Temporal Bone Dissection - The Zurich Guidelines (2006)

In collaboralion wilh

Deparlment ot ENT, Lucerne Cantonal Hospital, Switzerland

TEMPORAL BONE DISSECTION - The ZURICH Guidelines Prof. Ugo FISCH, M.D. ENT Center, Hirslanden Hospital, Zurich, Switzerland

In collaboration with Assoc. Prof. Thomas LINDER, M .D. Department of ENT, Lucerne Cantonal Hospital, Switzerland

89 Illustrations by Katja Dalkowski, M.D. Buckenhof, Germany

This booklet is based on teaching material distributed at the yearly held Temporal Bone Dissection Courses organized by the Fisch International Microsurgery Foundation at the Anatomy Department of the University of Zu rich, Switzerland Chairman: Prof. Peter Groscurth, M.D.

We are grateful to the follow ing persons, who have helped in our courses for more than 15 years and contributed in developing the principles exposed in this booklet: Prof. John May, M.D. Wake Forest University, Winston Salem NC, USA Prof. Rodrigo Posada, M.D. University of Pereira Pereira, Colombia

FISCH INTERNATIONAL MICROSURGERY FOUNDATION

Temporal Bone Dissection - The Zurich Guidelines

4

Illustrations by: Katja Dalkowski, M.D. Grasweg 42 0-91054 Buckenhof, Germany Email: [email protected]

Temporal Bone Dissection - The Zurich Guidelines Prof. Ugo FISCH, M.D. ENT Center, Hirslanden Hospital, Zurich. Switzerland In col laboration with Assoc. Prof. Thomas LINDER, M.D. Department of ENT, Lucerne Cantonal Hospital. Switzerland Contact: Fisch International Microsurgery Foundat ion Forchstr. 26. CH-8703 Erlenbach Switzerland Phone: +41 (0) 1 9106828 Fax: +41 (0)1 9106126 Email: [email protected] C 20Cl6 Endo-Press "'. Tutthngen, Geliliany ISBN 3-89756-106-9. Pnnted In Gem1any

P.O. Box, 0-78503 Tutlhngen Phone: +497461114590 Fax.: +497461nOB-529 E-mail:

EndopressOt -onhne.de

Edit ions in other languages than English and German are in preparation. For up-tO-date informati on. please contact EndoPress"" Tuttlingen. at the address mentioned above.

Please note: Medical knowledge IS aver changmg. As new research

and clinica l e~perience broaden our know ledge, changes in treatment and drvg therapy may be reqUIred. The auth~ and editors of the material herein have consulted sources believed to be reliable in their efforts to proVide information thaI IS complete and in accordance With the standards accepted at the time of publication. However. in view of the poSSibility of human error by the authors, editorS. or publlshef 01 the work here,n. or changes In medICal knowledge. n<her the authors. editors. publisher, nor any other party who has been inVolved in the preparation 01 thIS work, warrants that the infOfmahon contained herem is 10 every respect accurate or complete. and they are not responSible for any errors or orlllSSIOflS or lor the results obtained from use 01 such InlO4TT1atlon. The onformatoon conlall1ed wlthtn thiS brochure IS Intended fOf use by doctOfS and other heallh care professoonals This matenal IS nol Inleoded fOf use as a baSIS for treatment OeclSoonS. and IS not a substitute fOf professional consul· tatlOO and/Of peer-reviewed medICal hletature. Some of the product names. patents. and reglsteted deslgns referred to 111 thiS booIIlet are In facl registered trademarlls Of proprlelary names even though specific reference 10 thiS fact IS nol always made In lhe text Therefore. the appearance of a name Without deSignation as propnetary IS not to be construed as a representation by the publisher that It is in the public domain .

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1106·2

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Temporal Bone Dissection - The Zurich Guidelines

Table of Contents A.1 Introduction .................. .. . . ........... .. . . . . .... . .. . ... ........

6

A.2 General Preparation ............. . . . . . ... .. . . . .. ... . .... . . . ....... . ....

6

A.3 Specific Surgical Techniques

...... . .. . . . . .. . . . .. . . .. . . . ...... . . . . .. ... •

7

Closed-Cavity Technique .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7

Tympano-Antrotomy (Meatoplasty, Canalplasty, Myringoplasty, Antrotomy, Epitympanotomy, Osslculoplasty, Mastoid Drainage) .... . . .... ........ B.1.1 Meatoplasty . . ..... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . B.1.2 Canalplasty ......................................... . . . . . . . . . . . . B 1.3 Myringoplasty ............ . . ...... ................ . . . .. . . .. ...... B.1.4 Antrotomy ................. . . .... ................ . . .... ......... B .1.5 Epitympanotomy .............. . . .. .................. . . .. ......... B.1.6 Transmastoid Drainage of the Antrum ...............................

7 7 g 13 15 15 16

B

B.1

B .2

Tympano-Mastoidec t omy (Meatoplasty, Canalplasty, Epitympanec tomy. Mastoidectomy, Posterior Tympanotomy, Ossiculoplasty, Myringoplasty, Mastoid Drainage) B.2.1 Mastoidectomy ............................................. B.2.2 Posterior Tympanotomy ...... ................ ...... .......... B.2.3 Epitympanectomy ........... ............ ...... ...... . . . . .. . .

17 17 18

Myringoplasty and Ossic uloplasty in Closed Cavities B.3.1 Myringoplasty ......... . .......................... . . .. . .•. .. B.3.2 Ossiculoplasty (Incus-Interposition) .................. . .. ...... .

20

Stapedotomy C.l Incus-Stapedotomy .............................................. C.2 Malleo-Stapedotomy ............ ... ................... ... .........

22 28

Open Cavity Techniques (Mastoido-Epitympanectomy, Open MET) D.1 Mastoidectomy ........ ........ ........................ .... . .. ... D.2 Epitympanotomy ................................................ . 0 .3 Completion of Mastoido-Epitympanectomy ..........................

32 34 34

E

Tympanoplasty (Myringoplasty and Ossiculoplasty) in Open Cavities .........• E.l Type III Tympanoplasty ....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . • E.2 Total Reconstruction of the Ossicular Chain .......................... E.2. l Fisch Titanium Total Prosthesis .......................... . . . . . . . . . . . E.2.2 Titanium Neo- Malleus . . . . . . . . . . . . . . . . . . . . . . . . • . . . . • . . . . • . . . . . . . . . .

35 35 36 36 41

F

Additional Temporal Bone Dissections F.l Subtotal Petrosectomy .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F.l.1 Subtotal Petrosectomy with Preservation of the Otic Capsule ........ ... F.l.2 Subtotal Petrosectomy with Removal of the Otic Capsule .... . . . . . . . . . . .

42 42 43

G

Suggested Reading . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

44

H

Prostheses and Instruments

B.3

C

o

H.l H.2

FISCH Titanium Middle Ear Prostheses. . . . . . . . . . . . . • . . . . . . . . . . • . . . • . . FISCH Special Instruments for Tympanoplasty, Mastoidectomy and Stapedotomy . . . . . . . . . . . . . . . . . • . . . . • . . . . . . . . . . . .

19

45 45

6

Temporal Bone Dissection - The Zurich Guidelines

A.1 Introduction

A.2 General Preparation

The series of surgical techniques described in this article relates to procedures that can be practiced in a course using two temporal bones. The first bone is used to demonstrate the closed-cavity tympana-mastoidectomy with related myringoplasty and ossiculoplasty (incus interpoSition), The second bone is used to demonstrate stapes surgery ~ncus-stapedotomy and malleo-stapedolomy) and open-cavity mastoido-epitympanectomy.

The temporal bone should be placed in the normal operat ing position, with the posterior aspect toward the surgeon and the temporomandibular joint away from the surgeon.

The surgical steps described in these guidelines require special instrumentation. The most important instruments are mentioned in the text, highlighted in italics. For more details on Prostheses and Instrumentation see Section H.

Initially, the external ear is left attached to the temporal bone to enable the meatoplasty technique to be performed Within closed cavities. Following meatoplasty (or when the pinna is not available), the external canal is transected 2 em lateral to the bone-cartilaginous junction. All excess soft tissue that is not used during the dissection is removed from the bone.

More information concerning the descnbed surgical procedures is given in Section G (Suggested Reading).

Remove excess bone from the temporal squama using a cutting burr to ensure that the remaining temporal bone fits Within the holder, permitting complete rotation in the anlero-posterior plane.

Identify the following anatomical landmarks (Fig. 1):

CD Temporal line ® Spine of Henle

® Tympanomastoid suture ® Tympanosquamous suture ® Petrotympanic fissure

@ Mastoid tiP

Zygomatic process

,

ArtICular tube«:le

I

Petrotympanic fissure

Styloid pmcess

TympaniC booe Mastoid process

- - @Mastold tip

CD Temporal line ® Spine 01 Henle @

Tympar.ornastold suture M. dlgaslncus M. sternocleidomastoideus

1

M. longus capi tis

M. spleniUS capitis

Temporal Bone Dissection - The Zurich Guidelines

7

A.3 Specific Surgical Techniques

B Closed-Cavity Technique B.1 Tympano-Antrotomy ,

The steps of this operation are: Meatoplasty, Ganalplasty, Ossiculoplasty, Myringoplasty, Antrotomy, Epitympanotomy and Mastoid Dramage.

'""'"'," '..,.. .': .' •

2,

B.1.1 Meatoplasty General Considerations Meatoplasty is a necessary step in addition to canalplasty when the cartilaginous portion of the external auditory canal (EAC) is too narrow in relation to its osseous portion (Fig. 2 a, C). Lateral stenosis of the EAC is commonly related to congenital anomalies, minor malformations, exostosis and postsurgical scarring. II may lead to hearing impairment, excessive accumulation of cerumen , chronic otitis exlema. difficulties in clinical examination and insufficient self-cleansing properties of the external ear following canalplasty.

The principle of meatoplasty is to remove the obstruction crea ted by excessive conchal cartilage and bone (Figs. 2 a, b; A-B). The operation is performed with a microscope.

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2.

Skin Incision The first superior skin incision begins at the 12 o'clock position between the tragus and helix, as is the case of an endaural approach (Fig. 3, A-B-C). and is continued down to the level of the superior edge of the bony external audi tory canal. The second incision is made at 6 o 'clock and continues through the ring of cartilage forming the inferior edge of the EAC (Fig. 3, D-E).

A third, medial skin incision connects both previous incisions horizontally along the posterior edge of the EAC (Fig. 3, C-O).

3

Elevation of the laterally Based Skin Flap The laterally based skin flap is elevated using tympanoplasty scissors. Care must be taken to keep the skin intact, particularly when separating it fro m the thin but strong attachment to the conchal cartilage (Fig. 4).

A

• 4 Endaural Retractor

8

Temporal Bone Dissection - The Zurich Guidelines

Excess of bone behind external auditOf)' canal

Bony external canal

Conchal cartilage

5.

5. Skin flap

Edge of excised conchal cartilage

Exposure and Excision of Conchal Cartilage Excess conchal cartilage is exposed (Fig . 5 a) and excised (Fig. 5 b). and the soft tissues situated between the excised cartilage and the underlying bone are also removed. B

Enlargement of the Bony EAC The posterior wall of t he bony EAC is enlarged using a diamond burr (Fig. 6).

Wound Closure

•

Belore closing the wound, a relieving Incision is made through the inferior part of the laterally based meatal skin flap (Fig . 7, F) to allow superior rotation of its upper part (Fig. 8, C, 0). In this way, the enlarged superior external auditory meatus is completely covered with skin. which is kept in position with 4-0 Et hibond sutures (Fig. 9). The inferior enlarged portion of the EAC is left open and w ill heal by secondary intention within 2-3 weeks.

