What are the approaches to mastoidectomy?

Approaches to Mastoidectomy

The two main surgical approaches to mastoidectomy are canal wall up (CWU) and canal wall down (CWD) mastoidectomy, with the choice determined by the extent of cholesteatoma, anatomical factors, and surgeon experience. 1, 2

Primary Surgical Approaches

Canal Wall Up (CWU) Mastoidectomy

• Preserves the posterior canal wall and maintains normal middle ear anatomy 1, 2
• Major advantage: Avoids creation of an open mastoid cavity postoperatively 2
• Critical limitation: Higher incidence of disease recurrence compared to CWD 2
• Best suited for limited disease without extensive posterior canal wall erosion 3

Canal Wall Down (CWD) Mastoidectomy

• Removes the posterior canal wall, creating an open mastoid cavity 1, 2
• Major advantage: Lower recurrence rates and better disease visualization 1, 2
• Significant drawback: Creates open cavity with 20-60% risk of persistent intermittent drainage 4
• Requires meatoplasty to facilitate cavity inspection and cleaning 5

Indications for Canal Wall Down Approach

CWD mastoidectomy is mandated when: 3

• Large labyrinthine fistula is present
• Extensive erosion of posterior auditory canal wall exists
• Prior canal wall up surgery has failed
• Contracted, sclerotic mastoid with extensive disease
• Inadequate exposure or inability to safely remove disease with CWU approach

Modified Approaches

Limited Mastoidectomy/Atticotomy (The "Third Way")

• Uses inside-outside approach through endaural incision 1
• Includes atticotomy, atticoantrostomy, or very limited mastoidectomy based on cholesteatoma size and location 1
• Creates small, dry, self-cleaning cavities without pinna protrusion 1
• Eliminates need for meatoplasty or obliteration 1

Mastoid Obliteration Techniques

• Cavity reconstruction with Palva flap reduces drainage risk from 20-60% to approximately 7% 4
• Mastoid obliteration with autologous bone shows low recurrence rates similar to traditional CWD 6
• Provides greater water resistance and quality of life improvements 6
• Safe, low-cost option with at least 12 months follow-up data 6

Canal Wall Down with Reconstruction

• Combines CWD with external ear canal reconstruction and tympanoplasty 5
• Includes mastoid obliteration to minimize cavity-related problems 5
• Balances disease eradication with functional outcomes 5

Critical Decision-Making Factors

The surgical approach must account for: 1, 5

• Extent and location of cholesteatoma
• Anatomic relationship between sensitive structures and bony destruction
• Patient's ability to comply with postoperative care
• Surgeon's experience and comfort level

Common Pitfalls to Avoid

• Never assume CWU is always preferable - the higher recurrence rate can lead to repeated surgeries 2
• Do not underestimate cavity problems with CWD - chronic drainage affects 20-60% without reconstruction 4
• Avoid inadequate follow-up - structured surveillance with otoscopy every 6-12 months and MRI every 1-2 years is mandatory for detecting recurrence 5
• Remember that cholesteatoma has high recidivism rates requiring repeated surgery if not adequately addressed initially 5