【專題】腹內疝的影像診斷

提一點小建議，每一幅圖像都應該打上體表標誌的，存儲圖像時的舉手之勞，用處很大的。看了以上的圖片及文字內容，受益非淺。平時這種病例較少，一旦碰到難以作出診斷，現在心裡有底了，謝謝！暈,這麼好的病例,看不到!痛感謝samar和graceof兩位版主參與翻譯，感謝foxet版主校正。CTofInternalHernias腹內疝的CT診斷Abstract摘要Computedtomography（CT）playsanimportantroleindiagnosisofacuteintestinalobstructionandplanningofsurgicaltreatment.Althoughinternalherniasareuncommon,theymaybeincludedinthedifferentialdiagnosisincasesofintestinalobstruction,especiallyintheabsenceofahistoryofabdominalsurgeryortrauma.CTfindingsofinternalherniasincludeevidenceofsmallbowelobstruction（SBO）;themostcommonmanifestationofinternalherniasisstrangulatingSBO,whichoccursafterclosed-loopobstruction.Therefore,inpatientssuspectedtohaveinternalhernias,earlysurgicalinterventionmaybeindicatedtoreducethehighmorbidityandmortalityrates.Inastudyof13casesofinternalhernias,ninedifferenttypesofinternalherniaswerefoundandthesurgicalandradiologicfindingswerecorrelated.ThefollowingfactorsmaybehelpfulinpreoperativediagnosisofinternalherniaswithCT:（a）knowledgeofthenormalanatomyoftheperitonealcavityandthecharacteristicanatomiclocationofeachtypeofinternalhernia;（b）observationofasaclikemassorclusterofdilatedsmallbowelloopsatanabnormalanatomiclocationinthepresenceofSBO;and（c）observationofanengorged,stretched,anddisplacedmesentericvascularpedicleandofconvergingvesselsatthehernialorifice.CT在急性腸梗阻的診斷和手術治療的準備中具有重要的價值。儘管腹內疝並不常見，但在腸梗阻病例的鑒別診斷中也需要排除這種可能，尤其是對那些沒有腹部手術史和創傷史的病例。腹內疝的CT表現包括小腸梗阻（SBO），腹內疝最常見的類型是絞窄性SBO，它發生在腸管的閉合梗阻之後，因此對懷疑腹內疝的病人要進行早期的手術探查，以降低其高發病率和高死亡率。一項對13例腹內疝的研究中發現有9種不同類型的腹內疝，手術中的表現和放射學的表現具有相關性。下列因素有助於CT預測診斷腹內疝：（a）了解腹腔正常的解剖和各型腹內疝的特徵解剖部位；（b）在SBO病人的異常解剖部位發現有囊狀團塊或小腸腸管擴張堆積；（c）觀察腸系膜血管蒂的充盈、伸展和移位情況，以及疝孔處的血管會聚情況。Introduction序論Internalherniasinvolveprotrusionoftheviscerathroughtheperitoneumormesenteryandintoacompartmentintheabdominalcavity.Themostcommonpresentationisanacuteintestinalobstructionofsmallbowelloopsthatdevelopsthroughnormalorabnormalapertures（1,2）.Theresponsiblehernialorificesareusuallypreexistinganatomicstructures,suchasforamina,recesses,andfossae.Pathologicdefectsofthemesenteryandvisceralperitoneum,whicharecausedbycongenitalmechanisms,surgery,trauma,inflammation,andcirculation,arealsopotentialherniationorifices（3,4）.腹內疝是腹腔內容物經腹膜或腸系膜凸入腹腔裂隙中，最常表現為小腸腸管進入正常或異常孔隙而導致腸梗阻，而疝孔通常是已經存在的解剖結構，比如裂孔、隱窩和陷凹，另外由先天性異常、手術、創傷、感染和循環異常導致腸系膜和臟層腹膜的病理性缺損也是潛在的疝孔。Preoperativediagnosisisdifficultbecauseclinicalsymptomsmayrangefromintermittentandmilddigestivecomplaintstoacute-onsetintestinalobstruction.Internalherniasaresilentiftheyareeasilyreducible,butthemajorityoftencauseepigastricdiscomfort,periumbilicalpain,andrecurrentepisodesofintestinalobstruction（3,5）.Internalherniasareclinicallyapparentonlywhenincarceratedinternalherniasresultfromsmallbowelobstruction（SBO）;therefore,adelayindiagnosismayleadtostrangulationandanincreasedriskofseriouscomplications.由於腹內疝的臨床癥狀的表現差別很大，可以是間歇性和輕度消化不適，也可以表現為急性發作的腸梗阻，所以術前診斷很困難。腹內疝如果易於復原則可以不表現癥狀，但絕大多數導致上腹不適、臍周疼痛和反覆發作的腸梗阻。腹內疝僅在小腸梗阻（SBO）發展到腹內疝嵌鈍才表現出明顯的臨床癥狀，因此，延誤診斷可導致腸絞窄並增加其他嚴重併發症的危險性。Wecategorizedvariousinternalherniasandpotentialorificeswithrelativefrequency（Table）onthebasisoftheirtopographicdistributionintheperitonealcavity（Figs1,2）accordingtotheclassificationofWelch（8）.我們按照Welch分類法對各種腹內疝和潛在疝孔及其發生頻率（表）根據其在腹腔內的分布區域（圖1，2）進行了分類。screen.width-333）this.width_=screen.width-333"width_=315height=176title="ClicktoviewfullT1.gif（315X176）"border=0align=absmiddle>*Pelvicherniasincludeherniasthroughthebroadligament,perirectalfossa,andfossaofDouglas.盆腔疝包括闊韌帶疝、直腸旁疝和Douglas窩疝。Therelativefrequencyofherniathroughthebroadligamentis4%C5%.闊韌帶疝的附屬頻率是4-5%。Figure1.Drawing（coronalview）showsthelocationsanddirectionsofinternalherniasoftheupperandlowerabdominalperitonealcavity.A=foramenofWinslowhernia,B=leftparaduodenalhernia,C=rightparaduodenalhernia,D=transmesenterichernia,E=pericecalhernia,F=transomentalhernia,G=intersigmoidhernia.（Adaptedandreprinted,withpermission,fromreference6.）圖1示意圖（冠狀面）顯示上腹腔和下腹腔腹內疝的部位和方向。A，Winslow孔疝；B，左側十二指腸旁疝；C，右側十二指腸旁疝；D，腸系膜疝；E，盲腸旁疝；F，網膜疝；G，乙狀結腸疝。screen.width-333）this.width_=screen.width-333"width_=450height=450title="ClicktoviewfullCTofInternalHernias_page2_image1.jpg（450X450）"border=0align=absmiddle>Figure2.Drawing（superiorview）showsthelocationsofinternalhernias,pouches,andfossaeofthepelviccavityinafemalepatient.H=supravesicalhernia,I=herniathroughthebroadligament,1=vesicouterinepouch,2=Douglas（rectouterine）pouch,3=perirectalfossa.（Adaptedandreprinted,withpermission,fromreference7.）圖2示意圖（上面觀）顯示女性患者盆腔腹內疝、隱窩和陷凹的部位。H，膀胱上疝；I，闊韌帶疝；1，膀胱子宮陷凹；2，子宮直腸陷凹；3，直腸旁窩。screen.width-333）this.width_=screen.width-333"width_=450height=300title="ClicktoviewfullCTofInternalHernias_page2_image2.jpg（450X300）"border=0align=absmiddle>Inthisarticle,wedescribeourclinicalexperiencewithinternalhernias,theimagingtechnique,anddiagnosiswithcomputedtomography（CT）,includingtheCTfindingsandtheirclinicalrelevanceaswellastheimportantroleofmultiCdetectorrowCT.Wethendiscussthelocationsandrelativefrequenciesofinternalhernias,whichincludeforamenofWinslow,paraduodenal,transmesenteric,transomental,pericecal,sigmoidmesocolon,andsupravesicalandpelvichernias.我們本文中描述了腹內疝及其顯像技術和CT診斷，包括CT表現和臨床相關性及其多層螺旋CT的重要性的臨床經驗，然後討論了腹內疝的部位和相關頻率，包括Winslow孔疝、十二指腸旁疝、腸系膜疝、網膜疝、盲腸旁疝、乙狀結腸系膜疝和膀胱上疝及盆腔疝。