Hammer and gouge mastoidectomy for acute mastoiditis - Vula ...

OPEN ACCESS ATLAS OF OTOLARYNGOLOGY, HEAD &NECK OPERATIVE SURGERYHAMMER & GOUGE CORTICAL MASTOIDECTOMY FOR ACUTEMASTOIDITISJohan Fagan & Robert JacklerThis surgical guide is intended for themany surgeons in the Developing Worldwho do not have access to modern mastoidsurgery equipment such functioningmastoid drills, or are regularly faced withpower cuts and therefore may be compelled to proceed with a mastoidectomy usinga hammer and gouge, and possibly only aheadlight and operating loupes.The text and illustrations are based on thedescription of mastoid surgery: A Treatiseon the Surgical Technique of Otorhinolaryngology(1939) by Georges Portmann.The text has been modified to incorporatemodern principles of otology. This operativeguide should be read in conjunctionwith the chapter Hammer and GougeRadical Mastoidectomy for Cholesteatoma,also on the IFOS educational websitewww.entdev.uct.ac.za.Mastoid surgery can only be safelyperformed when the surgeon has anintimate knowledge of temporal boneanatomy. It is imperative that surgeonspractice temporal bone dissections asdescribed in the IFOS educational website.Surgeons are also referred to a detailedTemporal bone dissection manual, and anexcellent YouTube demonstration ofsimulated modern mastoid surgery on theIFOS educational website.Informed ConsentThis should include anaesthetic andsurgical risks and issues relating toaggravated hearing loss, facial nerveinjury, vertigo, taste disturbance, injury tothe brain and meninges, and woundcomplicationsAnaesthesiaSurgery may be performed under local orgeneral anaesthesia.General anaesthesia: Avoid muscleparalysis to facilitate detection of facialnerve irritation or injury.Local anaesthesia: With six whealsforming a semicircle, the posterior portionof the auricle and the mastoid region aresurrounded by a series of crisscrossinjections, thus obtaining a profuseinfiltration which encompasses the entireoperative field. Injections are made at thelevel of each of these wheals which notonly crisscross with the adjacent ones butinfiltrate the internal portion, resulting in adiffuse anaesthesia. The superficial levelsare infiltrated first and then the deeperones. This area of anaesthesia should bevery wide and extend considerably beyondthe limits of the mastoid region, especiallyposteriorly, for the exact extent of the bonylesions is never known before starting theoperation. The most posterior wheal of theanaesthetic area should be locatedapproximately 4.0 cm. from theretroauricular groove.Magnification and lightingMagnification is ideally required oncedissection reaches the middle ear, and forremoval of the facial ridge. Should anoperating microscope not be available,then operating loupes with 2.5xmagnification should be used. Goodlighting is essential, especially whenworking in the middle ear. In the absenceof an operating microscope or strongoperating lights, a headlight may suffice.

InstrumentationGouges and chisels should be keptextremely sharp, so as to ensure controlledbone resection. Blunt instrumentationrequires undue force to be applied, andgouges/chisels may slip off bone andplunge and damage critical structures suchas brain, lateral sinus, facial nerve, innerear, and carotid artery. For the bone workthe surgeon requires the following:Curved periosteal elevatorMalletThree gouges: Large, medium, smallFlat chiselCurettesRongeurs/bone nibblers (small,medium and large)Retractors (2), ideally self-retractingCanal elevator/McDonalds dissectorBlunt probeMicroinstruments: Curved needle,Plester knife, sickle knife, curetteSuction tipsPosition of PatientThe patient is laid supine with the headturned towards the normal ear.Position of Surgeon and AssistantsThe surgeon stands on the side of theaffected ear. Two assistants are stationedon the other side, facing the surgeon. The1 st assistant is nearest to the head. The 2 ndassistant is exactly opposite the surgeon.Operative FieldThe mastoid, auricle, and preauricularregions are extensively swabbed withtincture of iodine. The patient is covered tothe neck with a sterile sheet. The operativefield is isolated by four towels. Over themis placed a fenestrated sheet, the orifice ofwhich encircles the auricle and mastoid.AntibioticsNo antibiotics are required formastoidectomy for uncomplicatedcholesteatoma, other than when there issecondary infection (mastoiditis).BIPP PasteBIPP Paste can be prepared and used toimpregnate ribbon gauze. This can be usedto pack the mastoid cavity or ear canal, andbecause of its antiseptic properties, may beleft in place for a few weeks.Bismuth subnitrate 20% w/w, iodoform40% w/w, paraffin liquid 40% w/w (w/w =weight for weight)Figure 1: Instruments for bone work2

