Prepared by Dr. Fadhil MohamedPrepared by Dr. Fadhil Mohamed

Introduced by Jansen at the House Ear Clinic in Introduced by Jansen at the House Ear Clinic in 1958.1958.

The aim is to exenterate the mastoid air cell The aim is to exenterate the mastoid air cell system as completely as possible.system as completely as possible.

To perform more conservative surgery & preserve To perform more conservative surgery & preserve the normal anatomy of the external auditory the normal anatomy of the external auditory canal.canal.

Leaves the patient with more options for hearing Leaves the patient with more options for hearing aids postoperatively.aids postoperatively.

Disadvantage : the higher postoperative rate of Disadvantage : the higher postoperative rate of cholesteatoma as compared to canal wall down cholesteatoma as compared to canal wall down procedures.procedures.

Postoperative cholesteatoma:either recurrent or Postoperative cholesteatoma:either recurrent or residual disease. residual disease.

Residual disease : presence of cholesteatoma due Residual disease : presence of cholesteatoma due to incomplete excision at the time of initial to incomplete excision at the time of initial surgery, surgery,

Recurrent disease : new formation of a Recurrent disease : new formation of a cholesteatoma from a new retraction pocket cholesteatoma from a new retraction pocket postoperatively. postoperatively.

Chances of failure can be decreased with certain Chances of failure can be decreased with certain preventative measures, including using Silastic preventative measures, including using Silastic sheeting, repairing bony defects of the posterior sheeting, repairing bony defects of the posterior canal wall, performing a staged second look canal wall, performing a staged second look surgery, and placing pressure equalization tubes. surgery, and placing pressure equalization tubes.

Planned second look surgery at 6 to 12 months Planned second look surgery at 6 to 12 months postoperatively to evaluate for residual or postoperatively to evaluate for residual or recurrent disease, with or without reconstruction recurrent disease, with or without reconstruction of the ossicular chain.of the ossicular chain.

The status of the ossicular chain is more The status of the ossicular chain is more predictive of postoperative hearing than the type predictive of postoperative hearing than the type of mastoidectomy performed.of mastoidectomy performed.

Indications:Indications: Complications of acute otitis media, chronic otitis Complications of acute otitis media, chronic otitis

media, cholesteatoma, exposure of structures media, cholesteatoma, exposure of structures within or deep to the temporal bone, within or deep to the temporal bone, cerebrospinal fluid otorrhea, facial nerve trauma,cerebrospinal fluid otorrhea, facial nerve trauma, and and neoplasm of the temporal bone.neoplasm of the temporal bone.

Preoperative preparation :Preoperative preparation : General examination to assess fitness for General examination to assess fitness for

G.A.G.A. CNS examination if intracranial CNS examination if intracranial

complications are suspected.complications are suspected. Facial nerve movement examination to Facial nerve movement examination to

exclude preoperative Facial nerve exclude preoperative Facial nerve paralysis.paralysis.

Full blood count.Full blood count. Ear swab: in cases of otorrhoea, Ear swab: in cases of otorrhoea,

intracranial complications.intracranial complications. Routine audiometry: measures Routine audiometry: measures

postoperative progress. postoperative progress. High-resolution C.T. of the temporal bones High-resolution C.T. of the temporal bones

: intraoperative planning , features of : intraoperative planning , features of surgical significance, such as a dehiscent surgical significance, such as a dehiscent facial nerve or tegmen tympani.facial nerve or tegmen tympani.

POSITIONING AND PREPARATION: The patient’s hair should be shaved The patient’s hair should be shaved

approximately 2-3 cm behind and above approximately 2-3 cm behind and above the ear to be operated upon. the ear to be operated upon.

The positioning of the patient is key in all otologic surgery.

For the CWU mastoidectomy, the patient should be positioned on the operating table such that the head is located at the foot of the bed.

The bed controls should be easily within reach of the anesthetist.

The patient should be securely strapped to the table .

The patient’s head should be located at The patient’s head should be located at the very end of the bed, closest to the the very end of the bed, closest to the surgeon’s side, and the head should be surgeon’s side, and the head should be rotated away from the surgeon and held in rotated away from the surgeon and held in position by a ring.position by a ring.

The facial nerve monitor, if it is to be used, The facial nerve monitor, if it is to be used, should be placed following the induction of should be placed following the induction of anesthesia. Electrodes are checked for anesthesia. Electrodes are checked for proper function prior to the case.proper function prior to the case.

The surgical field should be prepped The surgical field should be prepped widely with the surgeon’s choice of sterile widely with the surgeon’s choice of sterile solution, including inside the external solution, including inside the external auditory canal. auditory canal.

