14 Esophagus

7/31/2019 14 Esophagus

1/38

Print | CloseW indow

Note :Largeim agesandtablesonthispagem aynecessitateprintinginlandscapem ode.

Skandalakis' Surg ica l Anatom y > Chapter 14 . Esophagus >

HI STORY

Theanatom icandsurgicalhistoryoftheesophagusisshow ninTable14-1.

Table 14-1. Anatom ic and Surg ica l His tory of th e Esophagus

Sm ithSurgicalPapyrus(3000-

2500B.C.)

Descriptionofa"gapingw oundinthethroatpenetratingthegullet"

Chinese(ca.1000B.C.) Descriptionofdysphagiasecondarytoesophagealcancer

Aristotle(384-322B.C.) Theorizedthattheesophagusgotitsnam efrom "itslengthandnarrow ness"

Galen(130-200A.D.) M entionedgrowthascauseofesophagealobstruction

Lanfranc(d.1315) Placedasilvertubeinthew indpipeofapatientw ithfalsepassagebetweentheesophagusandtracheatoassistbreathing

Vesalius 1543 Usedendotrachealtubetom aintainventilationinanim als

Durston 1670 Mayhaveseenacaseofesophagealatresia

W illis 1679 Firstdescriptionofachalasia;treatm entbydilatation

Gibson 1696 Describeda"m onstrousbirth"withtracheoesophagealfistula

M onroe(1670-1740) Repairedthetracheaandesophagusofapatientw ithseveredtracheaandpuncturedesophagus

Goursald&Roland 1750 M entionedesophagotom yandrem ovalofforeignbodies

Ludlow 1769 D escribedpharyngoesophagealdiverticulumTarenget 1786 Mentionedstrictureofthecervicalesophagus

Bell 1816 Perform edexternaldrainageofthediverticulum

Cam pbell 1848 Triedtoconvinceaprofessionalswordswallow ertoparticipateinexperim entalendoscopy;thelatterreplied,"Iknow Ican

sw allow asword,butI'llbedam nedifIcansw allow atrum pet"

Cheever 1867 Perform edsuccessfulesophagotom ies

Bevan 1868 Describedanesophagoscopew hichusedlightreflectedfrom am irror.Useddeviceforforeignbodyextractionand

exam inationofstricturesandtum ors.

Kussm aul 1868 Designedanesophagoscopeilluminatedbyagaslam p

Trendelenburg 1871 Perform edtracheostom yandinsertedanendotrachealtubew ithaninflatabletam ponw hileadm inisteringanesthesia

Billroth 1871 S tudiedstrictureoftheesophagus

Lam b 1873 Publishedfirstreportofanesophagealfistulawithoutatresia

Zenker 1877 Discussedetiology,pathology,andsym ptom atologyofthepharyngoesophagealdiverticulum (Zenker'sdiverticulum )

Czerny 1877 Perform edesophagealresectionandsuturedthelowerendoftheesophagusintotheneck.Thepatientsurvived.

Nicoladoni 1877 Perform edfirstoperationonapharyngealdiverticulum

Niehans ? Excisedanesophagealdiverticulum ;patientdiedofhem orrhagesecondarytofistula

M acewen 1880 Insertedendotrachealtubesbym outhw ithoutperform inglaryngotom yortracheostom y

M ikulicz-Radecki 1881 Developedesophagoscopeandgastroscope

G ross 1884 Treatedstrictureoftheesophagus

O'Dw yer 1885 Developedendotrachealintubationfordiphtheria,etc.

M ikulicz-Radecki 1886 Treatedcarcinom aoftheesophagusbyresectionandplasticreconstruction

W heeler 1886 Perform edfirstknownsuccessfulresectionofZenker'sdiverticulum

Fell 1887 Usedafootbellowsattachedtoatracheostom ycannulaforartificialventilation

Nassilov 1888 Suggested,butdidnotem ploy,anextrapleuralroutethroughtheposteriorm ediastinum totheesophagus

Biondi 1895 Proposedresectionbypullingthestom achupwardintothechest,followedbyesophagealanastom osis

Milton 1897 Recom m endedm idlinesternotom yforanteriorapproachtothem ediastinum

vonHacker 1899 Diagnosedesophagealcarcinom abyesophagoscopyandbiopsy

Gottstein 1901 Suggestedesophagom yotom yfortreatm entofcardiospasm

Gosset 1903 Describedtransdiaphragmaticesophagogastrostom ythroughthoracotom y

Sauerbruch 1904 Developedandusedanegative-pressuresystem cham ber

Roux 1907 Perform edasuccessfulesophagojejunostom y

Voelcker 1908 Perform edthefirstsuccessfulresectionofthelowerthoracicesophagusbytransabdom inalesophagogastrectom y

Schm id 1912 Perform e ddiverticulopexyoncadavers

Torek 1913 Successfullyrem ovedtheesophagusforcancer.Thepatientw asleftw ithcervicalesophagostom yandgastrostom y.

H eller 1913 Perform edesophagom yotom yfordysphagia

VonAch 1913 Usedbluntdissectionfromneckandabdom enforesophagectom y

Denk 1913 Usedbluntdissectionforesophagealrem oval,w ithlaterrestorationofesophagealcontinuity.Theoperationw asnot

successful.

Zaaijer 1913 Perform edfirstsuccessfultransthoracicresectionforcarcinom aofthecardia

M osher 1917 Usinganendoscope,incisedtheseptum betw eentheesophagusandaZenker'sdiverticulum

Hill 1918 Perform edfirstdiverticulopexyonalivingpatient

Knig 1922 Fixedadiverticularsactothehyoidbone

Torek 1927 Describedpharyngealsuperpressureforsurgery

GrayTurner 1931 Exploredthedistalesophagusfrom theabdom en

1. oldal, sszesen: 38 oldalPrint: Chapter 14. Esophagus

2012.03.20.mk:@MSITStore:D:\Sebszet\Surgical%20Anatomy%20The%20Embryologic%20A...


2/38

Historytablecom piledbyDavidA.M cCluskyIIIandJohnE.Skandalakis.

References

Elm slieRG .Perspectivesinthedevelopm entofoesophagealsurgery.In:Jam iesonGG(ed).SurgeryoftheOesophagus.New York:ChurchillLivingstone,1988,pp.

3-8.

HaegerK.TheIllustratedHistoryofSurgery.London:HaroldStarke,1988.

KittleCF.Thehistoryofesophagealsurgery.In:W astellC,NyhusLM ,DonahuePE(eds).SurgeryoftheEsophagus,Stom ach,andSm allIntestine(5thed).Boston:

Little,Brow n,1995,pp.4-29.

NaefAP.TheStoryofThoracicSurgery.Lew istonNY:HansHuber,1990.

SkandalakisJE,GraySW ,ShepardD,BourneGH.Sm oothM uscleTum orsoftheAlim entaryCanal:Leiom yom asandLeiom yosarcom as,aReview of2525Cases.

Springfield,IL:CharlesC.Thom as,1962.

SkandalakisJE,GraySW .Em bryologyforSurgeons(2nded).Baltim ore:W illiam s&W ilkins,1994.

W arrenR.Surgery.Philadelphia:W BSaunders,1963.

Ohsawa 1933 Perform edfirstintrathoracicgastroesophagealanastom osistorestoregutcontinuity

Adam s&Phem ister 1938 Reportedsuccessfulesophagealresectionsw ithesophagogastricanastom osis

Leven&Ladd 1939 Independentlyperform edsuccessfulm ultiple-stagesurgerytotreatesophagealfistulasandatresia

Haight&Towsley 1941 Perform edasingle-stageanastom osisoftheesophagusw ithinthem ediastinum

Churchill&Sw eet 1942 Perform edesophagectom yw ithend-to-sideanastom osis

Garlock 1943 Developedtechniqueforesophagealsurgery

Kaplan 1951 Reportedthefirstuseofelectivecricopharyngealm yotom y

Sw eet 1954 D evelopedsurgicaltechniqueforresection

Skandalakisetal. 1962 Collectivereview ofcasesofsm oothm uscletum orsoftheesophagusasreportedinthew orldliterature

Belsey 1966 D evelopedsurgeryforachalasia

Ellisetal. 1969 StudiedphysiologyofachalasiaandZenker'sdiverticulum

Gavriliu 1975 Reviveduseofthegastrictubeforesophagealreplacem ent

O rringer 1978 R ecom m endedesophagectom yw ithoutthoracotom y

Lieberm ann-M effert 1996 Studiedsurgery,anatom y,andem bryologyoftheesophagus

EMBRYOGENESI S

Nor m a l Dev elopm en t

Inthehum an,theprim itiveforegutform sduringthefourthw eekofgestationbyalongitudinalfoldingandincorporationofthedorsalpartoftheyolk

sacintotheem bryo.2,3,4Thetracheadevelopsfrom theforegutabout22-23daysafterfertilizationasam edianventraldiverticulum 4(Fig.14-1).

Im m ediatelyafterthisdiverticulum form s,thestom achdevelopsfurtherdistallybyanasym m etricalextension3-6(Fig.14-2).

Fig. 14-1.

Divisionoftheprim itiveforegut,w ithstippledareashow ingthefutureesophagealportion.Arrow sindicatethelocalm orphogeneticm ovem ents.Inset:Transverse

sectionthroughprim itiveforegut.Left,Trachea(ventral);Right,Esophagus(dorsal).(Modifiedfrom SkandalakisJE,GraySW .Em bryologyforSurgeons(2nded).

Baltim ore:W illiam s&W ilkins,1994;withperm ission.)

Fig. 14-2.




3/38

Foregu t

Severalphenom enatakeplaceatapproxim atelythe34thday.Thegenesisofthesubm ucosalandm uscularlayersofbothtracheaandesophagus

begins.Thedistalesophaguselongatesfirst,follow edbytheproxim al.Characteristically,theelongatedesophagealsegm entcarriesthegastric-dilated

prim ordium below theform ingdiaphragm .M ostlikely,how ever,elongationresultsfrom pharyngealascentratherthangastricdescent(Fig.14-2).

Separategrow thprocessesofthetracheaandesophagusoccurbeforethefifthweekofintrauterinelife.Theesophagusattainsitsfinaldim ensionsinthe

seventhweek.Atbirthitslengthis8-10cm ,w hichdoublesinthefirstfew yearsoflife.

Earlyinthesixthweek,them esenchym alcircularm usclecoatdevelops.Threetoninew eekslater,longitudinalm usculatureappears.4Duringthe4th

m onth,them uscularism ucosaappears.Bloodvesselsentertheesophagealw allduringtheseventhm onth,andlym phcapillariesenterthewallbetw een

thethirdandfourthm onthsoflifeafterbirth.7

Attheseventhtoeighthweektheesophageallum en(Fig.14-3)isalm ostfilledw ithcellsfrom theproliferatedesophagealepithelium .Becausethefillingisnevercom pleteandsm allvacuolesarepresent,theso-calledsolidstagedoesnotexistassuch.Aroundthe10thw eekthelum enisrestoredsincethe

vacuolescoalesce.

Theem bryonicgut,show ingtheprim itiveesophagusandthechangesinthepositionofthestom ach.A,Presum ptivestom achareaoftheundifferentiatedforegutat2.5m m (fourthweek).B,At4.2m m (fifthw eek).C,Shapeofthestom achat6.3m m (6thw eek).D, At10m m (endofsixthw eek).E,Shapeanddescentof

stom achessentiallycom pletedat17.5m m (endofsecondm onth).C7,Seventhcervicalsegm ent;T1,Firstthoracicsegm ent;T12,Tw elfththoracicsegm ent;L1,

Firstlum barsegm ent.(Modifiedfrom SkandalakisJE,GraySW .Em bryologyforSurgeons(2nded).Baltim ore:W illiam s&W ilkins,1994)Adaptedfrom

Blechschm idtE.Thestagesofhum andevelopm entbeforebirth.Philadelphia:W BSaunders,1961;w ithperm ission.)

Fig. 14-3.




4/38

Changesarealsotakingplaceintheesophagealciliatedepithelium ,w hichbecom esstratifiedsquam ousintheproxim alandm iddleesophagus.Colum nar

epithelium rem ainsunchangedinthedistalesophagus.

Theesophagealw allreceivesbothsym pathetic(thoracictrunkandceliacplexus)andparasym pathetic(vagusnerve)innervation.