Surgical anatomy for MastoidectomyFigure 2: Coronal section through middleear and temporal boneBrown: Tympanic segment of base of squamous bone;Green: Antral region; Rose: Subantral region; Red:Region of tip; Blue: Sinus region; Yellow: Cerebellarregion or region of mastoid veinFigure 4: Surface boundaries of mastoidregionsSurgical Steps: Cortical MastoidectomyUnlike with mastoid surgery forcholesteatoma, mastoidectomy for acutemastoiditis may be associated withsignificant blood loss, especially in theabsence of mono- or bipolar coagulation.Patients may even require bloodtransfusion.First Step: Incision of Superficial TissuesFigure 3: Axial view of temporal boneanatomyFigure 5: Incision of Superficial Tissues3

The 1 st assistant retracts the auricletowards himself, using both hands. The 3 rdfinger of the lower hand is pressed stronglyunder the mastoid tip in order to compressthe posterior auricular artery. The otherassistant is prepared to sponge/swab withmastoid sponges/swabs held in angularforceps. The surgeon incises theretroauricular crease down to bone fromleft to right, from the linea temporalis tothe inferior part of the crease, or vice versa(Figure 5). In the event of a retroauricularabscess, the abscess cavity may be enteredat this point or during periosteal elevation.Second Step: Periosteal ElevationFollowing haemostasis and ligation ofbleeding vessels, the mastoid is completelyexposed proceeding posteriorly to theincision, without elevating the anteriorcartilaginous canal. This is easy in thesuperior portion where the periosteumfrees itself, but becomes more laborioustoward the inferior and posteroinferiorportions where the muscular insertionsmust be sectioned with the elevator. Figure6 demonstrates how the cartilaginous canalhas been respected (Figure 6).Third Step: Exploration of BoneIn the absence of electrocoagulation, 2Kocher hemostats are applied to theperiosteum, one in front and one in back,assuring haemostasis. Two sharp toothedretractors are held by the assistant. One isplaced forward to retract the auricle in thecanal without separating it from the bone.The other embraces the posterior lip of thewound, retracting it backward to uncoverthe operative surface. A self-retainingretractor may also be employed. Aftercompleting the periosteal elevation, thesurgeon carefully examines the mastoidsurface for changes in form, colour, andsurface (Figure 7).Figure 7: Examine the mastoid surfaceFigure 6: Periosteal elevationForm: In adjoining illustration one seesthe crest of the linea temporalis, the spineof Henlé, and the sieve-like region, theretromeatal depression, and the bulge ofthe posterosuperior region. The anteriormastoid portion is free of all muscularinsertions. The muscles from the nape ofthe neck and the sternocleidomastoidmuscle are inserted into the posteriorportion of the mastoid. These two regionsare separated by the posterior externalpetrosquamous suture. With acutemastoiditis these landmarks may be absentand the mastoid may then present anevenly rounded bulge, having the4

appearance of an egg. The spine of Henléremains and is the only really importantlandmark.Colour: Normally the bone appears whiteor oozes blood through the porous portionsof the retromeatal region. However, inmastoiditis the external cortex bleedsdiffusely due to the deep inflammatoryprocess. If there is underlying empyema,the wall appears bluish.4 th cut: 1cm behind 1 st , thus completinga circle of trephinationThe 1 st 3 taps of the gouge areperpendicular to the bony surfaceThe 4 th tap is applied obliquely toavoid the lateral sinus which may besuperficial or prominent.Surface: Some irregularities may appearalong the surface of the mastoid. Theseoften consist of inflammatory granulationswhich are apparent through the externalposterior petrosquamous suture or of afistula, which may be verified with the aidof a probe. The existence of a fistula issought wherever the incision hasuncovered free pus.Fourth Step: Trephining - Exploration ofSuperficial Antral RegionA large gouge is placed immediately belowthe linea temporalis (Figure 8). It is heldbetween the thumb and first two fingers,with the ring finger serving as a brake. Theinstrument is held in the position shown inthe illustration, being directed vertically atright angles to the bone surface.Site of Trephination: If a fistula is presentand is at the level of the antral region or itsimmediate vicinity, the trephine isperformed at that level. If no fistula existsor is very far from the antral region, thetrephining is done as follows. An area ofapproach is outlined with the gouge byapplying it above and behind the canal atthe following points (Figures 9, 10):Figure 8: Trephining and exploring antralregionFifth Step: Exploration of SuperficialSubantral Region and TipAfter trephining and curetting thesuperficial antral region, the gouge isdirected toward the inferior portion of themastoid, making a superficial verticaltrench. The instrument is held between thethumb and first two fingers of the left handwith the two remaining fingers resting onthe bony surface to provide control and toavoid dangerous slip of the gouge.1 st cut: 2 - 3mm. behind spine of Henlé2 nd cut: just below linea temporalis3 rd cut: parallels, but 1cm. below 2 ndcut5

