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EndoscopicDacryocystorhinostomy

June1,2023

AllenLue,M.D.

EndoscopicdacryocystorhinostomyorDCRhastraditionallybeenperformedfornasolacrimalductobstructionviaanexternalapproach,althoughtheprocedureisactuallyuniquelysuitedforanendoscopicapproach.

ThefirstreporteddacryocystectomywasperformedbyCelsusin50AD.Thiswasprobablydoneforatumor.GalenasofPergamoswasreportedlythenextpersontoperformasurgeryonthelacrimalsac.Heperformedamedialcanthalincisionandcauterizedwithmoltenlead.Anelinthe1700swasthefirsttoirrigatethelacrimalductforthissymptomofobstruction.Bowmaninthe1800slaterreportedthetechniqueofactuallyputtingaprobethroughtheducttorelieveobstructionofthenasolacrimalsystem.Toti,anItalianin1904,wasreallythefirstpersontoperformexternaldacryocystorhinostomyforobstruction.Hemadeanincisionthroughtheskinandcreatedanewostiumbetweenthenasolacrimalsackandthenose.Byremovingthisbone,drainagetothenosewasallowedthroughbypassinganyobstructiondistally.Histechniqueisstillbeingusedtodayandisgenerallythoughtofasthegoldstandardforsurgeryofnasolacrimalductobstruction.In1895,Caldwellreportedhisexperiencewiththeendonasalapproachbutshowedmediocreresultsandsotheexternalprocedurewasusedforquitesometime.However,Ricein1990reportedhisexperienceusingendoscopicinstrumentstocreatethisneo-ostiumandsincethentherehasbeenquiteabitofliteratureonthesubject.

Thelacrimalsystemconsistsofsuperiorandinferiorpuncta,whichturnintothesuperiorandinferiorcanaliculi,whichthenjoinintothecommoncanaliculus.Thisregionisknownastheupperlacrimalsystem.Thecommoncanaliculusturnsintothenasolacrimalsac,whichisabout12-15-mmlong,whicheventuallynarrowsintothenasolacrimalduct,whichisabout18-mmlong,andthateventuallyemptiesintotheinferiormeatus.Thesacandtheductcomprisethelowerlacrimalsystem.

Tearsmovefromtheeyeintothenosethroughamechanismcalledthelacrimalpump.Lidmovementcausesthepunctatocloseagainsteachother,pushingtearsintothelacrimalsac,whichcontainsthelacrimallake.Whentheeyesopenanegativepressureiscreatedinthelacrimallake,pushingitdownfurtherintothenose.

Thenasalanatomyofthelacrimalsystemisprettystraightforwardandveryfamiliartoanyendoscopicsinussurgeon.Thelacrimalfossaoverliesthelacrimalsac.Averygoodlandmarkistheanteriorportionofthemiddleturbinate.Thelacrimalfossaisboundedbytheanteriorlacrimalcrest,whichconsistsofthefrontalprocessofthemaxillarybone.Theposteriorlacrimalcrestismadeupofthelacrimalboneitself.

Howdoyouevaluateepiphora,whichisreallythemainindicationforaDCR?Firstweshoulddefineourterms.Epiphoraisexcesstearingduetoinsufficientdrainage..OneeveryimportantconcepttonoteaboutaDCRisthatdrainagewillonlyrelieveobstructiondistally.Iftheobstructionisinthepunctaorthecanaliculus,dacryocystorhinostomywillnothelp.Weshouldalsodistinguishepiphorafrompseudo-epiphora,whichisessentiallyrefluxtearing:themainglandovercompensatessecretionbecauseoflackofsecretionfromminorglandsofalongthelidmargin.

Therearemultiplecausesofthenasolacrimalductobstruction,themostcommonofwhichisrecurrentdacryocystitis.Inaseriesof109patientsfromFinland,approximately70%ofthosepatientswithnasolacrimalductobstructionhadrecurrentboutsofdacryocystitis.Contributingfactorsincludenasalallergy,septaldeviationandsinusitis.Lacrimalstonesalsocauseobstruction.Thereisacontroversyintheliteratureastowhetherornotthestonesprecedethedacryocystitisandcauseitduetotheobstructionofthestoneoraretheresultofactualinfections.Tumorscanalsocausenasolacrimalductobstruction,inparticularfromexternalcompression.Thesetumorsareusuallymalignantepithelialneoplasms.Intumorsthemassoftenextendssuperiortothemedialcanthus,whileininflammationorinfection,themassusuallystaysinferiortothisline.Lacrimalsaccystscanalsocauseobstructioninthepediatricpopulation.Otherthings,suchassurgicaltraumaorexternaltraumamayalsocauseobstructionoftheduct.Radiationtherapywillalsosclerosetheductandcauseobstruction

