【专题】腹内疝的影像诊断

提一点小建议，每一幅图像都应该打上体表标志的，存储图像时的举手之劳，用处很大的。看了以上的图片及文字内容，受益非浅。平时这种病例较少，一旦碰到难以作出诊断，现在心里有底了，谢谢！晕,这么好的病例,看不到!痛感谢samar和graceof两位版主参与翻译，感谢foxet版主校正。CTofInternalHernias腹内疝的CT诊断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在急性肠梗阻的诊断和手术治疗的准备中具有重要的价值。尽管腹内疝并不常见，但在肠梗阻病例的鉴别诊断中也需要排除这种可能，尤其是对那些没有腹部手术史和创伤史的病例。腹内疝的CT表现包括小肠梗阻（SBO），腹内疝最常见的类型是绞窄性SBO，它发生在肠管的闭合梗阻之后，因此对怀疑腹内疝的病人要进行早期的手术探查，以降低其高发病率和高死亡率。一项对13例腹内疝的研究中发现有9种不同类型的腹内疝，手术中的表现和放射学的表现具有相关性。下列因素有助于CT预测诊断腹内疝：（a）了解腹腔正常的解剖和各型腹内疝的特征解剖部位；（b）在SBO病人的异常解剖部位发现有囊状团块或小肠肠管扩张堆积；（c）观察肠系膜血管蒂的充盈、伸展和移位情况，以及疝孔处的血管会聚情况。Introduction序论Internalherniasinvolveprotrusionoftheviscerathroughtheperitoneumormesenteryandintoacompartmentintheabdominalcavity.Themostcommonpresentationisanacuteintestinalobstructionofsmallbowelloopsthatdevelopsthroughnormalorabnormalapertures（1,2）.Theresponsiblehernialorificesareusuallypreexistinganatomicstructures,suchasforamina,recesses,andfossae.Pathologicdefectsofthemesenteryandvisceralperitoneum,whicharecausedbycongenitalmechanisms,surgery,trauma,inflammation,andcirculation,arealsopotentialherniationorifices（3,4）.腹内疝是腹腔内容物经腹膜或肠系膜凸入腹腔裂隙中，最常表现为小肠肠管进入正常或异常孔隙而导致肠梗阻，而疝孔通常是已经存在的解剖结构，比如裂孔、隐窝和陷凹，另外由先天性异常、手术、创伤、感染和循环异常导致肠系膜和脏层腹膜的病理性缺损也是潜在的疝孔。Preoperativediagnosisisdifficultbecauseclinicalsymptomsmayrangefromintermittentandmilddigestivecomplaintstoacute-onsetintestinalobstruction.Internalherniasaresilentiftheyareeasilyreducible,butthemajorityoftencauseepigastricdiscomfort,periumbilicalpain,andrecurrentepisodesofintestinalobstruction（3,5）.Internalherniasareclinicallyapparentonlywhenincarceratedinternalherniasresultfromsmallbowelobstruction（SBO）;therefore,adelayindiagnosismayleadtostrangulationandanincreasedriskofseriouscomplications.由于腹内疝的临床症状的表现差别很大，可以是间歇性和轻度消化不适，也可以表现为急性发作的肠梗阻，所以术前诊断很困难。腹内疝如果易于复原则可以不表现症状，但绝大多数导致上腹不适、脐周疼痛和反复发作的肠梗阻。腹内疝仅在小肠梗阻（SBO）发展到腹内疝嵌钝才表现出明显的临床症状，因此，延误诊断可导致肠绞窄并增加其他严重并发症的危险性。Wecategorizedvariousinternalherniasandpotentialorificeswithrelativefrequency（Table）onthebasisoftheirtopographicdistributionintheperitonealcavity（Figs1,2）accordingtotheclassificationofWelch（8）.我们按照Welch分类法对各种腹内疝和潜在疝孔及其发生频率（表）根据其在腹腔内的分布区域（图1，2）进行了分类。screen.width-333）this.width=screen.width-333'width=315height=176title='ClicktoviewfullT1.gif（315X176）'border=0align=absmiddle>*Pelvicherniasincludeherniasthroughthebroadligament,perirectalfossa,andfossaofDouglas.