TympanoplastyChristopher Muller, M.D.Arun Gadre, M.D.

University of Texas Medical BranchGalveston, TX

OutlineDefine termsHistoryAnatomy and EmbryologyPhysiology of sound transmissionEtiology Preoperative evaluationTechniquesTympanoplasty in childrenComplicationsResults

IntroductionMyringoplasty - reconstruction of a perforation of the tympanic membrane (TM)Assumes normal middle ear (ME) mucosa and ossiclesTM is not elevated from its sulcusTympanoplasty reconstruction of the TMAlso includes addressing middle ear pathologyCholesteatoma, adhesionsOssicular chain problemsUsually involves elevating the TM from its sulcus

IntroductionTympanoplasty is sub-classified based onMedial or lateral graftingAssociated type of ossicular chain reconstruction (OCR)

History1640 BanzerFirst attempt at repair of a TM perforationUsed pigs bladder as a lateral graft1853 ToynbeePlaced a rubber disk attached to a silver wire over the TMReported significant hearing improvement1863 Yearsley placed a cotton ball over a perforation1877 BlakePaper patch

History1876 RoosaTreated TM perf. with chemical cautery1878 Berthold Coined the term myringoplastyPlaced cork plaster against TM to remove epitheliumApplied a FTSG

History1950s Wullstein and ZollnerSTSG over de-epithelialized TM1956 - WullsteinDescribed five types of tympanoplasty 1957 first medial graft performed by Shea with vein graft1961 Storrs introduced the use of temporalis fascia graftingMedial grafting1961 and 1967 House, Glasscock and SheehyDeveloped and refined techniques for lateral grafting

Anatomy and Embryology of the Tympanic Membrane

Embryology

Embryology4th week of gestationTM develops from three sourcesEctoderm 1st branchial grooveEndoderm 1st branchial pouchMesoderm 1st and 2nd branchial arches

Embryology

AnatomyTM is oval in shape8 mm X 10 mm55 degrees to the floor of the meatusNear circumferential fibro-cartilaginous thickening Annular ligament or annulus3 layers 130 microns thickOuter epithelial keratinizing squamousMiddle fibrous superficial radial, deep circularInner mucosaEpithelial migratory patternCentrifugal growth for the umbo outward

Anatomy

Anatomy

AnatomyBlood supplyInner surfaceAnt. Tymp a.Outer surfaceDeep auricular a.

Blood Supply

Anatomy

Physiology of the TMMiddle earTransforms air waves to fluid wavesTwo mechanismsArea affect of TMTM area:foot plate area 17:1Lever action of the ossicles1.3:1 malleus to incus ratio22:1 combined transformer ratio of middle earTranslates to 25 dB

Physiology of hearing with TM perforationsEffects on hearingDecreased transformer ratioRound window stimulation causes inner ear fluid waves that cancel out those at the oval windowSound pressure entering the perforation acts on the medial surface of the TM against that on the lateral surface

Etiology of TM perforationsInfection most common causeBacteriaMycobacteriumVirusesTraumaPenetrating traumaSelf induced with cue tip most common penetrating causeBluntTemporal bone fracturesLongitudinal fractures more common than transverse fracturesSlap injury

Etiology of TM perforationsTraumaThermalWelders and steelworkersLightningBarotraumaCadaver studies 14-33 lbs/inKeller (1958) 195-199 dB sound pressureIatrogenicRetained ventilation tube Nicoles et al. 40% incidence of perforation with retained tubes > 36 months vs. 19% < 36 months

Etiology of TM perforationsTraumatic TM perforations1992 Kristensen80% heal spontaneouslyThermal injuries 40% heal spontaneouslyOther negative factorsAge > 30 yearsLarge kidney bean shaped central perforationsPosterosuperior perforationsInfection

Preoperative EvaluationHistoryHearing lossTinnitusVertigoOtalgiaOtorrheaFacial paralysisPrior otologic proceduresMedical history DM, heart, lung, kidney, liver

