--- title: "Canal wall Down VS Canal wall Up Mastoidectomy" description: "Key differences between Canal wall down and Canal wall up Mastoidectomy." source: "The ENT Resident" author: "Dr. Mausumi Das" canonical_url: "https://www.theentresident.com/ent-notes-lectures/canal-wall-down-up-mastoidectomy" categories: ["Otology", "Surgery", "Differences Tables in ENT"] video: "https://www.youtube.com/watch?v=kUCWEPRC1r0" image: "https://media.theentresident.com/og-images/canal-wall-down-up-mastoidectomy.png" --- # Canal wall Down VS Canal wall Up Mastoidectomy Key differences between Canal wall down and Canal wall up Mastoidectomy. Watch the full video lecture on YouTube: https://www.youtube.com/watch?v=kUCWEPRC1r0 ## đŸĻģ Mastoidectomy: Canal Wall Up vs Canal Wall Down ### Key Anatomical Landmarks | Structure | Description | Clinical Importance | | --- | --- | --- | | **Aditus** | Communication between middle ear and mastoid antrum | Surgical pathway | | **Posterior canal wall** | Common wall between EAC (front) and mastoid antrum (back) | Decides CWU vs CWD | | **Spine of Henle** | Bony projection in posterosuperior EAC | Surface landmark | | **McEwan's triangle (Suprameatal triangle)** | Bounded by: supramastoid crest (superior), posterosuperior EAC line (anterior), tangent joining them (posterior) | Mastoid antrum ~1.5 cm deep | | **Facial bridge** | Part of posterior bony canal wall overlying fossa incudis | Removed in Canal wall down surgery for exposure | | **Facial ridge** | Posterior canal wall overlying bony facial canal | Lowered during surgery, cannot be removed fully (risk of Facial Nerve injury) | | **Anterior buttress** | Junction of posterior canal wall with tegmen | Surgical landmark | | **Posterior buttress** | Junction of posterior canal wall with EAC floor | Surgical landmark | --- ### Definition of Mastoidectomy | Term | Definition | | --- | --- | | **Mastoidectomy** | Surgical removal of mastoid air cells in temporal bone to eradicate disease & access middle ear cleft | | **Canal Wall Up (CWU)** | Posterior canal wall **preserved** → mastoid cavity remains separate from EAC | | **Canal Wall Down (CWD)** | Posterior canal wall **removed** → mastoid cavity + EAC become one large cavity | --- ### Goals | Procedure | Aim | | --- | --- | | **Canal Wall Up (CWU)** | Eradicate disease **while preserving near-normal canal anatomy** and hearing mechanism | | **Canal Wall Down (CWD)** | Eradicate disease with **wide exteriorization**, ensuring a safe, dry ear | --- ### Common Surgeries | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Cortical mastoidectomy (aka Simple/Schwartz/Complete Mastoidectomy) | Atticotomy | | Combined approach tympanoplasty (CAT) | Atticoantrostomy | | – | Modified radical mastoidectomy | | – | Radical mastoidectomy | --- ### Indications | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Limited cholesteatoma (attic/antrum only) | Extensive/recurrent cholesteatoma | | Good Eustachian tube function | Posterior canal wall erosion | | Reliable patient follow-up | Poor Eustachian tube function | | Preferred first surgery (esp. children) | Unreliable follow-up | | – | Complicated CSOM (intracranial/extracranial) | | – | Revision surgeries | --- ### Exposure & Clearance | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Limited exposure – sinus tympani, anterior epitympanum, hypotympanum difficult to visualize | Wide exposure – direct view of all recesses | | Higher chance of residual disease | More complete clearance | --- ### Recurrence | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Higher recurrence/residual disease (10–40%) | Lower recurrence (2–10%), easier detection | --- ### Hearing Outcomes | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Better – normal canal acoustics, ossicular reconstruction easier | Poorer – large cavity, less favorable acoustics, though ossiculoplasty still possible | --- ### Postoperative Canal Appearance | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Normal EAC preserved | Enlarged meatus with large mastoid cavity | --- ### Cavity Care & Follow-up | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | No cavity care required; ear is self-cleansing | Lifelong periodic cleaning (aural toileting) | | Requires strict follow-up & second-look surgery (6–18 months) | Less stringent follow-up needed | --- ### Complications | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Higher residual/recurrent disease, retraction pocket formation | Cavity-related problems: otorrhea, granulation tissue, meatal stenosis | --- ### Patient Limitations | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | No long-term restrictions; swimming allowed | Swimming/bathing restrictions (risk of infection, caloric vertigo) | --- ### Auditory Rehabilitation | Canal Wall Up (CWU) | Canal Wall Down (CWD) | | --- | --- | | Easier to fit hearing aids | Hearing aid fitting difficult due to large cavity/infections | --- ### Advantages vs Disadvantages | Canal Wall Up (CWU) Advantages | Canal Wall Up (CWU) Disadvantages | | --- | --- | | Preserves EAC anatomy | Limited exposure | | Better hearing outcome | Higher recurrence (10–40%) | | No cavity, no lifelong care | Requires second-look surgery | | Fewer lifestyle restrictions | Retraction pocket risk if Eustachian Tube function poor | | Preferred in children | – | | Canal Wall Down (CWD) Advantages | Canal Wall Down (CWD) Disadvantages | | --- | --- | | Excellent exposure, complete clearance | Creates large cavity → cavity related issues | | Lower recurrence (2–10%) | Lifelong cleaning needed | | Recurrence easily visible | Water restrictions (no swimming) | | No need for second look | Cosmetic deformity (enlarged meatus, postauricular hollow) | | Useful in unreliable follow up | Worse hearing outcome, hearing aid fitting difficult | --- ### Types of Mastoidectomy (Quick Definitions) | Surgery | Type | Key Features | | --- | --- | --- | | **Cortical mastoidectomy** | CWU | Exenteration of all accessible mastoid air cells; posterior canal wall intact; preserves TM & ossicles | | **Radical mastoidectomy** | CWD | Removes mastoid + middle ear + attic + antrum; posterior canal wall removed; removes TM remnants, all ossicles except stapes footplate; ET opening closed | | **Modified radical mastoidectomy** | CWD | Like radical but **preserves** TM remnants, functioning ossicles, and ET opening | --- ## About This Note This free ENT note on Canal wall Down VS Canal wall Up Mastoidectomy was written by Dr. Mausumi Das and is paired with a corresponding video lecture. 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