Surgical Treatment for Troublesome Mastoid Cavities: Canal Wall Reconstruction With Bony Obliteration Versus Subtotal Petrosectomy

Introduction: A chronically discharging modified radical mastoid cavity may require surgical intervention. We aim to explore two techniques.

Objective: To compare outcomes of subtotal petrosectomy (STP) and canal wall reconstruction with bony obliteration technique (CWR-BOT).

Study design: Retrospective cohort study.

Setting: A tertiary referral center.

Patients: All patients with a chronically discharging mastoid cavity surgically treated at the Radboud University Medical Center by STP or CWR-BOT in 2015 to 2020, excluding patients with preoperative cholesteatoma.

Main outcome measures: Dry ear rate, audiometry, and rehabilitation.

Secondary outcome measures: Healing time, number of postoperative visits, complications, cholesteatoma, and need for revision surgeries.

Results: Thirty-four (58%) patients underwent STP, and 25 (42%) CWR-BOT. A dry ear was established in 100% of patients (STP) and 87% (CWR-BOT). The air-bone gap (ABG) increased by 12 dB in STP, and decreased by 11 dB in CWR-BOT. Postoperative ABG of CWR-BOT patients was better when preoperative computed tomography imaging showed aerated middle ear aeration. ABG improvement was higher when ossicular chain reconstruction took place. Mean follow-up time was 32.5 months (STP) versus 40.5 months (CWR-BOT). Healing time was 1.2 months (STP) versus 4.1 months (CWR-BOT). The number of postoperative visits was 2.5 (STP) versus 5 (CWR-BOT). Cholesteatoma was found in 15% (STP) versus 4% (CWR-BOT) of patients. Complication rate was 18% (STP) and 24% (CWR-BOT) with a need for revision in 21% (STP) and 8% (CWR-BOT), including revisions for cholesteatoma.

Conclusion: STP and CWR-BOT are excellent treatment options for obtaining a dry ear in patients with a chronically discharging mastoid cavity. This article outlines essential contributing factors in counseling patients when opting for one or the other. Magnetic resonance imaging with diffusion-weighted imaging follow-up should be conducted at 3 and 5 years postoperatively.