Inthesectionsoninternalhernias,wedescribetheanatomiclocationsandembryologicfeaturesofpotentialhernialorifices（foramina,fossae,recesses,defectsofthemesenteryandvisceralperitoneum）andtheclinical,surgical,andradiologicfindings,includingthecharacteristicCTappearances.WealsopresentCTimages,somesurgicalresults,andsomeintraoperativephotographs.Finally,webrieflydescribethemanagementofinternalhernias.在腹內疝章節，我們描述了潛在疝孔（腸系膜和臟層腹膜的裂孔、陷凹、隱窩和缺損）的解剖部位和胚胎學特徵和臨床、手術、影像學表現包括CT的特徵性表現，我們也列舉了一些CT圖像、手術結果和術中照片，最後我們簡要的描述了腹內疝的治療。ClinicalExperience臨床經驗FromNovember1995toFebruary2004,aretrospectivereviewofmedicalrecordsandradiologicimagesrevealed13patients（eightmale,fivefemale）withsurgicallyprovedinternalherniasatourinstitutionandbranchhospitals.Theiragerangedfrom12to86years（meanage,56.1years）withmorethanhalfofthepatientsoverage50years.AllpatientsexceptonewithclinicalandradiologicfindingssuggestiveofacuteintestinalobstructionunderwentsingledetectorrowCToftheabdomenandpelvisatthetimeofadmission.OnepatientunderwentCT4daysafterconservativetreatment.Fourpatientswithlow-gradeobstructionunderwententeroclysis,whichisparticularlyhelpfulindepictingandgradingtheseverityofpartialobstructionanddemonstratingsitesofincompleteobstruction.我們對1995年11月到2004年2月在我們機構和分院的醫療文件和影像學圖像進行了回顧性分析，發現13例經手術證實的腹內疝，其中8例男性，5例女性，年齡從12到86歲（平均年齡56.1歲），超過一半病人大於50歲。除1例病人外所有其他臨床和影像學表現懷疑急性腸梗阻的病人在住院時均進行了腹部和盆腔的單排CT掃描，一例病人在經過保守治療4天後進行了CT掃描；4例輕度梗阻的病人進行了腸道造影，這非常有助於對部分性腸梗阻進行描述和程度分級並顯示不完全梗阻的位置。CTexaminationswereperformedwiththefollowingimagingunits:ProSeedSA（GEHealthcareTechnologies,Waukesha,Wis）（n=7）;Hi-speedDXI（GEHealthcareTechnologies）（n=1）;TCT-700S（Toshiba,Tokyo,Japan）（n=1）;TCT-60A（Toshiba）（n=2）;andSCT-7000（Shimadzu,Kyoto,Japan）（n=2）.CT檢查設備包括：ProSeedSA（GEHealthcareTechnologies,Waukesha,Wis）（n=7）;Hi-speedDXI（GEHealthcareTechnologies）（n=1）;TCT-700S（Toshiba,Tokyo,Japan）（n=1）;TCT-60A（Toshiba）（n=2）;andSCT-7000（Shimadzu,Kyoto,Japan）（n=2）.Thedurationofsymptomsbeforehospitaladmissionrangedfromaslittleas3hourstoaslongas3months.TheintervalbetweenCTexaminationatthetimeofadmissionandsurgeryrangedfrom2hoursto20days.Sixpatientsunderwentemergencyoperationswithin7hoursofCTexamination.Fourpatientsweretreatedconservativelywithinsertionofanasogastrictubeoralongintestinaltubetodraintheintestinalfluid,butthesepatientsunderwentoperationswithin12C42hoursofCTexaminationbecauseofaggravatedsymptoms.Theremainingthreepatientsunderwentoperationswithin4C20daysafterCTexaminationsbecauseatfirsttheyweremakinggoodprogresswithconservativetreatmentbymeansofnasogastricorlongintestinaltubedecompression,buttheirsymptomsbecameaggravatedlittlebylittle.住院之前，病人的癥狀持續的時間少的3小時，多的達3個月。住院時CT檢查和手術的間隔範圍從2小時到20天。6例病人在CT檢查的7小時內就進行了急症手術。4例病人進行了保守治療包括經鼻胃管或腸管引流腸液，但由於病情惡化，在CT檢查後的12―42小時內進行了手術。其餘的3例病人在CT檢查4―20天後才進行手術，是由於起初經鼻胃管或腸管減壓保守治療效果較好，但後來癥狀漸漸惡化。Duringlaparotomyineachpatient,reductionoftheherniacontents,resectionofnecroticbowelloops,andprimaryanastomosis（enterostomyinonecase）wereperformed.Gangrenouschangesintheincarceratedbowelloopswerepresentinsevenpatients,andsixpatientshadviablebowelloops.Elevenpatientshadnohistoryofabdominalsurgeryortrauma.Onlytwopatientshadahistoryofappendectomy.手術中對每位病人的腸內容物進行複位，切除壞死腸管並進行基本吻合（1例進行了腸造漏術）。7例病人出現了絞窄腸管的壞疽性變，6例為存活腸管。11例病人沒有先前的腹部手術或外傷史，僅有2例病人曾有過闌尾切除病史。Nonspecificabdominalsymptomsofintestinalobstructionwereobservedinall13patients.Theseincludedsomedegreeofepigastricpain,abdominalpain,tenderness,abnormalbowelsounds,nausea,vomiting,andpalpationofamass.所有13例病人都有非特異性的腹部癥狀，包括不同程度的上腹疼痛、腹痛、壓痛、腸鳴音異常、噁心、嘔吐和捫及團塊。ImagingTechnique顯影技術Gastrointestinalstudiesenhancedwithintraluminalcontrastmaterial（barium-enhancedstudies,enteroclysis）andabdominalCTenableaccuratediagnosisofanytypeofinternalhernia（9,10）.Inmechanicalhigh-gradeSBO,smallbowelfollow-throughstudyhasalimitationinemergencyuse.EnteroclysiscanbeperformedmorequicklyandhasbeenshowntohavehighaccuracyintheevaluationofSBO,butiscontraindicatedinpatientswithhigh-gradeclosed-loopobstructionandinthosewithsuspectedhernialstrangulation（11）.Recently,CThasdemonstratedtheimportanceofpreoperativediagnosisofearlyorpartialobstructionandclosed-loopobstruction.胃腸造影（鋇劑增強檢查，腸道造影檢查）和腹部CT能準確的診斷各種類型的腹內疝。急診應用小腸通過試驗對診斷重度機械性SBO病例有一定難度。腸道造影術能更迅速地評價SBO，並有高度的準確性，但在重度閉合性梗阻和懷疑絞窄疝的病人中屬於禁忌。近來表明CT對術前診斷早期或部分性梗阻和閉合性梗阻具有重要的價值。InourCTexamination,intravenousadministrationofcontrastmaterialisessentialtodeterminethecauseofobstructionandidentifyanyassociatedhernialstrangulation.AllpatientsexceptoneunderwentCTperformedwith100mLofcontrastmaterialadministeredintravenouslyatarateof1C2mL/sec.Thedelaybetweenthestartofinjectionandimagingvariedbetween70and90seconds.Allimageswereacquiredwith7C10-mmcollimationandapitchof1.2C1.5.OnepatientunderwentnonenhancedCTbecauseshewasallergictothecontrastmaterial;CTimagesclearlydemonstratedthepresenceofstrangulatingbowelloopsasdiffusemesentericfluidandhaziness.在我們的CT檢查中靜脈應用造影劑對於明確梗阻的病因和分辨各種有關的疝性絞窄很有必要。除1例外，所有接受CT檢查的病人均靜脈注射造影劑100mL，1―2mL/s。開始注射和掃描之間延遲70-90秒。圖像厚7-10mm，旋距1.2-1.5。1例病人由於對造影劑過敏而進行非強化CT，CT圖像清晰的顯示腸管絞窄，瀰漫性的腸系膜積液並分界不清。BecauseofthedifficultyofpreoperativeCTdiagnosis,multiCdetectorrowCTmayplayanimportantrole.Currently,multiCdetectorrowtechnologyprovidessubstantialimprovementsinthequalityoftwo-andthree-dimensionalreformattedimages,whichhaveevolvedinadditiontotheaxialimages.ManyimagesobtainedwithmultiCdetectorrowCTareinterpretedatworkstationsbymanuallypagingupanddownorreformattingbymeansofhigh-qualitythree-dimensionalreformationtechniques,suchasmultiplanarreformation（MPR）,shadedsurfacedisplay（SSD）,volumerendering（VR）,andmaximumintensityprojection（MIP）.