Preoperative EvaluationPhysical exam complete H/N examFacial nerveExternal earTullios PhenomenonOtomicroscopyEar canalTMPerforation location, sizeRetraction pockets, granulation tissueStatus of middle ear through perforationAudiometry preferable with a dry earAir and bone lines, acoustic reflexesTympanometry+/- CT temporal bone

Indications for SurgeryConductive hearing loss due to TM perforation or ossicular dysfunctionChronic or recurrent otitis media secondary to contamination Progressive hearing loss due to chronic middle ear pathologyPerforation or hearing loss persistent > 3 months due to trauma, infection, or surgeryInability to bathe or participate in water sports safely

Goals of SurgeryEstablish an intact TMEradicate middle ear disease and create an air-containing middle ear spaceRestore hearing by building a secure connection between the ear drum and the cochlea

TechniquesOverlay technique (lateral grafting)Underlay technique (medial grafting)

Lateral Grafting

Postauricular incision

Harvest of temporalis Fascia Graft

Elevation of the vascular strip

Lateral Grafting

Removal of canal and TM skin Drilling the anterior canal bulge

Ensure complete removal of TM epithelium

Shaping the fascia graft

Replacing the canal skin

Medial Grafting

Medial Graft Position

Debride the edges of the perforationsPurposeSeparates the continuity of the inner mucosa with the outer epitheliumDisrupts the fistulous tract

Elevation of the tympanomeatal flapInspect the undersurface of the TM for squamInspect the middle earOssiclesErosionmobilityRound window reflexEustachian tube

Pack middle ear with gelfoam

Placing medial fascia graft

Replacing the tympanomeatal flap

Medial vs. Lateral Graft Tympanoplasty

Blunting of Annulus

Blunting at Annulus

Classification of TympanoplastyWullstein (1956)Type I tympanoplasty TM is grafted to an intact ossicular chainType II tympanoplasty Malleus is partially eroded TM +/- malleus remnant is grafted to the incusType III tympanoplasty Malleus and incus are erodedTM is grafted to the stapes suprastructure

Wullstein classification continuedType IV tympanoplastyStapes suprastructure is eroded but foot plate is mobileTM is grafted to a mobile foot plateType V TympanoplastyTM is grafted to a fenestration in the horizontal semicircular canalClassification does not take into account middle ear pathology

Type III tympanoplasty

TORP using cartilage stiffener

Type IV Tympanopasty

Classification of TympanoplastyBelluciProposed a dual classificationAdded status of middle earGroup I Dry earGroup II Occasional drainageGroup III Persistent drainage with mastoiditisGroup IV Persistent drainage and nasopharyngeal malformation (cleft palate and choanal atresia)

Classification of TympanoplastyAustins classificationDescribes the residual ossicular remnants(M+/I+/S+) intact ossicular chain(M+/S+) or (M+/S-) good prognosis(M-/S+) or (M-/S+) poor prognosis

M malleusS stapesI - incus

Postoperative CareDay surgeryMastoid dressing removed postop day oneIncisions cleaned bid with H2O2 and topical abxPatient instructionsAvoid nose blowingSneeze with mouth openAvoid heavy lifting (>10 lbs) or strainingDry ear precautionsOne week staples or steri-strips are removed and ear drops are startedThree weeks, gelfoam is removed from the EAC2-3 months, postop audiogram is performed

Graft MaterialsFTSG, STSGInitial good resultsSubsequent desquamation and infection with high delayed failure rateCanal skinSimilar to STSGVein grafts (Shea)Atrophy

Graft MaterialsTemporalis fasciaHermann (1960) and Storrs (1961)Large quantityNo separate incisionSturdyLow metabolic rateHomograft TMExcellent success similar to fasciaTheoretic risk of infectious disease transmission (prions, HIV)Availability