R emember

Branch ia l Arch Fo rmat i on and t he Esophagus

Theem bryonicm esoderm albranchialarchesplayarolebyparticipatinginthearrangem entofvesselsandnerves.Som eoftheem bryonicm esoderm al

branchialarcheshaveadirectrelationw iththeesophagusbytheirproductionofvesselsandtheirassociationtospecificnerves.

Thethirdbranchialarchisassociatedw iththeglossopharyngeal(IX)nerve.Itparticipatesinaverysm allw ayinthepossibleform ationofpharyngeal

m usclesandthepharyngeallining.Thethirdaorticarchliesw ithinthethirdbranchialarch.Theexternalcarotidarteryarisesdenovofrom thethird

aorticarch.Thecom m oncarotidandtheproxim alinternalcarotidarteriesarederivedfrom thethirdaorticarch.Thesuperiorthyroidarteryperhaps

participatesinthebloodsupplyaroundthepharyngoesophagealjunction.

Thefourthbranchialarchisassociatedw iththevagus(X)nerve.Therightfourthaorticarchcontributestotheform ationoftheproxim alportionofthe

rightsubclavianartery.Theleftsubclavianarterym aybederivedfrom thesixthintersegm entalartery.Thethyrocervicaltrunkarisesfrom the

subclavianarteries.Theinferiorthyroidarteryspringsdirectlyfrom thesubclavianarteryin15% ofindividuals,8andfrom thethyrocervicaltrunkin85% .Theinferiorthyroidarteryisresponsibleforthebloodsupplyoftheupperesophagus.Thearchoftheaortaandtherightdorsalaortaarealso

productsofthefourtharch.M inutevesselsfrom theaortam ayparticipateinthebloodsupplyoftheesophagus.

Thesixthaorticarch,theso-calledpulm onaryarch,m ostlikelydoesnotparticipateinthebloodsupplyoftheesophagus.

Congeni t a l Anom al ies and Surg ica l Repa i r

Abnorm algrow thprocessesofthetracheaandesophagusproduceagreatnum berofanom alies.Problem sinthegastroesophagealjunctionproduce

otherlessdram aticeffects(Fig.14-4A&B).

Changesintheshapeoftheesophageallum en.A,At19m m (eighthweek).B,At37m m (ninthweek).C,At42m m (lateninthweek).D,At120m m (aboutthe

fifteenthw eek).(Adaptedfrom Lew isFT.Thedevelopm entofthedigestivetractandoftheorgansofrespiration:thedevelopm entoftheoesophagus.In:KeibelF,

M allFP.Hum anEm bryology,VolII.Philadelphia:JBLippincott,1912;w ithperm ission.)

Bothendoderm andm esoderm participateintheform ationoftheesophagealw all.Theendoderm producestheesophagealepithelium andglands,andthem esoderm producestheconnectivetissue,m uscularcoat,andangioblasts.

Fig. 14-4.




5/38

Itisnotw ithinthescopeofthischaptertopresentadetaileddiscussionofem bryologyandem bryologicanom aliesoftheesophagus.Kluth9w asableto

classify10typesoftracheoesophagealdefectsand88subtypesofthisanom alyalone.Theinterestedstudentofem bryogenesisisencouragedtoread

Em bryologyforSurgeons.10Them aintypesofcongenitalesophagealanom aliesarepresentedinTable14-2.

aFrom Chittm ittrapapS,SpitzL,KielyEM ,BreretonRJ.Oesophagealatresiaandassociatedanom alies.ArchDisChild1989;64:364-368.

VACTERL,vertebral(abnorm alities),anal(atresia),cardiac(abnorm alities),tracheoesophageal(fistula)and/oresophageal(atresia),renal(agenesisanddysplasia)

lim b(defects);LES,low eresophagealsphincter.

Source:M odifiedfrom SkandalakisJE,GraySW (Eds).Em bryologyforSurgeons,2ndEd.Baltim ore:W illiam s&W ilkins,1994;withperm ission.

Jobeetal.11reportedthatCollis'gastroplastyperm itsatension-freefundoplicationforthetreatm entofshortenedesophagus,butm aintenanceofacid-

suppressiontherapyisadvised.Astosurgicalrepair,Holder12andHolderandAshcraft13advisethatligationofthefistularandprim aryanastom osis,if

possible,shouldbedoneveryearly,preferablywithin24hoursafterbirth,toavoidpneum onitis.Filsonetal.14reportedondelayedprim aryesophageal

anastom osis.Healeyetal.15statedthatdelayedrepairofbothesophagealatresiaandtracheoesophagealfistula,regardlessofgaplength,canpreserve

theesophagus.

A,Pulsiondiverticulaarelocatedm ostcom m onlyinthedistalesophagus.Heterotopicgastricm ucosam ostcom m onlyislocatedattheproxim alesophagus.B,

Usuallocationsofm alform ationsoftheesophagus.(Modifiedfrom SkandalakisJE,GraySW .Em bryologyforSurgeons(2nded).Baltim ore:W illiam s&W ilkins,

1994;w ithperm ission.)

Table 14-2. Anomal ies of the Esophagus

An om aly Pr enat al Age at

Onset

First

Appearance

Sex Chiefly

Af fec ted

R el at i ve Fr e qu e nc y Co m m e n t s

Esophagealatresia,stenosis,and

tracheoesophagealfistula

21to34days Atbirth Equal Com m on

Laryngotracheoesophagealcleft 3rdto5thw eek Atbirth Equal Rare TypeItoIV(larynxtobronchi)

VACTERLassociations Variable;3to5w k

Atbirth Equal 10to23% ofesophagealatresiaa

Esophagealwebsandrings 7thwk(?)(if

congenital)

Anyage M ale Rare M ayneverproducesym ptom s

Trueduplication 7thw k Anyage ? Veryrare M ayneverproducesym ptom s

Enterogenouscysts Endof3rdw k Brithtoanyage Fem ale(?) Rare

Diverticula(excludingtractiondiverticula) 5thm otobirth

(?)

Anyage M ale U ncom m on M uscularw eaknessm ayexistindefinitely

w ithoutherniationoccurring

H eterotopicm ucosa 5thm otobirth Anyage(ifat

all)

Equal(?) Com m on M ayneverproducesym ptom s

Congenitalshortesophagus 7thw k Birthtoanyage M ale Rare M ayneverproducesym ptom s

Achalasia Late6thw k(?) Infancy Equal Uncom m on Casesappearinginlaterlifearenotof

em bryonicorigin

Chalasia Late6thw k(?) Shortlyafter

birth

Equal Verycom m on Resolvesspontaneouslyinm ostcasesas

LESm atures

SURGI CAL ANATOMY

NO TETOTHEREAD ER:Theorganizationofthischapterdifferssom ew hatfrom thatofotherchaptersinthatthephysiology,histology,andm ostsurgical

applicationsoftheesophagushavebeenincorporatedintothepresentationofsurgicalanatom y.

Theesophagus,asoftm usculartube,allow sfoodtopassbetw eenthepharynxandthestom ach.

Aristotle(384-322BC),Greekphilosopherandphysician,suggestedthatthesourceofthewordesophagusrelatedto"itslengthanditsnarrow ness."16

Theterm 'soriginism orelikelyrelatedtotheGreekterm oisopagos,createdfrom oisein("tocarry")andphagos("toeat")orfrom phagema("food").

Theterm ,adoptedbyM edievalLatinandLateM iddleEnglish,becam eisophagusorysophagus.16-18CurrentspellinginGerm anandinBritishEnglishis

oesophagus,inFrenchesophage,andinItalianesfago.




6/38

InOldRom anLatin,thepopularnounfortheesophagusw asgula.18,19 Gulaw asdefinedasanarrow passage,them outh,orthethroat.From thisLatin

term arosetheEnglishvernacularterm gully,signifyinganarrow courseforwater,anoutlet,ortheneckofabottle.TherelatedOldLatinadjective,

gulosusorgoulu,m eantgreedy,voracious,orgluttonous.TheFrenchwordgulaiskeptaliveasgouleorgueule,m eaningsnoutorm outh.19M ore

recently,theterm gullethasreem ergedinEnglishasasynonym foresophagus.InAm ericanEnglish,esophagusrefersexclusivelyto"thetubeor

channelfrom them outhtothestom ach,byw hichfoodanddrinkpass."18,19

Posi t ion o f t he Esophagus

Theesophagusisam idlinestructureanteriortothespineandposteriortothetrachea.From itsoriginatthecricoidcartilageintheneckoppositethe

fifthtosixthcervicalvertebra,itpassesintothethoraxatthelevelofthesternalnotchandtravelscaudallyw ithinthechestintheposterior

m ediastinum .Itterm inatesintheabdom enattheesophagogastricjunctionoppositethetw elfththoracicvertebra(Fig.14-5).Theesophagealhiatusof

thediaphragm isatthelevelofthetenththoracicvertebra.

Designat ions o f t he Esophagus

Theesophagus,w hichprogressivelydescendsthroughtheneck,chest,andabdom en,hasbeenclassifiedfrom threedifferentm edicalperspectives:

classicalanatom y,function,andsurgicalunderstanding(Fig.14-5).Theseview pointsarediscussedinthefollow ingparagraphs.

Classicalanatom ydividestheesophagusintothreeparts:

Fortheclinician,thisview isunserviceableandhasledtootherperspectives.

Functiondividestheesophagusaccordingtoitsdifferingform sofm otilityintothefollow ingthreezones(Fig.14-5)20:

How ever,thisclassificationalsoem bracesthecoordinatedactionsoftheupperintestinalsystem ,includingtheoropharynx,esophagealsphinctersand

body,andstom ach.Inthiscontext,Diam ant20em phasizesthat"controlm echanism sw ithinthecentralnervoussystem aswellasperipherallywithinthe

intram uralneuralandm uscleproperties,servetointegratethesefunctionalzonesinaregionofthegutw herevoluntaryandinvoluntarycontrol

m echanism sacttogether,andw heretheactivityoftw odifferenttypesofm uscleisintim atelycoordinated."

Surgeonscanbenefitfrom view ingtheesophagusasatw o-partstructuredividedintoproxim alanddistalsegm entsborderingatthetrachealbifurcation

(Fig.14-5).Thisapproachbestm atchessurgicalneedsandtherapeuticstrategies.21Therearethreereasonsforthisapproach:

(1)Antipodallym phaticflow proceedsfrom theareaofthetrachealbifurcationcraniallyandcaudally.4,22,23Thisaffectsthedirectionofearlylym phatic

tum orspreadandtheproceduresoflym phadenectom y.24

Fig. 14-5.

Divisions,term inology,andrelationshipsoftheesophagus.UES,upperesophagealsphincter;LES,low eresophagealsphincter.(CourtesyDr.DorotheaLieberm ann-

M effert;m odified.)