由於術前CT診斷困難，多層螺旋CT可提供重要的作用。當前，除了軸點陣圖像以外，多層螺旋CT技術在二維和三維圖像重建中提供了實質性的改進，在多排CT掃描的圖像可以在工作站一一瀏覽，並能以多種重建技術進行後處理，如多層面重建，表面重建，容積重建，及最大密度投影。MultiCdetectorrowCTwiththree-dimensionalreformattingataworkstationprovidesimportantadvantagesoverconventionalimagingmethodsinevaluationofthesmallintestineandsurroundingstructures（mesentery,mesentericvasculature,andperitonealcavity）.MultiCdetectorrowCTcanplayamoreactiveroleinidentificationofthesite,level,andcauseofSBO,includinginternalhernias（12,13）.多排螺旋CT可以在工作站重建圖像，在評價小腸及其周圍結構（腸系膜，腸系膜血管，及腹膜腔）方面比傳統像技術有了重大進步，在撿出SOB位置，水平及起因方面扮演可以更積極的角色。Oraladministrationofcontrastmaterialandwaterisnotnecessaryinviewofthepatients』severeconditionbecauseintraluminalfluidcollectedwithinanSBOsegmentalreadyservesasanaturalcontrastagent,demonstratingthebowelwallclearly（12,13）.Ontheotherhand,multiCdetectorrowCTcoupledwithadministrationofwaterandoralcontrastmaterialallowsthediagnosisofSBO.SomeinvestigatorsadvocateuseofCTenteroclysis,whichprovidesaflexiblemethodofviewingSBO（14）.病情嚴重的，不需要再口服造影劑和水，因為SBO段積聚的管腔內液體足以形成天然的對比，可以清晰的顯示腸壁。另一方面，多層螺旋CT和口服造影劑與水配合能診斷SBO。一些研究者主張使用CT腸造影術可以靈活的觀察SBO。DiagnosisofInternalHerniaswithCT腹內疝的CT診斷Becauseclinicaldiagnosisofinternalherniasisdifficult,imagingstudiesmayplayanimportantroleifaccurateandreliableCTfindingscanbeobtained.However,CTevaluationofanytypeofinternalherniaisrareintheradiologyliterature,exceptforafewreportsonparaduodenalandtransmesenterichernias.由於臨床診斷腹內疝很困難，如果能獲取準確可靠的CT圖像表現，那麼它就能起到重要的作用。然而，在放射文獻中除了有幾篇十二指腸旁疝和腸系膜疝的報道外，各種類型腹內疝的CT評估很少。ThemostcommoninternalherniaisstrangulatingSBO,whichoccursafteraclosed-loopobstruction.CTfindingsofinternalherniasincludeevidenceofSBO.Todiagnosethehernialstrangulation,manyresearchersstresstheimportanceofobservingtheconfigurationoftheobstructedloop,mesentericchanges,andtheenhancementpatternsofthebowelwall（15C19）.Inthisarticle,weevaluatetwocharacteristicCTfindings:bowelconfigurationandmesentericchanges.Theformerconsistsofasaclikemassorclusterofdilatedbowelloops.Thelatterconsistsofamesentericvascularpediclethatisengorged,stretched,anddisplaced;inaddition,thedilatedbowelloopshaveconvergingvesselsattheentranceofthehernialorifice,thusrevealingtheimpairedvenousdrainageandcontinuousinfluxofthearterialflow（1,3,9,10,15C19）.最常見的腹內疝是發生於閉合性梗阻後的絞窄性SBO，腹內疝的CT表現就包括SBO的存在。為了能診斷疝性絞窄，很多研究者強調要觀察梗阻腸管的形態、腸系膜的改變和腸管壁的增強模式。本文中我們對兩種特徵性的CT表現進行評價：腸管形態和腸系膜改變，前者包括擴張腸管囊性團塊或堆積，後者包括腸系膜血管蒂的充盈、伸展和移位。另外，在疝孔入口處的擴張腸管的血管匯聚，這可顯示受損的靜脈迴流和連續的動脈灌注。LocationsandRelativeFrequenciesofInternalHernias腹內疝的部位和相關發生頻率Theoccurrenceofabdominalinternalherniasisrare.Theyarereportedin0.2%C0.9%ofautopsies（2）andin0.5%C4.1%ofcasesofintestinalobstruction（3,8,20）.Thelocationsandrelativefrequenciesofinternalherniasareasfollows:paraduodenal,53%;pericecal,13%;foramenofWinslow,8%;transmesentericandtransmesocolic,8%;pelvicandsupravesical,6%;sigmoidmesocolon,6%;andtransomental,1%C4%（1C3,20,21）.腹內疝比較少見，屍檢發現率在0.2%―0.9%，腸梗阻病例中佔0.5%―4.1%。腹內疝的部位和相關發生頻率如下：十二指腸旁，53%；盲腸旁，13%；Winslow孔，8%；經腸系膜和結腸系膜，8%；盆腔和膀胱上，6%；乙狀結腸，6%；網膜，1%―4%。ForamenofWinslowHernia網膜孔疝Anatomy解剖ThelessersacandthegreaterperitonealcavitycommunicatethroughtheepiploicforamenofWinslow.Thispotentialopeningisa3-cmverticalslitsituatedbeneaththeupperpartoftherightborderofthelessersac,cephaladtotheduodenalbulbanddeeptotheliver（Fig1,A）.Thisforamenislocatedanteriortotheinferiorvenacavaandposteriortothehepatoduodenalligament,includingtheportalvein,commonbileduct,andhepaticartery（1C3,22）.網膜囊和腹膜腔通過網膜孔（Winslow孔）相通，這個潛在的孔為上下徑約3cm的縱形裂口，從網膜囊的右上緣開口，位於十二指腸球部的頭側和肝臟的深面（圖1，A）。網膜孔的後方是下腔靜脈，前方是肝十二指腸韌帶，其內包含門靜脈、膽總管和肝動脈。Features特徵ForamenofWinslowherniasmakeup8%ofallinternalhernias（1C3）.Theintestinalsegmentmostcommonlyinvolvedisthesmallintestine（60%C70%）.Theterminalileum,cecum,andascendingcolonareinvolvedatarateofabout25%C30%（1,2）.Herniasinvolvingthetransversecolon,omentum,andgallbladderarerare,althoughsomehavebeenreportedintheliterature.PredisposingfactorsincludeanenlargedforamenofWinslowandexcessivelymobileintestinalloopsduetoalongmesenteryorpersistenceoftheascendingmesocolonandanascendingcolonthatisnotfusedtotheparietalperitoneum（1C4,23C26）.網膜孔疝占腹內疝的8%，疝入的腸道一般是小腸（60%C70%），迴腸末端、盲腸和升結腸疝入的概率約25%C30%。疝入橫結腸、網膜和膽囊的概率很低，僅偶有文獻報道。網膜孔擴大，腸系膜過長或升結腸系膜殘存而致的腸襻活動度過大，以及升結腸沒有和壁層腹膜融合是易患因素。Characteristicplainradiographicfindingsaregas-containingintestinalloopshighintheabdomenandmedialandposteriortothestomachassociatedwithSBO（Fig3）.Thececumandascendingcolonmaybeabsentfromtheirusuallocationsiftheyarepartoftheherniatedviscera.Barium-enhancedradiographyofthesmallintestineshowsdilatationofbowelloopsandusuallyrevealstheobstructionattherightupperabdomen.Narrowingorobstructionatthehepaticflexuremaybevisualizedwithbariumenemaexaminationiftheherniainvolvesthececumandascendingcolon（23）.ThefollowingarethecharacteristicCTappearances:（a）presenceofmesenterybetweentheinferiorvenacavaandmainportalvein,（b）anair-fluidcollectioninthelessersacwithabeakdirectedtowardtheforamenofWinslow,（c）absenceoftheascendingcolonintherightgutter,and（d）twoormorebowelloopsinthehighsubhepaticspaces（1C3,24C26）.