盆腔疝包括阔韧带疝、直肠旁疝和Douglas窝疝。Therelativefrequencyofherniathroughthebroadligamentis4%C5%.阔韧带疝的附属频率是4-5%。Figure1.Drawing（coronalview）showsthelocationsanddirectionsofinternalherniasoftheupperandlowerabdominalperitonealcavity.A=foramenofWinslowhernia,B=leftparaduodenalhernia,C=rightparaduodenalhernia,D=transmesenterichernia,E=pericecalhernia,F=transomentalhernia,G=intersigmoidhernia.（Adaptedandreprinted,withpermission,fromreference6.）图1示意图（冠状面）显示上腹腔和下腹腔腹内疝的部位和方向。A，Winslow孔疝；B，左侧十二指肠旁疝；C，右侧十二指肠旁疝；D，肠系膜疝；E，盲肠旁疝；F，网膜疝；G，乙状结肠疝。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.）图2示意图（上面观）显示女性患者盆腔腹内疝、隐窝和陷凹的部位。H，膀胱上疝；I，阔韧带疝；1，膀胱子宫陷凹；2，子宫直肠陷凹；3，直肠旁窝。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.我们本文中描述了腹内疝及其显像技术和CT诊断，包括CT表现和临床相关性及其多层螺旋CT的重要性的临床经验，然后讨论了腹内疝的部位和相关频率，包括Winslow孔疝、十二指肠旁疝、肠系膜疝、网膜疝、盲肠旁疝、乙状结肠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.在腹内疝章节，我们描述了潜在疝孔（肠系膜和脏层腹膜的裂孔、陷凹、隐窝和缺损）的解剖部位和胚胎学特征和临床、手术、影像学表现包括CT的特征性表现，我们也列举了一些CT图像、手术结果和术中照片，最后我们简要的描述了腹内疝的治疗。ClinicalExperience临床经验FromNovember1995toFebruary2004,aretrospectivereviewofmedicalrecordsandradiologicimagesrevealed13patients（eightmale,fivefemale）withsurgicallyprovedinternalherniasatourinstitutionandbranchhospitals.Theiragerangedfrom12to86years（meanage,56.1years）withmorethanhalfofthepatientsoverage50years.AllpatientsexceptonewithclinicalandradiologicfindingssuggestiveofacuteintestinalobstructionunderwentsingledetectorrowCToftheabdomenandpelvisatthetimeofadmission.OnepatientunderwentCT4daysafterconservativetreatment.Fourpatientswithlow-gradeobstructionunderwententeroclysis,whichisparticularlyhelpfulindepictingandgradingtheseverityofpartialobstructionanddemonstratingsitesofincompleteobstruction.我们对1995年11月到2004年2月在我们机构和分院的医疗文件和影像学图像进行了回顾性分析，发现13例经手术证实的腹内疝，其中8例男性，5例女性，年龄从12到86岁（平均年龄56.1岁），超过一半病人大于50岁。除1例病人外所有其他临床和影像学表现怀疑急性肠梗阻的病人在住院时均进行了腹部和盆腔的单排CT扫描，一例病人在经过保守治疗4天后进行了CT扫描；4例轻度梗阻的病人进行了肠道造影，这非常有助于对部分性肠梗阻进行描述和程度分级并显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检查设备包括：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，病人的症状持续的时间少的3小时，多的达3个月。住院时CT检查和手术的间隔范围从2小时到20天。6例病人在CT检查的7小时内就进行了急症手术。4例病人进行了保守治疗包括经鼻胃管或肠管引流肠液，但由于病情恶化，在CT检查后的12―42小时内进行了手术。其余的3例病人在CT检查4―20天后才进行手术，是由于起初经鼻胃管或肠管减压保守治疗效果较好，但后来症状渐渐恶化。