Cervica

Thoracic

Abdom inal

Upperesophagealsphincter(UES)

Esophagealbody

Low eresophagealsphincter(LES)




7/38

(2)Thesurgicalview pointincorporatestheexpectedlocationsoftum orsandtheirrespectiveprognoses.Carcinom asoccurw ithgreatestfrequencyinthe

m ucosaofthedistalhalfoftheesophagus.25,26Theprognosisfordistaltum orsisfarbetterthanthatfortherarertum orslocatedintheproxim alhalfof

theesophagus.26Proxim altum orsalsorapidlyperforatetheesophagealw alltoinvadeadjacentstructuressuchasthetrachea,bronchi,andadjacent

spacessuchasthem ediastinum .26

(3)Thisclassificationconform sw iththeem bryologicdevelopm entfrom tw odifferenttissuesourcesandthespecificarrangem entofvessels,m uscle

types,andinnervation.4,22,23,27,28Furthersubdivisionofthesesegm entsintocervicalandproxim althoracicanddistalthoracicandabdom inalsections

m aybejustified.26

Conf igu ra t ion o f th e Esophagus

Theesophagusisthenarrow esttubeofthegastrointestinaltract.Itoriginatesatthedistalendofthelaryngopharynx(hypopharynx),atthelevelofthesixthcervicalvertebra.Itterm inatesbywideningtoform thestom ach,them ostvolum inouspartofthegastrointestinaltract.Theesophagusisflatinits

upperandm iddleparts(Fig.14-6A)androundedinitslow erpart(Fig.14-6B).W hendistended,thesepartspresentdiam etersof2.5cm by1.6cm and

2.5cm by2.4cm ,respectively.Theesophagealtubecollapseswhenatrestandrangesinsizefrom 0.6cm to1.5cm indiam eter.29

Ingeneral,theaxisoftheesophagusisstraightw ithonlythreem inordeviationsalongitstrajectory.Thefirstdeviationistow ardtheleftatthebaseof

theneck(seeFig.14-5,arrow 1).Thesecondisatthelevelofthesevenththoracicvertebra,w heretheesophagusturnsslightlytotherightofthespine

(seeFig.14-5,arrow 2).Thethirdandm ostprom inentdeviationislocatedjustabovetheesophagogastric(gastroesophageal)junction,w herethe

esophagusshiftsdorsallyandtotheleft(seeFig.14-5,arrow 3).Anydistortionofthisaxisrevealedbyradiologicalevaluationstronglysuggests

m ediastinalinvasionandretraction.Thecauseism ostoftenam alignantprocess.25,30

Dimens ions o f t he Esophagus

In52adultcadaversthelengthoftheesophagusbetweenthecricoidcartilageandcardiacnotchrangedfrom 21cm to34cm (27cm average).In

fem alecadaverstheaveragedistancewas23cm (standarddeviationof2),andinthem alecadaversitw as28cm (standarddeviationof3).Thelength

relateddirectlytotheheightofthebody(153cm to187cm ).Thecervicalportionw as3cm to5cm ,thethoracic18cm to22cm ,andtheabdom inal3

cm to6cm inlength(Fig.14-5).Inpractice,cliniciansm easuretheesophagusbyusingthenostrilsortheincisorsasthelandm arkform anom etricand

endoscopicprocedures.Thedistancesarefrom 13cm to16cm tothecricoidcartilage,23cm to26cm tothetrachealbifurcation,and39cm to48cm

tothegastricopening.4,23

Tissue Comp os i t ion o f t he Esophagus

Theconstructionoftheesophagusparallelsthebasicplanofthetissueorganizationofthedigestivetube,exceptforthelackofaserosalcoating.The

fourlayers(Fig.14-7)arethetunicam ucosa,telasubm ucosa,tunicam uscularis,andtunicaadventitia.

Fig. 14-6.

Transversesectionthroughtheneckandupperchestofahum anautopsyspecim en.A,Thehistologicalsectionshow stheesophagusstillinm idlineposterior

position.B,Inthem oredistallevelofthem acroscopiccutsurface,theesophagushasshiftedtow ardtheleft(rightinphotograph).Notetheintim atelocalrelationshipbetweenesophagusandtrachea.1,Esophagus;2,Trachea;3,Thyroidgland;4,Vessels;5,Pleura.(CourtesyDr.DorotheaLieberm ann-M effert;

m odified.)




8/38

Tunica Mucosa

EPI THELI UM I NCLUDI NG GLANDS

Them ucosallayerconfinestheesophageallum en.Itconsistsofthefollow ingthreeparts.

POI NTS OF CLI NI CAL AND SURGI CAL RELEVANCE

Thetransitionbetw eenthem ucosaofthelaryngopharynxandesophagusisinconspicuous.31M acroscopically,theendoscopistseestheesophageal

m ucosaasareddishcolorinitscranialportion.Itturnspalertow ardthelow erthirdoftheesophagus.Thesm oothsurfaceoftheesophagealm ucosacan

bereadilydistinguishedfrom thedark,m am illatedgastricm ucosa.

Thetransitionbetw eenthesquam ousesophagealandcolum nargastricepithelium isanobjectivelyrecognizablereferencepoint.Thisabrupt,serrated

line,know nastheZ-line(Fig.14-8),has"fourtosixsm all,longorshorttongues."32Itisnorm allylocatednearthegastricorifice33,34orjustaboveit.

Endoscopiststhusbasetheirdeterm inationondifferencesincolor,thedegreeoftransparencyoftheepithelium ,m ucosalstructure,andepithelial

thickness.32

Fig. 14-7.

Schem aticillustrationofthetissueorganizationoftheesophagus(E) ,theesophagogastricjunction(EGJ),andthestom ach(S).Theobliquenarrow nessattheentry

intothestom achisshow nintheleftuppercorner.LC,lessercurvature;GC,greatercurvature.1,Tunicaadventitia;2,Tunicam uscularisw ith(a)longitudinaland

(b)circularlayersincludingthem yenteric(Auerbach)nerveplexus;3,Telasubm ucosaincludingthesubm ucous(M eissner)nerveplexusandbloodandlym phatic

vessels;4,Tunicam ucosaw ith(a )m uscularism ucosa,(b )lam inapropriam ucosa,and(c )epithelium includingglands.Arrowindicatesthetransition(Z-line)

betw eenesophagealandgastricepithelium .(Modifiedfrom Lieberm ann-M effertD,DuranceauA.Anatom yandem bryology.In:OrringerM B,Zuidem aGD (eds).

Shackelford'sSurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W BSaunders,1996,pp.3-38;reprintedbyperm ission.)

Squamous epitheliumisofthestratified,nonkeratinizingtype.Itnorm allycoverstheinnersurfaceofthelaryngopharynxandthetubularesophagus

Esophagealm ucosacontainsexclusivelyalveolarserousglands.Esophagealcardiacglands,closelyresem blingthecardiacglandsofthestom ach,arepresent

betw eenthecricoidcartilageandthefifthtrachealring.

Esophagealglandsaresm all,tubular,m ucoustypeglandslodgedoutsidethem uscularism ucosa(Fig.14-7).31

Fig. 14-8.




9/38

Anyproxim alshiftofgastric-orintestinal-typecolum narepithelium intotheesophagusisconsideredpathological.Thechangeresultsfrom long-lasting

gastroesophagealrefluxthatcauseschronicdam agetotheesophagealm ucosa.35,36Theultim ateresultm aybethat"thedistalesophagustoagreater

orlesserextentiscircum ferentiallylinedbycolum narepithelium "32transform edtothegastricorintestinaltype.Thispathology,calledBarrett's

esophagus,isregardedasaprecancerouscondition.26,32,34,36

Katadaetal.37andW etscheretal.38reportedthatincreasedapoptosisintheesophagealepithelium w henBarrett'sesophagusispresentm aybea

protectivem echanism counteractingincreasedproliferation.InhibitionofapoptosisinBarrett'sesophagusisinterpretedbytheseinvestigatorsas

possiblyprom otingneoplasticprogressivediseases.W hatisapoptosis?Inbrief,itisprogram m edcelldeath,theintricaciesofw hicharereview edina

paperbyKuanandPassaro.39AccordingtoCarlson(personalcom m unicationtoW oodandSkandalakis,Feb.19,1998)thefibroblasts"com m itsuicide"

attheendofhealing.Thephenom enonofapoptosisneedsm orestudy.

Theauthorsofthischapterrecom m endbiopsyinallBarrett'spatients.Collardetal.40

believethatearlydetectionofhigh-gradedysplasiainBarrett'sesophagusandradicalesophagealresectionw ithradicallym phnoderesectiongivesthebestchanceofcure.Farrelletal.41reportedthatfundoplication

w illprovideequivalentreliefofsym ptom sforGER D(gastroesophagealrefluxdisease)patientsw ithandwithoutBarrett'sesophagus.

LAMI NA PROPRI A MUCOSA

Sim ilartothelam inapropriaofthestom ach,thelam inapropriam ucosaoftheesophagusconsistsofconnectivetissuebuiltupofareolar,elastic,and

collagenousfibernetworks(seealsoFig.14-24).Inthepharynx,thislayeristhin.Intheesophagus,thelayerism orevolum inousandcontainssm all

bloodvessels,presum ablyterm inallym phatics,follicles,esophagealglandsofm ucoustype,and,intheterm inalesophagus,glandsthatresem ble

cardiacglands.Projectingintotheepithelium ,thelayerform sthepapillae.

LAMI NA MUSCULARI S MUCOSA

Thelam inam uscularism ucosaisathinlayerofshortsm oothm usclebundles.Itbegins6m m to8m m caudaltothepharyngoesophagealjunction.

Thesem usclebundlesarearrangedtransverselythroughouttheesophagealw all.

Inthelaryngopharynx,them ucosalfoldsareratherobliquelyoriented.Achangeoccursjustcaudaltothepharyngoesophagealjunctionw herethe

lam inam uscularism ucosadraw sthelum enintothreeorfourlargelongitudinalesophagealfolds(Fig.14-8).

Structuralchangesoccuratthelow erendoftheesophagus.Herethelam inam uscularism ucosaattainsitsgreatestsizeintheesophagus,42

exhibitsagreaternum berofsm alltransversefolds(Fig.14-8),andtakesarippledshapew hencontracted.33,42,43Thecauseoftheseripplesm aybethelocal

increaseofm uscularm assandthefan-shapedinsertionofitsfibersintothelam inapropriam ucosa.44W hentheendoscopistinflatestheesophageal

lum en,thewallextendsw idelyandthefoldsdisappear.

Atthepointofentryintothestom achtheorientationofthem ucosalfoldsabruptlychangesfrom longitudinalesophagealfoldstotransversegastricfolds

(Fig.14-8).

Tela Subm ucosa

Thetelasubm ucosalayerliesbetw eenthem ucosaandthem uscularcoat.Thetelasubm ucosaofthepharynxisafirm sheaththatfunctionsasan

aponeurosis(pharyngealaponeurosis)45,46anddiffersfrom thelooselyseparatinglayerpresentinthew alloftheesophagusandstom ach(Fig.14-7).At

thislocationthetelasubm ucosaconsistsof:

Esophagealglandsaresm allbranchingglandsofm ixedtypewithductspenetratingthelam inam uscularism ucosa.Thesubm ucosaincreasesinthickness

Schem aticdiagram ofthetissuestructuresattheesophagogastricjunctionasseenfrom thelum inalaspect.Esophagusandstom achhavebeenopenedalongside

thegreatergastriccurvature.Thesidew allsareevertedandshow theintersectingline( i).Thelessercurvatureisinthecenter.Thesubperitonealconnectivetissue

spaceextendsfrom theinsertionofthe(a )uppertothe(b )low erleafletofthephrenoesophagealm em brane.(Modifiedfrom Lieberm ann-M effertD,DuranceauA.

Anatom yandem bryology.In:OrringerM B,Zuidem aGD(eds).Shackelford'sSurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W B

Saunders,1996,pp.3-38,reprintedbyperm ission.)

Looseareolarconnectivetissuecontainingelasticandcollagenfibers

Num erousfinebloodvessels(Fig.14-7)

Anetw orkoflym phaticchannels(Fig.14-7;seealsoFigs.14-24and14-27)

Nerves,includingthesubm ucousnerveplexus(Meissner'splexus)

Thedeepm ucousglands(Fig.14-7)




10/38

acrosstheesophagogastricjunction.

Tunica Muscular i s

Sim ilartoFigures14-9and14-10,thepharyngealm usculatureism ainlyobliquelyarranged.Thetransitionfrom theobliquem uscularfiberstothe

transversecricopharyngealm uscleproducesatriangularareaofsparsem usclecover(Figs.14-9,14-10)cranialtotheupperesophagealsphincter,as

hasbeendescribedanddepictedbyKillian.47Asinglem uscularlayercoatsthelum enofthepharynx,w hereastw odifferentm uscularlayerscoatthatof

theesophagus(Fig.14-10).Them uscleoftheesophagusconsistsofalongitudinallyarrangedouterlayerandatransverseinnerlayer(Fig.14-11).

Fig. 14-9.

Dispositionofthem usclebundlesatthepharynx(P),pharyngoesophagealjunction(PEJ),andesophagus(E) view edfrom posterior.Hum anunopeneddryfiber

specim enfrom autopsyw ithconnectivetissuesrem oved.1, M iddlepharyngealconstrictorm uscle;2,Parsthyropharyngeal;3,Parscricopharyngealoftheinferior

pharyngealconstrictorm usclethatcorrespondswiththeupperesophagealsphincter(UES).Killian'striangleliescranialtotheUES.4,Circularm usclelayerofthe

esophagus.Longitudinalm usclelayerrem ovedw ithonlyresidualbundlespreservedatthelateralaspect.5,Residualsofthethyroidglands;6,Trachea.(Courtesy

Dr.DorotheaLieberm ann-M effert.)

Fig. 14-10.