腹部平片的特徵是上腹部胃內側和後方發現與小腸梗阻有關的含氣性腸襻（圖3）。小腸鋇劑增強X線片顯示腸襻擴張，且通常在右上腹發現梗阻的部位。如果盲腸和升結腸是疝的內容物，則在正常位置不能找到它們，通過鋇劑灌腸可能在結腸肝曲發現狹窄或梗阻部位。CT的特徵表現如下：（a）下腔靜脈和門靜脈主幹之間發現腸系膜，（b）網膜囊內見朝網膜孔方向鳥嘴狀的液氣積聚，（c）右腹外側區不能找到升結腸，和（d）高位肝下見二段以上腸襻。Figure3.ForamenofWinslowherniaina45-year-oldmanwithacuteepigastricpainof18hoursduration.（a）Abdominalradiographshowsgas-containingsmallbowelloops（arrows）inthecenteroftheupperabdomenbetweentheliverandthegastricairbubble.（b）ImageobtainedwithenteroclysisperformedthroughalongintestinaltubeshowsanSBOattherighthepaticflexure（arrow）.（c）Contrast-enhancedCTscanoftheupperabdomenshowstheclusterofdilatedsmallbowelloops（arrowheads）inthelessersac.Therearestretchedandconvergingmesentericvessels（arrow）betweentheportalveininthehepatoduodenalligament（H）andtheinferiorvenacava（I）.（d）CTscanobtainedatthelevelofthepancreaticheadshowscrowdedmesentericvesselsfromthesuperiormesentericvein（arrow）betweentheascendingportionoftheduodenum（D）andthepancreatichead（P）.Arrowheads=smallbowelloops.Atlaparotomyperformed31hoursafterCT,adhesionbetweenthegastrocolicligamentandthetransversemesocolonwasfound.Approximately50cmofileum,located200cmfromtheligamentofTreitz,washerniatedintothelessersac.Theherniatedilealloopsdemonstratedonlycongestivechangeswithoutgangrene.圖3.一個45歲男性網膜孔疝，上痛持續18小時：（a）腹部X線片顯示中上腹肝與胃泡之間的含氣性小腸腸襻（箭頭）。（b）通過長的導管灌腸造影法顯示肝曲小腸梗阻（箭頭）。（c）上腹部CT增強掃描顯示網膜囊內擴張的簇狀腸襻。下腔靜脈（I）和肝十二指腸韌帶內的門靜脈（H）之間見拉長和會聚的腸系膜血管（箭頭）。（d）胰頭水平CT掃描顯示簇狀的腸系膜上靜脈（箭頭）位於十二指腸（D）升部和胰頭（P）之間。三角形箭頭示小腸腸襻。剖腹手術31小時後CT掃描，胃結腸韌帶和橫結腸系膜見粘連。手術證實距十二指腸懸韌帶200厘米處，大約50厘米長的迴腸疝入網膜囊，腸管僅見充血改變而無壞疽。screen.width-333）this.width_=screen.width-333"width_=640height=577title="ClicktoviewfullCTofInternalHernias_page5_image1.jpg（900X812）"border=0align=absmiddle>ParaduodenalHernia十二指腸旁疝Anatomy解剖Paraduodenalfossaeoriginateascongenitalperitonealanomaliesowingtofailureofmesentericfusionwiththeparietalperitoneumandanassociatedabnormalrotationduringimprisonmentofthesmallintestinebeneaththedevelopingcolon（1C3,22,27C33）.十二指腸旁隱窩的產生是由於先天性的腹膜異常，即腸系膜與壁層腹膜融合失敗，同時小腸在局限於整條結腸中間位置的發育過程中旋轉異常。Inthepast,ninedifferentfossaeinthevicinityoftheduodenumhavebeendescribed,butclinicallyjustfivefossaeareimportant:thesuperiorduodenalfossa,inferiorduodenalfossa（fossaofTreitz）,paraduodenalfossa（fossaofLandzert）,intermesocolicfossa（fossaofBroesike）,andmesentericoparietalfossa（fossaofWaldeyer）（27,28）.Figure4showsthelocationsofthesefossaeandtheirfrequenciesatautopsy.ThefossaofLandzert,presentinabout2%ofautopsies,isrecognizedasinducingleftparaduodenalhernia（PDH）.ThefossaofWaldeyer,presentinabout1%ofautopsies,isrecognizedasinducingrightPDH（22）.以前，文獻報道有9個十二指腸附近的隱窩，但臨床上僅5個比較重要，分別是十二指腸上隱窩、十二指腸下隱窩、十二指腸旁隱窩（Landzert隱窩）、結腸系膜間隱窩（Broesike隱窩）和空腸旁隱窩（Waldeyer隱窩）。圖4顯示了這些隱窩的位置和其屍檢的檢出率。Landzert隱窩屍檢的檢出率約2%，易引起左側十二指腸旁疝（PDH）。Waldeyer隱窩的屍檢檢出率約1%，易引起右側PDH。Figure4.Drawing（coronalview）showsthelocationsofduodenalfossae.Arrowsindicatethedirectionsofherniasthroughthesefossae.Thefrequencywithwhicheachfossaisfoundatautopsyisgiveninparentheses.1=superiorduodenalfossa（50%）,2=inferiorduodenalfossa（fossaofTreitz）（75%）,3=paraduodenalfossa（fossaofLandzert）（2%）,4=intermesocolicfossa（fossaofBroesike）,5=mesentericoparietalfossa（fossaofWaldeyer）（1%）.（Adaptedandreprinted,withpermission,fromreference6.）圖4.　彩圖（冠狀觀）顯示了十二指腸隱窩的位置。箭頭表示疝囊疝入這些隱窩的方向。圓括弧內是屍檢發現每個隱窩的檢出率。1＝十二指腸上隱窩（50%），2＝十二指腸下隱窩（即Treitz隱窩，75%），3＝十二指腸旁隱窩（Landzert隱窩（2%），4＝結腸系膜間隱窩（即Broesike隱窩），5＝空腸旁隱窩（Waldeyer隱窩，1%）。（經作者同意，改編和翻印自參考文獻6。）screen.width-333）this.width_=screen.width-333"width_=450height=451title="ClicktoviewfullCTofInternalHernias_page6_image1.jpg（450X451）"border=0align=absmiddle>Features特徵PDHsconstituteapproximately53%ofallinternalhernias.Approximatelythree-fourthsoftheseherniasoccurontheleftandaremorepredominantinmenthaninwomen,witharatioofabout3:1（1C3）.十二指腸旁疝占所有腹內疝的53%，大約四分之三發生於左側，男性比女性明顯好發，兩者的比率約3∶1。LeftPDHdevelopsthroughthefossaofLandzertintothedescendingmesocolonandleftofthetransversemesocolonandresultsfromfailureoffusionoftheinferiormesenterytotheparietalperitoneum（29）.ThefossaofLandzertislocatedattheduodenojejunaljunction,whichisazoneofconfluenceofthedescendingmesocolon,transversemesocolon,andsmallbowelmesentery（30）.Theherniatedsmallbowelloopsmaybecomeentrappedwithinthismesentericsac.ThecharacteristicCTappearanceconsistsofanabnormalclusterorsaclikemassofdilatedsmallbowelloopslyingbetweenthepancreasandstomachtotheleftoftheligamentofTreitz（Fig5）.Thereisusuallymasseffectthatdisplacestheposteriorwallofthestomach,theduodenalflexureinferiorly,andthetransversecoloninferiorly（30,31）.Themesentericvesselsthatsupplytheherniatedsmallbowelsegmentsarecrowded,engorged,andstretchedattheentranceofthehernialsac（Fig6）（9,10）.Becausetheanteriorwallofthesaccontainstheinferiormesentericveinandleftcolicartery,CTdemonstratesthesevesselsasalandmarkabovetheencapsulatedbowelloops.由於腸系膜與壁腹膜融合失敗，可發生左側十二指腸旁疝，臟器穿過Landzert隱窩進入降結腸系膜和左側橫結腸系膜。Landzert隱窩位於十二指腸與空腸的交接處，該處降結腸系膜、橫結腸系膜和小腸系膜發生融合，小腸會疝入這個腸系膜隱窩。CT表現的特徵是十二指腸懸韌帶左側，胰和胃之間見囊狀成簇擴張的小腸腸襻（圖5），並由於重力作用壓迫胃後壁、下方的十二指腸彎曲處和橫結腸。供應疝囊內小腸的腸系膜血管在疝囊入口處群集、充盈和拉長（圖6）。因為疝囊的前壁包含腸系膜下靜脈和左結腸動脈，所以這些血管可作為CT區分疝囊內外的腸管的界標。Figure5.LeftPDHina72-year-oldmanwithacute,intermittentepigastricpainof24hoursduration.