Duringlaparotomyineachpatient,reductionoftheherniacontents,resectionofnecroticbowelloops,andprimaryanastomosis（enterostomyinonecase）wereperformed.Gangrenouschangesintheincarceratedbowelloopswerepresentinsevenpatients,andsixpatientshadviablebowelloops.Elevenpatientshadnohistoryofabdominalsurgeryortrauma.Onlytwopatientshadahistoryofappendectomy.手术中对每位病人的肠内容物进行复位，切除坏死肠管并进行基本吻合（1例进行了肠造漏术）。7例病人出现了绞窄肠管的坏疽性变，6例为存活肠管。11例病人没有先前的腹部手术或外伤史，仅有2例病人曾有过阑尾切除病史。Nonspecificabdominalsymptomsofintestinalobstructionwereobservedinall13patients.Theseincludedsomedegreeofepigastricpain,abdominalpain,tenderness,abnormalbowelsounds,nausea,vomiting,andpalpationofamass.所有13例病人都有非特异性的腹部症状，包括不同程度的上腹疼痛、腹痛、压痛、肠鸣音异常、恶心、呕吐和扪及团块。ImagingTechnique显影技术Gastrointestinalstudiesenhancedwithintraluminalcontrastmaterial（barium-enhancedstudies,enteroclysis）andabdominalCTenableaccuratediagnosisofanytypeofinternalhernia（9,10）.Inmechanicalhigh-gradeSBO,smallbowelfollow-throughstudyhasalimitationinemergencyuse.EnteroclysiscanbeperformedmorequicklyandhasbeenshowntohavehighaccuracyintheevaluationofSBO,butiscontraindicatedinpatientswithhigh-gradeclosed-loopobstructionandinthosewithsuspectedhernialstrangulation（11）.Recently,CThasdemonstratedtheimportanceofpreoperativediagnosisofearlyorpartialobstructionandclosed-loopobstruction.胃肠造影（钡剂增强检查，肠道造影检查）和腹部CT能准确的诊断各种类型的腹内疝。急诊应用小肠通过试验对诊断重度机械性SBO病例有一定难度。肠道造影术能更迅速地评价SBO，并有高度的准确性，但在重度闭合性梗阻和怀疑绞窄疝的病人中属于禁忌。近来表明CT对术前诊断早期或部分性梗阻和闭合性梗阻具有重要的价值。InourCTexamination,intravenousadministrationofcontrastmaterialisessentialtodeterminethecauseofobstructionandidentifyanyassociatedhernialstrangulation.AllpatientsexceptoneunderwentCTperformedwith100mLofcontrastmaterialadministeredintravenouslyatarateof1C2mL/sec.Thedelaybetweenthestartofinjectionandimagingvariedbetween70and90seconds.Allimageswereacquiredwith7C10-mmcollimationandapitchof1.2C1.5.OnepatientunderwentnonenhancedCTbecauseshewasallergictothecontrastmaterial;CTimagesclearlydemonstratedthepresenceofstrangulatingbowelloopsasdiffusemesentericfluidandhaziness.在我们的CT检查中静脉应用造影剂对于明确梗阻的病因和分辨各种有关的疝性绞窄很有必要。除1例外，所有接受CT检查的病人均静脉注射造影剂100mL，1―2mL/s。开始注射和扫描之间延迟70-90秒。图像厚7-10mm，旋距1.2-1.5。1例病人由于对造影剂过敏而进行非强化CT，CT图像清晰的显示肠管绞窄，弥漫性的肠系膜积液并分界不清。