Thedispositionofthem usclefasciclesatthepharyngoesophagealjunctionfrom theposterioraspect.Thereisonesinglelayerinthepharynxwiththeupperpartof

theconstrictorm uscleobliquelyarranged(m .thyreopharyngeus)andthelow erparttransverse(m .cricopharyngeus).Thisdirectionchangeproducestriangle

cranialtocricopharyngealm uscle.Thecricopharyngeusiscontinuedbytheesophagealm usculature,w ithitstwolayersinoppositeorientation:longitudinaland

transverse.(From Lieberm ann-M effertD.Thepharyngoesophagealsegm ent:anatom yandinnervation.DisEsoph1995;8:242-251;reprintedbyperm ission.)

Fig. 14-11.




11/38

Functionally,thepharynxandesophaguspresentacontinuum ofsequentialcontractions.Incontrast,histologicallythem uscletypesinthesetw oareas

arecom pletelydifferent.Them uscleofthepharynxisstriated,w hilethelow ertubularesophagusissm ooth.Directlybelow thepharyngoesophageal

junction,isolatedsm oothm usclebundles28,48appearinterm ingledw iththestriatedm uscles.Thenum berofsm oothm usclebundlesincreasesw ithinthe

firstcentim eteroftheesophagealtunicam uscularis.Thisoccurssom ew hathigherintheinner,anteriorm usclelayerthanintheouter,longitudinal

layer.4,23,28Nosharptransitionlinesoccur.Insteadbothm uscletypesrem aininterw ovenw ithoutanyapparentanatom icboundary.Astheydescend,

thesm oothm usclecom ponentssim plybecom em orenum erousandreplace inthesam eproportion thestriatedm uscle(Fig.14-12).Finally,only

isolatedfibersorstrandsofthestriatedtypelodgewithinthesm oothm uscles.4,23,28Caudaltothetrachealbifurcation,thefibersofbothlayersare

exclusivelyofsm oothm uscletype.28,48M easurem entsshow ednoessentialindividualvariation.28

Thearrangem entanddispositionofthem usculatureofthepharynx,esophagus,andstom achview edfrom theleftlateralaspect.UES,Upperesophagealsphincter;

LES,Low eresophagealsphincter.(Modifiedfrom Lieberm ann-M effertD,DuranceauA.Anatom yandem bryology.In:OrringerM B,Zuidem aGD(eds).Shackelford's

SurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W BSaunders,1996,pp.3-38,reprintedbyperm ission.)

Fig. 14-12.

Distributionandtransitionofstriatedandsm oothm usculatureinthehum anadultesophagus.Nostriatedm uscleexistscaudaltothetrachealbifurcation.(Modified

from Lieberm ann-M effertD.Anatom y,em bryology,andhistology.In:PearsonFG ,DeslauriersJ,GinsbergRJ,HiebertCA,M cKneallyMF,UrschelHC(eds).

EsophagealSurgery.New York:ChurchillLivingstone,1996,pp.1-25,reprintedbyperm ission.)




12/38

Tun i ca Adven t i t i a

Tunicaadventitiaispresentedlaterinthechapter.

Pecu l ia r i t ies o f t he Tubu lar Esophagus

Theprim aryorientationsoftheesophagusm usclelayersarelongitudinalandcircular(Fig.14-9andFig.14-10)andthethicknessofbothlayersofthe

esophagealtubeissim ilar,only1m m to1.5m m foreachlayer.Thereisnodifferenceattributabletoage.33,42

Longi tud ina l Musc le Layer

Thelongitudinallayeroriginatesatthecranialm arginofthecricoidcartilageandatthefirm subm ucosaltissuecoveringthearytenoidm usclesthrough

thecricoesophagealtendon(Fig.14-13).Thelongitudinalm usculaturerepresentsonesheathofm ultiple,flat,delicatem usclebundlesthatw rapthe

esophagealw allinacom pletelayer.Adjacentbundlesrarelyconverge,butconnectw itheachotherandwiththecircularm usclebundlesbyseptaof

looseconnectivetissue(perim ysium ).Finevesselsandnervesirregularlyperforatethem usclelayersandcreatelocalovalorlongitudinalslits.The

m usclebundlestraveldirectlylongitudinallydow ntheesophagusforaconsiderabledistance(Fig.14-11)beforetheycrossthegastricorifice.Herethey

becom eorganizedpartlytransverselyalongsidetheanteriorandposteriorgastricw all(Fig.14-11).Beyondtheesophagogastricjunction,the

longitudinalm usclescontinueintothosecoveringthestom ach.

Ci rcu lar Musc le Layer

Thecircularlayerisacontinuationofthecricopharyngeusm uscle,them ostcaudalpartofthem usculatureofthepharynx(Fig.14-11)andthelow est

pointofvoluntarycontrolofsw allow ing.Itbeginsatthelevelofthecricoidcartilageanddescendsalongtheesophagusbyw rappingitcom pletely.Atno

placedothem usclesform closedrings,butpresentim perfectcircleswithsuperim posedends.33

Additionaldistinctivethreadlikem usclestrandsfacetheinnersurfaceofthecircularlayertow ardtheendoftheesophagusandcanbeseenbeneaththe

m ucosaandsubm ucosaaftertheyarerem oved.Theyareshort,thin,sparse,irregularlydistributed,andstraightw ithX-orY-shapedendings.They

correspondtoLaim er's49descriptionandillustrationof"bracketfibers."How ever,theyneverform acontinuouslayerorafascicularnetwork.

Sphinc ters

Sphinctersdividethealim entarycanalintofunctionalsegm ents.Theyarecharacterizedbyarestingtonethatishigherthaninthetwoadjacent

segm ents.Sphinctersareanatom icallyill-defined.

Thewordsphincterisderivedfrom theGreekterm forstring,cord,orlaceandhaslongbeenusedtodesignateacircularm uscle.50Galenem ployedthe

nam eform usculararrangem entsthatw ereabletotieup,tostrangleorthrottle,buthealsoterm edsom eofthem constrictoresoradstrictores

accordingtotheirpropertytoconstrict,draw togetherorcontract.Becauseoftheircircularshape,suchm usclesw erealsoterm edm usculiorbiculares.

Fig. 14-13.

Thishum anautopsyspecim en,fixedw ithalcohol,show sview intothelaryngopharynx,pharyngoesophagealjunction,andcervicalesophagus(1 )from theposterior

aspect.Thesoftpharyngealw all(2 )isshow n,w iththeconstrictorm usculaturedividedandthelineofintersection(3 )reflectedlaterally(arrows).Thetunica

m ucosacoveringtheconstrictorm usclesandthecricoesophagealtendon(4)hasbeenpreserved,butrem ovedabovebothpiriform fossae,lateraltothecricoesophagealtendon(4 )andtheposteriorcricoarytenoidm uscle(5 )toexposethelaryngealpartoftheinferiorlaryngealnerve(recurrentlaryngealnerve[RLN ])

andsuperiorlaryngealnerve(6, 7).CervicalbranchoftheRLN(8 )anditsentryintothelarynxisshow nbetweentwoarrow s.Subclavianarteryisindicatedby(9 ).

Longitudinalm uscleoftheesophagus(1 )insertsatthecranialm arginofthecricoidcartilageandinthefirm connectivetissuecaudaltothecuneiform and

corniculatetubercles(10)oppositetheepiglottis(11)usingthecricoesophagealtendon.(CourtesyDr.DorotheaLieberm ann-Meffert;m odified.)




13/38

M orerecently,intheanatom icdefinition,sphincterdesignatesacircularoranularm usclesurroundinganopening,51 oraringlikebandofm usclefibers

thatconstrictapassage.17

Theterm cardia,alternativelyusedfortheareaoftheesophagogastricjunction,hastwom eanings:oneistheheart;theother,thegastric

orifice.52,53,54Thenounw asfirstrecordedintheHippocraticw ritingsandreferredtoasthecardiacendofthestom ach.52

Upper Esophageal Sphinc ter ( UES)

Thecom plexm echanism softhepharyngoesophagealfunctions20,55,56thatinvolvesw allow ing,breathing,andspeecharepossiblebecauseofvarious

tissuem aterialssuchasbonyandcartilaginousstructures,andsoftstructuressuchasthepalate,pharynx,andesophagealm usclesincludingthe

supplyingvesselsandnerves.

Thepharynxincludesthenasopharynx,oropharynx,andlaryngopharynx(hypopharynx).Thelaryngopharynxdividesintotw otubes,thelarynxw iththe

trachea,andtheesophagus(Fig.14-14).Thelarynxisform edbyafram ew orkofcartilagesconnectedbym em branesandligam ents;theyarem ovedby

thelaryngealm uscles.Thesestructuresareresponsibleforthem echanism sofairpassage,epiglotticm ovem ent,phonation,and,togetherw iththe

inferiorlaryngealconstrictorm uscles,sphincteractionatthepharyngoesophagealjunction.

Theupperesophagealsphincter(UES )liesattheendofthepharynxandcontrolstheentryintotheesophagusandlarynx.Itisconstructedoftwo

anatom icelem ents.Theanteriorwallisrigid,correspondingtotheposteriorsurfaceofthecricoidcartilagethatalsoform stheposteriorwallofthe

larynx(Fig.14-13).TheposteriorwalloftheUESissoftandform edbyonecontinuousm usclesling,thetransverse,horseshoelikeloopofthelow erpart

oftheinferiorpharyngealconstrictorm uscle(Figs.14-9and14-10).Thiscricopharyngeusm uscleinsertsatthelateralprocessofthecricoidcartilage.

M easurem entsofthem uscularthicknessacrossthepharynxandupperesophagusshow edthatthecricopharyngeus(sphincter)m uscleissm allerbyfar

thanthem oreproxim alpartsofthebilateral,obliquelyarrangedinferiorandm iddlepharyngealconstrictorm uscle.57

Thesphincterservesprim arilytopreventdistensionoftheesophagusduringrespirationandtoprotectthetracheaandlungsagainsttheuptakeofreflux

m aterialorrefluxaspiration.Norm allythesphincterrem ainsinastateofstrong,nerve-controlledtoniccontractionbetw eenepisodesofsw allow ing.

O nm anom etry,theUEShasalengthof2cm to4.5cm andcanbeidentifiedradiologicallybyaposteriorindentation.Theupperesophagealsphincter's

asym m etricalpressurem easurem ents58clearlyequatewithitsanatom icconstruction.

Low er Esophag eal Sphin c ter ( LES)

Thelow eresophagealsphincter(LES)beginsapproxim ately3cm cranialtothejunctionw iththestom ach.Herethenum berofm usclefibersofthe

circularlayerofthetubularesophagusincreaseandsuperim poseoneachother,producingaprogressivem uscularthickening(Fig.14-15).Thisis

consistentw iththerearrangem entofthem usclebundlesacrossthejunctiontothestom ach(Fig.14-16left).Them usclebundlesatthesideofthe

greatergastriccurvaturechangedirectiontoform theobliquegastricslingfibers.Thoseatthesideofthelessercurvatureretaintheirprevioushorizontalorientationtobecom etheshortm uscleclasps33show ninFigures14-11,14-16left,and14-17.

Fig. 14-14.

Positionalrelationshipsofanatom icstructuresinvolvedinswallow ing,breathing,andspeech.Show ninsagittalsection.(CourtesyDr.DorotheaLieberm ann-M effert;

m odified.)

Fig. 14-15.




14/38

M easurem entsofthicknessoftunicam uscularisbetw eenesophagusandstom ach.Averagethicknessm easuredin32form aldehyde-fixedhum anspecim ensat4

pointsofcircum ferenceandat5m m steps,usingthem axim um thicknessaslandm ark.Num bersclearlydem onstrateasym m etryofLES (low eresophageal

sphincter).EGJ,Esophagogastricjunction.(Modifiedfrom SteinHJ,Lieberm ann-M effertD,DeM eesterTR,Siew ertJR.Threedim ensionalpressureim ageand

m uscularstructureofthehum anlow eresophagealsphincter.Surgery1995;117:692-698,reprintedbyperm ission.)

Fig. 14-16.

