Tympanomastoidectomy

Considerations

• • Canal wall preservation

  • 2013: Tympanomastoidectomy: Comparison between canal wall-down and canal wall-up techniques in surgery for chronic otitis media

  • Otoendoscopy

  • 2012: Tympanomastoidectomy with otoendoscopy

Preparation

• • Equipment

    • Trays 

    • 2 HNS pump chairs

    • Leica microscope

      • Place assistant viewing eye piece to opposite side of the operated ear (if operating on the left ear, place to right of the surgeon's eye piece)

      • Balance

      • Set focal length to 250 

    • NIM for facial nerve monitoring 

    • Otologic drill

    • likely endoscopic ear tray with pediatric sinus scopes and camera

• Place NIM electrodes for facial nerve monitoring - Be mindful when removing drapes to not stick yourself 

• Trim postauricular hair 

• Clean ear, inject EAC and postauricular 

• Drape

  • Blot betadine prep off the field

  • Drape: eye drape over ear followed by thyroid drape

    • • Option: Split drape but drape wide so there's lots of the ear drape exposed post-auricularly, so you can place the ear pouch onto the ear drape plastic rather than the split drape (Macy modification)

        • • plastic on plastic which provides a better seal to prevent drainage onto the floor

  • Mastoid catch basin

Procedure

• • Start w 5-6 mm speculum, dilate up until the speculum sits snug in the canal

    • • if spec is too unstable in the canal, you need a bigger spec

  • Initial canal incision

    • • 3 suction in left hand

      • Just complete the lateral incisions, save the medial incisions when you turn the ear 

      • 6 and 12 o'clock incisions w beaver blade

      • circumannular incision w large round knife

• • • make sure you're leaving enough flap medially and laterally

      • • account for scutum defects and the need for curetting the scutum 

• • • • back elevate the flap

• • Turn the ear forward

    • • Complete post auricular incision with the 15 blade

      • sharply dissect superiorly to the temporalis fascia 

        • • Pearl: when you lift the ear up, the TPF will raise up, but the temporalis fascia will stay down

          • once at the level of the temporalis fascia, carry the incision all the way down to the mastoid tip 

          • retract ear with Weitlaner 

      • Periosteal incisions 

        • • Considerations in flap design

            • • Low likelihood for CWD, anterior based flap (7 or reverse 7)

              • High likelihood for CWD, posterior based flap (5 or reverse 5) (Yoshi style)

          • Connect to the 12 o'clock canal incision at the superior bony EAC with the 15 blade

            • • now you have this part of the tympanomeatal flap identified

          • Complete the periosteal flap incisions with the Bovie

          • Raise the periosteum with the periosteal elevator over the mastoid 

• • • • • • • Use the Freer around the antrum of the EAC

• • • • • • Setup Weitlaner to hold ear forward, can also place 2nd Weitlaner

          • Bring in microscope and elevated the rest of the lateral canal flap with large round knife 

          • With hemostat and 1/2 in penrose, pull the penrose from post auricular to the EAC and retract the ear forward. 

            • • clamp anteriorly with hemostat. 

  • Raising medial TMF

    • • 12 and 6 o'clock incisions with sickle blade

      • Then raise flap with large round knife

        • • Technique

            • • keep on bone

              • 3 suction behind the round knife 

              • make sure to raise superior and inferior flaps anterior enough

              • if superior and inferior cuts aren't through and through, can elevate underneath then finish cuts with Belucci scissors

• • • • • • • elevate widely

• • • • • • lift annulus starting in the inferior quadrant

            • • if it's a very ateletactic drum, may have to enter straight posteriorly, just be cognizant of chorda

          • once a little annulus is up, use Rosen enter into the middle space (make sure you're button holing the TM)

          • once middle ear space visualized, use annulus elevator and make a sweep inferior along the annular groove to lift the inferior drum quickly 

          • use Rosen to elevate the superior aspect of the flap

            • • likely part of the cholesteatoma matrix is abutting along the scutum/scutum defect and superior quadrant. Elevate widely and make sure to elevate the drum beyond the anterior aspect of the matrix sac

          • follow chorda to the malleus 

            • • Consideration: if chorda is going right through the sac and adherent to the sac, may consider sacrificing chorda

  • Define your landmarks: 

    • • Identify your malleus, incus, stapes, facial nerve

        • • Really, you want to define your stapes above all

          • Considerations:

            • • do not dissect blindly along the floor of the middle ear

                • avulsion of stapes

                • trauma to the facial n

  • If going to drill the mastoid

    • • separate your IS joint to prevent SNHL

  • Dissect the matrix what you can with blunt dissectors 

Sample operative report

Post-op

• • Medications

    • Norco or comporable Rx 

    • Optional: Amoxicillin x 7 d

    • POD 1-2 start Floxin

• Dressing

  • POD 2 remove Glasscock 

Pearls & Pitfalls

• If previous extensive mastoid disease or poor EAC exposure, make lateral canal incisions (12 and 6 o'clock going laterally without worrying about medial incisions), connect with large round knife, back elevate and go postauricular

• If staying transcanal make standard TM flap incisions (don't short flap it!)

• If drilling the facial recess or significant scutal defect, think about reinforcing it with cartilage

• If decent amount of cholesteatoma found plan to place silastic and not reconstruct ossicular chain

High-Yield

Links

• eMedicine - Tympanoplasty

  • eMedicine - Mastoidectomy 

• YouTube (3:22) - Canal Wall Down Mastoidectomy with Meatoplasty

  • YouTube (1:33:47) - WML R Tympanoplasty Mastoid L Tape 1 Excellent teaching video from the House Ear Institute