J. Coloproctol. (Rio J.) vol.35 número4

jcoloproctol(rioj).2015;35(4):212–216

w w w . j c o l . o r g . b r

Journal

of

Coloproctology

Original

Article

Vermiform

appendix:

positions

and

length

–

a

study

of

377

cases

and

literature

review

Sandro

Cilindro

de

Souza

,

Sérgio

Ricardo

Matos

Rodrigues

da

Costa

,

Iana

Gonc¸alves

Silva

de

Souza

a_{InstitutoMédico-LegaldeFeiradeSantana,SecretariadeSeguranc¸aPúblicadoEstadodaBahia,Salvador,BA,Brazil}

b_{DepartmentofAnatomy,FaculdadesAdventistasdaBahia,Capoeiruc¸u,BA,Brazil}

c_{InstitutoMédico-LegalNinaRodrigues,SecretariadeSeguranc¸aPúblicadoEstadodaBahia,Salvador,BA,Brazil}

d_{CenterforHealthSciences,UniversidadeFederaldaBahia,Salvador,BA,Brazil}

a

r

t

i

c

l

e

i

n

f

o

Articlehistory:

Received21June2015 Accepted15August2015

Availableonline25September2015

Keywords:

Vermiformappendix Cecum

Anatomicalvariation Appendicitis

a

b

s

t

r

a

c

t

Objective:Evaluation ofthefrequencyoftherelativepositionsandlengthofvermiform appendixinagroupofcorpsesexaminedbytheauthors.

Method:Dissectionof377adultcadaversautopsied.

Resultsandconclusions:Retrocecal: 43.5%; subcecal:24.4% post-ileal:14.3%, pelvic:9.3%; paracecal:5.8%;andpre-ilealappendices:2.4%,otherpositions:0.27%,meanlength:11.4cm. ©2015SociedadeBrasileiradeColoproctologia.PublishedbyElsevierEditoraLtda.All rightsreserved.

Apêndice

vermiforme:

posic¸ões

e

comprimento

–

estudo

de

377

casos

e

revisão

de

literatura

Palavras-chave:

Apêndicevermiforme Ceco

Variac¸ãoanatômica Apendicite

r

e

s

u

m

o

Objetivo:Avaliac¸ãoda frequênciadas posic¸õesrelativasedocomprimentodoapêndice vermiformeemumgrupodecadáveresexaminadospelosautores.

Método:Dissecc¸ãode377cadáveresadultosnecropsiados.

Resultadose conclusões:Apêndices retrocecais:43,5%, subcecais:24,4%, pós-ileais:14,3%, pélvico:9,3%,paracecais:5,8%,pré-ileais2,4%,outrasposic¸ões:0,27%.Comprimentomédio: 11,4cm.

©2015SociedadeBrasileiradeColoproctologia.PublicadoporElsevierEditoraLtda. Todososdireitosreservados.

∗ _{Correspondingauthor.}

E-mail:[email protected](S.C.deSouza).

http://dx.doi.org/10.1016/j.jcol.2015.08.003

Introduction

Vermiform appendix (from the Latin appendix: “dan-gling”+“vermis”+‘form”,i.e.:“danglingworm-shapedthing”) isadiverticulumofthececumandmarksthebeginningofthe colonintheconfluenceoftaenias.Theappendixis posterior-mediallyattachedtothececum,about2cmbelowtheileocecal junction.1–6