Correlationbetw eenradialandaxialm usclethickness(inm m )andm usculararrangem ent(left),andthreedim ensionalm anom etricpressureim age(right)acrossthehum anesophagogastricjunction(EGJ),i.e.low eresophagealsphincter.RadialpressuresattheEG J(inm m ofm ercury)wereplottedaroundaxisrepresenting

atm osphericpressure.PW,Posteriorw all;GC,Greatercurvature;AW,Anteriorw all;LC,Lessercurvature;SM -M,Subm ucosa-M ucosa;M P,M uscularispropria

(sm oothm uscle).(Modifiedfrom SteinHJ,Lieberm ann-M effertD,DeM eesterTR,Siew ertJR.Threedim ensionalpressureim ageandm uscularstructureofthe

hum anlow eresophagealsphincter.Surgery1995;117:692-698,reprintedbyperm ission.)

Fig. 14-17.




15/38

Thegastricslingfibersbeginattheterm inalesophagus(Fig.14-11),hookaroundtheesophagogastricjunction,andform theangleofHis.Theythen

rundow nattheanteriorandposterioraspectofthestom achandfanoutwardinthedirectionofthegreatergastriccurvature.Theretheyform slings

(Fig.14-11)andendbetw eenthefibersoftheinnerm usclelayerofthegastricantrum .33

TheshortbundlesonthelessercurvesidethatLieberm ann-Meffertcallsclasps33anchorfirm lyintheconnectivetissuealongtheinnerm arginofthe

sheathofthegastricslingfibers(Fig.14-11).Tosom eextent,theseclaspsaresuspendedfrom orpartlysupportedbyfibersofthegastricsling(Fig.14-

17).DiDioandAnderson51show Curti's59originalphotographoftheclaspsintheirpublicationonsphincters,buttheydonotm entionthem .

Them axim um m uscularthicknessoccursatthejunctionbetw eentheesophagusandstom achandtapersoffw ithinthestom ach(Fig.14-15).

M acroscopicexam inationofthefreshspecim enorofthelivingindividualdoesnotrevealm arkedthickening.Thissoft,oftenstretchedm uscletissue

readilyescapespalpationduetoitsconcealedpositionnearthespine,coveredbythefilm yconnectivetissueandfatunderthephrenoesophageal

m em brane.Theanatom icspecim en,how ever,show sthem usculatureinthecontractedstage.Them axim um m uscularthicknessof4m m atthe

esophagogastricjunctionistw icethatoftheesophagusandthestom ach.

Itm ustbestressedinthiscontextthatthenorm alpressuresoftheLESarem uchlow erthanthoseofothersphincters.Theyrangeonlyfrom 14.5m m

Hgto34m m Hg58,60w hile,forexam ple,thepressureoftheupperesophagealsphincterrangesfrom 30m m Hgto142m m Hg.58


Therearrangem entofthepharyngealm uscleintotheUES m usculatureleavesanareaofpotentialtissuew eakness(Killian'striangle).Itm aybe

predisposedtotheform ationofaprotrusionofthepharyngealw allcranialtotheUES.47Suchadiverticulum m aycontainthefullthicknessofthew allor

onlym ucosaandsubm ucosa,54butbecauseitoriginatesinthepharynx,itnevercontainsm uscularism ucosa.Zenker'sdiverticulum is,bydefinition,the

m idlineprotrusion.47Laterallaryngopharyngealdiverticuladevelopattheentryofvessels,asdescribedatlengthbyothers.45,46Theyseem toberareinhum ans.Them echanism sleadingtotheform ationofadiverticulum arenotyetclear,andanatom icandpathophysiologiccausesarestilldebated.For

surgicaltreatm entofZenker'sdiverticulum Peracchiaetal.61advisedm inim allyinvasivesurgeryusingalinearendostaplerintroducedthroughaW eerda

endoscope.

Theliteratureincludesabundantclaim sthatthediaphragm aticcrurarepresentthem echanicalequivalentoftheLES.How ever,dissectionofthe

diaphragm and/ordisruptionofthephrenoesophagealm em branealteredneithertheLESpressurenorthepressurecharacteristics.62Regardingthe

norm alanatom iclocationoftheLES ,m uscularrearrangem entandm axim um thicknessarem ostprom inentpreciselyattheesophagogastricjunction,at

thetransitionofesophagealintogastricfolds.33

Thefollow ingpointssupporttheargum entthattheuniquem uscularstructuresattheendoftheesophagusconstitutethephysiologicLES:

M usclestructuresatesophagogastricjunction(atlow eresophagealsphincter)(view from lum inalaspect).Esophagusandstom achopenedalongsidegreatergastric

curvature,thesidew allseverted,andm ucosaandsubm ucosastrippedoff.M usclefasciclesofthegastricsling(1)andclasps(2) exposedandshow ingthefascicular

relationship.Hum anautopsyspecim en.(CourtesyofDr.Nakam uraandProf.M inoriOi,Tokyo.)

Sim ultaneousradiom orphologicalm otilitystudiesusingw allm arkersidentifiedthelocationofm axim um m uscularthickeningatthesiteoftheLEShighpressure

zone.62

W henm usclestripsoftheesophagogastricjunctionareplacedinvitrointoabathoflow dosepentagastrin,theym aintain,orevenincrease,toniccontractions.

M usclestripstakenfrom levelsaboveorbelow donot.63

Theextentofthespecializedm usclestructureisidenticalw iththelengthofthefunctionalsphincter.58,60Theasym m etricm usclebundlearrangem entoftheinnerlayerm atchestheasym m etricthickeningoftheesophagogastricjunctionalm usculature(Fig.14-11bandFig.14-16).Theestablishedaxialandradialasym m etryof

thefunctionalsphincterreflectstheasym m etryofthem uscularstructures.Thisisshow nbydifferentm anom etrytechniques58,64includingthenew technique65-67ofthree-dim ensionalim aging(Fig.14-16right).Inaddition,theirregulardistributionofforceswithintheLESclearlydem onstratestheabsenceofam uscular"ring."

Thespecialm usculature,m usculararrangem ent,andcorrespondingthickeningextendupw ardfor3cm to4cm throughthediaphragm andpassbeyondthedistal




16/38

Advent i t ia and Stab i l i z ing S t ruc tur es

Tun i ca Adven t i t i a

Incontrasttothebuccopharyngealfasciaintheneck,theperiesophagealtissue,oradventitia,iscom posedoflooseconnectivetissuethatenvelopsthe

esophagusandconnectsitw iththem ediastinum andtheneighboringstructures.Itcontainssm allvessels,lym phaticchannels,andnervefibers.

Tissue Mant le

Theesophaguslieslooselytiedthroughtheadventitiainitsbedofareolarconnectivetissue.Nom esenteryorserosacoatsitw ithinthem ediastinum .

Thispropertyallow stheesophagusgreatm obilitybothintransverseandlongitudinaldirections.Asaconsequence,respirationinducesanesophageal

m ovem entoversom em illim eters,andswallow ingresultsindisplacem entoverafew centim eters.79

Theuniquelocationoftheesophagussubjectsittobluntstrippingfrom them ediastinum w henperform edbythesurgeoninpull-through

esophagectom y.25,27,80,81Bluntdissectionm ayoccasionallybehazardous,how ever,andisstronglycontraindicatedinthepresenceofperiesophageal

tum orinvasion,particularlyifitoccursclosetotheazygosveinorifinflam m atoryadhesionsarepresent.

Theintim ateproxim ityofesophagus,trachea,andpleura(seeFig.14-6)allthew aydow ntothetrachealbifurcation,inconjunctionw iththelackofany

interveningpartitionsorconnectivetissuesheaths,pavesthew ayforreadyandrapidlocalspreadofm alignancyandfistulaform ation.

Tissues Anchor in g and Stab i l i z ing th e Esophagu s

Afram ew orkofbony,cartilaginous,andm em branousstructuresstabilizethepharynxandesophagus(Fig.14-18).Thebuccopharyngealm em brane

attachesthenasopharynxandlaryngopharynxtotheircartilagesandtothecranium and,byw ayoftheprevertebralfascia,tothevertebralcolum n.The

attachm entsoftheesophagusarefarm oreflexiblethanthoseofthepharynx.

endoftheesophagusintothestom achw allforanother1cm to2cm .Theareaofthegreatestfiberconcentrationandm usclethicknessisattheangleofHis.33

Therefore,onem aysuggestthatthegastricslingfibersexerttheantirefluxeffectofthesphincter.53,68,69

Surgicaldisruptionofthejunctionalm usculaturebypartialortotalm yotom yorm yectom ysignificantlyreducesorevenabolishesLESpressurevalues.68,69Forsurgicalm anagem entofpatientsw ithachalasia,them ainprincipleisdivisionoftheLESm usculature.Recently,am odifiedHeller'soperationw ithm yotom yofthe

anteriorw alloftheesophagogastricjunctionhasbeenperform ed.How ever,theproperlengthofthem yotom yisstilldebated.68,70,71Theincisionhasbeencom m onlyrecom m endedtobeginatleast10cm proxim allyontheesophagusandtoextendthem yotom yatleast3cm intothebodyofthestom ach.Thisis

considerablylongerthantheanatom icsphincter.Bom beckandassociates68andEllisandothers72lim itedthelengthofthegastricm yotom yto0.5cm and1cm ,respectively,inordertopreservethefunctionofthesphincter,toavoidrefluxbyitsdisruption,andtoavoiddisruptionofthem uscularslingoftheobliquegastric

fibers.Gozzettiandcow orkers70questionthebenefitofthisfunction-preservingprocedure.How ever,althoughstillextendingthem yotom yfarintothestom ach,theytakegreatcarenottodam agethesphinctericfunctionofthegastricfiberslinganddivideonlythe"m uscularclasps"atthelessercurvature.

Cosentinietal.73reportedexcellenttofairresultsw ithm yotom yandantirefluxsurgeryin23patientsinwhom previousdilatationshadnotyieldedsatisfactory

results.Holzm anetal.74reportedthatlaparoscopicm yotom yisasim pleandeffectivetreatm entforachalasia.SpiessandKahrilas75reportedthatlaparoscopicHeller'sm yotom yisem ergingastheoptim alsurgicaltherapyforachalasia.SincelaparoscopicHellerm yotom yissuperiorinrelievingdysphagiaandpreventing

heartburnforsom e patients,Stewartetal.76preferittothorascopicHellerm yotom y.

KoshyandNostrant77reportedgoodresultsusingbotulinum toxininpatientsw ithesophagealm otordisorders.Endoscopicandballoontreatm entforvariousdysm otilitydisordersarealsoadvised.

Gow enetal.78identifiedfiveriskfactorsforgastroesophagealintussusceptioninpatientsw ithnoncardiacchestpain:

Eatingdisordersoralchoholabuse

Suddensustainedexertion

Sm allbow elobstruction

Acidbilepepticdisease

Pregnancy

Fig. 14-18.




17/38

ATTACHMENT OF THE CRANI AL END OF THE ESOPHAGUS

Atthecranialendoftheesophagusthecricoesophagealtendon,w hichisastrongtendon2cm to3cm longand1cm w ide,attachesthelongitudinal

esophagealm uscleontotheposteriorplaneofthelam inaofthecricoidcartilage(Fig.14-13,Fig.14-18).

ATTACHMENT OF THE TUBULAR ESOPHAGUS

Betweentheoriginoftheesophagusandthebifurcationofthetrachea,severaldelicatefiberstrands or,m oreprecisely,m em branes anchorthe

esophagealw allelasticallytothetrachea,thepleura,anddorsallytow ardtheprevertebralfascia(Fig.14-18).4,23,82

Research Resul ts

LargefieldhistologicaltransversesectionsintwostudiesbyLieberm ann-M effertetal.4,82show edthatthefiberstrands,orm em branes,thatanchorthe

esophagealw allvaryinnum ber,size,andextensionbutw erepresentinalltheirspecim ens.Theyarecom posedm ainlyofelasticandcollagenfibers

(Fig.14-19).O ccasionallytheycontainstriatedorsm oothm usclebundles.

Atthetrachea,thefiberstrandsinsertm ostoftenm ediolaterallyintothedenseconnectivetissuethatform sthetrachealm em braneorinthe

perichondrium ofthecartilages.Theythenturntow ardthelateralaspectoftheesophagealw all,expandneartheesophagealm uscle,andbecom e

continuouswiththeperim ysium (Fig.14-19).

InhistologicalcrosssectionsbyLieberm ann-M effertetal.,4,82thecoiledstrandspresenteddefinitivelengthsfrom 1m m to17m m andthicknessesof30

to300m icrons(1000m icronsinonesingularcase).W henanalyzedinconsecutiveserialsections,thestrandsactuallyform edlam inatedm em branesof

1.5m m to3cm incraniocaudalextent.Thesam estudiesfoundalargernum berofsim ilarfiberstrandsoriginatinginallspecim ensdorsalto,andlateral

from theesophagus,andradiatingintothem eshesoftheperiesophagealconnectivetissuespaceorinsertingintothetissueofthepleura.