• E

NOTE: A meatoplasty can be performed on the temporal bone only if the pinna has been preserved. Pertorming a meatoplasty will not allow the surgeon to carry out the first steps of the retroauricular approach described under

F

B 1.2. Relieving inciSion

7

E

•

9

Temporal Bone Dissection - The Zurich Guidelines

9

Aetroauricular

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B.1.2 Canalplasty

General Considerations The goal of any tympanomastoid surgical procedure should be the circumferenttal enlargement of the bony extemal canal to visualize the entire ring of the tympanic annulus using one position of the microscope (Fig. 10).

Periosteal Flap The outline of the relroauricular periosteal flap is formed with a knife (No. 15 blade) and should be approximately the size of the index finger (Fig. 11 , A). The periosteal flap is elevated from the bone with a mastoid raspatory (Fig. 11, B).

12

Exposure of the EAC The posterior limb of the canal incision (Fig. 12, A-B) is pertormed with a No. 15 blade, maintaining a level below the entrance of the bony external canal. The EAC is then opened and the canal incision is extended anteriorly (Fig. 13, B-C) 10 the 2 o 'clock position (right side). The soft tissues are moved away from the bone using a Key raspatory.

13

11b

Temporal Bone Dissecr on - The Zurich Guidelines

10

c

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14.

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7em

15.

150

"•

Meatal Skin Flap

Visualization of the entire tympanic membrane using one position of the microscope is made possible by forming a large meatal skin flap that is carefully dissected oul of the canal with its inferiorly based pedicle left in place. In the clinical setting, the advantage of this type of flap is that its blood supply is maintained through its pedicle. 15c

Incisions for the Meatal Skin Flap The meatal flap is incised using a No. 11 blade mounted in a special rounded scalpel handle. The blade is guided along the lines shown in Fig s. 14 a (right ear) and 14 b (left ear).

Two Incisions are made: the first spirally ascending from medial to lateral (Figs. 14a, b; D-C), and the second running medially and circumferentially (D-E). The spiral Incision starts 2 mm lateral to the annulus at 7 o'clock (right temporal bone) and swings up laterally along the anterior canal wall to meet the previously cut external canal skin at 2 o'dock (C). Be aware that skin incisions in the temporal bone do not bleed and are at times difficult to visualize. Therefore, it is highly advisable to keep in mind the t rack previously used by the tip of the knife and to make the incision in a step-by-step fashion. The corresponding skin incisions for the left ear are shown in Fig. 14 b.

Elevation of the Meatal Skin Flap The skin is elevated from t he bone using a Fisch microraspatory in the right hand and a microsuction tube in the left hand (Figs. 15 a , b). The microsuction tube should have a length of 7 cm to permit the surgeon's left hand to rest comfortably on the head of the patient (Fig . 15 b). The tiP of the microsuction tube holds the skin away. The amount of negative pressure of the microsuction tube is controlled with the left index finger (Fig. 15 b). The tip of the microraspatory shoutd always remain in contact with bone. Small movements separate the meatal skin from the bony EAC in the vertical and horizontal planes (Fig. 15 c). A small st rip of gauze soaked in saline soiution protects t he skin during separation from t he bone with the Fisch microraspatory.

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Temporal Bone Dissection - The Zurich Guidelines

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D

A

16<

16d

Circumferential Skin Incision Following elevation of the lateral part of t he meatal skin flap, the circumferential incision of the meatal skin is creat ed, beginning and ending (Fig. 16 a , D-E) 2 mm lateral to the tympanic annulus at 7 o'clock (right ear) or at 5 o'clock (left ear), at the starting point of the spiral incision (see also Figs. 14 a, b). The anterior limb of the incision is carried out using tympanoplasty microscissolS (modified Bellucci scissors) along the edge of the antero-inferior bony overhang of the EAG. The posterior limb of the incision is initiated by cutting through the posterior surface of the meatal skin flap with a No. 11 blade mounted to a rounded scalpel knife (Fig. 16 b). The incision is then continued along the superior canal wall connecting the anterior and posterior limb with straight mlcrotympanoplasty scissolS (Fig. 16 c). Fig. 16 d shows the completed meatal skin flap (see also Fig. 14 a).

~_c

Meatal skm nap Medial skin

ofEAC

Elevation of Meatal Skin Flap from the Tympanic Bone Gare is taken at this stage to expose the complete tympanic bone, including its lateral sur1ace. This requires an extension of the base of the meatal skin flap from the tympanomastoid sut ure in t he antero-superior direction to include the posterior and lateral sur1ace of the tympanic bone (Fig. 17, C-D).

Skin covering lateral portion of tympanic bone

17

DE

Temporal Bone Dissection - The Zurich Guidelines

12

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TymparlOsquamous suture

Exposed lateral surface 01 tympaniC bone

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Meatal skin flap

Medial skm of

EAC Key raspatory Tympanomastoid suture

18

19

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Separation of the skin covering the posterior surface of the tympanic bone is accomplished uSing a Key raspatory. The tip of the raspatory is moved along the lateral portion of the anterior bony canal wall, and then gently rotated anteriorly to completely uncover the superior edge of the tympanic bone (Fig. 18). In this way. the lateral surface of the tympanic bone Is completely exposed from the tympanomastoid to the tympana-squamous suture. This exposure is a prerequisite to performing an adequate circumferential canalplasty (Fig . 19). 20a

Canalplasty

Most commonly, viewing is limited to the antero-inferior portion of the drum owing to an excess of tympanic bone. The correct enlargement of the EAC is obtained by drilling away the overhanging bone with sharp and diamond burrs (Figs. 20 a-c).

20b

In a narrow EAC, It is difficult to identify the antero-inferior tympanic annulus, which may be completely covered by bone. In this situation, a groove (trough) is made in the bony infenor canal wall at 6 o'clock (Fig. 21 ) until the white line of the tympanic annulus becomes clearly visible. This techmque of the mfenor trough was developed to avoid injuring the facial nerve, jugular bulb or internal carotid artery because these structures are out of reach if the drilling is performed along the inferior EAC wall and remains lateral to the tympaniC annulus (Fig . 21 ). After identification, the tympanic annulus is progressively exposed as far as the anterior and posterior tympanic spine. When all bone overhangs are eliminated, the complete drum can be viewed without having to readjust the position of the microscope (Fig . 22 a and b). After correct canalplasty, it may become necessary to apply relieving incisions on the medial meatal skin to return it to a proper position (Fig. 22 b).

20c

Temporal Bone Dissection - The Zurich Guidelines

13

Tympanic annulus

TympaniC annulus

22,

21

B.1.3 Myringoplasty Middle Ear Inspection and Preparation for Grafting Freshening the Perforation Margins The margin of the large central perforation is refreshed uSing ultra fine biOPSY forceps (Fig . 23 a). This is done before elevation of the tympanomeatal flap to provide sufficient stability of the drum.

22"

Elevation of the Tympanomeatal Flap A posterosuperior tympanomeataJ flap is elevated with the microraspatory starting from the posterior tympanic spine to expose the malleus handle, the long process of the incus, and the stapes (Fig . 23 b). The chorda tympani is preserved and separated from the undersurface of the drum using a Fisch Tenotom. The inferior annulus is separated from his bony sulcus using a microdissector (Fig . 23 c).

r

Elevation of the tympanomeatal flap is continued to the 4 o'clock position (on the right side versus 8 o'clock in a left bone) to gain sufficient anterior access for fixation of the underlay graft. Note that the lerms "under- and overlay ~ are used in relation to the bony tympanic sulcus and not in reference to the tympanic membrane (see also B.3.1. Myringoplasty, page 19) Never elevate the annulus of the nght anterior tympana-meatal angle between 2 and 4 o'clock (or between 8 and 10 o'clock, respectIVely, on the /eft side). Elevation of the anterior annulus leads to blunting and impairs the functional results of tympanoplasty.

23b

•• •• ••

Division of the Tympanomeatal Flap (Swinging-Door Technique) The elevated Iympanomeatal flap is divided posteriorly using tympanoplasty microscissors to form two swinging-door flaps (Fig 23 d). 23,

23d

14

Temporal Bone Dissection - The Zurich Guidelines

Inspection of the Ossicular Chain Enlarge the postero-superior canal wall with a small curette 10 expose the anterior malleal process and ligament, the InclJdo-malieal toint, and the complete stapes (Figs. 24 a, b). Check the integrity of the ossicular chain and verify its mObility. Disarticulate the incudo-stapediaJ joint using a Joint knife (Fig . 24 b) to prevent cochlear damage while manipulating the ossicles (particularly the malleus handle). Epithelial debris is cleaned from the malleus tip using a 1.5 mm 45 0 hook while the malleus handle is lateralized with a second hook (Fig. 24c),

,

Adjun ctive Anterior Fixation of the Underlay Graft (Subtotal Perforation) In the presence 01 subtotal or anterior perforat ions, the tympanic annulus is separated from t he sulcus betw een 1 and 2 o'clock (right ear) (Fig. 25 a). The antero-superior portion of the temporalis fascia will be kep t in position t hrough t his gap. This eliminates the need to introduce Gelfoam 1M into the protympanum to fix the fascia against the lateral wall of the latter.

24.

An,_ matleal ligament

Anterior mallea! process

Drilling of the New Tympanic Sulcus A new tympaniC sulcus is drilled with a small diamond burr along the medial bony edge of the EAC between 4 and 2 o'clock (Fig. 25 b). This ledge of bone is used for later positioning of the fascia as seen in the insert of Fig. 25 b .

Anterior tympaniC spine

Posterior tympanic spine

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15

Temporal Bone Dissection - The Zurich Guidelines

Fixation Points for Underlay Grafting In subtotal and large antero-inferlor perforations, the underlay fascial graft will be supported by the following points:

• •

•

•

CD On the ledge of the new anlero-inferior tympanic sUlcus. Under the malleus handle.
\ ••

•

,

•

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,,

••• ••• •

,•

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B.1.4 Antrotomy

26

The anlrotomy is carried out when the function of the eustachian tube is questionable or when the middle ear mucosa is abnormal. The position of the antrum is determined by the intersection of the temporal line and a line parallel to the posterior canal wall (Fig. 27),

.I-

The middle cranial fossa dura and the sigmoid sinus are identified by drilling away the bone until they become visible through the last shell of covering bone (skele tonization) . The antrum is found by removing the bone along the skeletonized middle cranial fossa dura. No bone should be removed over the entrance of the EAC. The antrum is opened until the lateral semicircular canal is exposed (Fig. 28).

.

... ••••

B.1 .5 Epitympanotomy 27

Water Test for Epitympanic Patency Irrigate the antrum wit h water dispensed from a rubber bulb and ensure that the Ringer's solution flows freely into the middle ear and out of the ear canal. If t his is not the case. drill away the bone along the skeletonized middle cranial fossa in an anterior direction until the incus and

malleus head have been identified and exposed (epitympanotomy). Obstructing scars or thickened mucosa surrounding the ossicles are removed to achieve adequate patency of the aditus ad antrum (epitympanectomy) (see Fig. 64, page 32).

.~ .

28

29

Temporal Bone Dissection - The Zurich Guidelines

16

30b

300

Transmastold drain

8 .1.6 Transmastoid Drainage of the Antrum

Retroauncular skin incision

, ,

After exposmg the antrum, a groove is drilled posteriorty along the sinodural angle to guide the transmastoid drain (Kala-Drain) (Fig. 30 a). The polyethylene drainage tube, having an outer diameter of 5 mm, has been bent by placing it over a curved metal stylus and healing it in an oven at a temperature of BOoe. The angle of the bent lube is 110°.

The Iransmastoid drain is placed with its bend in the antrum through a separate rel roauricular slab incision using a curved clamp. (Figs. 30b, c).

Stab incision for drain

30c

B,2 Tympana-Mastoidectomy

General Considerations The sleps required for a closed Mastoido-Epitympanec(omy with Tympanoplasty (MEl) are:

Meatoplasty, Ganalplasty. Epltympanectomy, Mastoidectomy, Posterior Tympanotomy. Osslculoplasty. Myringoplasty, and Mastoid Dramage. Some of these surgical steps are the same as for retroauricular tympano-antrotomy and have been discussed in the preceeding chapter (see page 7).