Thepositionoftheappendixisextremelyvariable–more thananyotherorgan–andifitistoolong,theappendixmay extendtoanypartoftheabdomen.1,3,7,8 _{Thus,asstatedby} Maingot,9_{theappendixistheonlyorganinthebodythathas} nofixedanatomy.Althoughnowadaysthis traditional prin-cipleis being questioned, it has its value,by emphasizing thefactthat oftenthe appendixisoneofthemostmobile viscera,althoughits lackofnormalpositionisnotin him-self so extraordinary.10 _{Taking into account that often the} appendixisamobilestructure,themedicalimportanceofits relativepositionhasbeenquestionedbysomeauthors.10_In general,however, someauthors describea significant rela-tionship between its location and acute appendicitis.11,12 Signs and symptomsmay show varyingdegree of discrep-ancywiththeexpectedsymptomatology,dependingonthe positionoftheappendix.Forexample,apelvicappendicitis canreachthewalloftheureterandbladder,resultingin uri-narysymptoms.Ontheotherhand,aretrocecalappendicitis canpromote inflammationofthepsoas majormuscle and causelowbackpain,lamenessandpainwithhipextension.A peri-ilealappendicitis,inturn,cantriggeradiarrhealpicture indistinguishableofthatstemmedfromgastroenteritis. Occa-sionally,thepictureissoatypicalthatonecanmakeamistake with respect to a myriad of non-surgical intra-abdominal disorders11,13 _{and taking into account the great} anatomi-calvariabilityofthe appendix,inthefaceofanepisodeof acuteabdominalpainthedoctormustregardappendicitisat leastas a second suspicion.11 _{In aretrocecal position, the} bloodvesselsmaybecompressedandfoldedbythececum. Thus,whenaninflammationoftheappendixoccursinthis position,its blood supply may becompromised.8 _{Finally, a} strongassociationhasbeenestablishedbetweenhidden loca-tionsoftheappendix(post-ileal,pelvic,retroperitoneal)and the developmentof anadvanced appendicitis, resulting in longerhospitalstaysandinhighincidenceofgangreneand perforation.2,14,15 _{The knowledge of all these nuances can} facilitatetheestablishmentofadiagnosis,allowinganearly treatment and minimizing the rate of complications from appendicitis.Therefore,thestudyofappendixpositionshas provenuseful,eveninourdays.12

Theaimof this study isto determinethe position and lengthofthevermiformappendixinagroupofcorpses exam-inedbytheauthors.

Materials

and

methods

ThisstudywasconductedfromJuly5,2007toFebruary6,2014 inthe ForensicMedicineInstitutesofthecitiesofSalvador (NinaRodrigues)andFeiradeSantana(Bahia).

Inthisstudy,alladultcadaversexamineddirectlybythe authorsduringtheusualnecropsyevaluationswereincluded. Thestudyexcludedcorpseswithoneormoreofthe follow-ingconditions:agedunder18years,pregnancy(atnecropsy), scars or sutures of laparotomy, intra-abdominal infection (localizedordiffuse),partialorcompleteintestinal obstruc-tion, gaseous distension of bowel loops, and decomposing corpses.

Theabdomenwasopenedbyaxifopubicmidlineincision. Thevermiformappendixwaslocatedbysimpleexposureof the lowerileocecalrecess or,indifficultcases,wefollowed theteniaetotheirjunctionattheapexofthececumandbase oftheappendix.1,8,12_{Theappendixpositionsweredefinedas} follows:1,8,12,16

• Retrocecal/retrocolic: the appendix courses upwardly

behindthececum,andmayreachtheinitialportionofthe ascendingcolon;

• Pelvic:theappendixisdirecteddownward,overthepsoas

major,withitstipsurpassingtheupperedgeofthelower pelvis.

• Post-ileal:thedistalportionoftheappendixisinaposition

posterior-superiortotheterminalileumanddirectedtothe spleen;

• Subcecal:theappendixislocatedunderthececum,resting

ontherightiliacfossaandseparatedfromtheiliacmuscle byalocalperitoneallining;

• Pre-ileal: the distalportion ofthe appendixislocatedin

a position anterior-superior to the terminal ileum and directedtothespleen;

• Paracecalposition:theappendixissituatedlaterallytothe

cecumandascendingcolon;

• Other(ectopic)positions:theappendixdoesnotfitinany

ofthepositionsabovedescribed.

Results

377appendiceswerestudied.Ofthewholegroupofcorpses, 87.8%(N=288)weremaleand12.2%(N=46),female.Theage rangedfrom18to89years(mean=33.6years).