（a）Contrast-enhancedCTscanoftheupperabdomenshowsasaclikemassofdilatedjejunalloopsbetweenthepancreatichead（P）andstomach.Thedescendingmesocolon（D）andstomacharedisplacedlaterally.Thedilatedinferiormesentericveinislocatedattheanteriorborderoftheencapsulatedloops.（b）CTscanobtained20mmbelowashowscrowdedandengorgedmesentericvessels（arrow）atthefossaofLandzert（L）.J=jejunalloops,S=stomach,arrowhead=inferiormesentericvein.（c）CTscanofthemidabdomenshowstheinferiormesentericvein（arrowhead）.Thisvesselisalandmarkfortheinferiormesocolon,whichislocatedattheanteromedialborderoftheencapsulatedjejunalloops（J）.（d）Diagram（coronalview）ofthesurgicalfindingsshowsthatthefossaofLandzertis4cmindiameter（arrowheads）.Atlaparotomyperformed42hoursafterCT,approximately200cmofviablejejunumwasfound（arrows）.圖5.　一例72歲男性左側十二指腸旁疝，陣發性劍突下劇痛24小時。（a）上腹部增強CT掃描顯示胰頭（P）和胃之間見囊狀成簇擴張的空腸，降結腸系膜和胃被推移到側方，擴張的腸系膜下靜脈是疝囊內腸襻的前界。（b）20mm下方CT顯示Landzert隱窩（L）群集和充盈的腸系膜血管（箭頭）。J=空腸，S=胃，箭頭=腸系膜下靜脈。（c）中腹部CT掃描腸系膜下靜脈（箭頭）。CT顯示了下腹部的結腸系膜血管，可作為疝囊的空腸腸襻（J）的前內側邊界界標。（d）CT檢查後42小時進行了剖腹手術，簡圖（冠狀觀）顯示Landzert隱窩長約4cm（三角形箭頭），疝囊內見長約200mm的存活空腸腸襻（長箭頭）。screen.width-333）this.width_=screen.width-333"width_=640height=465title="ClicktoviewfullCTofInternalHernias_page7_image1.jpg（900X654）"border=0align=absmiddle>Figure6.LeftPDHina55-year-oldwomanwhoexperiencedaggravatedepigastricpainfollowedby3monthsoffrequentandintermittentpain.（a）Contrast-enhancedCTscanoftheupperabdomenshowsasac-likemassofproximaljejunalloops（J）.Inthiscase,CTdidnotshowtheinferiormesentericvein,whichisalandmarkforleftPDH.（b）CTscanobtained30mmbelowashowsahorseshoelikeconfigurationofcollapsedjejunalloops（arrowheads）anddilatedmesentericvessels（arrow）betweenthepancreas（P）andstomach（S）withoutmasseffect.Atlaparotomyperformed7hoursafterCT,theherniatedjejunalloopswereviablewithnogangrene.圖6.　一例55歲女性左側十二指腸旁疝，間斷髮作的劍突下疼痛3個月，逐漸加重。（a）上腹部增強CT掃描顯示近段空腸（J）形成的囊狀包塊。這個病例沒有顯示腸系膜下靜脈。（b）以上層面往下30mm,CT顯示在沒有受壓變形的胰腺（P）與胃（S）之間，馬蹄形坍塌的空腸腸管（三角形箭頭）和擴張的腸系膜血管（長箭頭）。CT檢查後7小時進行了剖腹手術，發現疝囊內存活的空腸腸襻。screen.width-333）this.width_=screen.width-333"width_=640height=228title="ClicktoviewfullCTofInternalHernias_page7_image2.jpg（900X321）"border=0align=absmiddle>RightPDHinvolvesthefossaofWaldeyer,whichislocatedimmediatelybehindthesuperiormesentericarteryandinferiortothetransversesegmentoftheduodenumwithorwithoutrotationanomaly.RightPDHoccursmostfrequentlyincasesofanonrotatedsmallintestineandanormallyorincompletelyrotatedcolon.Accordingtotheextentofmalrotation,rightPDHisassociatedwithlocationofthesuperiormesentericveintotheleftof,andventralto,thesuperiormesentericarteryandwithabsenceofthenormalhorizontalduodenum.BecausethefossaofWaldeyerextendstotherightanddownward,directlyinfrontoftheposteriorparietalperitoneum,rightPDHdevelopsintotheascendingmesocolonwitharightcolicveinanteriorly.Thesuperiormesentericarteryandrightcolicveinarelocatedattheanterior-medialborderoftheencapsulatedsmallbowelloopsandarealandmarkforrightPDH（Fig7）（30）.右側十二指腸旁疝多涉及Waldeyer隱窩，該隱窩位於腸系膜上動脈後方，十二指腸水平部的下方，伴或不伴十二指腸旋轉異常。右側十二指腸旁疝患者小腸多未轉位，結腸多正常或不完全轉位。根據旋轉不良的程度不同，腸系膜上靜脈位於腸系膜上動脈的左側和前側，以及沒有正常十二指腸水平部。因為Waldeyer隱窩向右下方延伸，恰好在後腹膜前方，右側十二指腸旁疝穿過升結腸系膜達其後方，其前方是右側結腸靜脈。腸系膜上動脈和右結腸靜脈是疝囊內小腸腸襻的前中邊界，是右側十二指腸旁疝的界標。Figure7.RightPDHina31-year-oldmanwithsuddenonsetofseverediffuseabdominalpain.（a）Contrast-enhancedCTscanoftheupperabdomenshowsasaclikemassoffluid-filledbowelloops（S）,mostofwhichwerejejunalandproximalilealloops.（b）CTscanobtained30mmbelowashowstheencapsulatedbowelloopsherniatedthroughthefossaofWaldeyer（W）,whichislocatedbehindthesuperiormesentericartery（arrowhead）justbelowthetransverseportionoftheduodenum（D）.I=ilealloops.（c）CTscanofthelowerabdomenshowsthesuperiormesentericartery（arrowhead）,whichisdisplacedanteriorlybytheentrappedbowelloops.Dilatedandconvergingvessels（arrows）areseeninthemesentery;dilatedilealloops（I）areseenintheleftmidabdomen.（d）Diagram（coronalview）ofthesurgicalfindingsshowsthatthefossaofWaldeyer（lightgrayarea）is10cmindiameter.Atlaparotomyperformed2hoursafterCT,350cmofstrangulatedsmallintestine,located70cmfromtheligamentofTreitz,wasfound.Becausethewithdrawnbowelloopswerepurple,jejunostomywasperformedwithoutresection.圖7.　一例31歲男性右側十二指腸旁疝，突然發作的腹部瀰漫性疼痛史。（a）上腹部增強CT掃描顯示囊性包塊，內見充滿液體的腸襻（S），主要是空腸和近段迴腸腸襻。（b）30mm下方CT掃描顯示腸襻穿過Waldeyer隱窩（W）形成疝囊。疝囊位於腸系膜上動脈（箭頭）的後方，十二指腸水平部的下方（D）。I=迴腸腸襻。（c）下腹部CT掃描顯示疝囊內的腸襻推移腸系膜上動脈（三角形箭頭），使其前移。腸系膜內見擴張和群聚的血管（箭頭）。左中腹見擴張的迴腸襻（I）。（d）簡圖（冠狀觀）顯示了外科手術發現Waldeyer隱窩（淡灰色區域）長約10cm，該例於CT檢查後2小時進行了剖腹手術，術中發現從Treitz韌帶下70cm開始，350cm長的絞窄小腸腸襻。因為複位後的小腸呈紫色，所以沒有行切除術，而做了空腸造瘺術。screen.width-333）this.width_=screen.width-333"width_=640height=450title="ClicktoviewfullCTofInternalHernias_page8_image1.jpg（900X633）"border=0align=absmiddle>TransmesentericHernia腸系膜疝Anatomy解剖Thesmallbowelmesenteryisabroad,fan-shapedfoldofperitoneumthatsuspendstheloopsofthesmallintestinefromtheposteriorabdominalwall（1,22）.Thetwolayersofperitonealreflectionformthemesentery,whichextendsfromitsoriginattheligamentofTreitztotherighttowardtheileocecalvalve（Fig1,D）.小腸系膜是比較寬廣的扇形腹膜皺襞，將小腸腸管懸掛於後腹壁。腸系膜的兩層反折腹膜從Treitz韌帶起點向回盲瓣右側延伸。Nearly35%oftransmesentericherniasoccurduringthepediatricperiodandareprobablycausedbyacongenitalmechanism.Mesentericdefectsareusually2C5cmindiameterandarelocatedclosetotheligamentofTreitzortheileocecalvalve（2,3）.Threeetiologichypotheseshavebeenproposedforcongenitalmesentericdefects:（a）partialregressionofthedorsalmesentery,（b）fenestrationduringthedevelopmentalenlargementofaninadequatelyvascularizedarea,and（c）anileocecalmesenterywithconsiderableandrapidlengtheninginfetallife（32）.Inadults,mostmesentericdefectsareprobablytheresultofsurgery,trauma,orinflammation.