17

Temporal Bone Dissection - The Zurich Guidelines

B.2.1 Mastoidectomy Ide ntification of the Fac ial Nerve (Fig. 31)

•

•

•

•

•

'"

Enlarge the antrotomy superiorly by skeletonizing the middle fossa dura. Perform the epltympanotomy to expose the incus and malleus head. Identify the tympanic segment of the facial nerve inferior to the lateral semicircular canal
B.2.2 Posterior Tympanotomy 32

The space between the pyramidal segment of the facial nerve, the chorda tympani, the buttress over the lateral process of the incus, and the posterior canal wall is called the facial recess (Fig. 32). There is great variability in size and pneumatization of this area. The bone between the pyramidal segment and the chorda tympani is drilled away (Fig. 33) while keeping an eye on the skeletonized mastoid and pyramidal segments of the facial nerve. The resulting opening to the middle ear is the posterior tympanotomy. Avoid exposing the facial nerve (leave a small shelf of bone to cover and protect the nerve) or touching the Incus with the burr. and do not injure the chorda tympani and the tym· panic annulus. Do not make the pestenor canal wall too thin to avoid delayed atrophy (Fig. 33).

33

18

Temporal Bone Dissection - The Zurich Guidelines

With the facial nef'Ve in view, the facial recess can be enlarged as much as possible. If the mastoid is narrow, the bony buttress behind the posterior ligament of the incus is removed to gain sufficient space. A diamond burr is used to lower the bone covenng the lateral semicircular canal, and the pyramidal and distal tympanic segments of the fallopian canal. This will also expose the chorda tympani (Fig. 34), Through the posterior tympanotomy and epitympanotomy the following middle ear structures should be identifiable:

34

•

stapes and stapedial tendon

•

tympanic segment of the facial nerve

• •

round window incus with short and long process

•

mal leus head, cochleariform process and tensor tympani tendon

•

eustachian tube orifice (occasionally, Fig. 45)

8 .2.3 Epitympanectomy • 1.5 mm 45' Hook

,Sa

The incudo-stapeclial joint is separated , and the incus is mobilized with a 1.5 mm. 45° hook (Fig. 35a) then removed by lateral rotation , preserving the chorda tympani (Fig. 35 b). The long process of the incus may be cut with a malleus nipper when the integrity of the chorda is at risk. The chorda is separated from the undersurtace of the malleus, and the malleus neck is cut with a malleus nipper (Fig. 35 e) or, if the anterior malleal ligament is hyalinized, with a 0.8 mm diamond burr (c.f. Fig. 58 e). The malleus head and the chorda tensor fold are removed to ensure free communication between protympanum and supratubal recess.

Malleus nlpP6l'

35b

Temporal Bone Dissection - The Zurich Guidelines

19

I •

36a

36b

B.3

Myringo- and Ossiculoplasty In Closed Cavities

8 .3.1

Myringoplasty

General Con sideratio ns The terms underlay and overlay are used in relation to the bony tympanic sulcus and not. as is usual . in reference to the tympanic membrane, Therefore. anterior underlay means that the temporalis fascia (or the piece of wet paper used for it) is placed under the anterior tympanic sulcus in contact with the lateral wal l of the protympanum. In this case, Ihe tympanic annulus and anterior remnant of the tympanic membrane remain over the anteriorly underlaid fascia. Pos terior overlay means that the fascia is situated over the posterior bony tympanic sulcus. When repositioned, the tympanic membrane remnant (or tympanomealal flap) will cover the posteriorly overlaid fascia.

37 (j)

Underlay Grafting For training purposes, use a wet piece of paper from the surgical glove packing . An inciSion IS made with a knife according 10 the expecled position of the malleus handle (Fig. 36 a). The swinging-door Iympanomeatal flaps are elevated (except antenorty between 2 and 4 o 'clock) 10 create sufficient space for inserting the graft under the anterior margin of the perforation, The graft is placed under the malleus handle and rests over the chorda and the pastero-inferior tympanic sulcus (Fig. 36 b). For subtotal or large anterosuperior perlorations, the graft should also be fixed between the sulcus and annulus tympanicus at the 1 0 'clock position for the right bone and at the 11 o 'clock position for the left ear.

The graft is supported althe following points (Fig. 37):


On Ihe inferior tympanic sulcus. @ Under the malleus handle.
Temporal Bone Dissection - The Zurich Guidelines

20

r ___-':F~,"':::h:mlCroraspatory

39.

38

39b

B.3.2

Ossiculoplasty

8 .3.2.1

Incus Interposition

8 .3.2.2

Autologous Incus

In the presence of intact stapes, malleus handle and anterior half of the drum, the preferred type of reconstruction is the interposition of the autologous incus. Measuring the Length and Angle of the Implant The correct length and angle of the implant is measured using a Fisch microraspatory that is 2.5 mm in length. Shaping the Autologous Incus The incus body is held firmly using a small curved clamp while drilling with a diamond burr (Fig. 39a). The long process and the posterior part of the incus body are shortened. Keep in mind that the plane used to shorten the incus body determines the angle of the interposed ossicle. The articular surface of the incus is carved, taking into consideration the inclination of the malleus handle (Fig. 39 b). A notch for the stapes head is drilled on the opposite side using 0.6 and 0 .8 mm diamond burrs (Fig. 39c).

Temporal Bone Dissection - The Zurich Guidelines

40a

21

40b

Interposition of the Modified Autologous Incus The modified incus is rotated in contact with the malleus handle over the stapes head using the largest microsuction and a 1.5 mm, 45° hook (Figs. 40 a, b). The chorda tympani runs cranial to and stabilizes the interposed incus (Figs. 40 a-c).

B.3.2.3 Titanium Incus A Titanium Incus Prosthesis (KARL STORZ, Tuttlingen, Germany) is used when the autologous incus is not available (Fig. 41 a). Prosthesis length selection (3, 4 or 5 mm) depends on the measurement obtained with the Fisch microraspatory (see Fig. 38). The prosthesis surlace connecting with the stapes head and malleus handle should be rough. This is achieved by dri lling the contact surfaces with a diamond burr. For this purpose, t he titanium incus should be held wit h special incus-holding forceps (Figs. 41 b, c ). The t itanium incus is transported into t he middle ear and introduced between the malleus handle and stapes head using a 2.5 mm, 45° hook inserted through holes made for this purpose (Fig. 41d). The prosthesis is posit ioned exactly as an interposed autologous ossicle (Fig. 41 e).

41. 2.5 mm Hook

.J C>

1--41.

41.

41<

41.

Temporal Bone Dissection - The Zurich Guidelines

22

C Stapedotomy General Considerations Tympanoplasty kmfe

fenestration into the stapes footplate. The same name is frequently used to indicate the introduction of a stapes prosthesIs between the incus and vestibule, regardless of whether the opening into the footplate is well calibrated or consists of a partial removal of the footplate (~small fenestra stapedectomyj. From t he authors' point of view, the definition of "stapedotomyN should be limited to the former situation and the latter should be cal led a "partial stapedectomy.

42.

N

B

"

,

............ _--- "':': ~"

42b

,

Stapedotomy means the creation of a small calibrated

IJ fA,; "

-r r"'r··~~i~( ~'''' f {T""" ~

/-A",/.1e.w

The introduction of a stapes prosthesis from the malleus to the vestibule has been called ~ vestibulopexy. " This term does not address whether the prosthesis reaches the vestibule through a calibrated opening. or through a partial or total stapedectomy. To avoid thiS confusion. the authors have introduced the terms incus-stapedotomy and malleostapedotomy for the exclusive use of a stapes prosthesiS from the Incus or malleus handle in conjunction with a stapedotomy opening. To achieve a stapedotomy opening through the footplate on a regular basis, It has proven of value to reverse the classic steps of stapedotomy and to create the calibrated opening before removing the stapes arch. In this case, the diameter of the stapedotomy opening should not exceed 0.5 mm, and the corresponding diameter of the stapes piston should be of 0.4 mm.

C.1 Incus·Stapedotomy Endaural Skin Incision The endaural skin incision (A-B in Fig. 42 a) is made using a No. 15 blade at the 12 o'clock position between the tragus cartilage and root of the helix. The soft tissues are cut to the level of the bony entrance of the canal (remove excess soft tissues over the bony external ear canal to gain sufficient exposure in the temporal bone specimen). Tympanomeatal Flap The tympanomeatal incisions are made with a NO.l1 blade mounted in a special rounded scalpel handle. The posterior limb of the tympanomeatal flap begins at 8 o 'clock, ascending spiraly from the tympanic annulus to the lateral edge of the external auditory canal (C-A in Fig . 42 b). The anterior limb is carried out from the 1 o'clock position to the Inferior edge of the endaural incision (D-A in Fig. 42 b). NOTE: A larger tympanomeatal flap (as for malleo-stapedotomy, see page 28) is used whenever total or partial fi xation of the malleus is suspected.

I

v<

"" "",,g,

l)..,."", ~ <J ,

,....L.

~w.

~ , f<-r:J

/ a.-

,.-;~

.

~ Te~porar Bone Dissection - The Zurich Guidelines

Canalplasty

23

43b

While elevating the tympanomeatal flap, the bony overhang of a prominent tympanosquamous spine or a protruding antera-superior canal wall needs to be removed to adequately inspect the anterior malleal process and ligament (Figs. 43a--c). A curette or diamond burr is used for this purpose (do not separate the Iympanomeatal flap from the tympanic sulcus and incisura Aivini during this step to avoid irrigation of the middle ear with contaminated Ringer's solution). Elevation of Tympanomeatal Flap The most important landmark in this step is the posterior tympanic spine (posterior end of the incisura tympaniea Aivini). The Iympanomeatal flap is elevated first from t he posterior spine using a Fisch microraspatory. Care is taken to keep the chorda attached to the flap (Fig. 44 a).

43<

Enlargement of the Supero- Posterior Canal Wall lateral

The bone covering the oval window, the inferior edge of the incudo-malleal joint and the anterior malleal process are removed using a curette. The rotational movements of the curette should be directed from medial to lateral to avoid trauma to the chorda and incus (Fig. 44 b).

+•• .•

~--~~

•

medial

,

"

440

44"

24

Temporal Bone Dissection - The Zurich Guidelines

Anterior maJleal ligament

45

Pyramidal process

~~ Stapedial tendon

46

Exposure of the Oval Window The exposure of the oval window is correct when the following structures are visible (Fig _45):

• • • • • •

Pyramidal process with the stapedial tendon Oval window with the stapes and incudo-stapedial joint Tympanic segment of the facial nerve Infenor incudo-malleal JOint Lateral (short) process of the malleus Anterior malleal process and ligament

Preparation of the Stapes Prosthesis A malleable measun'ng rod is used to determine the distance between t he footplate and the lateral surface of the incus (Fig . 46), This measurement should be increased by 0.5 mm to account for the protrusion of the prosthesis piston into the vestibule. The resulting total length of the prosthesis will average 5.2 mm. A 0.4 x 8.5 mm Titanium Stapes Prosthesis (KARL STORZ. Tuttlingen. Germany) is trimmed on a special Titanium Cutting Block (Fig. 47) and placed in the preformed 0.4 mm hole for later use.

47

The stapes prosthesis is available in two other sizes: 0.4 x 10 mm and 0.4 x 7 mm. The longest prosthesis is used in deep middle ears (partially malformed ears), the shortest in shallow middle ears (partially open cavities). The different lerJgths relate to the different distance between prosthesis loop and 0.4 mm cylinder. > 1 mm_.:.j

< lmm---

...

Perforation o f the Foo tplate A calibrated opening of 0.5 mm diameter is made in the safe area (the central area between the middle and inferior third of the stapes footplate) where the saccule and utricle lie more than 1 mm below footplate level (Fig. 48 a). The stapedotomy opening should be positioned in such a way that the prosthesis will remain perpendicular to the footplate .