The corpses’ weight ranged from 46.5 to 90.5kg (mean=69.5kg). Their height ranged from 1.67 to 1.82m (mean=1.71m).Indescendingorder,thepositionsfoundfor theappendixwereasfollows(Fig.1):retrocecal:43.5%(164), subcecal: 24.4% (92), post-ileal: 14.3% (54), pelvic: 9.3%(35) paracecal: 5.8%(22), pre-ileal:2.4%(9), andother positions: 0.27%(1).

Mostretrocecalappendices(98.8%–162)wererestingfreely ontheretrocecalrecess.Inonlytwocases(1.2%),the mesoap-pendixwasabsentandtheappendixwascompletelyadhered totheposteriorwallofthececumorascendingcolon.

The appendix length ranged from 1.0 to 20.0cm (mean=11.4cm).

Discussion

214

4th_{: Pelvic: 9.3%}

2nd_{: Subcecal: 24.4%}

5th_{: Paracecal: 5.8%}

3rd: Post-ileal: 14.3%

1st_{: Retrocecal: 43.5%}

6th_{: Pre-ileal: 2.4%}

7th_{: Others:}

0.27%

Fig.1–Positionsofthevermiformappendix.

severalauthorshaverecordedhundredsofreferencesunder theirappropriatesubdivisions.Nousefulpurposehasbeen achievedbyrepeatingthishugeamountofdata.19_Therefore, thereferencesreviewedinthecurrentstudywerepurposely limited,andaresummarizedinTable1.

Thelargest series documentedin the literature studied were 4680,19 _10,0001 _and40,00013 _{appendices. Inthe study} byWakeley (10,000 cases),1 _{theappendix wasinretrocecal} (65.28%),pelvic(31.01%),subcecal(2.26%),pre-ileal(1%)and post-ileal(0.4%)position.Subsequentanatomicaland surgi-calstudies in theliterature (11series until 1993) and data obtainedbyourgroup(Table1)showconsiderable contradic-tionwithrespecttothisclassicstudy.Probablytheauthors haveuseddifferentdefinitionsanddatacollection methodol-ogy,ordemographicvariationsoccurred.Thus,comparisons between reports may be challenging or even impossible, thankstolackofcriteria uniformity.Giventhese disagree-ments, currently we are not sure yet about the defined percentages.5,17 _{However,inmostreportsthe valuesofthe} mostcommonpositions(retrocecalandpelvic)provide rea-sonableapproximations.12

Inthemostpart,therecordsarebasedonautopsy find-ings.Inthesestudies,thepositionmostcommonlyfoundhas beentheretrocecalone,withanoccurrencerangingfrom18 to65%ofspecimens.1,13–16,19,20_{Consistentwiththesefindings,} inthisstudy,weobservedmoreoftenappendicesina retro-cecalposition(43.5%),andthisfindingwaswithintherange reportedbyotherresearchers(18–65%).Whenpreviousreports werereviewed,itwasfoundthattheretrocecalpositionhas beenlessfrequentinAfricanversusCaucasianpopulations.12 Thepositionoftheappendixiscloselyrelatedtothe devel-opment of the cecum. Although initially with its location underthe liver,afterthe 10thweekofintrauterinelifethe fetalintestine returnstotheabdominalcavity, causingthe cecumtograduallydescendintotherightiliacfossa,witha