近35%的腸系膜疝發生在兒童時期，可能是由於先天性原因導致。腸系膜上的缺損直徑通常在2-5cm，位於鄰近Treitz韌帶或回盲瓣處。有人提出3種先天性腸系膜缺損的可能病因：（a）背側腸系膜的部分退化；（b）乏血區的擴大導致裂孔形成；（c）回盲部腸系膜在胎兒期快速的延長。成人中大多數的腸系膜缺損可能是由於手術、創傷或感染導致。Features特徵Transmesentericandtransmesocolicherniasaccountfor8%ofallinternalhernias（1C3）.Becauseoftheabsenceofalimitinghernialsac,mechanicalSBOusuallyoccursincasesoftransmesenterichernia（Fig8）,anditisimpossibletodifferentiateclosed-loopobstructionscausedbyherniationthroughthemesentericdefectfromthosecausedbyprolapseoftheintestineunderadhesivebands.Avolvulusmayfurthercomplicatetheprocessandcauserapidhernialstrangulationandintestinalgangrene（Fig9）（1,3,32）.Atransmesentericherniausuallymanifestsinassociationwithproximalsmallboweldilatation,withatransitionzonetoanormalorcollapsedintestine.Becausethebowelmesentericdefectitselfisnotvisualized,observationoftheclusteringofsmallbowelloopsandabnormalitiesofthemesentericvesselsplaysanimportantroleindiagnosisoftransmesenterichernia.CTshowsthatthemesentericvascularpedicleischaracteristicallyengorged,stretched,andcrowded;inaddition,convergingmesentericvesselsarelocatedattheentranceofthehernialsac（34）andthereisdisplacementofthemainmesenterictrunk（9,10,32）.腸系膜疝和結腸系膜疝占所有腹內疝的8%。由於後者沒有局限性的疝囊，機械性SBO通常發生在腸系膜疝的病例中（圖8），而且不能區分經腸系膜缺損疝導致的閉合性腸梗阻與粘連帶下的腸脫垂導致的閉合性腸梗阻。腸扭轉是進一步的併發症，從而導致迅速的疝性絞窄和腸壞疽（圖9）。腸系膜疝通常顯示為近端小腸的擴張，與正常或塌陷腸管間存在過渡區。由於小腸系膜缺損本身不能顯示，堆積的小腸腸管的梗阻和腸系膜血管的異常是診斷腸系膜疝的重要所在。CT表現為特徵性的腸系膜血管蒂充盈、拉長和擁擠，另外，匯聚的腸系膜血管位於疝囊的入口處，腸系膜的主幹發生移位。Figure8.Transmesentericherniaina36-year-oldwomanwithlowerabdominalpainof10daysduration.Shewastreatedconservativelyfor20daysbymeansofdecompressionwithanasogastrictubeorlongintestinaltube,intravenousfluids,andantibioticsbecauseofanundiagnosedSBO.However,theSBOdevelopeddespitetreatment.（a）Contrast-enhancedCTscanofthemidabdomenshowsdilatedandfluid-filledsmallbowelloops（S）andcrowdedandstretchedvessels（arrow）.（b）CTscanofthepelvisshowscrowdedandconvergingvessels（arrow）atthehernialorifice.（c）ImageobtainedwithenteroclysisperformedthroughtheintestinaltubeshowstheSBO（arrow）.（d）Diagram（coronalview）ofthesurgicalfindingsshowsthatapproximately180cmofstrangulatedileum（arrows）,located5cmfromtheileocecalvalve,washerniatedthroughthemesentericdefect（arrowheads）.Atlaparotomy,asegmentofgangrenousileumwasresected.（e）Intraoperativephotographshowsthehernialorifice,whichisovaland4cmindiameter.圖8一36歲婦女的腸系膜疝，持續10天下腹痛。給予了20天的保守治療，包括經鼻胃管或腸管減壓、靜脈輸液和抗生素。然而儘管經過治療還是出現了SBO。（a）增強CT掃描顯示中腹部小腸腸管積液擴張（S），血管匯聚並拉長（箭頭）。（b）盆腔CT掃描顯示疝孔處的血管擁擠彙集（箭頭）。（c）經腸管行腸道造影的圖像顯示SBO（箭頭）。（d）手術所見的示意圖（冠狀面）顯示距回盲瓣5cm的迴腸有大約180cm發生絞窄，是經腸系膜上的缺損（短箭頭）導致的疝。術中將壞疽的迴腸段予以切除。（e）術中圖片顯示疝孔，呈卵圓形，直徑4cm。（縮略圖，點擊圖片鏈接看原圖）Figure9.Transmesentericherniaina12-year-oldgirlwhoexperienced36hoursofdiffuseabdominalpainandsuddendevelopmentofcramps.Abdominalexaminationshowedseveredistentionandtendernessatthemidabdomen.Laboratoryinvestigationsrevealedahemoglobinlevelof8.4g/dL.（a）NonenhancedCTscanofthemidabdomenshowsdiffusemesentericfluidandhaziness（arrows）andmildlydilatedsmallbowelloops.Theattenuationoftheintraluminalfluidisincreased（arrowheads）becauseredbloodcellsmayhavebeenreleasedinthelumen.Laparotomywasperformed12hoursafterCT.（b）Intraoperativephotographshowsthehernialorifice（arrow）,whichis3cmindiameter.Approximately260cmofsmallintestine,located100cmfromtheileocecalvalve,washerniatedthroughthemesentericdefectandtwisted360°;230cmwasgangrenousandwasthusresected.一12歲女孩的腸系膜疝，表現為瀰漫性腹疼36小時後突發絞疼。腹部檢查發現中腹部嚴重膨隆並且敏感。實驗室檢查發現血紅蛋白8.4g/dL。（a）中腹部非強化CT掃描顯示瀰漫性的腸系膜積液並模糊不清（箭頭），小腸腸管輕度擴張。由於紅細胞進入管腔內，腔內的積液衰減增加。CT檢查12小時後進行了手術。（b）術中圖片顯示疝孔（箭頭），直徑3cm。距回盲瓣100cm處的小腸約有260cm經腸系膜缺損疝出並旋轉360°，230cm的腸管發生壞疽並被切除。screen.width-333）this.width_=screen.width-333"width_=640height=228title="ClicktoviewfullCTofInternalHernias_page10_image1.jpg（900X321）"border=0align=absmiddle>TransomentalHernia網膜疝Transomentalherniasconstituteapproximately1%C4%ofallinternalhernias.Therearetwotypes:Inthefirsttype,herniationoccursthroughafreegreateromentum;thistypeismorecommon,andnosacispresent.Inthesecondtype,whichisrare,herniationintothelessersacoccursthroughthegastrocolicligament（33,35,36）.網膜疝約佔所有腹內疝的1-4%，分為兩型：第一種類型是經遊離的大網膜疝，這種類型比較常見，不存在疝囊；另一種類型很少見，是經胃結腸韌帶疝入一小囊內。Inthefirsttype,thehernialorificeonthegreateromentumislocatedintheperipherynearthefreeedge（Fig10）andisusuallyaslitlikeopeningfrom2to10cmindiameter（1C4,37）.Thecauseoftheomentaldefecthasnotbeenidentified,butithasbeensuggestedthatmosthaveacongenitalorigin,althoughinflammation,trauma,andcirculationmayalsocauseomentalperforations.Smallbowelloops,thececum,andthesigmoidcolonareinvolvedinthisdefect.Theclinicalandradiologicfindingsarealmostidenticaltothoseoftransmesenterichernias（Fig11）（1,3,38）.在第一種類型中，大網膜上的疝孔位於近遊離緣的外周，通常呈裂隙樣開口，直徑2-10cm。網膜缺損的原因不是很明確，儘管感染、創傷和循環異常也能導致網膜穿孔，但大多數有先天性的因素。這種缺損可累及小腸、盲腸和乙狀結腸。臨床和影像學表現和腸系膜疝的表現幾乎一樣（圖11）。Figure10.Transomentalherniaina76-year-oldwomanwitha6-dayhistoryoflowerabdominalpain.（a）Contrast-enhancedCTscanofthepelvisshowsaclusteroffluid-filledsmallbowelloops（arrowheads）withpoororabsentenhancementofbowelwallsadjacenttothemidabdominalwall.Themesentericvascularpedicle（arrow）,whichiscrowdedandengorgedwithvessels,isobservedatthehernialorifice.Laparotomywasperformed3hoursafterCT.