•

25

Temporal Bone Oissection - The Zurich Guidelines

Manual perforators

Caliper (0.4 mm)

I 0.3

0.4

0.5

0.6

48"

A set of four manual perforators (0.3, 0.4. 0.5 and 0.6 mm diameters. Fig . 48b) is used to create the stapedotomy opening. The perforators are rotated back and forth between thumb and index finger. The tip of each perforator is only partially introduced into the vestibule. The correct size of the opening (0.5 mm) is con firmed with a 0.4 mm caliper (Fig. 48 c).

Introduc tion and Fixatio n of the Stapes Prosthesis Large smooth alligator forceps

The stapes prosthesis is picked up from the cutting block using large straight smooth alligator forceps (Fig. 49 a). The piston IS first placed over the stapes footplate and aligned with the long process of the incus. The length of the prosthesis is correct if the piston loop exceeds the la teral surface to the incus by 0.5 mm (Fig. 49 b). II the prosthesis is the correct length, it is moved over the stapedotomy opening with a 1.0 mm. 45° hook and carefully advanced into the vestibule (Fig. 49 b). The loop is then crimped over the incus with small straight smooth alligator forceps (Fig. 49 c). 49.

1.0 mm.

Small smooth alligator forceps

45' Hook

• •

491>

49c

Temporal Bone Dissection - The Zurich Guidelines

26

Chorda tympani Tympanoplasty Jomt knife

SOb

SO.

Removal of the Stapes Suprastructure With the prosthesis in place, the incudo-stapedial joint is separated with ajelnt knife (Fig . 5Oa). the stapedial tendon is sectioned with tympanoplasty microscissors (Fig. 50 b), the posterior crus is cui with cruratamy scissors that are controlled with both hands (Fig. 50 c), and the anterior crus is crushed at the level of the footplate with a 2.5 mm, 45° hook (Figs. 50 d and e). The stapes arch is removed, and final mobility of the ossicular chain is confirmed. There should be no free movement of the prosthesis loop when either the incus or malleus is moved (Fig . 50 f) ,

Crurotomy scissors

50e

----.

1.5 mm Hook

2.5 mm Hook

SOd

,

Temporal Bone Dissect ion - The Zurich Guidelines

1.5 mm

45~

27

Hook

Venous blood

'10

51b

Sealing of the 5tapedotomy Opening and Repositioning of the Tympanomeatal Flap Three connective tissue pledgets from the endaural incision are placed around the stapedotomy opening (Fig. 51 a) Venous blood obtained from the cubital vein of the patient prior to surgery and one drop of fibrin glue are used to seal the oval window niche (Fig. 51 b). The tympanomeatal flap is repositioned, and two small Gelfoam ™ pledgets soaked in corticosporin are used to keep the flap in poSit ion (Fig. 52).

Fibrin

""" '10

o o

. ''

o ;:~.,~",~",;:_

,....' •"-'''',' 'I":' ,"

", '" (''''

Gelfoam and Ot ospofln

.,.

.', • •.

. 0, '. ";'

•• . ."

o 52

.'•'.••.,,. '".' . ....'

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"•

•

'.• •' •' ,

28

Temporal Bone Dissection - The Zurich Guidelines

Spina tympani anteoor

A

,. . .. ..•...•• .....

." : 0

-•

'

~

D A

•• •

... •••••••••

'.'. '. .:~,.--------"

-._---

C Spina tympani

53

54

C.2 Malleo·Stapedotomy

completmg the canalplasty to avoid contamination of the middle ear cavity with contaminated saline solution used for irrigation while drilling .

posterior

Endaural Approac h This surgical step is identical to incus stapedotomy (Fig. 423, page 22). Tympanomeatal Flap The tympanomeatal flap used for malleo-stapedotomy is larger than that described for incus-stapedotomy. The posterior limb (C-B. Fig . 53) is the same, but the anterior limb (D-B. Fig. 53) extends to 4 o'clock on the right side and 8 o'clock on the left. The soft tissues are elevated from the underlying bone using a Key raspatory. At t his stage, the endaural ret ractors are replaced to obtain maximal exposure wit hout injuring the skin margins (this surgical step does not apply to the temporal bone). The tympanomeatal flap is raised from the underlying bone with a Fisch microraspatory and a microsuction tube (Fig. 15, page 10). In Figure 54, the anterior and posterior tympanic spines are exposed for anatomical demonstration. In reality, the tympanomeatal flap should not be separated from the Incisura tympanica Rlvini before

Antero-superior Canalplasty The canal skin is elevated from the wall of the ear canal with a Fisch microraspatory. The antero-superior overhang of bone is then removed with sharp and diamond burrs until the anterior and posterior tympanic spines can be identified (see also Fig. 43 b, page 23). The tympanomeatal flap should remain attached to the bone at the entrance of the middle ear until drilling is completed to avoid contaminating the cavum tympani with irrigation fluid.

Elevation of the Tympanomeatal Flap The tympanomeatal flap is first elevated from the posterior tympanic spine using a left Fisch microraspatory (right ear) that is introduced under the rim of bone lateral and superior to t he chorda tympani. The Shrapnell membrane is then elevated from the malleus neck and lateral malleal process until the anterior tympanic spine and t he beginning of the anterior tympanic annulus become visible.

Antenor maBeal process Lat""" malleal process Antenor malleal ligament

Spma tympani posterior

55

56

ho,,'~ tympani

29

Temporal Bone Dissection - The Zurich Guidelines

Antenor malleal process Antenor tympanIC

""M

M

, ,

Incudo malleal jOint

I

57,

Pyramidal process

57.

Exposure for Malleo-Stapedotomy

Removal of Incus and Malleus Head

The correct exposure for malleo-stapedotomy is obtained by using a curette to enlarge the supero-posterior edge of the bony external canal (see Fig. 44, page 23). The follow ing structures should be exposed (Fig. 57 b):

The malleo-stapedotomy is performed when there is total or partial fixation of the malleus and/or incus. A fixed incus is removed after cutllng its loog process with a malleus nipper to avoid damage to the chorda tympani during extraction (see also Fig. 35 c, page 18). The malleus nipper is not used to section the malleus neck because this maneuver would leave the anterior malleal process intact (Fig. 58 b).

• Pyramidal process with the stapedial tendon • Oval window with the stapes and incudo-stapedial Joint • Tympanic segment of Fallopian canal • Inferior part of the incudo-malleal loint • Lateral malleal process and malleus neck • Anteri or malleal process and ligament • Anterior tympanic spine

CalCi fied anterior malleal ligament

The corda tympani should be kept intact whenever possible. Remember that an intact chorda is the calling card of the otologist.'

58a Malleus nipper

• •

Temporal Bone Dissection - The Zurich Guidelines

30

A fixed malleus head is removed most effectively by cutting Its neck with a 0.6 or 0 .8 mm diamond burr (Fig. sac). While drilling. the malleus handle is held with a large toothed straight alligator forceps controlled by the left hand . The drilling starts over the anterior malleal process, which is just anterior to the lateral process (Fig . SSe) and continues in a superior and antero-poslerior direction across the malleus neck. This C· shaped line of drilling per-

mils the anterior malleal process to be included in the

: ::::::

resection. Great care is taken to keep the chorda tympani intact. The chorda tympani runs under the anterior malleal process from which it must be separated by using a hook prior to drilling.

Preparation of the Stapes Prosthesis The previously mentioned Titanium Stapes Prosthesis, 0.4 mm diameter and 8.5 mm length, is used for both incus-stapedotomy and malleo-stapedotomy. The initial steps for preparing the prosthesIs are the same for both types of stapedotomy (see page 24). The average distance between the proximal malleus handle and the stapes footplate is 6.5 mm (including 0.5 mm to allow for protrusion of the piston into the vestibule). The Titanium Stapes ProsthesIs is trimmed on a titanium cutting block (Fig. 59). The surface of the cutting block should be humidified with saline solution to eliminate unnecessary movement of the prosthesis. The diameter of the prosthesiS loop is enlarged to the size of the malleus handle by moving it along a 1.5 mm, 45 0 hook with watchmaker forceps and then stored in the 0.4 mm hole of the cutting block.

Shapin9 of Prosthesis-Shaft for the Malleus Handle The shaft of the prosthesis may be bent along various planes on the cutting block to accommodate the anterior position of the malleus. This is done while the prosthesis is in t he 0.4 mm hole of the cutting block by genlly bending it to the correct extent by pushing the shaft with watchmaker forceps (Fig. 60). This same maneuver can be performed in a lateral d irection if required by the steep position of the malleus handle.

59

60

•

Temporal Bone Dissection - The Zurich Guidelines

31

Perforation of the Footplate This step is performed using manual perforators as for an incus-stapedotomy. An Erbium-YAG laser is used in special cases (e.g. mobile foot plate). Removal of Stapes Arch The stapes arch is removed after perforation of the lootplate. Both crura are cut using crurotomy scissors (see Fig. 50 c , page 26). The stapedial tendon is cut last to insure stability while cutting the crura. Introduction and Fixation of the Stapes Prosthesis The picking up and the introduction 01 the prosthesis in the middle ear are done in a manner similar to incus-stapedotomy (see Fig . 49, page 25). The exposure given by the large tympanomeatal flap and the anterosupet'lor canalplasty is such that both, the malleus handle and the footplate are visible with one position of the microscope. The prosthesis is first placed on the footplate to ensure that the length and bend are adequate (the prosthesis cylinder must be perpendicular to the foot plate). The prosthesis cylinder IS then introduced into the vestibule for 0.5 mm (measured from the lateral surface of t he footplate) using a 1 mm, 45° hook.

Titanium stapes prostheSIs (0.4 mm diameter)

."

Fixation of Stapes Prosthesis The prosthesis loop is attached to the malleus handle just distal to the lateral malleal process (Extensive separation of the drum from the malleus handle should be avolded.~ . Crimping the prosthesis to the malleus handle is performed uSing large (Fig. 61 a) and small smooth straight alligator forceps (Fig. 61 b). Each forceps is held with both hands. The prosthesis loop should be immobile after crimping. Sealing of the Stapedotomy Opening and Repositioning of the Tympanomeatal Flap These surgical staps are done as for incus-stapedotomy (see Fig. 51, page 27).

•

•

Titanium stapes prosthesis (04 mm diameter)

.,.

32

Temporal Bone Dissection - The Zurich Guidelines

o Open Cavity (Open MastoidoEpitympanectomy or Open MET) General Considerations The surgical principles of an open MET are:


1 62

Checklist for Bone Work In Open MET The recommended sequence of bone removal for an open MET is (Fig. 62):


MC'

Dura RetrOSlgmold cells

Wide lateral bone removal over the root of the zygoma with skeletonization of the middle cranial fossa dura and sigmoid sinus, exposure of digastric muscle, and skeltonizallOn of stylomastoid foramen. ® Identification of the tympanic segment of the fallopian canal and posterior bony semicircular canal, and lowering of the facial ridge. CD Radical exenteration and extenonzation of the retrofacial. retrolabyrinthine and the retrosigmoid cells.
63

Sigmoid SinUS

0.1 Mastoidectomy Lateral Bone Removal Mastoidectomy begins with wide removal of lateral bone from the zygomatic arch to the sinodural angle (Fig. 63). The dissection is continued with skeletonization of the middle cranial foss dura, the sigmoid sinus and sinodural angle. The lateral semicircular canal is identified in the antrum and the lateral surface of the digastriC muscle is exposed (Fig. 64). Epitympanotomy

Digastric muscle

64

The antrum is opened and the dissection is extended anteriorly to periorm an epitympanotomy (Fig. 64 and Fig. 28, page 15). The tympanic segment of the facial nerve is identified at t he inferior edge of the lateral semicircular canal (see also Fig. 32, page 17). The bone at the mastoid tip covering the lateral suriace of t he digastric muscle is removed. No bony overhangs along the d issection field should remain (particularly over the middle cranial fossa dura and behind the sigmoid sinus).

