ActaMed.Okayama,2002 Vol.56,No.5,pp.245-253 Copyrightｃ2002byOkayamaUniversityMedicalSchool. OriginalArticle http://www.lib.okayama-u.ac.jp/www/acta/ HepatopancreaticArterialRing:BilateralSymmetricTypology inHumanCeliaco-MesentericArterialSystem MotohiroKosaka,KanjiHoriuchi,KeiichiroNishida,TakehitoTaguchi, TakuroMurakami,andAijiOhtsuka DepartmentofHumanMorphology,DepartmentofOrthopaedicSurgery,OkayamaUniversityGraduateSchoolof MedicineandDentistry,andDepartmentofRadiologicalTechnology,FacultyofHealthSciences, OkayamaUniversityMedicalSchool,Okayama700-8558,Japan Theceliacandmesentericarterialsystem includingtheleftgastric,splenic,commonhepatic,and superiormesentericarteriesshowsvarioustypesoforigins,courses,ramificationsandanastomoses. Inordertoexplainthevariousexpressionsofthissystem,wehaveproposedatypologicalmodel,in which celiacomesentericarteriesdevelopaspairedorbilaterallysymmetricalprimordialvessels originatedfrom theanterioraspectoftheaorta,andthesevesselsanastomoseeachotherwith longitudinalandhorizontalpathways.Here,wereport3unusualcasescharacterizedbyarterial rings, formed by the left gastric, left accessory hepatic, proper hepatic, anterior pan- creaticoduodenal, and dorsalpancreatic arteries. The dorsalpancreatic and anterior pan- creaticoduodenalarteriesarelocatedtotherightandleftoftheembryonicpancreasdevelopingin thedorsalmesentery,respectively.Suchhepatopancreaticarterialringssimultaneouslycontaining rightandleftelementscanonlybeexplainedusingourtypologicalmodel,inwhichtheconceptof pairedarteriesorbilateralsymmetryisintroduced. Keywords:arterialvariation,celiactrunk,superiormesentericartery,typology,bilateralsymmetry hreeunpairedarteries theceliactrunkandthe tomoses［1-14］.Theceliactrunkoritsbranchesmay T superiorandinferiormesentericarteries usu- alsogiveooneorboth(leftandright)theinferior allyoriginatefrom theanterioraspectoftheabdominal phrenic arteries［15］. These variations have been aorta,andsupplytheabdominaldigestiveorgansand classifiedandexplainedusingclassicaltypologicalmodels spleen.Amongthese,theceliactrunk,awideventral［16,17］.Theclassicalmodelsarecharacterizedby4 branchjustbelowtheaortichiatus,passesalmosthori- longitudinallyanastomosedvessels(leftgastric,splenic, zontallyforwardofandslightlyabovethepancreasand commonhepatic,andsuperiormesenteric),whichin- splenicvein,thendividingintothefollowing:theleft dependentlyoriginatefrom theabdominalaorta.Some gastric,commonhepatic,andsplenicarteries.These commonvariations,suchashepatomesenterictrunkor threeandthesuperiormesentericarteriesvaryintermsof independentoriginofleftgastricartery,arewellaccount- patternoforigins,courses,ramifications,andanas- edforusingthisclassicmodel,althoughitdoesnot explaintheformationofsomerarevariationssuchas hepatogastricorsplenomesenterictrunkformation.Previ- ReceivedMarch7,2002;acceptedMay23,2002. Correspondingauthor.Phone:＋81-86-235-7089;Fax:＋81-86-235-7095 ously,wepresentedtypologicaldiagramsofthephrenico- E-mail:aiji＠md.okayama-u.ac.jp(A.Ohtsuka) celiaco-mesentericarterialsystem［8,9,15］.These 246 Kosakaetal. ActaMed.Okayama Vol.56,No.5 diagramswereusefulforintroducingtheconceptof ahumangrossanatomycourseformedicalstudentsatthe left-rightbilateralitytoexplainseveralunpairedorunilat- OkayamaUniversityMedicalSchool. eralvariationsinthisarterialsystem. Inthepresentstudy,wepresentrareanomalouscases Results characterizedbyarterialringformationoftheleftgastric- leftaccessoryhepatic-properhepatic-anteriorpancreati- (Fig.1). Theleftgastricandsplenic coduodenal-dorsalpancreaticarteries.Forexplanationof arteriesformedacommontrunkwiththeleftinferior sucharterialringformation,thebilateralityconceptis phrenicarteryandarosefromtheanterioraspectofthe required;somesegmentsoftheringbelongtotheright abdominalaortabeneaththeaortichiatus.Thisphrenico- system,otherstotheleft. gastro-splenictrunkimmediatelygaveotheleftinferior phrenicartery,anddividedintotheleftgastricandsplenic MaterialsandMethods arteriesbehindtheomentalbursa.Theleftgastricartery ascendedalongtheleftgastropancreaticfoldandreached In1996-2000,weencounteredsignificanthepatopan- theupperendofthelessercurvatureofthestomach.The creaticarterialringsin3Japaneseadultcadavers.Age, leftaccessoryhepaticarteryissuedfrom theleftgastric sex,clinicaldiagnosisatdeath,andabdominalsurgical arteryintheleftgastropancreaticfold,thenranalongthe history ofthesecasesaresummarized in Table1. fissure for the ligamentum venosum in the lesser Cadaverswerefixedconventionallybyarterialperfusion omentum,givingabranchtotheesophagus,andreached with10 formalinthroughtherightorleftradialartery, thehepaticportalregion.Thesplenicarterygaveothe andsubsequentlydehydratedwith50-60 ethanolat anteriorrightaccessoryhepaticartery［11］attheupper 40°C.Untildissection,theywerestored,for6months