BecauseofthedifficultyofpreoperativeCTdiagnosis,multiCdetectorrowCTmayplayanimportantrole.Currently,multiCdetectorrowtechnologyprovidessubstantialimprovementsinthequalityoftwo-andthree-dimensionalreformattedimages,whichhaveevolvedinadditiontotheaxialimages.ManyimagesobtainedwithmultiCdetectorrowCTareinterpretedatworkstationsbymanuallypagingupanddownorreformattingbymeansofhigh-qualitythree-dimensionalreformationtechniques,suchasmultiplanarreformation（MPR）,shadedsurfacedisplay（SSD）,volumerendering（VR）,andmaximumintensityprojection（MIP）.由于术前CT诊断困难，多层螺旋CT可提供重要的作用。当前，除了轴位图像以外，多层螺旋CT技术在二维和三维图像重建中提供了实质性的改进，在多排CT扫描的图像可以在工作站一一浏览，并能以多种重建技术进行后处理，如多层面重建，表面重建，容积重建，及最大密度投影。MultiCdetectorrowCTwiththree-dimensionalreformattingataworkstationprovidesimportantadvantagesoverconventionalimagingmethodsinevaluationofthesmallintestineandsurroundingstructures（mesentery,mesentericvasculature,andperitonealcavity）.MultiCdetectorrowCTcanplayamoreactiveroleinidentificationofthesite,level,andcauseofSBO,includinginternalhernias（12,13）.多排螺旋CT可以在工作站重建图像，在评价小肠及其周围结构（肠系膜，肠系膜血管，及腹膜腔）方面比传统像技术有了重大进步，在捡出SOB位置，水平及起因方面扮演可以更积极的角色。Oraladministrationofcontrastmaterialandwaterisnotnecessaryinviewofthepatients’severeconditionbecauseintraluminalfluidcollectedwithinanSBOsegmentalreadyservesasanaturalcontrastagent,demonstratingthebowelwallclearly（12,13）.Ontheotherhand,multiCdetectorrowCTcoupledwithadministrationofwaterandoralcontrastmaterialallowsthediagnosisofSBO.SomeinvestigatorsadvocateuseofCTenteroclysis,whichprovidesaflexiblemethodofviewingSBO（14）.病情严重的，不需要再口服造影剂和水，因为SBO段积聚的管腔内液体足以形成天然的对比，可以清晰的显示肠壁。另一方面，多层螺旋CT和口服造影剂与水配合能诊断SBO。一些研究者主张使用CT肠造影术可以灵活的观察SBO。DiagnosisofInternalHerniaswithCT腹内疝的CT诊断Becauseclinicaldiagnosisofinternalherniasisdifficult,imagingstudiesmayplayanimportantroleifaccurateandreliableCTfindingscanbeobtained.However,CTevaluationofanytypeofinternalherniaisrareintheradiologyliterature,exceptforafewreportsonparaduodenalandtransmesenterichernias.由于临床诊断腹内疝很困难，如果能获取准确可靠的CT图像表现，那么它就能起到重要的作用。然而，在放射文献中除了有几篇十二指肠旁疝和肠系膜疝的报道外，各种类型腹内疝的CT评估很少。ThemostcommoninternalherniaisstrangulatingSBO,whichoccursafteraclosed-loopobstruction.CTfindingsofinternalherniasincludeevidenceofSBO.Todiagnosethehernialstrangulation,manyresearchersstresstheimportanceofobservingtheconfigurationoftheobstructedloop,mesentericchanges,andtheenhancementpatternsofthebowelwall（15C19）.Inthisarticle,weevaluatetwocharacteristicCTfindings:bowelconfigurationandmesentericchanges.Theformerconsistsofasaclikemassorclusterofdilatedbowelloops.Thelatterconsistsofamesentericvascularpediclethatisengorged,stretched,anddisplaced;inaddition,thedilatedbowelloopshaveconvergingvesselsattheentranceofthehernialorifice,thusrevealingtheimpairedvenousdrainageandcontinuousinfluxofthearterialflow（1,3,9,10,15C19）.最常见的腹内疝是发生于闭合性梗阻后的绞窄性SBO，腹内疝的CT表现就包括SBO的存在。为了能诊断疝性绞窄，很多研究者强调要观察梗阻肠管的形态、肠系膜的改变和肠管壁的增强模式。本文中我们对两种特征性的CT表现进行评价：肠管形态和肠系膜改变，前者包括扩张肠管囊性团块或堆积，后者包括肠系膜血管蒂的充盈、伸展和移位。另外，在疝孔入口处的扩张肠管的血管汇聚，这可显示受损的静脉回流和连续的动脉灌注。LocationsandRelativeFrequenciesofInternalHernias腹内疝的部位和相关发生频率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）.腹内疝比较少见，尸检发现率在0.2%―0.9%，肠梗阻病例中占0.5%―4.1%。腹内疝的部位和相关发生频率如下：十二指肠旁，53%；盲肠旁，13%；Winslow孔，8%；经肠系膜和结肠系膜，8%；盆腔和膀胱上，6%；乙状结肠，6%；网膜，1%―4%。ForamenofWinslowHernia网膜孔疝Anatomy解剖ThelessersacandthegreaterperitonealcavitycommunicatethroughtheepiploicforamenofWinslow.Thispotentialopeningisa3-cmverticalslitsituatedbeneaththeupperpartoftherightborderofthelessersac,cephaladtotheduodenalbulbanddeeptotheliver（Fig1,A）.Thisforamenislocatedanteriortotheinferiorvenacavaandposteriortothehepatoduodenalligament,includingtheportalvein,commonbileduct,andhepaticartery（1C3,22）.网膜囊和腹膜腔通过网膜孔（Winslow孔）相通，这个潜在的孔为上下径约3cm的纵形裂口，从网膜囊的右上缘开口，位于十二指肠球部的头侧和肝脏的深面（图1，A）。网膜孔的后方是下腔静脉，前方是肝十二指肠韧带，其内包含门静脉、胆总管和肝动脉。Features特征ForamenofWinslowherniasmakeup8%ofallinternalhernias（1C3）.Theintestinalsegmentmostcommonlyinvolvedisthesmallintestine（60%C70%）.Theterminalileum,cecum,andascendingcolonareinvolvedatarateofabout25%C30%（1,2）.Herniasinvolvingthetransversecolon,omentum,andgallbladderarerare,althoughsomehavebeenreportedintheliterature.PredisposingfactorsincludeanenlargedforamenofWinslowandexcessivelymobileintestinalloopsduetoalongmesenteryorpersistenceoftheascendingmesocolonandanascendingcolonthatisnotfusedtotheparietalperitoneum（1C4,23C26）.网膜孔疝占腹内疝的8%，疝入的肠道一般是小肠（60%C70%），回肠末端、盲肠和升结肠疝入的概率约25%C30%。疝入横结肠、网膜和胆囊的概率很低，仅偶有文献报道。网膜孔扩大，肠系膜过长或升结肠系膜残存而致的肠襻活动度过大，以及升结肠没有和壁层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）.腹部平片的特征是上腹部胃内侧和后方发现与小肠梗阻有关的含气性肠襻（图3）。小肠钡剂增强X线片显示肠襻扩张，且通常在右上腹发现梗阻的部位。如果盲肠和升结肠是疝的内容物，则在正常位置不能找到它们，通过钡剂灌肠可能在结肠肝曲发现狭窄或梗阻部位。CT的特征表现如下：（a）下腔静脉和门静脉主干之间发现肠系膜，（b）网膜囊内见朝网膜孔方向鸟嘴状的液气积聚，（c）右腹外侧区不能找到升结肠，和（d）高位肝下见二段以上肠襻。