[Comparison of the clinical outcomes between endoscopic butterfly inlay cartilage tympanoplasty and underlay cartilage tympanoplasty in small-to-medium-sized tympanic membrane perforations]

Abstract

Objective:To compare the differences in postoperative healing rates, hearing improvement, and complication rates between endoscopic butterfly inlay cartilage tympanoplasty and underlay cartilage tympanoplasty in Small-to-Medium-Sized Tympanic Membrane Perforations, and to provide clinical basis for indication of the butterfly inlay cartilage tympanoplasty. Methods:This study enrolled patients with chronic suppurative otitis media or traumatic tympanic membrane perforations who were treated at the Department of Otorhinolaryngology Head and Neck Surgery, the First Affiliated Hospital of Chongqing Medical University, between January 2022 and May 2023. Inclusion criteria comprised a dry ear period exceeding 3 months, absence of middle ear or mastoid pathology confirmed by temporal bone CT, and an air-bone gap of less than 40 dB. All surgeries were performed by the same surgeon using tympanoplasty techniques. Based on the surgical approach and perforation size, patients were categorized into four groups: Group A（butterfly cartilage tympanoplasty, perforation ≤3 mm）: 23 cases. Group B（butterfly cartilage tympanoplasty, perforation 3-5 mm）: 17 cases. Group C（full-thickness cartilage underlay tympanoplasty, perforation ≤3 mm）: 12 cases. Group D（full-thickness cartilage underlay tympanoplasty, perforation 3-5 mm）: 22 cases. Data collected included perforation duration, preoperative Eustachian Tube Score（ETS）, pure-tone audiometry, otoscopic findings, and postoperative follow-up data on pure-tone thresholds, otoscopic outcomes, and complications such as graft infection and otorrhea. Results: The mean postoperative follow-up period was 4 months （range: 3-12 months）. A total of 74 patients were enrolled, including 40 undergoing butterfly cartilage tympanoplasty and 34 receiving full-thickness cartilage inlay tympanoplasty. In the <3 mm perforation subgroup, the patients receiving butterfly technique （23 cases） exhibited a postoperative air-bone gap （ABG） improvement of （2.33±8.21） dB, and those receiving the inlay technique （12 cases） showed an ABG improvement of （2.49±7.9） dB, with no statistically significant difference between the two groups （P>0.05）. In the 3-5 mm perforation subgroup, the patients receiving butterfly technique （17 cases） demonstrated an ABG improvement of （8.16±5.69） dB, and those receiving the inlay technique （22 cases） achieved an ABG improvement of （8.08±10.42） dB, which were not significantly different （P>0.05）. Tympanic membrane healing rates across the four subgroups were 95.65%, 94.12%, 100%, and 95.45%, respectively, with no statistically significant differences （P>0.05）. Conclusion:In patients with tympanic membrane perforations ≤3 mm and 3-5 mm, butterfly cartilage tympanoplasty achieves comparable audiological outcomes to full-thickness cartilage underlay tympanoplasty. Compared with the underlay technique, the butterfly method is less invasive, preserves the normal anatomical structure of the tympanic membrane, requires a shorter dry ear period, and yields higher patient satisfaction. Therefore, it can be safely recommended for perforations ≤5 mm that do not require tympanotomy exploration.

Keywords: butterfly tympanoplasty; otoscope; tympanic membrane perforation.