Figure 9: 1 st & 2 nd cutsFigure 11: Gouge directed toward inferiorportion of mastoidSixth Step: Opening of Apical RegionAfter exploring and curetting the antral andsubantral regions, the surgeon workstoward the tip, creating a superficial,vertical trench, and exposing diseasedmastoid cells (Figures 12, 13). Only if thetip is osteitic need it be resected with thegouge or rongeur.Figure 10: completing a circle oftrephinationFifth Step: Exploration of SuperficialSubantral Region and TipAfter trephining and curetting thesuperficial antral region, the gouge isdirected toward the inferior portion of themastoid, making a superficial verticaltrench. The instrument is held between thethumb and first two fingers of the left handwith the two remaining fingers resting onthe bony surface to provide control and toavoid dangerous slip of the gouge (Figure11).Figure 12: Creating a vertical trench6

the lateral sinus. This region ismeticulously curetted (Figure 15).Figure 13: Vertical trenchSeventh Step: Exploration of PosteroinferiorRegionThe posteroinferior region, which is alsocalled the region of the mastoid vein, isopened with the gouge. The instrument isheld in the same position as describedpreviously but is slanted obliquely frombehind forward and gently forced in withlight taps of the mallet. The procedureprogresses backward toward the posteriorportion of the mastoid from below up.(Figure 14)Figure 14: Opening posteroinferior regionOpening this posteroinferior regionexposes the inner table of the skull whichat this level forms the bony outer shell ofFigure 15: Completed posteroinferiordissectionIf the bony disease is very extensive, thesoft tissues may have to be sectioned by ahorizontal incision perpendicular to theretroauricular incision, forming a “T”, andadditional posterior exposure of themastoid bone done.Eighth Step: Exploration of PosterosuperiorRegion and Lateral Sinus /Sinodural Angle (Figure 16)Trephination is continued from below upand behind forward, burrowingprogressively into the mastoid and to jointhe superficial antral region. The taps onthe gouge are performed cautiously. Theyare made on a tangent to permit the gradualremoval of the cortex over the lateral sinusor even to uncover the venous wall, if thisshould be necessary. The rongeur isdangerous when handled blindly and maypenetrate dura and injure the brain. Thegouge is much more manageable; its actionmore easily controlled. The posterior limitof trephination is determined by the statusof the bone. The process continues untilnormal resistant bone, which does notbleed, is encountered. If haemorrhageoccurs from the mastoid vein, this may be7

cauterized or occluded with bone wax. Agauze pack impregnated with theadrenaline and kept in place for severalminutes may reduce bleeding.obliquely on the bony surface. Smallslanting blows made with the gouge permita very careful sculpturing of the cortex ofthe lateral sinus.Lateral Sinus Thrombosis and PerisinusAbscessesAcute mastoiditis may be complicated by aperisinus (extradural) abscess, lateral sinusthrombosis, or there may be pus within thesinus (Figure 18).Figure 16: Exploring the sinodural angleNinth Step: Exploring Lateral SinusThe posterosuperior region of the mastoidis also called the region of the lateral sinus(Figure 17).Figure 18: Thrombosed (L) lateral sinuswith posterior fossa abscessFigure 17: The lateral sinusSince this vessel is sometimes verysuperficial, the gouge is the onlyinstrument that should be used. It is heldbetween the thumb and the first twofingers of the left hand and placedIn the absence of preoperative CT scanningfacilities, the sinus should be uncapped ofbone. If a perisinus abscess is encountered,it is drained into the mastoid cavity. Thesinus is aspirated with a needle andsyringe. Should there be no free flow ofblood, it might be thrombosed, or theremay be an intrasinus abscess that needs tobe drained.Tenth Step: Search for AntrumThe antrum is sought with a small gougedirected from behind forward towards thespine of Henlé, paralleling the canal and8