Temporal Bone Dissection - The Zurich Guidelines

33

TympaniC segment

of facial nerve

~(_Stylomastoid

::.-

/

fOl"amer1

of

canal

65

66 Stylomastoid foramen Stylomastoid periosteal fibres

Mastoid Tip Surgery and Facial Nerve Identification The superior edge and the lateral surface of the digastric muscle is followed until the stylomastoid periosteal fibers are visible. The stylomastoid foramen is identified and the bone along and lateral to the white periosteal fibers is removed (Fig . 65). At this stage, a crack forms lateral to the stylomastoid foramen , mobilizing the remaining mastoid lip 2

(see Fig. 71 , page 35), Lowering of the Facial Ridge

67

The posterior semicircular canal is identified. The three essential landmarks are now visible, determining the position of the mastoid and pyramidal segments of the facial nerve (Fig. 66). These are:

ill
the tympanic segment of the facial nerve the inferior edge of the posterior semicircular canal, and the stylo-mastoid foramen .

•

The anterior remnant of the superior canal wall is removed 10 fully expose the ossicular chain . •

Completion of Mastoidectomy The incus is disarticulated from the stapes, and Ihe incus and malleus are removed. If the malleus handle can be preserved, the tensor tympani tendon should also be preserved to stabilize the latter. The retrofacial (1), the retrolabyrinthine (2) and the retrosigmoid (3) cel l t racts are exenterated and exteriorized. The jugular bulb is skeletonized (Fig . 67: Inserts a and b)

67.

.7.

Temporal Bone Dissection - The Zurich Guidelines

34

Sinus epitympani

' .........

,

I I

68

69

0.2 Epitympanotomy Epitympanotomy

The supralabyrinthine (3) and supratubal (4) recess are exenterated and exteriorized to expose the ampullary end of the lateral and superior semicircular canals (Fig. 68). The awareness of the close proximity of the labyrint hine and tympanic segments of the facial nerve prevents injury of the geniculate ganglion (5).

0.3 Completion of MastoidoEpitympanectomy Exteriorizatio n of Antero -Superior Cavity An extensive antero-inferior canalplasly is per10rmed to remove all bone overhangs at the root of the zygomatic arch (Fig. 69: Insert). The tympanic bone should be lowered to meet the level of the stylomastoid foramen (6). A diamond burr is used when neanng the mandibular condyle while watching for color changes that indicate its proximity.

New Tympanic Sulcus

70

If there is no remnant tympanic annulus, drill a new tympanic sulcus (Fig. 70, (7)) in the bony canal wall from the 1 to 9 o'clock poSItions (right side). The resulting bony ledge will accommodate the fascial graft used for myringoplasty. The profile and position of the new ledge are shown in the inserts shown in Figure 70. If an anterior tympanic membrane remnant is present , the new sulcus is performed from 4 to 9 o'clock because the tympanic annulus is left in sil u along the sacred anten'or tympano-meatal angle (see Figs. 25, 26 and 36).

35

Temporal Bone Dissection - The Zurich Guidelines

Gelfilm or thick silastic

I

I

71

72a

Mastoid T ip Removal

MicrosuClIOn N' 2

The mastoid tip is removed with rongeurs along the frac ture line produced during identification of t he stylomastoid foramen (see Fig. 72 a). The rongeur is rotated from medial to lateral, and a large curved scissors is used to separate the soft tissues attached to the undersuriace of the mastoid tip.

2.5 mm. 45~ HooI<

E. Tympanoplasty (Myringo- and Ossiculoplasty in Open Cavities) E.l. Type III Tympanoplasty General Considerations This type of reconstruction is periormed in the presence of an intact mobile stapes. If a portion of the anterior tympanic membrane remains intact, an anterior fascial underlay is used, If no tympanic membrane is left, an overlay graft becomes necessary (an overlay being a graft placed over bone; i.e. , over the old or new tympanic sulcus. limiting the aerated middle ear space; see also B.3. 1. Myringoplasty, Genera l Consid eratio ns, page 19).

72b

New Tympanic

Sulcus

Myringoplasty with Anterior Fascial Underlay

I )

A thick (1 mm) Silastic· sheeting (Getfilm fM is used in the presence of an active infection) is introduced into the middle ear up to t he tympanic ost ium of the eustachian tube (Fig. 72a). A fresh temporalis fascia (a wet piece of paper in the laboratory) is placed under the anterior remnant of the tympanic membrane (underlay grafting) over the new tympanic sulcus inferiorly. and over the facial ridge and tympanic segment of the fallopian canal postero-superior (Fig. 72 b). The stapes head should be higher than the surrounding fascia (outward bulging. Fig. 72 c). If the stapes head is too low. a piece of tragal or conchal cart ilage with a notch is used to increase its lengt h.

",

Temporal Bone Dissection - The Zurich Guidelines

36

Temporalis

Fascia

73b

73.

When the tympanic membrane is absent, a thick (1 mm) $ilaslic sheeting is introduced into the middle ear to avoid scar tissue formatIon between the fascia and mucosa (Fig . 73 a), The fresh temporalis fascia (or tragal perichondrium) is then placed over the circumferential new tympanic sulcus, the tympanic segment of the fallopian canal and the semicanal of the tensor tympani muscle (overlay grafting) (Fig. 73 b),

74.

74b

E.2

Total Reconstruction of the Ossicular Chain

E.2.1 The Fisch Titanium Total Prosthesis E.2.1.1 Preparation of Prosthesis Holding forceps

The Fisch Titanium Total Prosthesis (FTTP) is composed of an L-shaped shaft with head and a shoe (fOOl) with spike (Fig. 74 a, b). The distance between the tympanic membrane and the footplate is determined with the malleable measuring rod. The FTTP can be used with or without the shoe.

740 Prosthesis w ith Shoe If the shoe IS used, 0.5 mm should be subtracted from the total measured length to account for the additional length of the shoe in the assembly. "".._ _ _....,

Blood or fibrin glue

The FTTP shaft is introduced in the 0.6 mm hole of the Titanium Cutting Block (see Fig . 59) and trimmed to the desired length (Fig . 74 a). The foot is placed into the 1.0 mm hole of the cutting block (Fig. 74 b). The F I I P shaft is grasped with a special curved holding forceps and introduced into the shoe (Fig. 74c). A drop of blood or fibrin glue can be used to increase the stability of the assembled prosthesis (Fig . 74 d). If more strength is required, a special crimping forceps can be used to squeeze the foot tightly to the shaft.

74<1

37

Temporal Bone Dissection - The Zurich Guidelines

Vertical plane

Prosthesis with Cartilage Disc

.

The mp is used without a shoe if the oval window is too narrow or the stapes arch remains in place, The shaft alone is also used if the patient does not accept the risk to the inner ear deriving from the introduction of the shoe's spike in the vestibule. If the shoe is not used. stabIlIzation of the shaft IS obtained by using a cartilage disc (see Figs. 80 and 8t , pages 39, 40).

•• •• ••

:

r

E.2.1.2 Shaping the Prosthesis Head Angulation The thickness of the FTIP head is only 0.1 mm. Therefore. the plane of the prosthesis head can be adapted to the drum position in the vertical and horizontal planes (Figs. 75a and b).

75.

.

Horizootal plane

4• ••• •• •

Size and Shape

\

•• •••

~

1

The mp head is 0.' mm thick and 5 mm in diameter. Special titanium scissors can be used to reduce the diameter of the prosthesis head to 3 or 4 mm by cutting away one or two outer rings (Figs. 76a, b and c).

It is also possible to remove the anterior half of the prosthesis head (when the malleus handle is present) or to give It any desired shape (Fig. 76 d).

75b

5mm , mm

760

7. .

•

3mm

•

?

•

Scissors for titanium total prothesis

76c

76d

.

•

Temporal Bone Dissection - The Zurich Guidelines

38

00

° 00 °<>00

l e ngth of L-s ha pe d Arm

<>

Another unique feature althe FTTP is the ability to change the length of its l-shaped arm to meet the specific requirements of the middle ear anatomy. particularly when the prosthesis head is reduced in size. For this purpose, the FTTP is grasped with two watchmaker forceps and straightened, then bent in the deSired angle as shown in Fig. 77 a-d.

E.2.1.3 F I I P Handling '70

Ho lding Forceps and Micro suction Tube The FTTP is transported from the cutting block to the middle ear with special curved holding forceps or with the largest microsuction tube.

77'

77,

77'

_

Mk:rosuction

,"be Holding forceps

,.

,

39

Temporal Bone Dissection - The Zurich Guidelines

.

•

--

... .

. '", ., ." ' "'//

.'

'\

•

79.

79b

Rotation of the Head of F riP under the Drum

Stabilization of the F II P on the Stapes Footplate. Use of Shoe with Spike

The loot of the FTIP is fixed with the spike on the central part 01 the footplate. The FTIP head is then rotated into positioo by raising the pars tensa with a 2.5 mm. 45° hook held in the left hand, while a second hook (1 .5 mm, 45°) IS manipulated by the nght hand to rotate the prosthesis head using one of its multiple central holes. The final position 01 the prosthesis head is under the central pars tensa, producing a slight bulging of the latter as a sign of sufficient tension to keep the prosthesis in the deSired position (Figs. 79 a and b). There IS no need to cover the prostheSis With cartilage because the prosthesis head can follow the movements 01 the tympanic membrane because 01 the flexibility of the 0.2 mm diameter angled titanium band connecting it to the shaft.

The best stabilization of the FTIP to the foot plate is achieved by perforating the central part of the stapes foolpiate to allow introduction of the 0.3 mm long spike of the prosthesis shoe (Fig. 60 a). The perforallOn is made with the smallest manual perforator. A mobile footplate is fixed during this maneuver with a 1.0 mm, 45° hook held in the left hand, which pushes the footplate slighty against the margin of the oval Window. An Erbium-VAG laser can also be used to perforate a mobile footplate. Usually one single pulse of 35 mJ is sufficient for this purpose.

Tragal cartilage

h.)

o

....'

,O' ,..

'" , I

, ,t, /'

,'". • • ",' 4'' . -,' •

,#

I'

-h~

...

,.,.., "

'I

., ,II '/

'

•• • •• •• •• •• ••

••

"

. .,.'

~ ,.,.

'

..

• ,#

.' I'

·h-

-"

•••

80b

80c

Tragal cart ilage

•

Temporal Bone Dissection - The Zurich Guidelines

40

Endaural skin InciSIOn ,~ ___ ~___~

.'

Tragal cartilage

'

\ L~--_'

'«')"

81b

81.

0.6 mm diamond burr

8"

8"

_ _ _ Anatomical forceps

f---=O~/ }

, mm

3mm 81.

8"

Shaft without Shoe Special holding forceps

81,

Nearly equal functional results have been obtained by placing the shaft of the FTTP without a shoe on the footplate. In this situation, however; a cartilage disc of 1 mm thickness obtained from the tragus or from the conchal cartilage must be used for stabilization. The cartilage disc has to fit tightly within the oval window niche. The technique used for the harvesting and preparation of the cartilage disc is shown in Figs. 81 a-g . When the stapes arch is intact, the F II P is a/so used without a shoe. In this case, the stabilization is achieved by wedging small pieces of cartilage (from the tragus or concha) between the wall of the oval window niche and the prosthesis (Fig . SOc).

41

Temporal Bone Dissect ion - The Zurich Guidelines

E.2.2 Fisch Titanium Neo-Malleus General Considerations

-

This technique is utilized In absence of malleus, incus and stapes arch, when the stapes footplate is fixed or when another type of total reconstruction of the ossicular chain has failed to improve the function of a mobile stapes. Neomalleus reconstruction is usually performed in two stages at an interval of three to six months, First Stage A piece of tragal perichondrium is obtained through the endaural approach (Figs. 61 a-<:). A rectangular piece of perichondrium is cut slighlly longer than the supero-inferior diameter of the drum. The 5 mm long titanium neo-malleus is introduced over the lateral surface of the graft through two small incisions (a No. 11 blade with rounded scalpel handle, graft on glass platform IS used) (Figs. 62 a, b).