Thetiny,delicate,lam inatedm em branes,individuallyvaryinginnum berandsize,arefarsm allerandshorterthanthelong,coarsefibroelasticcordsthat

Laim er49depictedin1883andNetter83lateradoptedintohisillustrations.Norwastheirorientationfoundtobelongitudinaltotheesophagotracheal

axis,82butinsteadw asregularlytransverse.Oneotherfactorusefulforthestabilizationoftheesophagusnotyetdiscussedisprovidedbythenum erous

finem em branesthatanchoritlaterallyintheconnectivetissuenetw orkofthem ediastinum andtothepleura,andalsom em branesthatextenddorsally,

presum ablytotheprevertebralfascia.

Clinical Considerations and Relevance.O nem ayagreethattheshortanchoringm em branesrestrictthem obilityoftheesophagus.Yet,thecapacityof

thecollagenm em branestoextendandoftheelasticcom ponentstorecoilyieldsadequatem obilitywhentheyarestretchedundernorm altension.W hen

thetinym em branesaretorn,theym aybreakeasilywithoutdam agetoeitherthetrachealorpleuralw all.

Theunpredictablepresenceofindividuallydevelopedcoarserm em branesm aycausedam agew hentheesophagusisstrippedduringesophagectom y.

Therefore,transdiaphragm aticesophagectom ym aybenefitfrom m ediastinoscopicdissectiontoreducetheincidenceoftearsincaseunusuallystrong

m em branesarepresent.Thedistalhalfoftheesophagusw ithinthem ediastinum ism orelooselyadherent.

Anchoringandstabilizingstructuresofesophagusandstom ach.Gastroretroperitonealattachm entsandreflectionsincludegastrophrenic,gastrosplenic,and

splenorenalligam ents,lesserom entum .UES,Upperesophagealsphincter;LES,Low eresophagealsphincter.(Modifiedfrom Lieberm ann-M effertD,DuranceauA.

Anatom yandem bryology.In:OrringerM B,Zuidem aGD(eds).Shackelford'sSurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W B

Saunders,1996,pp.3-38,reprintedbyperm ission).

Fig. 14-19.

Oneoftinyfiberm em branes(single arrow)connectingesophagus(1 )w ithtrachea(2) ;5 thicktransversehistologicalsection.M em branem im icsslightlycoiledbandintransversesection,250 m thickand14m m long,and90% elasticfiberelem ents.Typicalfan-shapedinsertionofbandintoperim ysium oflongitudinal,outerlayerofesophagealm usculature(double arrow).Hum anautopsyspecim en,4cm caudaltothelow erm arginofthecricoidcartilage.(Modifiedfrom

Lieberm ann-M effertD,HuberW ,HberleB,W urzingerLJ,Siew ertJR.Relationshipbetweenesophagus,tracheaandpleura.In:NabeyaK,HanaokaT,Nogam iH

(eds).RecentAdvancesinDiseasesoftheEsophagus.New York:Springer,1993,pp.1045-1049,reprintedbyperm ission).




18/38

ATTACHMENT AT THE DI STAL END

Initspassagethroughtheesophagealhiatus,theesophagusisboundedbythetw odiaphragm aticcruraandthephrenoesophagealm em brane(Fig.14-

18).

Thesubdiaphragm aticandtheendothoracicconnectivetissuesofthediaphragm blendtocreatethephrenoesophagealm em brane(Fig.14-18).This

tissuesheathhasalsobeencalledLaim er'sfasciaorAllison'sm em brane.Becauseitoriginatesfrom afascia,thephrenoesophagealm em braneis

relativelystrong.Them em branesplitsintoparts,describedinthefollow ingparagraphs.

Theuppersheathofthem em braneextendsupw ardfor2cm to4cm throughthehiatus(seeFig.14-8).Hereitsfiberstraversetheesophagealm uscle

andinsertintothetunicam uscularisandthesubm ucosa.84Thisresem blestheinsertionofthetinym em branesthatattachtheesophagealm uscletothe

m em branouspartofthetrachea(Fig.14-19).

Thelow ersheathpassesdow nalongsidethecardiatothelevelofthetopofthegastricfundus.Hereitblendsintothegastricserosa(seeFig.14-8),the

hepatogastricligam ent,andthedorsalgastricm esentery(Fig.14-18).

Thelow ersheathofthephrenoesophagealm em branecanberecognizedduringsurgeryandlaparoscopybyitsw ell-definedlow eredgeandslightly

yellow tissuecolor,evenifsevereperiesophagitisispresent.Them em braneiscom posedofequalportionsofelasticandcollagenousfiberelem ents,

guaranteeingsufficientplasticity.Itw rapstheesophagogastricjunctionlikeawidecollar(Fig.14-18).Despiteasom ew hatloosefibrousconnectionw ith

thewalloftheesophagogastricjunctionthroughtheunderlyingareolarconnectivetissue,theentirephrenoesophagealm em braneclearlyseparatesfrom

theesophagealm uscleacrossthejunction.4,23

Cl in ica l Considerat ions and Relevance

Thestructuralarrangem entofthephrenoesophagealm em braneallow sfreeverticalm ovem entoftheterm inalesophagusandofthejunctionofthe

stom achinrelationtothediaphragm .Itisableto"slipthroughthehiatusasinatendonsheath."85

W ithadvancingage,thetissueproportionsofthephrenoesophagealm em branechange.Collagenousfibersprogressivelyreplacetheelasticfibers,84

looseningtheattachm ents.Them em branebecom esslackandinelastic,andfattissueusuallygathersw ithintheareolarconnectivetissuebetweenthe

m em braneandthem uscularw all.Theresultisalossofpliability.Theseevents,w hencom binedw ithawidehiatus,m aycontributetothedevelopm entofthediaphragm atichernia.84Abnorm allylooseanchorageofthephrenoesophagealm em braneinyouth,togetherw ithanextraordinarilylarge

accum ulationofadiposetissueintheconnectivetissuespacebetweenthephrenoesophagealm em braneandthecardiam usclem aycausesim ilar

problem s.84

Innorm alindividuals,variousfirm ligam entsandm em branesattachthecardiaandgastricfundusposteriorlytothefascialretroperitonealplanes,

providingadequatestabilitytotheesophagogastricjunction.

Inslidinghiatalhernia,boththeterm inalesophagusandgastricfundusprotrudeintothethorax.Inthelesscom m onparaesophagealhernia,the

term inalesophagusispositionednorm ally,butthegastricfundusandbodyadvancebesidetheesophagusintothem ediastinum throughthe

diaphragm atichiatus.86

Inthediscussionofthedifferentetiologicalfactorsleadingtohiatalhernia,onepotentiallyim portantanatom icaspecthasbeenconsistentlyignored.This

isthecloseproxim ityofthegastricfundustothehiatus.Inconjunctionw ithweakeningandslackeningofthegastricattachm entsbyaging,thism ay

producethepreconditionforherniation.4,23Thisconditionw ouldbeconsistentw ithwhatEliska84hassuggestedforslidingherniasandwiththe

observationofEllis,86w hofoundthatthe"sym ptom susuallydeveloponlyinadultsorintheelderly."

Comp ar tm ents and Spaces

Thelooseconnectivetissueinw hichboththeesophagusandtracheaareem beddedisboundedbyfascialplanesanteriorlyandposteriorly,form ingtw o

potentialspacesbetweenneckandchest.Theanteriororpretracheal(previsceral)spaceislim iteddistallybythefibroustissueofthepericardium .The

posteriororprevertebralspacem ay,how ever,extendfrom thebaseoftheskulldow ntothediaphragm .

Theposteriorspaceisofclinicalim portancebecausem ostinstrum entalperforationsoccurinthelaryngopharynxabovethecricopharyngealsphincter.

Subsequentoutflow oftheheavilycontam inatedesophagealcontentspreadsrapidlydow nthefascialspace.Rupturesoftheesophagus(Boerhaave's

syndrom e)andleakageofanesophagealanastom osisoccurringw ithinthechestusuallycauseasim ilareffectbyspreadingupordow nthroughthese

planes.Earlydiagnosisisvitalforthepatient,becausetheprognosisforesophagealperforationisstillpooranddependsentirelyuponsw iftsurgical

treatm ent.

Cons t r ic t ions

Som estructurescom pressthelum enofthetubeandcauseclinicallyidentifiablenarrow ings.Thefirstconstrictioniscausedbythetonusofthe

cricopharyngeusm usclesandisidentifiedabout15cm caudaltotheincisors.Thesecond,theaorticcom pression,iscausedbythecrossingoftheaortic

archandtheleftm ainbronchusat22cm from theincisors.Thethirdnarrow ingisinconstant.Ifprom inent,itislocatedabout44cm from theincisors

andm aybecausedbythetoniceffectofthelow eresophagealsphincter.Thetw om uscularconstrictionscorrespondw iththeupperandthelow er

esophagealsphinctersandcanbeidentifiedm anom etricallyateitherendoftheesophagus.

Vesse ls and Nerves : S t ruc tur es o f Suppor t

Vesselsandnervesaresupportingstructuresoftheesophagus.4,22Theydonotproperlybelongtotheesophagealtissue,butthechannellikevascularor

solidnervecordsfeed,drain,andprovidem otilityandsensoryim pulsestothetissuecom ponentsoftheesophagealw all.Inshort,thesestructures

m aintainesophagealfunction.

Forthepurposeofdifferentiatingthepartsofthesystem locatedexternaltotheesophagusfrom thosew ithinthew all,thestructureshavebeen

classifiedasextrinsicorintrinsic.Botharediscussedbelow .

Ar te r i a l Supp l y

O nem ightbeconcernedaboutfatalm ediastinalbleedingfrom esophagealvessels;how ever,"bluntstripping"oftheesophagusw ithoutthoracotom yfor

carcinom ahasbeenshow ntoberelativelysafe.25,27,80,81Therem arkablylow bloodlossduringtheprocedureandthelow susceptibilityto

postoperativeanastom oticleakssuggestaprim arilypooresophagealvascularsupply.Nevertheless,thesurgicallym obilizedesophagusretainsviability

"overalongdistance,"inthewordsofW illiam sandSpencerPayne,w henhandledcarefully.87

EXTRAMURAL, EXTRI NSI C ARTERIES

ThepharynxandtheUES aresuppliedbysm allarteriesoriginatingfrom thesuperiorthyroidarteries.

I n fer ior Thyr o id Ar ter ies: Cerv ica l Esophagus

Thecervicalesophagusissuppliedbythepairedinferiorthyroidarteries(Fig.14-20).Theyarisefrom thethyrocervicaltrunkofthesubclavianartery.

Theinferiorthyroidarteriesgiveoffbranches2cm to3cm longcalledtracheoesophagealarteries.Thesetravelcaudalandm edialoneachsidetow ard




19/38

thetracheoesophagealgroove.Thevesselsofbothsidesare"joinedbyanastom otictw igsalongthetrachea"88 anddivideintothreetofourtrachealbranchesw ithtwotothreebranchestotheesophagus.These,inturn,subdividew ithintheperiesophagealtissueintovesselsoflessthan500 m

lum inaldiam eterbeforetheyentertheesophagealw all.Variants,suchasdirectesophagealbranchesfrom thesubclavianartery,thesuperiorthyroid

artery,thethyroideaim aartery,andthecom m oncarotidarteryareinfrequentandratherinsignificant.27,89

Tracheobronchia l and Bronchoesophageal Ar ter ies: I n t r a thor ac ic Esophagus

Theintrathoracicesophagusreceivesbloodfrom tw osources(Fig.14-20):theunpairedtracheobronchialarteries,27,89w hichariseasagroupfrom the

concavityoftheaorticarch27andcannum berbetw eenoneandfour;andthebronchoesophagealartery.Thetracheobronchialarteriesgiveoffseveralsm allbranchestotheesophagusw hichsubdividewithintheperiesophagealtissueintovesselsof350 m to500 m indiam eter.Frequently,one

bronchoesophagealarteryoriginates1cm to3cm caudaltothevascularbundlefrom theanterolateralaspectofthedescendingaorta.27Inthisarea,

w hichrelatestothetrachealbifurcation,allthevesselsarestraightandshort(lessthan1.5cm )andform afirm connectionbetw eentheaorta,trachea,

andesophagus.Variants,ifany,suchasbranchesfrom intercostalarteries,89seem tobeinsignificantforthebloodsupplyofthehum anesophagus.