counterclockwise twisting motion around its longitudinal axis. Simultaneously, the anterolateral wall of the cecum stretches and grows faster than the other parts, and this resultsindisplacementoftheappendixfromitsoriginal posi-tion attheapexofthececum,toananteromedialposition. Duringthisprocessofcecaldescent,theappendixcanbend behindthececum,andifatthattimethedevelopmentof perit-onealliningisoccurring,theappendixwillremainfixedinthis retrocecalposture.Ontheotherhand,iftheappendixremain freeanddirecteddownwardduringthedescentofthececum, thentheappendixwillremainpermanentlyasanorganwith freemobilityafteritsfixationtothecolon.1,2,10,15,16_Inadults, theappendixmaybefixedinaretrocecalpositionbythe fibro-sisresultingfrompreviousepisodesofacuteappendicitis.14,15 Therefore,inviewoftheextrememobilityoftheappendix, andtakingintoaccountthefastandextensivechangesinthe surroundingparts,andalsoconsideringthepositionchanges sufferedbytheappendixwhenfollowingthececalmigration, itmaybeconcludedthattheappendixissubjecttomoreor lessintenseaccidentalcircumstancesthatwillmodifyitsfinal positioningandthatareresponsibleforthevariouspositions inwhichthis organisdescribed.1,17 _{Gender,age,body} pos-turechanges,andvaryingdegreesofcecalcontractionhave not been described as determinantsof the positionof the appendix.12,17

Inthecurrentstudy,the2ndand3rdpositionsmost com-mon are the subcecal (24.4%) and post-ileal (14.3%) – an unexpectedresult,sinceinnoneofthereviewedstudiessuch a high frequencywasfound (Table 1). These findings were attributedtothelocalcharacteristicsofthestudypopulation, predominantly made up ofmestizos ofvarious ethnicities. Inthesubcecalposition,theappendixisinafully intraperi-tonealcondition.Ifinflamed,itcancausediffuseperitonitis. Thus, this position can beregarded as the most suscepti-bletocomplications.8_{Duringembryonicdevelopment,further} growthoftherightwallofthececumorastrongertorsionof thececumandascendingcoloncanshiftthebaseofappendix towardtheileo-cecaljunctionarea,resultinginpre-ilealand, inextremecases,post-ilealappendices.1,10,17

Inthisseries,thepelvicpositionwasthefourthmost fre-quent(9.3%).However,inmostofthereviewedstudies(Table1) thepelvicpositionappearsinthesecondplace,andseveral authors describethis positionasthemostprevalent, espe-cially innon-surgical casesand inolderindividuals.12 _The highfrequencyofpelvicappendiceshasbeenassociatedwith thepresenceoftheso-calledgenitomesentericfold,whichisa foldofperitoneumcoursingverticallyfromtheposteriorface ofthe terminalileumtothedeepright inguinal ringor,in women, tothe rightovary. Theappendix, asit follows the cecum andturns up and totheleft, mustcomeinto close proximitywiththisfold,andtendstobedeflecteddownward, towardthepelviccavity.1,5,17

j

coloproctol

(rio

j).

2

0

1

5;

3

5(4)

:212–216

215

Reference n Type Length(mean) Retrocecal Subcecal Pelvic Pre-ileal Post-ileal Paracecal Ectopic

Liertz,1909 (abstract)

2.092 – 35% 9% 42.1% 13.9% –

Collins,1932 4.680

Postmortem

8.21cm 20.21% 1.24% 7.9% Appendiceswithanteriorlocation:70.72% –

Wakeley,1933 10.000

–

65.28% 2.26% 31.01% 1.00% 0.4% – 0.05%

Peterson,1934 373 31% – 42.2% 26.8% –

Shah,1945 405 61.2% 3.7% 8.2% Paracecal,parailealandectopic:26.9%

186 30.1% 7% 34.9% Paracecal,parailealandectopic:28%

Waas,1959 266 35.3% 13% 24.1% Paracecal,parailealandectopic:28.6%

Bailey,1959 (abstract)

– Post-surgical 74% 1.5% 21% 1% 5% 2% –

Maisel,1960 300 Postmortem 26.7% 5% 58% 1.3% 3.3% –

Collins,1963 40.000 Post-surgical 25.95% Appendicesanteriortocecum:74.05% –

Solanke,1970 125 Postmortem 38.4% 11.2% 31.2% Paracecal,parailealandectopic:19.2%

Buschard,1973 141(Denmark) Post-surgical andpost mortem

9.91cm 56.7% 2.1% 33.4% 7.8% –

93(Czechoslovakia)

Postmortem 9.12cm 44.1% 0 44.1% 11.8% –

Katzarski,1979 103 12cm(♂)and11.4cm(♀) 20.3% – 43.6% –

Williamson, 1981

481 Post-surgical – 21.8% –

Ajmani,1983 100 Postmortem 9.5cm(♂)and8.7cm(♀) 58% 5% 23% 2% 10% 2% –

Grunditz,1983 247 Radiological _– 17% –

Ojeifo,1989 548 Post-surgical

andpost mortem

216

Agenesisofthe appendix, double appendixand ectopic appendixhavebeenreportedatafrequencyunder1%.12,15_The authorsfoundonlyanectopicappendix(0.27%)inapre-cecal position.