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.图3.一个45岁男性网膜孔疝，上痛持续18小时：（a）腹部X线片显示中上腹肝与胃泡之间的含气性小肠肠襻（箭头）。（b）通过长的导管灌肠造影法显示肝曲小肠梗阻（箭头）。（c）上腹部CT增强扫描显示网膜囊内扩张的簇状肠襻。下腔静脉（I）和肝十二指肠韧带内的门静脉（H）之间见拉长和会聚的肠系膜血管（箭头）。（d）胰头水平CT扫描显示簇状的肠系膜上静脉（箭头）位于十二指肠（D）升部和胰头（P）之间。三角形箭头示小肠肠襻。剖腹手术31小时后CT扫描，胃结肠韧带和横结肠系膜见粘连。手术证实距十二指肠悬韧带200厘米处，大约50厘米长的回肠疝入网膜囊，肠管仅见充血改变而无坏疽。screen.width-333）this.width=screen.width-333'width=640height=577title='ClicktoviewfullCTofInternalHernias_page5_image1.jpg（900X812）'border=0align=absmiddle>ParaduodenalHernia十二指肠旁疝Anatomy解剖Paraduodenalfossaeoriginateascongenitalperitonealanomaliesowingtofailureofmesentericfusionwiththeparietalperitoneumandanassociatedabnormalrotationduringimprisonmentofthesmallintestinebeneaththedevelopingcolon（1C3,22,27C33）.十二指肠旁隐窝的产生是由于先天性的腹膜异常，即肠系膜与壁层腹膜融合失败，同时小肠在局限于整条结肠中间位置的发育过程中旋转异常。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，文献报道有9个十二指肠附近的隐窝，但临床上仅5个比较重要，分别是十二指肠上隐窝、十二指肠下隐窝、十二指肠旁隐窝（Landzert隐窝）、结肠系膜间隐窝（Broesike隐窝）和空肠旁隐窝（Waldeyer隐窝）。图4显示了这些隐窝的位置和其尸检的检出率。Landzert隐窝尸检的检出率约2%，易引起左侧十二指肠旁疝（PDH）。Waldeyer隐窝的尸检检出率约1%，易引起右侧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.）图4.　彩图（冠状观）显示了十二指肠隐窝的位置。箭头表示疝囊疝入这些隐窝的方向。圆括号内是尸检发现每个隐窝的检出率。1＝十二指肠上隐窝（50%），2＝十二指肠下隐窝（即Treitz隐窝，75%），3＝十二指肠旁隐窝（Landzert隐窝（2%），4＝结肠系膜间隐窝（即Broesike隐窝），5＝空肠旁隐窝（Waldeyer隐窝，1%）。（经作者同意，改编和翻印自参考文献6。）screen.width-333）this.width=screen.width-333'width=450height=451title='ClicktoviewfullCTofInternalHernias_page6_image1.jpg（450X451）'border=0align=absmiddle>Features特征PDHsconstituteapproximately53%ofallinternalhernias.Approximatelythree-fourthsoftheseherniasoccurontheleftandaremorepredominantinmenthaninwomen,witharatioofabout3:1（1C3）.十二指肠旁疝占所有腹内疝的53%，大约四分之三发生于左侧，男性比女性明显好发，两者的比率约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.由于肠系膜与壁腹膜融合失败，可发生左侧十二指肠旁疝，脏器穿过Landzert隐窝进入降结肠系膜和左侧横结肠系膜。Landzert隐窝位于十二指肠与空肠的交接处，该处降结肠系膜、横结肠系膜和小肠系膜发生融合，小肠会疝入这个肠系膜隐窝。CT表现的特征是十二指肠悬韧带左侧，胰和胃之间见囊状成簇扩张的小肠肠襻（图5），并由于重力作用压迫胃后壁、下方的十二指肠弯曲处和横结肠。供应疝囊内小肠的肠系膜血管在疝囊入口处群集、充盈和拉长（图6）。因为疝囊的前壁包含肠系膜下静脉和左结肠动脉，所以这些血管可作为CT区分疝囊内外的肠管的界标。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）.图5.　一例72岁男性左侧十二指肠旁疝，阵发性剑突下剧痛24小时。（a）上腹部增强CT扫描显示胰头（P）和胃之间见囊状成簇扩张的空肠，降结肠系膜和胃被推移到侧方，扩张的肠系膜下静脉是疝囊内肠襻的前界。（b）20mm下方CT显示Landzert隐窝（L）群集和充盈的肠系膜血管（箭头）。J=空肠，S=胃，箭头=肠系膜下静脉。（c）中腹部CT扫描肠系膜下静脉（箭头）。CT显示了下腹部的结肠系膜血管，可作为疝囊的空肠肠襻（J）的前内侧边界界标。