The perichondrium with the attached neo-malleus is introduced under the partially elevated tympanic membrane and is anchored inferiorly through the gap created at 6 0' clock (right side) between t he tympanic annulus and SUlcus. The perichondrium will rest superiorly as an overlayed graft between the superior canal wall and the tympa nomeatal flap. The titanium neo-mal/eus is aligned over the oval window (Fig. 62 c).

82.

Stapes only (fi_ad or mobile)

82b

Second Stage The second stage is performed three to six months later if no signs of tubal dysfuction have appeared. The tympanomeatal flap IS elevated and the superior end of the implanted neo-malleus is identified. The nee-malleus has various grooves for fixation of the loop of a stapes prosthesis. Only one of these indentations and not the complete superior end (as shown in the pict ure) is exposed to avoid excessive movement and to keep the neo-malleus in the desired position. A 0.5 mm stapedotomy is performed (using manual perforators or a laser) in the center of the (fixed or mobile) footplate (Fig . 63 a).

The Titanium Stapes Prosthesis is brought into place. introduced 0.5 mm from t he lateral surface of t he footplate in the vestibule, and crimped on the titanium neo-malleus using smooth small straight alligator forceps (Fig. 63 b). The stapedotomy hole is sealed with three connective tissue pledgets, venous blood from the cubital vein, and fibrin glue (see Stapedotomy Figs. 51 a-c, page 27).

82,

Temporal Bone Dissection - The Zurich Guidelines

42

•

Eustachian t ube

GeniCulate gangioo

. Pericarolld celts

Supra tubal cells

Internal carotid ar1ery

Supra· cells

.rt"Y

"'"'"

~-----

Jabynnth lne

Retro-

Lateral semiCircular

Internal carot id

Supenor

,

semiCircular canal

Jugular bulb Posterior

•

semicircular canal

Retrolacial cells Retrosigmoid cells

84

85

F Additional Temporal Bone Dissection

traumatic nature (e.g ., following transverse fractures of the temporal bone). to introduce CI in sclerotic temporal bones, or when there is a meningitiS risk due to a possible CSF leak.

General Considerations Additional temporal bone dissections may be carried out at the end of the procedure. They represent a transition from temporal bone to lateral skull base surgery. In the authors' opinion, these dissections belong within the curriculum of a modern otologist. who in fact should not remain a middle ear surgeon, but become a temporal bone surgeon.

Exenteration of Pneumatic Cell Trac t s The cell tracts of the middle ear cleft (Fig. 84) are exenterated in the follOWing order: retrosigmoid, retrofacial, retro~ labynnthine, supralabynnthine, supratubal, infralabyrinthine and pencarotld. Most of these cellular tracts have been dealt with when per10rming an open MET. In fact. an open~cavlty procedure performed according to the authors' surgical principles is a ~subtotal petrosecto~ my," with the exception of the infcalabyn'nth/ne and peri~ carotid cells that are left intact.

F.1 Subtotal Petrosectomy (SP) The principle of SP is "the complete elimination of the pneumatic middle ear cleft associated with the permanent occlusion of the isthmus of the eustachian tube The cavity may be left open or be obliterated (with pedicled muscle flaps or free abdominal fat grafts). In the latter case, the EAC is closed in two layers as a blind sack.

Surgical site following exenteration of pneumatic cell tracts and preservation of the otic capsule

W

•

There are two types of subtotal petrosectomy, one with OfesecvatlQQ the other with removal of the otic capsule (For more details see: "Microsurgery of the Skull Base U. Fisch and D. Mattox, Georg Thieme Stuttgart New York ft

1988).

F.1,1 Subtotal Petro sectomy with Preservation of the Otic Capsule General Considerations This operation is is per10rmed to remove extensive tempo~ ral bone cholesteatomas, adenomas, extensive facia l nerve neuromas, angiomas and Class B paragangliomas. It is also used to seal congenital CSF leaks and those of a

The pneumatic cell tracts of the temporal bone (with the exception of the apical) are removed (Fig. 85). To make sure that no cells are left behind . the jugular bulb and the vertical intra temporal carotid artery are skeletonized. The tympanic segment of the facial nerve is also skele~ tonized until the geniculate ganglion and the greater superficial petrosal nerve are identified. Note that the labyrinthine segment of the facial nerve is medial to and covered by its tympanic segment. and that the proximal tympanic segment and the geniculate ganglion form a border between the supratubal and supra labyrinthine recess~ es. The otic capsule and, therefore. inner ear function are preserved. Pericarotid cells and obliteration of the eustachian tube The vertical segment of the intratemporal carotid artery (ICA) is exposed to the bend indicating the beginning of the horizontal segment Note that the isthmus of the eustachian tube is below and anterior to the ICA. The semicanal of the tensor tympani muscle covers part of the posterior aspect of the horizontal segment of the ICA. Remember that the ICA may be dehiscent along the medial wall of the

43

Temporal Bone Dissection - The Zurich Guidelines

Isthmus of Eustachian tube

protympanum (Fig. 86). The anterocarotid pneumatic cells can extend into the pyramid apex, and their exenteration may require precise work with a diamond burr. When all pericarotid cells are exenterated, the isthmus of the eustachian tube is ready for obliteration with bone wax.

Semlcanal of the tensor tympani m. •

F.1.2 Subtotal Petrosectomy with Removal of the Otic Capsule General Considerations The otic capsule is removed to gain access to lesions situated along the medial aspect of the inner ear spaces (e.g., supralabyrinthine and infralabyrinthine-apical cholesteatomas, and temporal paragangliomas class C3-4 Del2,Oi 1-2). The SP with removal of the otic capsula is also part of the transotic approach used for acoustic neuromas associated with a total loss of hearing. Remember that SP with removal of the otic capsula is not a transcoch/ear approach. The transcochlear approach (House WF, Hitselberger WE: The transcochlear approach to the skull base, Arch Otolaryngol 1976, 102: 334-342) coosists of the removal of the cochlea and posterior rerouting of the facial nerve, leaving the middle ear and fAG intact. (For more details 00 the SP with and without removal of the otic capsule, see Fisch U. Mattox D: Microsurgery of the Skull Base, Thieme Stuttgart and New York 1988). Lesioos requiring SP With removal of the ollc capsula involve the dura and, therefore, require obliteration of the pneumatic middle ear cleft.

86

Oehiscent internal carotid artery

GenICulum of facial nerve

Supratubal recess

Supralabyrinthlr"18

...,'"

Labynnlhlr"18 ~ segment ... 01 facial nerve

Removal of the Posterior Otic Capsula (Labyrinth) The semicircular canals are removed as in a trans/abyrinthine approach (Fi9 . 87). The tympanic and labyrinthine segments of the facial nelVe must be watched. Removal of the cochlea continues until the medial wall of the vestibule, the posterior ampullary and the superior ampullary nelVe become visible. The labyrinthine segment of the facial nelVe is identified 2 mm anterior and 2 mm lateral to the superior edge of t he internal auditory canal. The posterior wall of the internal auditory canal is skeletonized to the porus acousticus internus (Fig. 88).

87

Tympanic segment of facial nerve

Temporal Bone Dissection - The Zurich Guidelines

44

Removal of the Anterior Otic Capsula (Cochlea)

Petrosal nerve Medial wall of vesllbule

Apical turn of cochlea Middle turn of cochlea

Labyrinthine

,..menl

ollacial nerve

Basal turn of cochlea

Internal auditory canal

Posterior ampulla!)' nerve

..

Posterior fossa dura

Sketetonize the mastoid segment of the facial nerve and the jugular bulb. Follow the lugular bulb as far as possible medial to the facial nerve toward the round window niche. Remove the bone covering the basal, middle and apical turn of the cochlea (the apical turn may be covered by the semicanal of the tensor tympani muscle) working anterior to the fac ial nerve (Fig. 68). Skeletonize the inferior and anterior walls of the internal auditory canal until you reach the anterior porus. Note that the internal auditory canal is situated deep and antenor to the skeletonized tympanic and mastoid facial nerve. Expose the posterior fossa dura between the internal auditory canal, superior petrosal sinus (medial to the semicanal of the tensor tympani muscle), vertical carotid artery, and jugu lar bulb (Fig. 89). Opening this dura would lead in the anterior cerebello-pontine angle. This is what is done in the transotic approach. which is the only approach permitting the surgeon to first separate the intracranial segment of the facial nerve from the anterior pole of the tumor. Final surgical site of SP with removal of the otic capsula

Horizontal segment of ICA Isthmus of Eustachian tube VertiCal segment of ICA Carotid

foramen Jugular bulb

Middle cranial fossa dura

The complete medial wall of the temporal bone is exposed between sigmoid sinus, superior petrosal sinus (separating dura of the middle and posterior cranial fossa), internal carotid artery and Jugular bulb. The cell tracts located medial to the otic capsula and extending toward the pyramid apex have been completely exenterated (Fig 89).

• ,,

P,,""o'

ampulla!), (singular) nerve

/"-..1' Posterior fossa dura Sigmoid sinus

G Suggested Reading The fo llowing books and papers contain detailed information on the microsurgical techniques presented in this manual: Book s U. FISCH in collaboration with J. MAY: Tympanoplasty. Mastoidectomy. and Stapes Surgery. (1" edition. 1994, Cl Georg Thieme Stuttgart - New York). U. FISCH, J. MAY, 1. LINDER: Tympanoplasty, Mastoidectomy, and Stapes Surgery. (2"" edition, forthcoming 2006; approx. 320 pp, 36 tables, approx. 155 illustrations, hardcover. ISBN 158890167x I 313137702x; C Georg Thieme Stuttgart - New York). A. POSADA: Spanish translation of Tympanoplasty, Mastoidectomy and Stapes Surgery 1998 A. POSADA: Spanish translation of the Course Book of the Fisch International Microsurgery Foundation. 2002 U. FISCH, D. MATIOX: Microsurgery of the Skull Base, 1988 10 Georg Thieme Stuttgart - New York, 2000 © Thieme Classic Edition R. POSADA: Spanish edition of Microsurgery of the Skull Base 1998

Temporal Bone Dissection - The Zurich Guidelines

Papers U. FISCH , PH. CHANG, TH. LINDER: Meatoplasty for Lateral StenOSIS of the External Auditory Canal, The Laryngoscope 112: 1310--1314, 2002 HOUSE WF, HITSELBERGER WE: The transcochlear approach to the skull base. Arch Otolaryngol: 102: 334-

342,1976

,

FISCH U., OEZBILEN G.A., A. HUBER: Malleostapedotomy in Revision Surgery for Otosclerosis, Otology & Neurotology, 22:776-785, 2001 HUBER A. , LINDER T. and FISCH U.: Is the Er: Yag Laser Damaging to Inner Ear Function?, Otology & Neurotology,

22: 311-315, 2001 NANDAPALAN V., POLLAK A., LANGNER A. and FISCH U.: The Anterior and Superior Malleal Ligaments in Otosclerosis, Otology & Nerotology, 23: 854 - 861 , 2002 KWOK P. , FISCH U., STRUTZ J. and MAY J.: Stapes Surgery: How Precisely Do Different Prostheses Attach to the Long Process of the Incus with Different Instruments and Different Surgeons?, Otology & Nerotology, 23: 289-

295,2002 HUBER A., KOIKE T., NANDAPALAN V., WADA H. and FISCH U.: Fixation of the Anterior Mallear Ligament: Diagnosis and Consequence for Hearing Results in Stapes Surgery, Annals of Otology, Rhinology & Laryngology, 112:

348 - 355, 2003 FISCH U., MAY J., LINDER TH . and NAUMANN I.C.: A New L-shaped Titanium Prost hesis for Total Reconst ruction 01 the Ossicular Chain, Otology & Neurotology, 25: 891 - 902 ,