Theauthorsfoundnocorrelationbetweenappendixlength andposition.Thiscorrelationhasalsonotbeenestablishedby otherresearchers.8,17,20

Conclusions

Inthepresentstudy,weobtainedthefollowingfrequenciesfor appendixpositions:retrocecal:43.5%,subcecal:24.4%, post-ileal:14.3%,pelvic:9.3%,paracecal:5.8%,pre-ileal:2.4%,other positions:0.27%.Thelengthrangedfrom1.0to20cm,witha meanof11.4cm.

Conflicts

of

interest

Theauthorsdeclarenoconflictsofinterest.

r

e

f

e

r

e

n

c

e

s

1. WakeleyCPG.Thepositionofthevermiformappendixas ascertainedbyanalysisof10,000cases.JAnat.1933;67:277–83.

2. ZernJT.Theapêndix:little,bigtrouble.DelMedJrl. 1995;67:326–34.

3. EllisH.Clinicalanatomy:arevisionandappliedanatomyfor clinicalstudents.9thed.Oxford:BlackwellScience;1997.

4. VolgAW,MitchelAWM.Gray’sanatomyforstudents.2nded. Philadelphia:Elsevier;2010.

5. GrayH.Gray’sanatomy.37thed.London:Churchill Livingstone;1989.

6.MonkhouseS.Mastermedicine:clinicalanatomy.Kidlington: Elsevier;2001.

7.TrevesF.Lecturesontheanatomyofthecanalintestinaland peritoneuminman.BritMedJ.1835;1:527–30.

8.AjmaniML,AjmaniK.Thepositionandarterialsupplyof vermiformappendix.AnatAnz.1983;153:369–74.

9.MaingotR.Postgraduatesurgery,vol.1.D.AppletonCentury Co.;1938.

10.DeGarisCF.Topographyanddevelopmentofthececusand appendix.AnnSurg.1941;113:540–8.

11.CourtneyMT,etal.Sabiston:tratadodecirurgia.17thed.Rio deJaneiro:Elsevier;2005.

12.OjeifoJO,EjiwunmiAB,IklakiJ.Thepositionofthevermiform appendixinNigerianswithareviewoftheliterature.West AfrJMed.1989;8:198–204.

13.CollinsDC.71,000humanappendixspecimens:afinalreport summarizingfortyyears’study.AmJProctol.1963;14: 365–81.

14.CollinsDC.Acuteretrocecalappendicitis.ArchSurg. 1938;36:729–43.

15.WilliamsonWA,BushRD,WilliamsLF.Retrocecal appendicitis.AmJSurg.1981;141:507–9.

16.MaiselH.Thepositionofthehumanvermiformappendixin fetalandadultagegroups.AnatRec.1960;136:385–91.

17.BuschardK,KjaeldgaardA.Investigationandanalysisofthe position,fixation,lengthandembryologyofthevermiform appendix.ActaChirScan.1973;139:293–8.

18.KarimOM,BoothroydAE,WyllieJH.McBurney’spoint–fact orfiction.AnnRCollSurgEngl.1990;72:304–8.

19.CollinsDC.Thelengthandpositionsofthevermiform appendix–astudyof4,680specimens.AnnSurg. 1932;96:1044–8.

20.GrunditzT,RydénCY,JanzonLars.Doestheretrocecal positioninfluencethecourseofacuteappendicitis.ActaChir Scand.1983;149:707–10.