Aor t ic Proper Esophageal Ar tery : I n t r a thor ac ic Esophagus

O ne(orrarely,tw o)unpairedproperesophagealarterywithalum inaldiam eterof1m m to2m m m ayarisem orecaudallyfrom theanterioraspectof

thedescendingaortaasanexclusivesourcefortheesophagus.27,89Ifpresent,thisvesseltravelsobliquelydow ntow ardtheesophaguswithinthem ediastinum todivideintorecurrentascendinganddescendingbranches.Bothsubdivideintoseveralperiesophagealvesselsoflessthan500 m in

diam eter.

Lef t Gast r ic and Splen ic Ar ter ies: Abdom inal Esophagus and Gast r ic Card ia

Theabdom inalesophagusandgastriccardiaaresuppliedbytheunpairedleftgastric27,89andsplenicarteries.27Thesederivefrom theceliacaxis(Fig.

14-20).W ithasm anyas11arterialbranches,theleftgastricarterym ainlysuppliestheanteriorandrightlateralaspectsoftheesophagealw all.Thesplenicarteryprim arilysupportstheposteriorandleftlateralaspects(cardiacnotch)byeitheroneortwodirectbranchesorbyvesselsofthegastric

fundus,includingconnectionsw iththeshortgastrics.Thebranchesfrom bothstem vesselsthatsupplytheesophagusextendstraightupw ard4cm to6cm w ithintheperiesophagealtissueacrossthediaphragm atichiatus.Atvariabledistancessm alltributariesoflessthan500 m internaldiam eterem erge

beforethem ainvesselspiercetheesophagealw all.27Theleftinferiorphrenicarteryaffordsadditionalarterialsupply.

I NTRAMURAL, INTRI NSIC ARTERIES

Havingpenetratedbothlayersofthem uscularw all,thesm allvesselsform thesubm ucosalplexus.M anyofthefinevesselsinthesubm ucosaparallel

eachotherinlongitudinalorientation.Lessfrequently,othersform circum ferentialvessels.90Num erousarteriolesandvenulesarepresentbeneaththe

epithelium .


O neim portantpointisthatafterenteringtheesophagustheperiesophagealbranchesextendtoform adenseandcom pleteintrinsicsubm ucosalnetwork

thatcancom pensateintheeventthatanarteryissevered.Thecontinuityoftheintram uralvascularityretainsviabilityandagoodcirculationovera

longdistancew ithinthesurgicallym obilizedesophagus.27,87Thisalsoexplainsw hycarefullyhandledligationofextram uralvesselsdoesnotcom prom ise

theunderlyingtissueandw hythelineofdissectionm aintainsadequatecirculation.

W iththeexceptionofonevesselofdirectaorticorigin,thevascularpatternderivesfrom thelargerstem vesselsneededforthesupplyofdifferentorgans(Table14-3).Thisdem onstratesthattheesophagusdependson"asharedvasculature."89

Fig. 14-20.

M ostcom m onpatternofarterialsupplyofesophagus.Dotted linesshow largerintram uralanastom oses.Dashed linesbehindstom achshow splenicarteryandits

esophagealbranches.Dim ensionsnotproportional.(Modifiedfrom Lieberm ann-M effertD,DuranceauA.Anatom yandem bryology.In:OrringerM B,Zuidem aGD

(eds).Shackelford'sSurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W BSaunders,1996,pp.3-38;reprintedbyperm ission.)

Table 14-3. Commo n Ext r ins ic B lood Sources of the Esophagu s

Sect ion * Sour ces Sh ar in g Or gan s




20/38

*Inneck,chest,andabdom en,theesophagussharesbloodsupplywithotherorgansbyusingsam evascularsources.

Source:CourtesyofDr.DorotheaLieberm ann-M effert.

Repetitivebranchingofthealreadysm allesophagealvesselsresultsintheform ationofverysm allvesselsintheperiesophagealtissuebeforetheirentry

intothew alloftheesophagus.Thesevessels,therefore,m ayundergocontractilehem ostasisw hentorn.

Acontinuousregularnetw orklocatedinthesubm ucosaconnectsalltheextram uralvessels.Thereisnopoorlysuppliedoravascularzone.Further,

surgicalexperienceclearlyshow sthatproblem sduetocirculatorydisturbancesaregreatlyoverestim ated.Anastom oticfailuresalm ostalw aysarisefrom

thevisceralsubstitute.91

Itiscrucialthattheesophagusreceivesanexcellentbloodsupplythroughlongitudinallyorientedintram uralvesselsthatperm ittheplacem entof

anastom osesatanylevel.Theintram uralnetw orkthusprovidesaluxurious,albeitfine,vascularityfortheesophagusbyasystem ofsm allarteries,

arterioles,andcapillaries.Nevertheless,thisareaneedscarefulsurgicalhandling.

Venous Dra i nage

Theintram ural,intrinsicveinscom m enceasfinevenulestoform thesubepithelialplexuswithinthelam inapropriaofthetunicam ucosa(Fig.14-21).

Theyreceivebloodfrom theadjacentcapillariesanddrainintothesubm ucosalplexus.92,93

Aharinejadetal.90recentlystudiedthehum anm icrovasculaturesystem indetail.Theyobservedthattw osm allveinsusuallyaccom panythe

circum ferentialarteriesinthelam inasubm ucosa.Perforatingveinsoriginatingfrom thesm allcom m unicatingveinsofthesubm ucousplexuspiercethe

m uscularw alloftheesophagustogetherw iththeperforatingarteries.Theyreceivetributariesfrom them usclecoatsandform theextram ural,extrinsic

veinsatthesurfaceoftheesophagus.90-93Novalvesw erefoundintheesophagealvenouscirculatorysystem .

Theextrinsicveinsdrainintothelocallycorrespondinglargevessels.Thesuperiorvesselsdraintothejugularveinsortheazygosandhem iazygosveins.

Theinferiorveinsterm inateintheleftgastricandsplenicveins.

Asw elldescribedin1918byElzeandBeck,94therearetw oclearlydelineatedvenousplexusesinthelaryngopharynxwithintheextrem elythin

subm ucosabeneaththem ucosa(Fig.14-22).Theseareexactlyatthelevelofthepharyngoesophagealjunction.O neplexusliesonthedorsalaspectof

theinferiorconstrictorm uscle;theotherinthem idlineposteriortothecricoidcartilage.

Cervical Twopairedstemvessels +Thyroidgland

+ Trachea

Thoracic Severalunpairedstem vessels + Trachea

+ Bronchi

Properunpairedvessel N one

Abdom inal Twopairedstem vessels +Stom ach

+ Spleen

Fig. 14-21.

Diagram ofvenousdrainageofesophagusinnorm alhum an.(Modifiedfrom KitanoS,TerblancheJ,KahnD,Bornm anPC.Venousanatom yofthelow eresophagus

inportalhypertension:practicalim plications.BrJSurg1986;73:525-531,reprintedbyperm ission.)

Fig. 14-22.




21/38

Tenspecim ens(unpublisheddatabyLieberm ann-Meffert,publicationinpreparation)show edbothplexusestobesim ilarinsize,approxim ately2cm to3

cm w ide,andconsistingofseveralthickveinswitham axim um w idthof4m m .Thesew ereprim arilylongitudinalinorientationandwerejoinedby

severaltransverseanastom oses.Theseveinsreceivebloodfrom them ucosaofthelaryngopharynx,larynx,andesophagusanddrainintothethyroid

andjugularveins.94Thesevenousplexusesm aycausearecognizablepostcricoidim pressionontheesophagus95,96andm aybeinvolvedinthe"globus

sensation"inpatientsw ithvenousstasisandtissuesw elling.47,94Theseplexusesm ayalsocontributetothecom petenceandactionoftheupper

esophagealsphincter.

Viannaetal.97clearlydocum entedaspecializedvenousarrangem entattheterm inalesophagus(Fig.14-23).Thesevenousanastom oseshavebeen

suggestedtopossiblysupplycom m unicationbetweentheazygosandtheportalsystem .Theinterm ediate"palisadezone"(Fig.14-23)m ayactasa

high-resistancewatershedbetweenbothsystem s,providingbidirectionalflow .97

Laryngopharyngealvenousplexusesview edfrom posterioraspectasdepictedbyElzeandBeck.94Thefirstdeepplexus(depictedontheleftsideofthedraw ing)liesm edialontheanteriorsideofthepharynxcoveringtheposterior,transverse,andobliquearyepiglotticm usclesandthehardposteriorsurfaceofthecricoid

cartilage(seenfrom thelum inalaspectofthepharynx).Aseconddeepplexus(shiftedaftercuttingofthew alltotherightsideofthedraw ing)liesexactlyonthe

oppositesideofthelum enofthepharynx,posteriorlyunderneaththeinferiorconstrictorm usclesandthecricopharyngealm uscles(UES ).(Modifiedfrom ElzeC,

BeckK.DievensenW undernetzedesHypopharynx.ZOhrenhk1918;77:185-194.)

Fig. 14-23.




22/38

Inapaperaboutprogressandchangesinsurgery,Idezuki98statedthatoverthelastfivedecades,theacceptedtreatm entofesophagealvariceswith

portalhypertensionhasm ovedfrom decom pressionshuntstoselectiveshuntsanddirectoperation,andnow toendoscopicsclerotherapy,som etim es

com binedw ithvaricealligation,ortotransjugularintrahepaticportosystem icshunt.Hashizum eetal.99reportedthatlaparoscopicgastric

devascularizationandsplenectom yforsclerotherapy-resistantesophagogastricvaricesinpatientsw ithhypersplenism isafeasibleandrelativelysafe

procedure.

Jenkinsetal.100statedthatdistalsplenorenalshuntisasafe,durable,andeffectiveprocedureforthetreatm entofrecurrentbleedingsecondaryto

gastroesophagealvaricesandportalhypertensioninpatientsw ithacceptableoperativeriskandgoodliverfunction.

Lympha t i c Dra i nage

Presum ablyduetotheconsiderabletechnicaldifficultyofidentifyingthem inutechannelsbothinvivoandpostm ortem ,anatom icknow ledgeofthe

lym phaticsystem oftheesophagusisextrem elylim ited.Accountsofpreviousinvestigationshavesofarnotbeensubstantiated.4,23Neverthelessone

m ayacceptthatthelym phaticsystem oftheesophagusincludesthelym phductsandlym phnodesasdescribedforotherpartsofthegut.

Lym phcapillariesm aycom m enceinthetissuespacesasanetw orkofendothelialchannels(Fig.14-24)orasblindendothelialsacculations(Fig.14-25)

sim ilartothosefoundinm esenterictissues.101,102

Radiographicillustrationofvenouscirculationinm iddleandlow eresophagus,esophagogastricjunction,andstom achafterinjectionw ithbarium gelatin.Various

zonespresentdifferentvenousarchitecture.Afew longitudinallyarrangedveinsintruncalzone(TZ),additionaltransverseveinsinperforatingzone(PfZ),unique

arrangem entofveinsinpalisadezone(PZ)thatseem stocorrespondtoareaofam pullaofradiologists,andgastriczone(GZ)w ithnetlikerearrangem entofveins.

(From ViannaA,HayesPC,M oscosoG,DriverM ,Portm annB,W estabyD,W illiam sR.Norm alvenouscirculationofthegastroesophagealjunction.Arouteofunderstandingvarices.Gastroenterology1987;93:876-889,reprintedbyperm ission.)

Fig. 14-24.




23/38

Initiallym phatics(arrows)betw eenlow erborderoftunicam ucosaandtelasubm ucosainthehistological( A) andelectronm icroscopic( B) display.Takenfrom

gastricwall,butisrelevantalsoforesophagus.MM,m uscularism ucosae.(A,from LehnertT,ErlandsonA,DecosseJJ.Lym phandbloodcapillariesofthehum an

gastricm ucosa.Am orphologicbasisform etastasisinearlygastriccarcinom a.Gastroenterology1985;89:939-950,reprintedbyperm ission.B,CourtesyDr.

DorotheaLieberm ann-M effert.)