excavating down towards the antrum withsmall taps of the mallet (Figure 19).Figure 20: Probing the aditusFigure 19: Accessing the antrumWith the superficial antral region open,this step is particularly easy and the antrumis accessible even when small and deeplylocated. The antrum is enlarged above andposteriorly, either with a gouge or curette.Small curettes which may result indangerous slips should not be used. Theaditus is located with a blunt angularprobe. This permits a determination of thestatus of the tegmen tympani superiorly,especially at the level of the antral roof.Twelfth Step: Opening the Deep AntralRegion (Figure 21)The antrum is enlarged toward its posteriorpart. Between the posterosuperior regionjust opened and the antrum there is a bonyridge which should be resected. Thisresection is performed with a gouge ofmedium calibre held obliquely frombehind forward between the thumb andfirst two fingers of the left hand; theremaining two fingers rest on the bonysurface. Thus a horizontal trench is madewhich is almost perpendicular to theanterior vertical one.Eleventh Step: Opening the Deep AntralRegionAfter widely opening the antrum, theaditus is sought with a blunt curved probe(Figure 20). It is carefully cleansed with amedium sized curette. Very small curettesshould not be used since they may slip andcause serious injuries.Figure 21: Approaching deep antralregion9

Thirteenth Step: Exploration of DeepSubantral Region (Retrofacial Groove)Between the deep antrum and mastoid tipthere remains a bony, often cellular, masswhich it is wise to remove. The antrum isthus continued below by a deep verticaltrench. Exploration of this regionsometimes reveals large cells located verydeep in the bone. This resection may beperformed with the gouge, using verticalblows first in front of the sinus then againstthe posterior wall of the canal which mustbe preserved. The curette, directed fromabove downwards, may be used. It iscontrolled by the index finger of the left ofhand to avoid injury to the lateral sinus ora too deep curettage towards the facialnerve anteriorly. If the deep subantralregion is narrow and the lateral sinusprominent, it is preferable to use a narrowjawedcurved rongeur (Figure 22).Fourteenth Step: Exploration andCleansing of Operative Cavity (Figures23, 24)The cavity is thoroughly explored andcleared of loose or adherent bony spicules.The edges and bottom are smoothed with acurette or rongeur. Suspicious areas areexplored with a blunt probe which locatespreviously unnoticed cells and determinesthe presence of inflammatory granulationson the dura mater.Figure 23: Cleaned cavityFigure 22: Using a narrow-jawed curvedrongeur in the deep subantral regionThe instrument is held in the right handwith the jaws parallel to the anterior aspectof the mastoid; this permits safe progressinto the deeper regions between the facialnerve in front and the lateral sinus at theback.Figure 24: Schematic representation ofanatomy of final cavity10

Fifteeeth Step: Drainage and suturingand postoperative CareA glove/corrugated/pencil drain is inserted(Figure 25). The skin edges are carefullyapproximated. A pressure dressing isapplied held in place by a bandagewrapped around the head.Figure 25: Pencil drain protruding fromwoundPost-operative antibiotics are administered.The patient should be carefully monitoredfor a number of days to detect intracranialseptic complications, as posterior fossacollections can have subtle clinical signs.TEMPOROZYGOMATICMASTOIDITISThe pneumatic cells adjacent to the middleear may develop not only in the mastoidbut also above the canal and thetemporomaxillary joint i.e. at the base ofthe squamous bone (zygomatic arch). Thebase of the squamosa may be pneumatizedeither by way of the intermediary of theantral system or through the cells openingdirectly into the attic. This pneumatization,however, may extend very high into thesquama temporalis. Infection of the cellsin the base of the squamous boneconstitutes a paramastoiditis or temporozygomaticmastoiditis, and necessitates aspecial operative technique.If the infection in the base of the squamousbone is a consequence of an infection ofthe antral system, i.e. a true mastoiditis, theopening of the cells of the tympanic andtemporomaxillary segments will only be anadditional procedure to the mastoidectomy,which has previously been described.If, on the other hand, the temporozygomaticmastoiditis is the result of aninfection arising directly from thetympanic cavity and not including themastoid itself, which may be verifiedeasily by the absence of clinical symptomsat this level and by a normal radiographicpicture of the mastoid, the operation willconsist only of the opening of the cells inthe temporozygomatic region.First Step: IncisionThe cutaneous incision of themastoidectomy is extended 3.0 or 4.0 cm.above and in front of the auricle of the ear.This incision obliquely crosses the lineatemporalis; it goes through to the bone,including the temporal muscle and theperiosteum.Second Step: Periosteal ElevationThe bone of the squama temporalis isexposed above and in front of the canal, ifnecessary, as far as the zygomatic arch.Whenever temporozygomatic mastoiditisis a complication of mastoiditis, theperiosteal elevation naturally extends toinclude the entire external surface of themastoid.11