marginofthepancreaticbody,ranleftalongthepancreas, orlonger, in astainless-steelbody storagesystem and reached the hilum ofthe spleen through the (Katoman,Tokyo,Japan).Dissectionwasperformedin phrenicolienalligament. Theanteriorrightaccessory hepaticarterydescendedontheposterioraspectofthe pancreas,turnedrightatitslowermargintoappearin Table1 Generaldescriptionofthecases frontoftheportalvein,andascendedonthepancreatic anteriorsurface, whereitbranched o theanterior Case Sex Age Diagnosisatdeath Abdominalsurgicalhistory superiorpancreaticoduodenal,rightgastroepiploic,and 1 Male 83y Lungcancer No posterior superior pancreaticoduodenalarteries. The 2 Female 83y Pneumonia No anteriorrightaccessoryhepaticartery,givingotheright 3 Male 73yCerebralinfarction No gastricarterytothelessercurvatureofthestomach, y,yearold. ascendedfurtherinthehepatoduodenalligamentalongthe Table2 AbbreviationsinFigures1-3,5,and6 a:abdominalaorta m2:leftandrightupperventriculararteries u:umbilicalartery c:intercostal(orlumbar)artery m3:leftandrightmiddleventriculararteries v:portalvein d:dorsalpancreaticartery m4:leftandrightlowerventriculararteries w:gastroduodenalartery e:superioranteriorpancreaticoduodenalartery m5:leftandrightupperintestinal(superiormesenteric) x:accessorygastricartery f:inferioranteriorpancreaticoduodenalartery arteries y:rightgastricartery g:leftgastricartery m6:leftandrightlowerintestinal(inferiormesenteric) B:commonbileduct h:commonhepaticartery arteries D:duodenum i:inferiorphrenicartery n:renalartery G:gallbladder ii:internaliliacartery o:leftaccessoryhepaticartery H:liver k1:anteriorrightaccessoryhepaticartery p:properhepaticartery I:intestine k2:posteriorrightaccessoryhepaticartery r:rightgastroepiploicartery K:kidney k3:leftaccessoryhepaticartery s:splenicartery P:pancreas m:superiormesentericartery t:testicular(ovarian)artery S:stomach m1:leftandrightsubphrenicarteries ti:internalthoracicartery Sp:spleen October2002 HepatopancreaticArterialRing 247 Fig.1 Linedrawingrepresentationofcase1.Threeaberrantaccessoryhepaticarteries(k1,k2,andk3)co-exist,andthecommonhepatic arteryislost.Noteacompletearterialringmadeofanastomosedleftandrightaccessoryhepaticarteries(asterisk).Abbreviations:see Table2. anteriorsideoftheportalvein,andreachedthehepatic (Fig.2). Theleftgastricandsplenic portalregion,wheretheanteriorrightaccessoryhepatic arteriesformedacommontrunk(gastro-splenictrunk), andleftaccessoryhepaticarteriesanastomosedtoforman whicharosefrom theanterioraspectoftheabdominal arterialarch.Thus,theseaccessoryhepaticarteries aorta.Theleftgastricarteryranthroughtheleftgas- formedanarterialringaroundthepancreasandlesser tropancreaticfoldtothelessercurvatureofthestomach. omentum.Therightandlefthepaticbranchesarosefrom Thesplenicartery,afterissuingthedorsalpancreatic thishepaticarterialarch. Additionally, thesuperior artery,ranalongthesuperiorborderofthepancreas,and mesentericarteryissuedtheposteriorrightaccessory reachedthespleen.Thedorsalpancreaticarterydescend- hepaticartery,whichranposteriorlytotheportalveinon edfrom theposterioraspectofthepancreastowardits thebacksideofthepancreas,whereitgaveobranches inferiormargin,whereitbecametheinferiorpancreatic tothepancreasandtheduodenum,thenascendedbehind artery.Thesuperiormesentericarteryoriginatedfrom thecommonbileductandportalveintoreachthegall theaortajustinferiortothegastro-splenictrunk,and bladderandthehepaticrightlobeandtosupplythem. issuedtheposteriorrightaccessoryhepaticartery.This 248 Kosakaetal. ActaMed.Okayama Vol.56,No.5 Fig.2 Linedrawingrepresentationofcase2.Thelackofausualcommonhepaticarteryiscompensatedforbyananomalousposterior rightaccessoryhepaticartery(k2),whichrunsbehindtheportalvein.Noteanarterialringmadeoftheaccessoryhepatic(k2),gastroduodenal (w),pancreaticoduodenal(e),andsuperiormesenteric(m)arteries.Otherabbreviations:seeTable2. accessoryhepaticarterypassedbehindtheportalveinand thecardiaandfundusofthestomach.Thegastroduodenal ranbetweenthecommonbileductandtheportalveinto arterygaveothesuperiorposteriorpancreaticoduodenal appearinfrontofthebileduct,wherethisarterybifurcat- artery,whichranontheposteriorsurfaceofthepancreas edintothegastroduodenalandproperhepaticarteries. and anastomosed with the inferior posterior pan- Theproperhepaticartery,afterbranchingotheright creaticoduodenalartery, a branch of the superior gastricartery,ascendedalongtheanterioraspectofthe mesentericartery. Subsequently, the gastroduodenal portalveintoreachtheportahepatis,whereitdivided arterygavethepancreaticheadabranch,whichinturn intorightandleftbranches.Therightbranchpassed anastomosed with theinferiorpancreaticartery (see throughbehindthehepaticduct,issuedabranchtothe above).Thenthegastroduodenalarterydividedintothe gallbladder,andenteredtherightlobeoftheliver.The rightgastroepiploicarteryandthesuperioranteriorpan-