（b）Diagram（coronalview）ofthesurgicalfindingsshowsthatthehernialorifice（arrow）isintheperipheryofthegreateromentum.（c）Intraoperativephotographshowsthehernialorifice（arrowhead）.Approximately80cmofileum,located70cmfromtheileocecalvalve,washerniatedthroughthedefect;55cmwasresectedduetogangrene（arrows）.圖10一76歲婦女的網膜疝，有下腹疼痛6天的病史。（a）盆腔增強造影CT顯示小腸積液堆積（短箭頭），鄰近中腹壁的小腸管壁輕度或沒有強化。疝孔處的腸系膜血管蒂（箭頭）擁擠，血管充盈。CT檢查3小時後進行了手術。（b）手術所見的示意圖（冠狀面）顯示疝孔（箭頭）位於大網膜的外周部。（c）術中圖片顯示疝孔（短箭頭）。距回盲瓣70cm的迴腸有約80cm經缺損疝出，55cm的腸管因為壞疽而被切除（箭頭）。screen.width-333）this.width_=screen.width-333"width_=640height=510title="Clicktoviewfull10.jpg（901X719）"border=0align=absmiddle>Figure11.Transomentalherniaina78-year-oldmanwithacuteepigastricpainof24hoursduration.Atadmission,thevitalsigns,laboratoryvalues,andresultsofphysicalexaminationwerenormalwiththeexceptionofmildepigastricpain.Onthesecondhospitalday,laboratoryinvestigationsshowedawhitebloodcellcountof20,300/mm3（20.3x109/L）.（a）Contrast-enhancedCTscanofthemidabdomenshowsdilatedandfluid-filledclosedbowelloops（S）surroundedbymassiveascites（arrowheads）.Engorgedandcrowdedmesentericvessels（arrow）areseenatthehernialorifice,whichisadjacenttotheabdominalwall.Laparotomywasperformed2hoursafterCT.（b）Diagram（coronalview）ofthesurgicalfindingsshowsthatthehernialorifice（arrow）is3cmindiameterwithafirmandfibrousedge.（c）Intraoperativephotographshowsapproximately90cmofgangrenousjejunalloops（arrows）,located120cmfromtheTreitzligament,whichwereresected.圖11一78歲男性患者的網膜疝，表現為持續24小時的急性上腹部疼痛，住院時的生命體征、實驗室檢查結果和體格檢查均正常，僅表現為中上腹疼痛。住院第二天，實驗室檢查發現白細胞計數20300/mm3（20.3×109/L）。（a）中腹部增強CT掃描顯示閉合腸管（S）積液擴張，周圍見大量腹水（短箭頭）。與腹壁相鄰的疝孔處可見腸系膜血管充盈擁擠（箭頭）。CT檢查後2小時進行了手術。（b）手術所見的示意圖（冠狀面）顯示疝孔直徑3cm（箭頭），其邊緣牢固呈纖維性。（c）術中圖片顯示距Treitz韌帶120cm的空腸有約90cm發生壞疽（箭頭），被手術切除。screen.width-333）this.width_=screen.width-333"width_=640height=576title="Clicktoviewfull11.jpg（824X742）"border=0align=absmiddle>PericecalHernia盲腸旁疝Anatomy解剖Embryologically,theanatomyofthececalandpericecalperitoneumisnotdetermineduntilthe5thfetalmonth,whenthemigrationofthemidgutiscomplete,withthececumfixedintherightcolicfossaandresorptionoftheperitonealsurfaces（39,40）.Fourdifferentpericecalrecessesformedbyfoldsoftheperitoneumhavebeenreported:thesuperiorileocecalrecess,inferiorileocecalrecess,retrocecalrecess,andparacolicsulci（Fig12）（3,39,40,42）.胚胎髮育中，胎兒5個月時盲腸和盲腸旁的腹膜解剖才明確，此時中腸移位完成，盲腸固定在右側結腸隱窩，重新附著腹膜面。據報道，根據腹膜皺襞將盲腸旁隱窩分為4個：回盲上隱窩、回盲下隱窩、盲腸後隱窩和結腸旁溝（圖12）。Figure12.Drawing（coronalview）showsthelocationsofpericecalrecesses.1=superiorileocecalrecess,2=inferiorileocecalrecess,3=retrocecalrecess,4=paracolicsulci.（Adaptedandreprinted,withpermission,fromreference41.）圖12示意圖顯示盲腸旁疝的部位。1，回盲上隱窩；2，回盲下隱窩；3，盲腸後隱窩；4，結腸旁溝。screen.width-333）this.width_=screen.width-333"width_=440height=297title="Clicktoviewfull12.jpg（440X297）"border=0align=absmiddle>Thesuperiorileocecalrecessisboundedinfrontbythevascularfoldofthececumandbehindbytheilealmesentery.Theinferiorileocecalrecessisboundedinfrontbytheileocecalfold,abovebytheposteriorilealsurfaceanditsmesentery,totherightbythececum,andbehindbytheuppermesoappendix（22）.Theretrocecalrecess,thelargestofthefourrecesses,isboundedanteriorlybytheposteriorwallofthececum,posteriorlybytheposteriorabdominalwall,superiorlybythereflectionofthevisceralperitoneumcoatingtheposteriorwallofthececum,andmediallyandlaterallybytwocecalfoldsoftheperitoneum（40）.Paracolicsulciarelateraldepressionsoftheperitoneuminvestingthececum.Theserecessesmaybeabsentorrarelyextendposteriortothececum,formingpocketslargeenoughtoadmitseveralfingers（42）.Furthermore,accordingtotheliterature（43,44）,supplementaryrecessesandfossaemaydevelopintheileocecalareabecauseofindividualvariationsintheprocessesofbowelrotationandperitonealfusion.Thesestructuresmayalsobecomehernialorifices.回盲上隱窩在盲腸血管襞前方和迴腸系膜的後方。回盲下隱窩在回盲襞前方和迴腸後表面及其系膜的下方，盲腸右側，闌尾上系膜的後方。盲腸後隱窩是四個隱窩中最大的，位於盲腸後壁的前面，後腹壁的後方，覆蓋盲腸後壁腹膜反折的上方，兩盲腸襞的中側方。結腸旁溝是腹膜側方圍繞盲腸的凹陷。這些隱窩不會或者很少向後延伸至盲腸，但其形成的「口袋」足以容納數只手指。另外，根據文獻報道，由於在腸管旋轉和腹膜融合過程中的個體差異，一些其他的附屬隱窩或陷窩可延伸到回盲區，這些結構也可變成疝孔Features特徵Pericecalherniasaccountfor13%ofallinternalhernias.Inmostcases,ilealloopsherniatethroughthedefectandoccupytherightparacolicgutter（Fig13）.ClinicaldiagnosisisdifficultbecauseclinicalsymptomsandphysicalexaminationusuallyindicateacuteSBO,butinchronicincarcerationdiagnosesareconfusedwithinflammatoryboweldisease,appendicealdisorders,orothercausesofSBO（4,39）.Inestablishingtheprecisepreoperativediagnosis,delayedradiographsfromasmallbowelseriesorbariumenemaexaminationsareconsideredtobehelpfulwhenthepatient』sconditionpermitstheseexaminations（1,3）.ThespecificCTappearanceofapericecalherniaisnotestablished,andtherearefewcasesintheliterature（40,42C44）.Inourtwocases,CTscansdemonstratedaclusteroffluid-filledsmallbowelloops（Fig14）locatedlateraltothececumandposteriortotheascendingcolon.Inaddition,abeakingappearanceindicativeoftetheringattheapertureoftheperitonealrecessanddilatationofsmallbowelloopswithatransitionzonewererevealed.OnthebasisoftheseCTfindings,pericecalherniacanbediagnosedwithhighcertainty（40）.盲腸旁疝占所有腹內疝的13%，大多數病例中迴腸經缺口疝出佔據右側結腸旁溝（圖13）。臨床的診斷有一定困難，儘管臨床的癥狀和體格檢查常可提示急性SBO，但在慢性絞窄時容易和炎性腸病、闌尾病變及其他原因引起的SBO相混淆。為了能做出準確的術前診斷，如果病人情況允許，進行小腸延遲X線檢查或鋇灌腸檢查可能會有幫助。