This is continued until normal bone isencountered.Figure 26: Exposed boneThird Step: Exploration of the BoneKocher haemostats are applied to theperiosteal flaps and the portion of thetemporal muscle, which bleed freely.Ligatures are applied to the muscularvessels. Two hooked retractors are held bythe second assistant. The region being wellexposed, the surgeon examines it foralterations in color, form, and surface. Heverifies the areas of osteitis and thepossible presence of a fistula, which maybe located in the squama temporalis underthe muscle (deep temporozygomaticmastoiditis) or on the zygomatic archimmediately above the canal (superficialtemporozygomatic mastoiditis).Figure 27: Trephination done above theear canalFifth Step: Exploration and Cleansing ofthe Operative CavityThe cavity is explored with great rare. Allthe bony spicules, whether free or adherentare removed. The edges of the interior ofthe cavity are smoothed with the fineangular rongeur (Figure 28). Thesucceeding steps of this operation are thesame as those in the mastoidectomy.Fourth Step: TrephiningIf a complete mastoidectomy has beenperformed, systematic exploration iscarried out with a small gouge, startingfrom the antral region and including theentire base of the squamous bone, beingguided by the existing lesions. If themastoid is normal and if the radiologicaland clinical examinations have shownabsolute integrity of the antral system,trephination is done above the canal inorder to curette and cleanse the cavities ofempyema and osteitic foci (Figure 27).Figure 28: Final cavity12

CERVICAL SEPSISLateral sinus thrombosis may becomplicated by extension of sepsis downthe internal jugular vein into the neck(Figure 29).gouge is usually very limited and quicklysettles. Bleeding can usually be controlledby packing off the sinus with surgical. Ifthe hemorrhage persists or threatens torecur, the cavity is firmly packed withiodoform impregnated ribbon gauze, theend of which exits from the wound next tothe drain. It is removed a few days later.Exposure of Meninges: Exposure of themeninges is not a concern. No change inmanagement is required.Tear of Meninges with CerebrospinalFluid leak: A tear of the meninges issimply repaired with silk or other suture. Ifnecessary, muscle or fascia can be used toaugment the repair.Figure 29: Extension of sepsis downinternal jugular veinInfection of the mastoid may also lead tothe formation of cervical abscesses whichvary according to their form ofexteriorization:Abscess of nape of neck inposteroinferior mastoiditisSubsternomastoid abscess (Bezold’sabscess)Internal aspect of mastoid tip, alongdigastric muscleDeep jugulodigastric cervical abscess(mastoiditis of Mouret)INTRAOPERATIVE INCIDENTSAccidental Opening of the Lateral Sinusor Mastoid VeinOpening of the lateral sinus is more severeif accidentally produced with a rongeur.The use of this instrument is thereforediscouraged in the posterior region of themastoid. Injury to the venous wall with theOpening of lateral or posteriorsemicircular canal: The canal is simplycovered with fascia, which is held in placeby muscle or gauze packingANTROTOMY IN THE INFANTAntrotomy is the surgical opening of theantrum, which is the principal mastoidcavity in the infant. Antrum is fullydeveloped, as opposed to the mastoid thatis not fully developed. The facial nerve ismore superficial at the mastoid tip than inthe adult.Indications include: Early acute mastoiditisunresponsive to antibiotics; complicatedmastoiditis; subperiosteal abscess;intracranial complications (meningitis,abscess); facial paralysis secondary tomastoiditis; suspected tuberculousmastoiditis (remove sequestrum and obtaintissue for diagnosis of TB; and mastoiditissecondary to cholesteatoma13

Author & EditorJohan Fagan MBChB, FCORL, MMedProfessor and ChairmanDivision of OtolaryngologyUniversity of Cape TownCape TownSouth Africajohannes.fagan@uct.ac.zaAuthorRobert Jackler MDSewall Professor and ChairDepartment of Otolaryngology-Head &Neck SurgeryAssociate Dean, Postgraduate MedicalEducationStanford University School of MedicineStanford, CA 94305-5101USAThe Open Access Atlas of Otolaryngology, Head &Neck Operative Surgery by Johan Fagan (Editor)johannes.fagan@uct.ac.za is licensed under a CreativeCommons Attribution- Non-Commercial 3.0 UnportedLicense14