Inthepatient'shistoryitisimportanttonotewhetherornottheepiphoraisunilateralorbilateral,andwhetherthetearingisconstantorintermittent.Unilateralconstanttearingwillusuallydirectyoutowardsanobstructivephenomenon.Thenatureofthedischargeisalsoimportant:clearorpurulent.

Environmentalfactors,suchasallergiesshouldbeelicited.Medicationhistoriesareimportantaswellasprevioushistoryoftraumaorsurgery.Onphysicalexamination,palpatetheregionofthenasolacrimalsactoseeifyoucanelicitanyreflexfromthepuncta.

Whenexaminingtheeyelid,noteifthereisanylaxity,andlookatthepunctumtoseeifthereisanyobstructionthatcanbeseen,orinflammation.Evaluatethecanaliculithroughprobing.PlaceaBowmanprobethroughthepuncta,andthenswingtheprobehorizontallytocannulatethesuperiorinferiorcanaliculus.Thereisadifferencebetweenahardversusasoftstop.Ahardstopwouldbeastopcreatedbybones,suchasthelacrimalbone.Asoftstopcanbefeltasanobstructioninthesofttissue.Evaluatethenasolacrimalductfurtherthroughirrigationoftheductwithasyringe.Anasalexaminationiscertainlyalsoveryimportanttonoteanyobstructivelesionsonthenose.

TheJonestestisatestofthepatencyofthenasolacrimalsystem.Thetestisperformedbyplacingfluoresceinintheconjunctivalsacandseeingwhetherornotthisfluoresceincanbevisualizedinthenose.Ifafteraperiodoffiveminutesthereisimpairedoutflow,itislikelythatthereisanobstructionsomewhereintheductorsomewhereinthesystem.Ifyoudonotseeanydyeinthenoseafterfiveminutes,thenyoucanperformasecondarytest,byirrigatingtheduct.Ifafterirrigatingtheductnodyeisfoundinthenose,thedyehasneverreallyreachedthelacrimalsactobeginwith.Theobstructionislikelyproximal.Ifyoudoseedyeinyourirrigate,thendyedidreachthenasolacrimalsac,anditislikelythatyourobstructionisdistal.

Youcanimagethenasolacrimalsystemusingadacryocystogram.Youcanalsouseadacryoscintigraphywithradiolabeledmaterials,andcertainlyyouwouldnotproceedwithanendoscopiccasewithoutperformingcomputedtomography.ACTcanbeveryusefultofindextrinsictumors,lacrimalsacmucoceles,showthestateofthesinusesandfinddacryolithsforyou.InaseriesperformedinAustralia,a10%incidenceofconditionsthatactuallychangedmanagementofnasolacrimalductobstructionwasfoundwhentheygotaCTscan.

Iftheobstructionisbeyondoratthesacinthelowerlacrimalductsystem,aDCRmaybeperformed.TheexternalDCRiscertainlystillthoughtofasthegoldstandardwithasuccessrateofapproximately91%.Revisionprocedureshaveasuccessrateofapproximately81%,althoughitshouldbenotedthatdissectionthroughthepreviousscarcanbesomewhatlaborious.Theexternalincisionismadejustinferiortothemedialcanthus,takingcaretoavoidtheangularartery.Thelacrimalsacisexposed,andyoudrillthroughthelacrimalfossathroughthefrontalprocessofthemaxillaryboneuntilyouenterthenasalcavity.Youcanalsocreatemucosalflaps,whichwillkeeptheostiumopen.ACrawfordtubeisplacedthrougheachpuncta,througheachcanaliculusandthenouttheneo-ostiumintothenose.Thisisusuallykeptinplaceanywherefromsixweekstosixmonthstomaintainthepatencyofthisneo-ostium.