盲腸旁疝的特異性CT表現還沒有確定，僅有幾篇相關的文獻報道。我們的這兩例，CT掃描顯示小腸堆集，腸管內液體積聚，位於盲腸的側方和升結腸的後方。另外，還顯示在腹膜隱窩裂隙處的鳥嘴征及其擴張的小腸腸管和過渡區。基於這些CT表現可以高度確定盲腸旁疝的診斷。Figure13.Pericecalherniathroughtheretrocecalrecessinan84-year-oldmanwithcolickyrightlowerquadrantpainandvomitingof48hoursduration.Heunderwentanappendectomyat54yearsofage.（a）Contrast-enhancedCTscanofthemidabdomenshowsaclusterofencapsulatedsmallbowelloops（arrowheads）inthelateralaspectoftherightparacolicgutterandbehindtheascendingcolon（A）.Dilatedandstretchedmesentericvessels（arrow）areseenwithinthecluster.（b）CTscanofthelowerabdomenshowsbeakingandcollapsedbowelloops（arrow）attheretrocecalrecess（arrowhead）.Theascendingcolon（A）isdisplacedanteriorly.Laparotomywasperformed12hoursafterCT.（c）Diagram（coronalview）ofthesurgicalfindingsshowsthatapproximately230cmofgangrenousjejunumandileum（arrows）,located120cmfromtheligamentofTreitz,washerniatedthroughtheretrocecalrecess（arrowheads）.Thegangrenousbowelloopswereresected.A=ascendingcolon.一84歲男性患者的經盲腸後隱窩的盲腸旁疝，表現為持續48小時的右下腹的疝氣痛和嘔吐。其54歲時曾進行過闌尾切除術。（a）中腹部的CT增強掃描顯示右側結腸旁溝側方和升結腸（A）後方的小腸堆集包繞（短箭頭），其內可見腸系膜血管擴張拉長（長箭頭）。（b）下腹部CT掃描顯示盲腸後隱窩（短箭頭）處腸管塌陷呈鳥嘴征（長箭頭）。升結腸（A）向前移位。CT掃描12小時後行剖腹術。（c）手術所見的示意圖（冠狀面）顯示距Treitz韌帶120cm的空腸和迴腸（長箭頭）有約230cm經盲腸後隱窩（短箭頭）疝出發生壞疽。壞疽腸管被手術切除。screen.width-333）this.width_=screen.width-333"width_=640height=517title="Clicktoviewfull13.jpg（900X728）"border=0align=absmiddle>Figure14.Pericecalherniathroughtheparacolicsulciinan86-year-oldmanwitha10-dayhistoryoflowerabdominalpainandvomiting.Heunderwentanappendectomyat56yearsofage.（a）Contrast-enhancedCTscanofthelowerabdomenshowsdilatedsmallbowelloops（S）andaclusteroffluid-filledsmallbowelloops（arrow）.Theascendingcolon（A）isdisplacedanteriorly,andascites（arrowhead）isseenintherightparacolicgutter.（b）CTscanofthepelvisshowsthatthebowelloopsoftheoralaspectoftheintestinearedilated（arrowhead）andthebowelloopsoftheanalaspectarecollapsed（arrow）.Laparotomywasperformed6hoursafterCT.（c）Diagram（coronalview）ofthesurgicalfindingsshowsthatapproximately20cmofstrangulatedileum（I）,located130cmfromtheileocecalvalve,washerniatedthrougha5-cm-diameterdefectoftheparacolicsulci（arrow）;10cmoftheincarceratedileumwasresectedduetogangrenouschanges.A=ascendingcolon.圖14一86歲男性患者的經結腸旁溝的盲腸旁疝，表現為持續10天的下腹疼痛和嘔吐。其56歲時曾進行過闌尾切除術。（a）下腹部的增強造影CT掃描顯示小腸（S）擴張積液並堆積（長箭頭），升結腸（A）向前移位，在右側結腸旁溝內可見腹水（短箭頭）。（b）盆腔CT掃描顯示近端腸管擴張（短箭頭），遠端腸管塌陷（長箭頭）。CT掃描6小時後行剖腹術。（c）手術所見的示意圖（冠狀面）顯示距回盲瓣30cm的迴腸（I）有約20cm經結腸旁溝上5cm的缺口（長箭頭）疝出發生絞窄，有10cm的絞窄迴腸因發生壞疽被手術切除。screen.width-333）this.width_=screen.width-333"width_=640height=520title="Clicktoviewfull14.jpg（900X732）"border=0align=absmiddle>SigmoidMesocolonHernia乙狀結腸系膜疝Anatomy解剖Thesigmoidmesocolonisaperitonealfoldattachingthesigmoidcolontothepelvicwall.Theapexisdividedneartheleftcommoniliacarteryandservesasapotentialsiteforaninternalhernia.Theintersigmoidfossa（Fig1,G）liesbehindthisapexoftheV-shapedparietalattachmentofthesigmoidmesocolon.Thispocketisfoundin65%ofautopsiesandvariesinsizefromadimpletoafossaadmittingthefifthfinger（1,3,22）.乙狀結腸系膜是固定乙狀結腸到骨盆壁的腹膜皺襞，其尖端在接近左側髂總動脈處分叉，成為潛在的腹內疝的部位。乙狀結腸間隱窩（圖1，G）就位於乙狀結腸系膜與壁附著的V形尖端的後面，屍檢中65%的可以發現這種隱窩存在，其大小從小的淺窩到可容五指的隱窩不等。Features特徵Sigmoidmesocolonherniasaccountfor6%ofallinternalhernias（1C3）andaredividedintothreecategories（45）:（a）intersigmoidhernia,（b）transmesosigmoidhernia,and（c）intermesosigmoidhernia.Becausepreoperativedifferentiationofthethreeherniatypesinvolvingthesigmoidmesocolonisoftendifficult,thediagnosisisconfirmedonlywithsurgicalmanagementinmostcases.Intersigmoidhernia,whichisthemostcommontype,isherniationintoacongenitalfossa,theintersigmoidfossa,situatedintheattachmentofthelateralaspectofthesigmoidmesocolon.Transmesosigmoidherniaisincarcerationofsmallbowelloopsthroughadefectinthesigmoidmesocolon.Thisdefectisovalandrangesindiameterfrom2to4cm（1,3,45,46）.Transmesosigmoidherniainvolvesbothlayersofthesigmoidmesenteryandallowsherniationofthesmallbowelloopstowardtheleftlowerabdomen,posterior-lateraltothesigmoidcolon.Thisherniaisdemonstratedtobewithoutanactualhernialsac（47,48）.Intramesosigmoidherniaisincarcerationwithahernialsacthroughacongenitaldefect,presentinonlyoneoftheconstituentleavesofthesigmoidmesentery（Fig15）（45）.乙狀結腸系膜疝占所有腹內疝的6%，可以分為3類：（a）乙狀結腸間疝；（b）經乙狀結腸系膜疝和（c）乙狀結腸系膜間疝。由於術前鑒別這三種累及乙狀結腸系膜的疝常常很困難，因此在絕大多數的病例中只有通過手術才能確診。乙狀結腸間疝是最常見的類型，是指疝入位於乙狀結腸系膜側方的先天性隱窩―乙狀結腸間隱窩。經乙狀結腸系膜疝是指經乙狀結腸系膜上的缺損的小腸的嵌頓，這種缺損呈口狀，直徑2-4cm。經乙狀結腸系膜疝穿過兩層乙狀結腸系膜，小腸腸管向左下腹乙狀結腸側後方疝出，這種疝被認為沒有急性的疝囊。乙狀結腸系膜間疝是指經乙狀結腸系膜僅僅只有一個葉，疝囊經過這個先天性的缺損導致的疝。Figure15.Intramesosigmoidherniaina79-year-oldmanwithacutelowerabdominalpainof3hoursduration.CTwasperformed4daysafterconservativetreatmentwithanasogastrictube.（a,b）Contrast-enhancedCTscansofthepelvis（bobtained20mmbelowa）showmultipledilatedsmallbowelloops（S）.Adilatedinferiormesentericvein（arrow）appearsasalandmarkattheedgeoftheinferiormesentery.Asaclikemassofincarceratedjejunalloops（arrowhead）islocatedanteriortotheleftpsoasmuscle.Laparotomywasperformed4daysafterCT.（c）Diagram（coronalview）ofthesurgicalfindingsshowsthat20cmofjejunum（J）,located230cmfromtheligamentofTreitz,washerniatedintoadefect（arrow）ontheleftsideofthesigmoidmesocolon.Thedefectwas3cmindiameterandwaslocatedintheanteriorlayeroftheleftsideofthesigmoidmesocolon.圖15一79歲男性患者的乙狀結腸系膜間疝，表現為急性的下腹部疼痛3小時。經鼻胃管保守治療4
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