Cartilage Tympanoplasty1958 JansenFirst used cartilage in the middle ear1963 Salen and JansenFirst reported use of cartilage for reconstruction of the TMExcellent for prevention of recurrent retraction pocketsMost successful when placed posteriosuperiorly and pars flaccida (Poe and Gadre, 1994)Recommended by Vrabec (2002) to be placed over TORP or PORP to prevent extrusion

Cartilage TympanoplastyResultsGerber (2000) and Dornhoffer (1997)Hearing results comparable to temporalis fascia and perichondrium even with complete TM reconstruction with cartilage

Cartilage Tympanoplasty

Cartilage Tympanoplasty

Cartilage Tympanoplasty

Cartilage Tympanoplasty

Tympanoplasty in ChildrenControversialConsidered less successful than adultsHigher incidence of ETD and otitis mediaWide range of success rates 35% to 93%Tos and Lau (1989)Found comparable success rates compared to adults for all ages in children (92%)Helps to lessen progression of ossicular pathology

Tympanoplasty in ChildrenManning 78% success Deskin and Vrabec (1999)Meta-analysis of all common variables assoc. w/ successFound only advancing age was statistically associated with improved outcomes.

ComplicationsInfectionPoor aseptic techniquePrior contaminationGraft failure is associated with postop infectionGraft failureInfectionInadequate packing (anterior mesotympanum)Inadequate overlay of graft with TM remnant (underlay)

ComplicationsChondritisInjury to the chorda tympani nerveSNHL and vertigoExcessive manipulation of the ossiclesIncreased conductive hearing lossUnrecognized eroded ISJBluntingThick graft extending onto the anterior canal wall in lateral graftingLateralization of the TM from the malleus handleExternal auditory canal stenosisLateral grafting

Results closure of perforations1992 Smyth (Toynbee Memorial Lecture)Stated that most series report 90% successMajority of studies have only one year f/uMost do not report atelectatic pocketsHalik and Smyth 60% success in revision casesFound improved results in patients with dry earsSimilar success with temporalis fascia versus homograftWorse results with anterior perforationsRecommend using fascia Anterior TM is less vascularFascia less susceptible to anoxia and is less antigenic than homograft

Results hearing Albu et al.Three most important prognostic indicatorsStatus of the middle is the most important predictive factorPresence of the handle of the malleus Perforations > 50%Halik and Smyth80% success rate closing ABG to within 10 dB at 5 years

Results overlay graftingSheehy and Anderson (1980)Compared 472 overlay97% success with fascia grafts84% success with canal skin1.3% complication rateAnterior blunting Lateralization80% had ABG within 10 dB

Results overlay vs. underlayDoyle et al. (1972)Compared 52 overlay to 79 underlay at a teaching institutionOverlay 36% re-perforation 27% with hearing improvement (15db ABG or better)Underlay14% re-perforation62% hearing improvement> complication rate with overlay group

Results overlay vs. underlayDoyle et al. (1972) ConclusionsIn experienced hands either technique can be equally successfulResidents and otolaryngologist of limited experienceMedial grafting gives better healing and fewer complicationsAll cases utilized endaural approach with is more techniquely demanding

Results overlay vs. underlayRizer (1997)Compared 551 underlay to 158 overlayClosure in 88.8% of underlay versus 95.6% of overlayClosure of ABG to 10 dB or less in 84.9% of underlay vs. 80.4% of overlaySimilar complication rates

Results overlay vs. underlayRizer (1997)Both groups no relationship in re-perforation with:Age of patientPerforation size or locationMiddle ear statusPresence of cholesteatoma

ConclusionTympanoplasty has a high rate of success in closing tympanic membrane perforations and improving hearingPatients should be chosen carefully based on the indications discussed and attempts at attaining a dry ear prior to surgery should be madePatients should be thoroughly counseled preoperatively about the expectations and goals of the surgeryTympanoplasty in the pediatric age group is controversialBoth underlay and overlay techniques for grafting are effective, however, the surgeon should do what he/she is most experienced and successful with