Eventhoughthesuccessrateishigh,therearecertaincomplicationstoanexternalDCR.Thereisanexternalscar,whichisavoidedwiththeendoscopicprocedure.Thereisalsodangerofinjurytothemedialcanthalstructures,andCSFleakhasbeenrecorded.Thereisa9%chanceofrecurrenceofsymptoms.Onecauseofrecurrenceofsymptomsisiftheobstructionisinthecommoncanaliculusproximaltowherethedrainageprocedureisdone.Thereisalsothepossibilityofclosureofasmallmalpositionedostium,entryintotheethmoidsinus,andcausesofintranasalobstruction.

TheendoscopicDCRwasfirstdescribedbyMcDonoghin1989.Heactuallythoughtabouttheprocedurewhenheexposedtheductbyaccidentduringoneofhissinusprocedures.ForanendoscopicDCR,theanteriorportionofthemiddleturbinateisusedasalandmark.Amucosalflapiselevated,exposingthelacrimalfossa.Thisboneisdrilledout,thatisthefrontalprocessofthemaxillaryboneandsomeofthelacrimalbone,exposingthenasallacrimalsac.Placeaprobetentingthesac,andincisethissactocreateaneo-ostiumsothattearscandrainfromthecanaliculusdirectlyintothenosethroughthemiddleturbinateandbypassanyobstructioninthenasolacrimalduct.ThisostiumiskeptopenwithaCrawfordtubestentwithasiliconetubeplacedthroughthepunctaintothesacandoutthenose.Thetubesarekeptinplaceforanywherefromsixweekstosixmonths.

TherearecertainadvantagesoftheendoscopicDCR.Thereisnoexternalscar.Itpreservesthelacrimalpumpsystem.Anyintranasalpathologythatmighthavecausedfailureofthefirstprocedurecanbeaddressed,includingadhesions,enlargedmiddleturbinateandseptaldeviation.Moreofthelacrimalsacispreservedwiththeendoscopicprocedure.Thereisactuallyonlya1in40instanceofairregurgitationduringnoseblowingnotedafterendoscopicprocedures,whiletheincidenceishigherwiththeexternalprocedure.ThereisalsodiminishedriskofaCSFleakwiththeendoscopicDCR.

Therearealsosomedisadvantages.ThemaindisadvantageisthatDCRisafairlynewprocedureandsolong-termresultsareunknown.Nomucosalflapsarecreated.Mucosalflapshavebeenfoundtodecreaserecurrenceratesintheexternalprocedures.AsmallerrhinostomyisperformedinDCRthanintheexternalprocedure.ItisinterestingtonotethatinastudybyLinbergtherewasnocorrelationbetweentheoriginalsizeofthebonyopeningandthesizeofthehealedostiumatsomelaterpoint.Infact,theaveragesizewas1.8-mm.

Inreviewingthesuccessrates,thefirstwasRicewhoreportedfourpatientswitha100%successrate.In1943,Whittetreportedon40patientswithan83%successrate.WeidenbocherfromGermanyhadan86%successrate.SprekelsenfromSpainhadaverylargeseriesof152patientsandhada96%successrate.Mostoftheseauthorsdefinesuccessasmaintenanceofpatencyafteraperiodofanywherefromthreemonthstoayear.

TherehasonlybeenoneprospectivestudycomparingendoscopictoexternalDCR,whichwasperformedbyHartikainenofFinland.Helookedat64patientsandfollowedupatoneyear.Hefoundapatencyrateof75%intheendoscopiccasesversus91%externally.Thisdidnot,however,reachastatisticallysignificantdifference.Itshouldbenotedthatafterrevisionprocedures,therewasa97%successrateinbothgroups.

Whatisnotupforargumentisthattheendoscopicapproachisactuallyidealforrevisioncases,particularlybecauseyoudonothavetodrilloutanynewbonethathadbeendonepreviouslybyanexternalapproach.In1991Metsonreportedon15patientswhowerestatuspostfailedexternalDCRandreporteda75%successrate.Again,themainadvantageisthatitisunnecessarytoremoveanybone.Thereisalsotheaddedadvantageofbeingabletoperformsecondarynasalprocedures.Metson,inthe1991study,performedthefollowingsecondaryendoscopicnasalprocedures:middleturbinateresections,septoplasty,andethmoidectomiesandantrostomies.