Various methods are used to secure the Various methods are used to secure the patient’s hair away from the field, patient’s hair away from the field, including painting the hair with Betadine, including painting the hair with Betadine, or taping it securely away with plastic tape or taping it securely away with plastic tape and benzoin. and benzoin.

The patient is then draped in the routine The patient is then draped in the routine fashion and placed in a slight fashion and placed in a slight Trendelenburg position& the head is Trendelenburg position& the head is draped with an ear hole. draped with an ear hole.

The operating room should be set up with The operating room should be set up with the anesthetist at the patient’s feet.the anesthetist at the patient’s feet.

The bed is rotated one-quarter turn The bed is rotated one-quarter turn following induction of anesthesia. following induction of anesthesia.

The surgeon should be seated at a The surgeon should be seated at a comfortable height at the patient’s head. comfortable height at the patient’s head.

The scrub nurse and instrument table The scrub nurse and instrument table should be located either adjacent to the should be located either adjacent to the surgeon toward the patient’s feet or surgeon toward the patient’s feet or across the table from the surgeon.across the table from the surgeon.

The operating microscope should be The operating microscope should be positioned at the patient’s head. positioned at the patient’s head.

The microscope should be balanced The microscope should be balanced properly before it is draped; the 200 or properly before it is draped; the 200 or 250 mm lens is used for otologic surgery.250 mm lens is used for otologic surgery.

INSTRUMENTATION:INSTRUMENTATION: Routine otologic instrumentation, Various Routine otologic instrumentation, Various

sizes of cutting and diamond burs are sizes of cutting and diamond burs are needed to complete the mastoidectomy. needed to complete the mastoidectomy.

A suction irrigation system is also crucial A suction irrigation system is also crucial for mastoid surgery. for mastoid surgery.

The suction system should be set up with The suction system should be set up with multiple canisters in series, to avoid multiple canisters in series, to avoid having to change canisters frequently having to change canisters frequently during the procedure.during the procedure.

Unipolar and bipolar cautery as well as Unipolar and bipolar cautery as well as otologic instrumentation for the middle ear otologic instrumentation for the middle ear should be available.should be available.

OPERATIVE TECHNIQUE:OPERATIVE TECHNIQUE: Once the patient is prepped and draped, Once the patient is prepped and draped,

local injection should be performed with 1 local injection should be performed with 1 to 2% lidocaine with 1:100,000 dilution to 2% lidocaine with 1:100,000 dilution epinephrine for vasoconstriction. epinephrine for vasoconstriction.

A postauricular injection should be made A postauricular injection should be made in the postauricular crease, extending in the postauricular crease, extending from the superior most aspect of the from the superior most aspect of the auricle to the mastoid tip.auricle to the mastoid tip.

Care should be taken not to extend the Care should be taken not to extend the injection beyond the mastoid tip.injection beyond the mastoid tip.

If meatal injections are required, they If meatal injections are required, they should be performed in all four quadrants should be performed in all four quadrants of the external auditory canal. of the external auditory canal.

Local anesthetic should be injected at the Local anesthetic should be injected at the bony cartilaginous junction while pressure bony cartilaginous junction while pressure is applied laterally with an ear speculum. is applied laterally with an ear speculum.

A blanch should be apparent extending A blanch should be apparent extending toward the tympanic membrane if the toward the tympanic membrane if the injection is performed properly.injection is performed properly.

After vasoconstriction has occurred, the After vasoconstriction has occurred, the postauricular incision should be made. postauricular incision should be made.

The incision should begin at the superior The incision should begin at the superior most aspect of the auricle in the most aspect of the auricle in the postauricular crease; it should be carried postauricular crease; it should be carried inferiorly either in the postauricular crease inferiorly either in the postauricular crease or up to 1 cm posterior to it. or up to 1 cm posterior to it.

The incision should extend to the mastoid The incision should extend to the mastoid tip, but not beyond it due to risk of injury tip, but not beyond it due to risk of injury to the facial nerve.to the facial nerve.

In children, the course of the facial nerve In children, the course of the facial nerve exiting the stylomastoid foramen can be exiting the stylomastoid foramen can be quite lateral; therefore, the postauricular quite lateral; therefore, the postauricular incision should be shifted posteriorly. incision should be shifted posteriorly.

The No. 15 blade should be used to make The No. 15 blade should be used to make the incision. The blade should be used to the incision. The blade should be used to carry the incision down to the level of the carry the incision down to the level of the temporalis fascia.temporalis fascia.