Fig. 14-25.




24/38

Thesubm ucosaofthehum anstom achhasrecentlybeenshow ntocontainanetw orkofnum erouslym phvessels.Theseshow parallelorientationalong

thelongitudinalaxisoftheorgan(Fig.14-26).Theysendoccasionalbranchestothecollectingsubadventitialandsurfacetrunks.97Allthesechannels

possessvalves(Fig.14-25).StudiesbyM ayrandLieberm ann-M effert103usingautopsyspecim ensandelectronm icroscopictechniquesim plythata

sim ilarpatternispresentintheesophagus.Initiallym phaticsseem tooriginateexclusivelyintheregionbetw eenthem ucosaandsubm ucosaandtoform longitudinallyarrangedcollectingchannelsinthesubm ucosa.

Initiallym phaticnetworkinm esenteryoriginatesinblindendothelialsacculationsandsm allchannels.M easurem entsrefertothediam eterofthelym phaticvessels.

(Reconstructionfrom apreparationafterdirectinvivoinjectionofdyeintolym phaticchannelsofgreaterom entum .)(ModifiedafterZw eifachBW ,PratherJW .

M anipulationofpressureinterm inallym phaticsinthem esentery.Am erJPhysiol1975;228:1326-1335;w ithperm ission.)

Fig. 14-26.




25/38

Thelym phatictrunksatthesurfaceoftheesophagusm aydrainintotheregionallym phnodes.Lym phfrom theesophagusm ostlikelydrainsintothe

follow inglym phnodes

104,105,106

:

Thelym phoftheabdom inalesophagusem ptiesintothefollow inglym phnodes:

Innoncancerousautopsyspecim ens,Lieberm ann-M effertetal.andMayrandLieberm ann-M effert4,103,107foundonlyafew sm alllym phnodesinthe

m ediastinum .Thelym phnodeswerelargerandm orenum erousaroundthetrachealbifurcation.M ostofthesecontainedblackcoal-likeparticles.The

authorscouldnotdeterm inewhetherthesenodesdrainedtheesophagusand/orthelungsoriftheytransportedproxim allyordistally.Thisobservation

coincidesw iththereportofW irthandFrom m hold108

w hofoundm ediastinallym phnodesinonly5percentof500norm allym phogram s.Theclassicalchainoflym phnodessurroundingtheesophagusasdescribedintextbooksandillustratedbyNetter83couldnotbesubstantiatedatthistim e.


Theclinicalobservationthatinitialtum orspreadfollow sthelongitudinalaxisoftheesophagusw ithinthesubm ucosaratherthanextendinginacircular

m annersupportsthefollow ingconcepts:

Thepaucityoflym phaticsw ithinthelam inam ucosaandtheabundanceofsubm ucosallym phaticchannels101,109(Fig.14-26)m ayexplainwhy

intram uralcancerspreadspredom inantlyw ithinthislayer.Undetectedm alignantm ucosallesionsm aybeaccom paniedbyextensivetum orspread

underneathanintactm ucosa.Tum orcellsm ayfollow thelym phaticchannelsforaconsiderabledistancebeforetheypassthem uscularcoattoem pty

intotheregionallym phnodes.

Tum or-freem arginattheresectionline,asconfirm edbytheanatom icpointofview (histologic),doesnotguaranteeradicaltum orrem oval.Thisfeature

m aybeconsistentw iththerelativelyhighpostoperativerecurrencerateattheresectionline,includingsatellitetum orsandm etastasisinthesubm ucosafardistantfrom theprim arytum or,25evenifthem arginsattheresectionlinehadbeenpreviouslytum or-free.

Law etal.110reportedthathistologictum orinfiltrationattheesophagealresectionm arginsonpatientsw ithesophagealcarcinom am ostlikelyisnot

responsibleforleakage.Theanastom oticrecurrencewasrelatedtothelengthofesophagealresectionm argin.

Locallym phaticdrainagewithinesophagealw all.A,Lym phaticflow asexpectedundernorm alhealthyconditionsandinearlym alignancy.Valves,presentevenin

sm allchannels,determ inetheflow direction(seeFig.14-27).B,Flow m ayreversew hentum orm assesblocklym phaticpathw ays;resultingelevated,reversed

pressurem ayinterferewithfunctionoflym phaticvalves.(A,M odifiedfrom Lieberm ann-M effertD,DuranceauA.Anatom yandem bryology.In:OrringerM B,

Zuidem aGD(eds).Shackelford'sSurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W BSaunders,1996,pp.3-38;reprintedby

perm ission.B,CourtesyDr.DorotheaLieberm ann-M effert,m odified.)

Fig. 14-27.

Lym phaticpathw aysofesophagus.Alsoshow show ,undernorm alconditions,lym phfrom areasabovetrachealbifurcationem ptiescranially,andlym phfrom below

thatpointpreferentiallyem ptiescaudallytopassthroughceliaclym phnodes.Flow attrachealbifurcationseem stobeorientedbidirectionally.Thisfeatureis

essentialtounderstandingofpotentialspreadofm alignancies.(Modifiedfrom Lieberm ann-M effertD.Anatom y,em bryology,andhistology.In:PearsonFG ,

DeslauriersJ,GinsbergRJ,HiebertCA,M cKneallyMF,UrschelHC(eds).EsophagealSurgery.New York:ChurchillLivingstone,1996,pp1-25,reprintedby

perm ission.)

Paratrachea

Tracheobronchialbifurcation

Juxtaesophageal

Intraaorticoesophageal

Superiorgastric

Pericardiac

Inferiordiaphragm atic

Lym phflow sm orereadilylongitudinallyinthesubm ucosalchannelsthanthroughthefew transverseconnectionsinthem uscle(Fig.14-26)

Lym phflow sonlyfinallythroughthesubadventitiallym phaticsandsm alltrunksintothem ediastinallym phnodes4,23

Asaconsequence,esophagealtum orsm ayspreadfarcraniallyorcaudallywithintheesophagealsubm ucosalchannelsbeforeobstructingthelum en




26/38

From clinicalobservationsincancerpatients,23,25,26thefollow ingpatternsm aybededuced(Fig.14-27):

Nakagaw aetal.112reportedthattum orangiogenesisexpressedasm icrovesseldensitycorrelatesw ithclinicopathologicparam etersfortum or

progression.Theyconsiderthisanindependentprognosticindicatorforpatientsundergoingextendedradicalesophagectom yforinvasive[squam ous

cell]esophagealcancer.

Cooperetal.113reportedthatcom binedchem oradiotherapyincreasesthesurvivalrateofpatientsw ithsquam ouscellcarcinom aoradenocarcinom aof

theesophagusoverradiotherapyalone.

I n n e r v a t i o n

Thepharynx,larynx,andesophagusareinnervatedbybothvisceralcom ponentsoftheautonom icnervoussystem ,thesym patheticandthe

parasym patheticsystem s,w hichexertm utuallyantagonisticinfluencesontheviscera.20,31,114,115Thesym patheticefferentpathw ays,com m oninthe

gut,areconcernedw ithvasoconstriction,contractionofsphincters,andrelaxationofthem uscularwall.Theparasym patheticefferentfibersincreasethe

glandularandperistalticactivityofthegut.20

SYMPATHETI C N ERVES

Thesym patheticnervessupplythepharynx,larynx,andproxim alesophagusthroughthecervicalandthoracicsym patheticchains(Fig.14-28).These

chainstraveldow nw ardlateraltothespineandfrom thecardiobronchialandtheperiesophagealsplanchnicnervesthatarisefrom theceliacplexus.

Interlacedwithfibersoftheparasym patheticcervicalandthoracicplexuses,thesym patheticnervoussystem usesthevagusnerveasacarrierforsom e

ofitsfibers.31

PARASYMPATHETI C NERVES

Theparasym patheticnervesupplyisthroughthevagus,thetenthcranialnerve.Thevaguscarriesgeneralsom aticandvisceralsensory,skeletalm otor,

andparasym patheticfiberstotheesophagus.Thelaryngopharynxreceivesgeneralsom aticsensoryandskeletalm otorinnervationviathevagusnerve.

Thesensoryneuroncellbodiescontributetoform ingtheganglionnodosum (Fig.14-28).

Therightandleftvagipassasthicktrunksthroughtherespectivejugularforam ina.Theinnervationofthem usculatureandm ucosaofthepharynx,

larynx,UES,andupperhalfoftheesophagusisbythebilateralsuperiorlaryngealnerves(SLN )and/orinferiorlaryngeal(recurrent)nerves(RLN ).The

SLN issaidtobem ainlysensoryandsecretory,althoughitsexternallaryngealbranchism otortothelarynxandthecricopharyngeus.TheRLNislargely

m otorandsuppliesm ostofthelaryngealm usclesandtheUES.

Thesuperiorlaryngealnerveoriginatesfrom thevagaltrunknearthenodoseganglion,travelsdow nalongsidethecarotidarteries,anddividesintothe

internallaryngealbranchandtheexternallaryngealnerve.Thislatternervesuppliesthecricothyroidm uscleandthecricopharyngeusportionofthe

inferiorpharyngealconstrictor,w hichservesastheupperesophagealsphincter.Theinternallaryngealnerve,containingparasym patheticandsensory

fibers,suppliesthelaryngealm ucosaabovethevocalfoldsandtheregionofthepiriform fossae.31,116-118

TheRLNarisesontherightsidefrom thevagusnerveinfrontofthesubclavianartery,turnsbackw ardaroundtheartery(Fig.14-28),andascends

obliquelytotherightlateralaspectofthetracheaandposteriortothecom m oncarotidartery.31,116,117

O ntheleftsidetheRLNarisesfrom thevagusnerveinfrontoftheaorticarch,turnsbackw ardaroundtheaortabehindtheligam entum arteriosum ,and

ascendsobliquelytotheleftofthetrachea.

Lym phfrom abovethecarinaflow scraniallytow ardthethoracicductorthesubclavianlym phtrunks31

Lym phfrom below thecarinaflow sm ainlytowardthecisternachyliviathelow erm ediastinal,leftgastric,andceliaclym phnodes31

Flow m aychangeunderpathologicalconditions.111W henlym phvesselsbecom eblockedanddilatedduetotum orinvasion,thevalvesbecom eineffectualandtheflow reverses(Fig.14-26).Thisphenom enonexplainstheretrograde,unexpectedspreadofsom eofthem alignanttum ors,butlim itsthevalueofestablishing

pathw aysofnorm alflow .

Fig. 14-28.

Innervationofesophagus.(Modifiedfrom Lieberm ann-M effertD,DuranceauA.Anatom yandem bryology.In:OrringerM B,Zuidem aGD (eds).Shackelford's

SurgeryoftheAlim entaryTract(4thed).VolITheEsophagus.Philadelphia:W BSaunders,1996,pp.3-38,reprintedbyperm ission.)




27/38

AsbothRLNstravelcranially,theyapproachtheesophagusandtrachea,oftenpositioninginthetracheoesophagealgroove,117 andtheydistributean

equalnum berofnervefiberstobothstructures(Fig.14-29).Reachingthepharyngoesophagealjunction,bothRLNsgaincloseproxim itytothe

esophagus,theleftsideusuallycloserthantheright.Nearthelow erpoleofthethyroidgland,bothnervesarealwaysintim atelyrelatedtotheglandand

oftenpassbetw eenbranchesoftheinferiorthyroidvessels(Fig.14-29).Som eofthenervebranchesdipintotheparenchym aofthegland.

O nbothsides,asinglethickterm inalbranchoftheRLNentersthelarynxjustbelow thecricopharyngealm uscleband(Fig.14-29).Herebothdivideinto

severalbranchestosupplyalltheintrinsiclaryngealm uscles(exceptthecricothyroid),includingthearytenoid(vocal)andepiglotticm uscles.

O ccasionallythem ajorterm inalbranchcom m unicatesw iththesuperiorlaryngealnerve107(seeFig.14-13).

Posteriortothelunghilum atthelevelofthetrachealbifurcation,thevagalnervesform anetworkoffascicles,thepulm onaryandesophagealplexus.

Theleftvaguscontributesprim arilytotheanterior,andtherightvagustotheposterioresophagealplexus.

Atthelow erendoftheesophagus,thefibersreorganizeintotw otrunksthatpassdow nontheanteriorandposterioresophagealw all.118Togetherw ith

14 Esophagus

Documents

Transcript of 14 Esophagus