29 ears with follow-up exceeding 180 days using PHI-10, Eustachian tube function tests, and revision surgery rates.

Plug placement was successful in 66 of 73 ears (90.4%). Plug size adjustment during initial surgery was performed in 5 ears (7.6%) based on persistent symptoms. Among 29 ears with long-term follow-up (median: 297.5 days), the overall revision surgery rate due to upsizing was 10.3%. However, among the 41 ears that presented with subjective symptoms at the time of surgery, only 1 case (2.4%) required revision surgery during follow-up. PHI-10 scores significantly improved from a median of 30 to 10 (p < 0.001), and sonotubometry sound pressure levels increased from 85 dB to 99 dB (p < 0.005). Tympanic membrane perforation was observed in one ear (preexisting), and ventilation tube placement for otitis media with effusion was required in 4 ears (13.8%).

KPS under local anesthesia in the sitting position allows for intraoperative symptom-based plug size selection, which may help reduce the need for revision surgery, especially in patients with active symptoms at the time of surgery. While the overall revision rate was 10.3%, it was markedly lower (2.4%) among symptomatic cases. Although the findings should be interpreted with caution due to the small sample size and retrospective design, this technique represents a promising approach for improving surgical outcomes in patients with refractory PET.