Blunt dissection with a finger should be Blunt dissection with a finger should be easily accomplished in this plane to easily accomplished in this plane to elevate flaps anteriorly and posteriorly. elevate flaps anteriorly and posteriorly.

Monopolar cautery is used to control Monopolar cautery is used to control bleeding. bleeding.

If a graft is needed for tympanoplasty, now If a graft is needed for tympanoplasty, now is the time to harvest one. is the time to harvest one.

The loose areolar tissue overlying the The loose areolar tissue overlying the temporalis fascia posterosuperior to the temporalis fascia posterosuperior to the auricle is elevated by injecting deep to it auricle is elevated by injecting deep to it with local anesthetic.with local anesthetic.

A self-retaining retractor is then placed to A self-retaining retractor is then placed to retract the ear anteriorly. retract the ear anteriorly.

A generous-size graft, approximately 1 A generous-size graft, approximately 1 cm2 in area is harvested. The graft is then cm2 in area is harvested. The graft is then placed on a heated block and flattened placed on a heated block and flattened with the back end of a forceps or knife with the back end of a forceps or knife handle, and left to dry.handle, and left to dry.

The monopolar cautery is then used to The monopolar cautery is then used to incise the temporalis fascia along the linea incise the temporalis fascia along the linea temporalis, extending from the zygomatic temporalis, extending from the zygomatic root posteriorly.root posteriorly.

The incision is carried down through the The incision is carried down through the periosteum to the temporal bone itself. periosteum to the temporal bone itself.

A vertical T incision is then made connecting A vertical T incision is then made connecting the horizontal incision to the mastoid tip. A the horizontal incision to the mastoid tip. A sizable flap is left anteriorly to facilitate sizable flap is left anteriorly to facilitate closure of the periosteum at the end of the closure of the periosteum at the end of the procedure.procedure.

The periosteum is then elevated The periosteum is then elevated anteriorly, posteriorly, and superiorly with anteriorly, posteriorly, and superiorly with a heavy Lempert elevator until the entire a heavy Lempert elevator until the entire mastoid cortex is exposed. mastoid cortex is exposed.

The operating microscope is then The operating microscope is then positioned such that the mastoid cortex is positioned such that the mastoid cortex is in view. in view.

A low-power lens should be used to A low-power lens should be used to visualize the entire cortex, external visualize the entire cortex, external auditory canal, and linea temporalis for auditory canal, and linea temporalis for orientation during dissection. orientation during dissection.

A large suction irrigator and large cutting A large suction irrigator and large cutting bur are used initially to make the first cuts bur are used initially to make the first cuts in the mastoid cortex. in the mastoid cortex.

The initial cuts are made posteriorly along The initial cuts are made posteriorly along the linea temporalis, and inferiorly along the linea temporalis, and inferiorly along the border of the external auditory canal the border of the external auditory canal extending into the mastoid tip. extending into the mastoid tip.

Dissection should begin at the zygomatic Dissection should begin at the zygomatic root, at the apex of the two initial cuts. root, at the apex of the two initial cuts.

During dissection, the direction of the cuts During dissection, the direction of the cuts should parallel the underlying structures should parallel the underlying structures to be identified.to be identified.

The large cutting bur should be used to The large cutting bur should be used to extend the dissection posteriorly and extend the dissection posteriorly and inferiorly, keeping the dissection at the inferiorly, keeping the dissection at the same depth throughout the mastoid cavity same depth throughout the mastoid cavity to facilitate identification of landmarks. to facilitate identification of landmarks.

When locating the tegmen tympani, the When locating the tegmen tympani, the cuts should be parallel and inferior to the cuts should be parallel and inferior to the linea temporalis to avoid injury to the linea temporalis to avoid injury to the underlying dura. underlying dura.

The sigmoid sinus is best identified The sigmoid sinus is best identified sweeping posteriorly along the inferior sweeping posteriorly along the inferior border of the mastoid.border of the mastoid.

The horizontal semicircular canal should The horizontal semicircular canal should be identified by sweeping posteriorly along be identified by sweeping posteriorly along the border of the external auditory canal. the border of the external auditory canal. This method avoids transection of This method avoids transection of important structures.important structures.

Once Korner’s septum has been entered Once Korner’s septum has been entered and the tegmen tympani, sigmoid sinus, and the tegmen tympani, sigmoid sinus, and horizontal canal have been identified, and horizontal canal have been identified, dissection should then be focused on dissection should then be focused on defining the sinodural angle and the antral defining the sinodural angle and the antral air cell.air cell.

The surgeon should ensure that the The surgeon should ensure that the tegmen is identified along the entire tegmen is identified along the entire course of the linea temporalis to facilitate course of the linea temporalis to facilitate exposure of the antrum and fossa incudis.exposure of the antrum and fossa incudis.