（d）CT检查后42小时进行了剖腹手术，简图（冠状观）显示Landzert隐窝长约4cm（三角形箭头），疝囊内见长约200mm的存活空肠肠襻（长箭头）。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.图6.　一例55岁女性左侧十二指肠旁疝，间断发作的剑突下疼痛3个月，逐渐加重。（a）上腹部增强CT扫描显示近段空肠（J）形成的囊状包块。这个病例没有显示肠系膜下静脉。（b）以上层面往下30mm,CT显示在没有受压变形的胰腺（P）与胃（S）之间，马蹄形坍塌的空肠肠管（三角形箭头）和扩张的肠系膜血管（长箭头）。CT检查后7小时进行了剖腹手术，发现疝囊内存活的空肠肠襻。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）.右侧十二指肠旁疝多涉及Waldeyer隐窝，该隐窝位于肠系膜上动脉后方，十二指肠水平部的下方，伴或不伴十二指肠旋转异常。右侧十二指肠旁疝患者小肠多未转位，结肠多正常或不完全转位。根据旋转不良的程度不同，肠系膜上静脉位于肠系膜上动脉的左侧和前侧，以及没有正常十二指肠水平部。因为Waldeyer隐窝向右下方延伸，恰好在后腹膜前方，右侧十二指肠旁疝穿过升结肠系膜达其后方，其前方是右侧结肠静脉。肠系膜上动脉和右结肠静脉是疝囊内小肠肠襻的前中边界，是右侧十二指肠旁疝的界标。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.图7.　一例31岁男性右侧十二指肠旁疝，突然发作的腹部弥漫性疼痛史。（a）上腹部增强CT扫描显示囊性包块，内见充满液体的肠襻（S），主要是空肠和近段回肠肠襻。（b）30mm下方CT扫描显示肠襻穿过Waldeyer隐窝（W）形成疝囊。疝囊位于肠系膜上动脉（箭头）的后方，十二指肠水平部的下方（D）。I=回肠肠襻。（c）下腹部CT扫描显示疝囊内的肠襻推移肠系膜上动脉（三角形箭头），使其前移。肠系膜内见扩张和群聚的血管（箭头）。左中腹见扩张的回肠襻（I）。（d）简图（冠状观）显示了外科手术发现Waldeyer隐窝（淡灰色区域）长约10cm，该例于CT检查后2小时进行了剖腹手术，术中发现从Treitz韧带下70cm开始，350cm长的绞窄小肠肠襻。因为复位后的小肠呈紫色，所以没有行切除术，而做了空肠造瘘术。screen.width-333）this.width=screen.width-333'width=640height=450title='ClicktoviewfullCTofInternalHernias_page8_image1.jpg（900X633）'border=0align=absmiddle>TransmesentericHernia肠系膜疝Anatomy解剖Thesmallbowelmesenteryisabroad,fan-shapedfoldofperitoneumthatsuspendstheloopsofthesmallintestinefromtheposteriorabdominalwall（1,22）.Thetwolayersofperitonealreflectionformthemesentery,whichextendsfromitsoriginattheligamentofTreitztotherighttowardtheileocecalvalve（Fig1,D）.小肠系膜是比较宽广的扇形腹膜皱襞，将小肠肠管悬挂于后腹壁。肠系膜的两层反折腹膜从Treitz韧带起点向回盲瓣右侧延伸。Nearly35%oftransmesentericherniasoccurduringthepediatricperiodandareprobablycausedbyacongenitalmechanism.Mesentericdefectsareusually2C5cmindiameterandarelocatedclosetotheligamentofTreitzortheileocecalvalve（2,3）.Threeetiologichypotheseshavebeenproposedforcongenitalmesentericdefects:（a）partialregressionofthedorsalmesentery,（b）fenestrationduringthedevelopmentalenlargementofaninadequatelyvascularizedarea,and（c）anileocecalmesenterywithconsiderableandrapidlengtheninginfetallife（32）.Inadults,mostmesentericdefectsareprobablytheresultofsurgery,trauma,orinflammation.近35%的肠系膜疝发生在儿童时期，可能是由于先天性原因导致。肠系膜上的缺损直径通常在2-5cm，位于邻近Treitz韧带或回盲瓣处。有人提出3种先天性肠系膜缺损的可能病因：（a）背侧肠系膜的部分退化；（b）乏血区的扩大导致裂孔形成；（c）回盲部肠系膜在胎儿期快速的延长。成人中大多数的肠系膜缺损可能是由于手术、创伤或感染导致。Features特征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）.