2004

H Prostheses and Instruments H.1

FISCH Titanium Middle Ear Prostheses

H.2

FISCH Special Instruments for Tympanoplasty, Mastoidectomy and Stapedotomy -

45

46

FISCH Special Instruments for Tympanoplasty, Mastoidectomy and Stapedotomy

Temporal Bone Dissection - The Zurich Guidelines

Temporal Bone Dissection

~

47

The Zurich Guidelines

ID

FISCH Endaural Retractor Curved Mastoid Retractor (BELLUCCI). length 13 cm (j) 219717 B FISCH Articulated Retroauricular Retractor Strong Curved Scissors (MAYO) @ 792003 FISCH Small Tympanoplasty Scissors @) 213410 @ 535312 Small Curved Clamp (Mosquito) Scalpel Handle No.3, length 12.5 cm 208000 FISCH Round Scalpel Handle, ® 208001 length 14 cm FISCH Dual Purpose Scalpel Handle, ® 211804 length 16 cm @ 214500 F Jeweler Forceps, soft spring @ 793303 F Small Tympanoplasty Forceps (Tissue Forceps), toothed @ 214000 F Small Tympanoplasty Forceps serrated FISCH Mastoid Raspatory @ 213011 KEY-Raspatory (curved FREER) @ 477500 FISCH Double End Sharp Curette @ 224003 (HOUSE , medium) ® 204729 FISCH Suction Tube, 1.2 mm ® 204730 FISCH Suction Tube, 1.5 mm FISCH Suction Tube, 2.0 mm @ 204732 FISCH Suction Tube, 2.2 mm @ 204733 Suction Cannula, angular, ~ 204352 size 0.7 mm, 7.0 cm 220213 (j) 219613

CD

@ 226605 @ 226606 @ 221 111

@ 221110

@ 221201 @ 221 100

0

221409

Large Biopsy Forceps (HARTMANN, 2.0 mm)

®

FISCH-BELLUCCI Ultra Fine Tympanoplasty Micro Scissors

222606

@ 222603

FISCH Small Tympanoplasty Micro Scis sors

@ 222601

Large Tympanoplasty Micro Scissors (FISCH-BELLUCCI)

~ 222710

FISCH Crurotomy SCissors, curved right

® ®

222720 222801

FISC H Crurotomy SCis sors, curved left

®

227525

FISCH Cutting Block for Titanium Prostheses Crimping Forceps, for FISCH Titanium Incus Prosthesis

227527

@ 204250

FISCH Suction Adaptor

®

227530

@ 226101

FISCH Micro Raspatory, curved right

@ 226102

FISCH M icro Raspato ry, curved left

@ 226301

FISCH Tenotome

@ 226810

Joint Knife, 45°, round

@ 225405

Pick 45°,16 cm, 0.5 mm

@ 2254 10

Pick 45°, 16em, 1.0 mm

@ 225415

Pic k 45°, 16 em, 1.5 mm

®

225425

Pick 45°, 16 em, 2.5 mm

@ 225205

Pick 90°, 16 em, 0.5 mm

@ 225210

Pick 90°, 16 em. 1.0 mm

@ 225215

Pick 90°,16 em. 1.5 mm

@ 225220

Pick 90°,16 em, 2.0 mm

@ 226514

FISCH Measuring Caliper, 0.4 mm

QII

FISCH Measuring Caliper, 0.6 mm

@ 224812 @ 224813

FISCH Anterior Footplate Elevator FISCH Posterior Footplate Elevator

®

226600

FISCH Manual Perforator, 0.3 mm

@ 226604

FISCH Manual Perforator, 0.4 mm

Small Biopsy Forceps (\'VULLSTEIN, 8 cm, O.g mm)

@ 162020

®

FISCH Measuring Rod

Large Straight Alligator Forceps, serrated (HARTMANN) (FISCH, 8 cm, 0.6 mm)

Suc tion Cannula, angular. size 1.0 mm, 7.0 cm

@ 226501

FISCH Small Straight Alligator Forceps, smooth, (crimping forceps for stapes prosthesis) FISCH Large Straight Alligator Forceps, smooth (crimping forceps for stapes prosthesis) FISCH Small Straight Alligator Forceps, serrated

@ 221406 F Ultra Fine Biopsy Forceps

@ 204354

226516

FISCH Manual Perforator, 0.5 mm FISCH Manual Perforator, 0.6 mm

FISCH Malleus Nipper

Holding Forceps, for FISCH Titanium Incus Prosthesis

@ 227532

FISCH Micro Hook, for transporting and positioning the FISCH Titanium Incus Prosthesis

(p 227528

Sc issors, for FISCH Titanium Total Prosthesis

@ 227526

Holding Forceps, for FISCH Titanium Total Prosthesis

~ 227534

Diamond Burr, 1.4 mm, 7 em for FISCH Titanium Incus Prosthesis Bipolar Coagulating Forceps, angular, tip 0.4 mm, insulated, length 16 em

8

843016

6

843016 F

Bipolar Coagulating Forceps, angular, tip 0.2 mm, insulated handle, non-insulatad from angle to tip, length 16 em

®

842016 F

Bipolar Coagulating Forceps, angled tip, pointed , tip 0.4 mm, insulated, length 16 em (not illustrated)

e

516013

Needle Holder, tungsten carbide Inserts, length 13 cm

@ 227900

e ®

23 1009 239728

SHEA Vein Press, 13 em FISCH Glass Cutting Board Metal Tray, for 20 straight ear micro instruments (not illustrated)

Temporal Bone Dissection - The Zurich Guidelines

48

219613

220213

219717

CD
220213

FISCH Endaural Retrac tor

219613

Curved Mastoid Retractor (BELLUCCI), length 13 em

@

219717 B

FISCH Artic ulated Retroauricular Retrac tor

792003

213410

o

792003

Strong Curved Scissors (MAYO). length 16 em

®

213410

FISCH Small Tympanoplasty Scissors

@

535312

Small Curved Clamp (Mosquito)

535312

49

Temporal Bone Dissection - The Zurich Guidelines

®

®

I 208000

o ® ®

211804

20800 1

208000

Scalpel Handle No, 3. length 12.5 cm

208001

FISCH Round Scalpel Handle, length 14 cm

211804

FISCH Dual Purpose Scalpel Handle, length 16 cm

®

@

i

2 14500 F

793303 F

214000 F

@l 214500 F

Jeweler Forceps, pointed. soft spring

®

Small Tympano pla sty Fo rceps (Tissue Forceps). toothed

793303 F

@ 214000 F

Small Tympanoplasty Forceps, serrated

50

Temporal Bone Dissection - The Zurich Guidelines

@

@

226101

, !, 226102

@-@

213011

477500

224003

@-@

204729 - 204733

204352 204354

@ 213011

FISCH Mastoid Raspatory, 10 mm

@

KEY-Raspatory (curved FREER). 18 mm

477500

@

204250

@ 224003

FISCH Double End Sharp Curette (HOUSE, medium)

@ 204729

FISCH Suction Tube, 1.2 mm Same, 1.5 mm Same, 2.0 mm Same, 2.2 mm

® ®

204730

®

204352 204354

204732 @ 204733

@ @

13

204250

Suction Cannula, angular, size 0.7 mm, 7.0 em Same, size 1.0 mm. 7.0 em FISCH Suction Adaptor

226101

FISCH Micro Raspatory, 16 em, CUNed right

@ 226102

FISCH Micro Raspatory, 16 em, curved left

226101-226102

Temporal Bone Dissection - The Zuneh GUidelines

51

I

®-@

,•

226301

226810

225405 - 225425

@ @

226301

FISCH Teno tome, 16 cm

226810

Joint Knife, 45". round

@ @ @ @

225405 225410 225415

Pic k 45°, 16 em. 0.5 mm Pick 45°, 16 em. 1.0 mm

®

225205 225210

Pick goo, 16 em, 0.5 mm

225215 225220

Pick 90°, 16em,l.5mm Pic k 90",1 6 em, 2.0 mm

@ @ @

225425

Pic k 45°, 16 em. 1.5 mm Pic k 45°,16 em, 2.5 mm

Pick 90", 16 em, 1.0 mm

225205 - 225220

52

Temporal Bone Dissection - The Zurich Guidelines

\

226501

226514 226516

224812

226600 - 226606

224813

®

226514 @ 2265 16

FISC H Measuring Caliper, 0.4 mm Same, 0.6 mm

®

226501

FISCH Measuring Rod, 16.5 em

@

224812

FISCH Anterior Footplate Elevator, curved upward 90"

@

224813

FISCH Posterior Footplate Elevator, curved downward 90"

~ 226600 @ 226604 @ 226605

0

226606

FISCH Manual Perforator, 0.3 mm

Same, 0.4 mm Same, 0.5 mm Same, 0.6 mm

,-

Temporal Bone Dissect ion - The Zurich GUidelines

2211 10

221111

221100

221201

-,

=

...

- - <--

221406 F 221409

@

221111

FISCH Small Straight Alligator Forceps, smooth, (crimping forceps for stapes prosthesis)

®

221 110

FISCH large Straight Alligator Forceps. smooth (crimping forceps for stapes prosthesis)

@

221201

FISCH Small Straight Alligator Forceps, serrated

@

221100

large Straight Alligator Forceps , serrated (HARTMANN), 0.4 x 3.5 mm

@

221406 F

Ultra Fine Biopsy Forceps (FISCH. B cm, 0.6 mm)

®

221409

Small Biopsy Forceps (WULlSTEIN. 0.9 mm)

@

162020

large Biopsy Forceps (HARTMANN , 2.0 mm)

162020

Temporal Bone Dissection - The Zurich Guidelines

54

®"'"'-222606

222710

222603

222720

•

222710 222720

222603

222606

222601

222801

®

222606

FISCH -BELLUCCI Ultra Fine Tympanoplasty Micro Scissors

~

222603

FISCH Small Tympanoplasty Micro Scissors

~

22260 1

large Tympanoplasty Micro Scissors (FISC H-BELLUCCI)

S

FISCH Crurotomy Scissors, curved right

~

222710 222720

S

222801

FISCH Malleus Nipper

Same, curved left

•

• @ 227525

FISCH Cutting Block, lor Titanium Prostheses

227525

55

Temporal Bone Dissection - The Zurich Guidelines

•

227530

227527

227532

227528

@

227527

Crimping Forceps, for FISCH Titanium Incus Prosthesis


227530

Holding Forceps, for FISCH Titanium Incus Prosthesis

0

227532

FISCH Micro Hook, for transporting and positioning the FISCH Titanium Incus Prosthesis

@

227528

Scissors, for FISCH Titanium Tolal Prosthesiss

@

227526

Holding Forceps, for FISCH Titanium Total Prosthesis

227526

227900

227534

843016

843016 F

842016 F

516013 231009

0 9

0

Diamond Burr, 1.4 mm, 7 cm , for FISCH Titanium Incus Prosthesis Bipolar Coagulating Forceps, angular, tip 0.4 mm. 843016 insulated, length 16 cm 843016 F Bipolar Coagulating Forceps, angular. 0.2 mm, insulated handle, non-insulated from angle to lip, length 16 cm 227534

0

842016 F Bipolar Coagulating Forceps, angled tip, pointed, t ip 0.4 mm, insulated, length 16 cm

(l)

516013

@ 227900

0

231009

Needle Holder, tungsten carbide inserts, length 13 cm SHEA Vein Press, 13 cm FISCH Glass Cutting Board

Temporal Bone Dissection - The Zurich Guidelines

56

FISCH TITANIUM Middle Ear Prostheses

1.

2275 10

227511

1.