TherearecertaincomplicationstoanendoscopicDCR.Someareuniquetotheendoscopicapproachandsomearesharedbytheexternalapproach.Inparticular,closureoftheostium,andintranasaladhesionsfromtheendoscopicprocedurecanoccur.Canalicularlaceration,pyogenicgranuloma,andCSFleakhavebeenreported.Orbitalhemorrhagecancertainlyoccurfromtheinteriorethmoidarteryduringtheendoscopicprocedure.

Recently,therehasbeenliteratureontheuseofthelasertoperformendoscopicDCR.Massarowasthefirsttoreportin1990.HeusedanArgonlaserandhadmediocreresults.However,recentlytheHolmium-Yaglaserhasfoundalotofuse.Itsadvantagesarefiberopticdelivery,effectiveboneablation,softtissuecoagulationandshallowdepthofpenetration,whichmakesitsafer.Alightpipeisplacedthroughthepuncta.Thepipegoesthroughthecanaliculus,intothenasolacrimalsacandcanlocalizethelacrimalfossa.Endoscopically,youcanplacethescopeandthelaser,atwhichpointyoucanobliteratethesofttissueandtheboneoverlyingtheregionofthelacrimalfossa.

TheliteraturewhichreportsretrospectivelyonthelaserDCRincludesMetson,whowasoneofthefirsttoreport:40patientswithan85%successrate.Sadiqhada70%successrateandSzubinshoweda97%successrate.AllofthesestudiesusedtheHolmium-Yaglaser.

Again,therehasonlybeenoneprospectiverandomizedstudycomparinglaserandexternalDCR.Thiswasactuallydonebythesamegroup(Hartikainen)possiblyusingthesamecontrolgroupfortheexternalapproach.Theystudied64patients,andhada95%successratewiththeexternalapproachatoneyearand63%successratewiththelaser.Thiswasasignificantdifference.Onenotablethingisthatthedurationofthesurgerywas23minutesforthelaserprocedureversus78minutesfortheexternalapproach,sothelaserapproachdidhavetheadvantageofsavingtime.

InconsideringthefutureforendoscopicDCR,weshouldlookattheuseofanti-metabolitessuchasMitomycin-C.Thisalkylatingagenthasfoundotheruseinophthalmologicproceduresincludingglaucomaandpterygiumremoval.Camarain2023increasedhissuccessrateforendoscopicDCRsfrom89%to99%andreportednocomplications.

Theotherthingonthehorizonisactuallyendolacrimalsurgery.ThescopeisactuallyplacedthroughthepunctumintothenasolacrimalsackandalaserisplacedthroughthescopeandtheostiumismadefromthenasolacrimalsacoutintothenosewithaKTPlasertoopenthebonywindow.Muellnerrecentlyreportedveryshort-termsuccessin21patients.

Inconclusion,anendoscopicDCRisasimple,minimallyinvasiveprocedurewithpromisingshort-termresults.Itwouldnotbeverychallengingtoanexperiencedendoscopicsurgeon.However,thelong-termpatencyratesarestillnotknown,ascomparedtothegoldstandardoftheexternalDCR,butcertainlytheendoscopicprocedureisideallysuitedforrevisionprocedures.

CasePresentation

Thepatientisa46-year-oldwhitefemalewhowasreferredforahistoryofrecurrentleftdacryocystitiswithsymptomsofleft-sidedtearingandpain.Shehashadmultiplecoursesoforalantibiotics,andhernasolacrimalductwascannulatedwithaCrawfordtubebyanophthalmologistinprivatepractice,buthersymptomsdidnotresolve.Shedeniesanyhistoryofnasalallergiesorsinuspathology.Thepatientisotherwisehealthyandhasnotundergoneprevioussurgeryintheheadandneck.

Onphysicalexam,herlefteyewasunremarkableexceptfortheCrawfordtubeinplacethroughbothpuncta.Examinationofherleftnasalpassagerevealedthesiliconetubeemergingfromthemiddlemeatus.Thenasalmucosaappearedhealthyandasmallleftseptalspurwasseen.ACTscanofthesinusesrevealedwell-aeratedsinuseswithoutevidenceofalesionobstructingthenasolacrimalsystem.

Intheoperatingroom,anendoscopicdacryocystorhinostomywasperformed.Theanterioredgeofthemiddleturbinatewastrimmedtoaidvisualization.Awindowoflacrimalbonewasremovedwithadrill,andthelacrimalsacwasincised.Anewsiliconetubewasplaced.Shehashadnofurtherproblemspost-operatively.

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