The antral air cell should be identified by The antral air cell should be identified by drilling anteriorly and superiorly at the drilling anteriorly and superiorly at the apex of the first two bur cuts, near the apex of the first two bur cuts, near the root of the zygoma. root of the zygoma.

A smaller cutting bur is used to better A smaller cutting bur is used to better define the antrum, a curette can be used. define the antrum, a curette can be used.

The drill should be placed medially and The drill should be placed medially and pulled laterally to protect the underlying pulled laterally to protect the underlying structures.structures.

The surgeon should take care not to form The surgeon should take care not to form ledges or overhanging bone particularly at ledges or overhanging bone particularly at this stage, as this may contribute to this stage, as this may contribute to inadvertent injury. inadvertent injury.

It should be remembered that the posterior wall is not perpendicular to the surface of the mastoid. To reach the antrum the direction of drilling should be medial and forward .

The bed may also be rotated away from The bed may also be rotated away from the surgeon and the microscope the surgeon and the microscope repositioned to provide better visualization repositioned to provide better visualization of the incus. of the incus.

Once the fossa incudis and the incus have Once the fossa incudis and the incus have been identified, a diamond bur should be been identified, a diamond bur should be used to control any bleeding from the used to control any bleeding from the mastoid bone and to smooth out any mastoid bone and to smooth out any rough areas remaining along the tegmen rough areas remaining along the tegmen or the posterior wall of the EAC. or the posterior wall of the EAC.

A wide opening with identification of the landmarks – sigmoid sinus, bone on the dura of the middie fossa, the lateral semicircular canal, the facial nerve and the chorda – speeds up the surgery and avoids the risk of damage.

If the bony shell of the sigmoid sinus is very prominent, the bone might be thinned, fractured (egg-shelled) and pushed backwards.

The facial nerve should be identified using The facial nerve should be identified using a large diamond bur.a large diamond bur.

The level of the nerve will be marked by The level of the nerve will be marked by the incus and the horizontal canal. the incus and the horizontal canal.

The nerve should be identified by gently The nerve should be identified by gently passing the drill anterior and parallel to passing the drill anterior and parallel to the sigmoid sinus, then moving anteriorly.the sigmoid sinus, then moving anteriorly.

The distinct appearance of the facial nerve The distinct appearance of the facial nerve and the chorda tympani will appear along and the chorda tympani will appear along the posterior aspect of the EAC, coursing the posterior aspect of the EAC, coursing inferiorly .inferiorly .

The facial recess is now ready to be opened The facial recess is now ready to be opened if necessary. The landmarks have been if necessary. The landmarks have been identified, including the fossa incudis, chorda identified, including the fossa incudis, chorda tympani, and mastoid portion of the facial tympani, and mastoid portion of the facial nerve.nerve.

A diamond bur or a cutting bur may be A diamond bur or a cutting bur may be used to open the recess. used to open the recess.

The mastoid bone and facial recess air cells The mastoid bone and facial recess air cells are entered, taking care to avoid injury to are entered, taking care to avoid injury to the facial nerve by making cuts parallel to the facial nerve by making cuts parallel to its course. its course.

Drilling is continued until the middle ear Drilling is continued until the middle ear space is entered .space is entered .

Work in the middle ear can now be Work in the middle ear can now be accomplished if necessary, and accomplished if necessary, and tympanoplasty can be carried out .tympanoplasty can be carried out .

A final check with an endoscope is helpful . If in cholesteatoma surgery the epithelium

cannot be removed safely, the procedure must be converted to open surgery.

CLOSURE:CLOSURE: Copious irrigation of the wound to remove Copious irrigation of the wound to remove

bone dust and fragments. bone dust and fragments. The operative wound is closed in three The operative wound is closed in three

layers .layers . The periosteum is closed using interrupted The periosteum is closed using interrupted

absorbable sutures such as 3-0 Vicryl. The absorbable sutures such as 3-0 Vicryl. The subcutaneous tissue is also closed using subcutaneous tissue is also closed using interrupted absorbable suture, then skin is interrupted absorbable suture, then skin is closed.closed.

Bacitracin is then placed on the wound Bacitracin is then placed on the wound and a nonstick dressing is applied. and a nonstick dressing is applied.

A mastoid dressing is then placed on the A mastoid dressing is then placed on the patient prior to awakening, to create a patient prior to awakening, to create a tight pressure dressing. tight pressure dressing.

The patient is then awakened and taken to The patient is then awakened and taken to the recovery room.the recovery room.