[Application of combined packing with two pedicled myoperiosteal flaps in canal wall down tympanomastoidectomy]

Objective:To explore the clinical efficacy of combined application of two pedicled myoperiosteal flaps for packing the mastoid cavity in canal wall down tympanomastoidectomy. Methods:A total of 85 patients who underwent canal wall down tympanomastoidectomy for middle ear cholesteatoma from January 2016 to January 2022 were included. All patients underwent preoperative temporal bone computed tomography（CT） examination, which confirmed they had pneumatized mastoids with extensive lesions or destruction of the posterior wall of the external auditory canal. Routine canal wall down mastoidectomy with tympanoplasty was performed, and two pedicled myoperiosteal flaps, with pedicles located at the temporal muscle and posteroinferior parts of the mastoid respectively, were used to pack the epitympanic antrum and mastoid tip regions. Patients were reexamined weekly after surgery until the surgical cavity was completely healed. Pure-tone audiometry and otoscopic examination were conducted 3 months postoperatively, and temporal bone CT was performed 1 year postoperatively. Subsequent follow-ups were scheduled every 3 months or 6 months. During the follow-up period, the shape and healing of the surgical cavity, recurrence of cholesteatoma, and the effect of hearing improvement were evaluated. Results:All patients successfully completed the surgery, with no complications such as facial paralysis, cerebrospinal fluid otorrhea, or vertigo, and no wound infection during the perioperative period. The average time for complete healing of the surgical cavity was 6 weeks, with a dry ear rate of 100%. Otoscopic examination at 3 months and temporal bone CT at 1 year postoperatively showed that the shape of the surgical cavity was close to that of a normal external auditory canal, with a slightly wider diameter. At 1 year postoperatively, 30.6% of patients had epitympanic retraction; at 2 years postoperatively, 43.5% of patients had epitympanic retraction, and 27.1% had mild retraction in the epitympanic antrum region. However, the overall surgical cavity was smooth and easy to clean. Hearing was significantly improved in 60.0% of patients, slightly improved in 25.9% of patients, and no significant change was observed in 14.1% of patients; no cases of hearing loss were reported. During the follow-up period of 2 to 7 years, no external auditory canal stenosis, surgical cavity infection, or cholesteatoma recurrence was found. Conclusion:The combined application of two pedicled myoperiosteal flaps in canal wall down tympanomastoidectomy can effectively reduce the size of the mastoid surgical cavity and optimize the cavity shape. Furthermore, these two pedicled myoperiosteal flaps are easy to manipulate and possess strong anti-infective ability, which can effectively solve the residual surgical cavity problem after canal wall down mastoidectomy.