FISCH TITANIUM St apes Pist o n, short distance between loop and cylinder, 7.0 x diam. 0.4 mm, short size, sterile FISCH TITANIUM Stapes Pist o n, medium distance between loop and cylinder, dia. 8.5 x dlam. 0.4 mm, normal size, sterile

227512

FISCH TITANIUM Stapes Pist on , long distance between loop and cylinder, dia. 10.0 x diam. 0.4 mm. long size, sterile

227520

FISCH TITANIUM To t al Prosthesis , with foot, 10.0 x diam. 0.6 mm, sterile

227515

FISCH TITANIUM Inc us Prosthes is , 3.0 mm (1.31 diam. 2.0 mm), normal size, sterile

227516

FISCH TITANIUM Inc us Prosthesis. 4.0 mm (1.31 dlam. 2.0 mm), long size, sterile

227517

FISCH TITANIUM Inc u s Prosthesis , 5.0 mm (1.31 diam. 2.0 mm), extra long size, sterile

227522

FISCH TITANIUM Neom alle us Prosthesis, 5.0 x diam. 1.1 mm, sterile

Temporal Bone Dissection - The Zurich Guidelines

Metal Tray for Sterilizing and Storage of Ear Instruments

239728

M etal Tray, for sterilizing and storage of ear instruments, perforated, bottom part with holder for 20 straight ear micro instruments with octagonal handle type 223300, lid with silicone bridges. external dimensions (w xd x hl: 285 x 175 x 36 mm

57

Temporal Bone Dissection - The Zurich Guidelines

58

UNIDRIVE ENT The multifunc tional unit f or ot o rhin o laryngology

a

Special Features and Specifica tion s

One unit - six functions: - Shaver system for surgery of the paranasal sinuses and anterior skull base - INTRA Drill - Sinus Burr - Micro Saw - STAMMBERGER-SACHSE Intranasal Drill - Dermatome Two outputs: Two motor outputs enable to connect two motors simultaneously. For example an intranasal drill and a paranasal sinus shaver or two INTRA drill hand pieces may be connected in parallel. New integrated irrigation and coolant pump: Absolutely homogenous, micro-processor controlled irrigation rate throughout the entire irrigation range. Quick and easy connection of the tubing set. Touch Screen: Straightforward function selection via touch screen. The unit stores the parameter values of the function selected during the last operation session.

Optimized user control via touch screen Operating elements are simple and clear to read due to color display Irrigator rod included •

Continuously adjustable revolution range

•

Maximum number of revolutions and motor torque: The set parameters are maintained throughout the drilling procedure by the microprocessor controlled electronic motor.

• •

Maximum number of revolutions can be preset ,.. . model with connections to the KARL STORZ Communication Bus System

59

Temporal Bone Dissection - The Zurich Guidelines

UNIDRIVE" ENT Specifications Shaver Mode Operation mode: Maximum revolutions (min '):

Sinus Burr Mode Operation mode: Maximum revolutions (min '):

oscillating in conjunctiOn with Micro Shaver Handpiece 40 7110 35 in conjunction with Paranasal Sinus Shaver Handpiece 40 711039 in conjunction With OriliCut-X Shaver Handpiece 40 711040

3.000 7.000 7.000

rotating

in conjunction with DrillCut-X Shaver Handpiece 40 711 0 40

12.000

Drilling mode Operation mode: Maximum revolut ions (min '):

counter clockwise or clockwise in conjunction with EG micro motor 20 711032

40.000

Micro saws mode Maximum revolut ions (min '):

in conjunction with EG micro motor 20 711032

20.000

Intranasal Drill mode Maximum revolutions (min '):

in conjunction with EG micro motor 20 711 0 32

60,000

Dermatome mode Maximum revolutions (min '):

in conjunction with EC micro motor 20 711032

8.000

Touch screen:

6.4"/300 cd/m'

Power supply:

100 -120, 230 - 240 VAG, 50/60 Hz

Dimensions (w x h x d):

304 x 164 x 263 mm

Weight:

6.1 kg

Two outputs for parallel connection of two motors Integrated irrigation pump Flow:

15 - 125 ml/min.

Available languages:

English, French, German, Spanish, Italian, Portuguese, Greek, Turkish Certified to: IEC 601-1 CE, according to MOD

20 711 0 72 20 711032 Special feature s of the high performance EC micro motor with INTRA coupling:

• • • •

Self-cooling, brushless high performance EG micro motor Smallest possible dimenSions Autoclavable Detachable connecting cable

• • •

INTRA coupling enables a wide variety of appl ications Maximum torque 4 Ncm Number of revolutions can be continuously adjusted from o - 40,000 rev./mln.

Temporal Bone Dissection - The Zurich Guidelines

60

UNIDRIVE ENT System Configurations recommended by KARL STORZ

B

00 20 711620·'

40 711601-1

UNIDRIVE ENT consisting o f: 20 711620-1 UNIDRIVE ENT with KARL STORZ-SGB • 100 - 120, 230 - 240 VAC, 50160 Hz

20 711640

Mains Cord Two-Pedal Footswitch, two-stage, with proportional function Silicone Tubing Set, for irrigation, sieriiizable

20 711621

Clip-Set, for use wit h tubing set 20 711640

20 090 1 70

SGB Connecting Cable, length lOa em

400A

20 012630

Accessories:

20 711032 20 711072 280052 B 260052 C mtp·

High Performance EC Micro M otor Connecting Cable, to connect EC molor 20 7110 32 to control unit Universal Sprayer, 0.5 I bottle, for use with 280052 C, - HAZARDOUS GOODS - UN 1950 Spray Diffuser, for use with 280052 B Set of Tubes, for single patient use

*) This product is marketed by mtp. For additional information, please apply t o:

~

mtp medical technical promotion g mbh, p.o. box 4529,78510 Tuttlingen, Germany Email: info@mt p-tut.de

Temporal Bone Dissection - The Zurich Guidelines

UNIDRIVE ENT System Components

Two·p.cjal Footlwltcll

I

I I 20 711640

U NIT

STe1'Z ---

SIDE

PATIENT SIDE

-. . •

B

-

.. ..

00

20 7Il0:rz 20 1110n

Micro Saw

"

-

1

Ei

2f>4000 - 2f>4300

2~-2!;3300

Temporal Bone Dissection - The Zurich Guidelines

62

INTRA Drill Handpiece Special Features: • Tool-free c losing and opening of the drill

• Right/left rotation • Max. rotating speed up to 40,000 min ' • Detachable irrigation channels

• light con struction • Operates with little vibrations • low maintenance , easy c leaning • Safe grip

252475

252475

INTRA Drill Handpiece, angled , 12.5 em, for use with straight shaft burrs, transmission 1:1 (40,000 rpm)

252495 252495

INTRA Orill Handpiece, straight, long shape, 10.4 em, for use with straight shaft burrs, transmission 1: 1 (40,000 rpm)

252490 252490

INTRA Drill Handpiece, st raight, 8.7 em, for use with straight shaft burrs, transmission 1:1 (40,000 rpm)

280052

280052

Universal Spray, combination cleaner and lubricant , for INTRA Drill Handpiece and EC motors, package of 6 sprayers 280052 Band 1 spray d iffuser 280052 C - HAZARDOUS GOOD - UN 1950

63

Temporal Bone Dissection - The Zurich Guidelines

Burrs Straight Shaft Burrs, length 7 em 7.0 em

Size

Dia. mm Standard

Tungsten Carbide

Transverse Tungst.Carb.

Diamond

Diamond coarse

262006

006

0.6

260006

007

0.7

260007

008

0.8

260008

261008

262008

010

1.0

260010

261010

262010

014

1.4

260014

261014

018

1.8

260018

261018

023

2.3

260023

261023

027

2.7

260027

261027

031

3.1

260031

261031

035

3.5

260035

261035

040

4.0

260040

261040

045

4.5

260045

261045

050

5.0

260050

26 1050

060

6.0

260060

261060

070

7.0

260070

261070

261006

262007

261114

262014 262018 262023

262223

262027

262227

262031

262231

262035

262235

262040

262240

262045

262245

261150

262050

262250

261160

262060

262260

262070

262270

261123

261131

261140

260000

Standard Straight Shaft Burrs, length 7 em, sizes 006 - 070, set of 15

261000

Tungsten Carbide Shaft Burrs, length 7 em, sizes 006 - 070, set of 14

262000

Diamond Straight Shaft Burrs, with smooth shaft, length 7 em, sizes 006 - 070, set of 15

262200

Rapid Diamond Straight Shaft Burrs, with coarse diamond coating for precise drilling and abrasion by light hand pressure. generating minimal heat. length 7 em, sizes 023 - 070, set of 9

280030

Rac k, for 36 straight shaft burrs with a length of 7 em, can be folded out, sterilizable. 22 x 11.5 x 2 em

Temporal Bone Dissection - The Zurich Guidelines

64

Burrs Straight Shaft Burrs, length 5.7 em

5.7 em

Size

e=

Dia. mm Standard

Diamond

Diamond

coarse

0

014

1.4

649614 K

649714 K

(0

018

1.8

649618 K

649718 K

0

023

2.3

649623 K

649723K

649723 GK

0

027

2.7

649627 K

649727 K

649727 GK

0

031

3.1

649631 K

649731 K

649731 GK

0

035

3.5

649635 K

649735 K

649735 GK

0

040

4.0

649640 K

649740 K

649740 GK

0

045

4.5

649645 K

649745 K

649745 GK

0

050

5.0

649650 K

649750 K

649750 GK

060

6.0

649660 K

649760 K

649760 GK

070

7.0

649670 K

649770 K

649770 GK

0

0

649600 K

Standard Straight Shaft Burrs, stainless steel. length 5.7 em, sizes 014 - 070, setof11

649700 K

Diamond Straight Shaft Burrs, stainless steel , lengt h 5.7 em. sizes 014 - 070, set of 11

649700 GK

Rapid Diamond Straight Shaft Burr, stainless, with coarse diamond coaling for precise drilling and grinding without applying pressure with minimal heat buildup. length 5.7 em, sizes 023 - 070, set of 9

Straight Shaft Burrs oblong, length 1 em

265050 - 265070

Size

Oia. mm Standard

050

5.0

265050

060

6.0

265060

070

7.0

265070

Temporal Bone Dissection - The Zurich Guidelines

65

Burrs LINDEMANN Conical, stainless, length 7 em Size

Dia. mm Standard

018

1.8

263518

021

2.1

263521

023

2.3

263523

Diamond Straight Shaft Saw, length 7 em Size

Oia. mm Standard

008

0.8

267008

010

1.0

267010

015

1.5

267015

Diamond Saw Crill, length 7 cm Size

Dia. mm Standard

008

0.8

268008

010

1.0

268010

015

1.5

268015 269000

-

...

-

.. , -

....

II

"

"

"

••

~ &:)~

'" .. .... on ... . . , _ _ _ _

_

...

280090

280090

Hole Gauge, for burrs, stainless, autoclavable

Temporal Bone Dissection - The Zurich Guidelines

66

Burrs - Accessories

280010

Rac k , with lid for 34 straight shaft burrs with 7 em shafts, sterilizable, 19.5x 9.5 x4 em

280080

280120

280080

Brush, for cleaning burrs, sterilizable, package of 5

280120

Temporal Bone Holder, bowl-shaped, with 3 fixat ion screws for tensioning the petrosal bone and wit h evacuation tube for irrigation liquid, incl. weight plate 280121 for stabilization of the bowl and rubber ring 8575 GKR for base to prevent sl ipping

280030 280030 K

280030

Rack, for 36 st raight shaft burrs with a lengt h of 7 em. can be folded Qut , sterilizable, 22 x 11.5 x 2 em

280030 K

Metal bar, for fixation at rack 280030. to hold 18 burrs with a lengt h of 7 em and 16 burrs with a length of 5.7 em, size 16 x 2.5 x 1 em

67

Temporal Bone Dissection - The Zurich Guidelines

Burrs - Accessories

39552 A •

. • ••

' •

•

.

..

: ..:

Including basket for small parts

39552 A

Sterilizin g a nd Sto rage Basket , provides safe storage of accessories for KARL STORZ drilling/grinding systems during cleaning and sterilization, Includes basket for small parts, for use with rack 280030, rack not included f o r st ora ge of: -

39552 B

Up to 6 drill handpieces Connecting cable EC micro motor Small parts

St erilizin g and Sto rage Bas ket, provides safe storage of accessories for KARL STORZ drilling/grinding systems during cleaning and sterilization, Includes basket for small parts, for use wi th rack 280030, rack inc luded fo r stora ge of: - Up to 6 drill hand pieces - Connecting cable - EC micro motor - Up to 36 drill bits and burrs - Small parts