肠系膜疝和结肠系膜疝占所有腹内疝的8%。由于后者没有局限性的疝囊，机械性SBO通常发生在肠系膜疝的病例中（图8），而且不能区分经肠系膜缺损疝导致的闭合性肠梗阻与粘连带下的肠脱垂导致的闭合性肠梗阻。肠扭转是进一步的并发症，从而导致迅速的疝性绞窄和肠坏疽（图9）。肠系膜疝通常显示为近端小肠的扩张，与正常或塌陷肠管间存在过渡区。由于小肠系膜缺损本身不能显示，堆积的小肠肠管的梗阻和肠系膜血管的异常是诊断肠系膜疝的重要所在。CT表现为特征性的肠系膜血管蒂充盈、拉长和拥挤，另外，汇聚的肠系膜血管位于疝囊的入口处，肠系膜的主干发生移位。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.图8一36岁妇女的肠系膜疝，持续10天下腹痛。给予了20天的保守治疗，包括经鼻胃管或肠管减压、静脉输液和抗生素。然而尽管经过治疗还是出现了SBO。（a）增强CT扫描显示中腹部小肠肠管积液扩张（S），血管汇聚并拉长（箭头）。（b）盆腔CT扫描显示疝孔处的血管拥挤汇集（箭头）。（c）经肠管行肠道造影的图像显示SBO（箭头）。（d）手术所见的示意图（冠状面）显示距回盲瓣5cm的回肠有大约180cm发生绞窄，是经肠系膜上的缺损（短箭头）导致的疝。术中将坏疽的回肠段予以切除。（e）术中图片显示疝孔，呈卵圆形，直径4cm。（缩略图，点击图片链接看原图）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岁女孩的肠系膜疝，表现为弥漫性腹疼36小时后突发绞疼。腹部检查发现中腹部严重膨隆并且敏感。实验室检查发现血红蛋白8.4g/dL。（a）中腹部非强化CT扫描显示弥漫性的肠系膜积液并模糊不清（箭头），小肠肠管轻度扩张。由于红细胞进入管腔内，腔内的积液衰减增加。CT检查12小时后进行了手术。（b）术中图片显示疝孔（箭头），直径3cm。距回盲瓣100cm处的小肠约有260cm经肠系膜缺损疝出并旋转360°，230cm的肠管发生坏疽并被切除。screen.width-333）this.width=screen.width-333'width=640height=228title='ClicktoviewfullCTofInternalHernias_page10_image1.jpg（900X321）'border=0align=absmiddle>TransomentalHernia网膜疝Transomentalherniasconstituteapproximately1%C4%ofallinternalhernias.Therearetwotypes:Inthefirsttype,herniationoccursthroughafreegreateromentum;thistypeismorecommon,andnosacispresent.Inthesecondtype,whichisrare,herniationintothelessersacoccursthroughthegastrocolicligament（33,35,36）.网膜疝约占所有腹内疝的1-4%，分为两型：第一种类型是经游离的大网膜疝，这种类型比较常见，不存在疝囊；另一种类型很少见，是经胃结肠韧带疝入一小囊内。Inthefirsttype,thehernialorificeonthegreateromentumislocatedintheperipherynearthefreeedge（Fig10）andisusuallyaslitlikeopeningfrom2to10cmindiameter（1C4,37）.Thecauseoftheomentaldefecthasnotbeenidentified,butithasbeensuggestedthatmosthaveacongenitalorigin,althoughinflammation,trauma,andcirculationmayalsocauseomentalperforations.Smallbowelloops,thececum,andthesigmoidcolonareinvolvedinthisdefect.Theclinicalandradiologicfindingsarealmostidenticaltothoseoftransmesenterichernias（Fig11）（1,3,38）.在第一种类型中，大网膜上的疝孔位于近游离缘的外周，通常呈裂隙样开口，直径2-10cm。网膜缺损的原因不是很明确，尽管感染、创伤和循环异常也能导致网膜穿孔，但大多数有先天性的因素。这种缺损可累及小肠、盲肠和乙状结肠。临床和影像学表现和肠系膜疝的表现几乎一样（图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）.图10一76岁妇女的网膜疝，有下腹疼痛6天的病史。（a）盆腔增强造影CT显示小肠积液堆积（短箭头），邻近中腹壁的小肠管壁轻度或没有强化。疝孔处的肠系膜血管蒂（箭头）拥挤，血管充盈。CT检查3小时后进行了手术。（b）手术所见的示意图（冠状面）显示疝孔（箭头）位于大网膜的外周部。（c）术中图片显示疝孔（短箭头）。距回盲瓣70cm的回肠有约80cm经缺损疝出，55cm的肠管因为坏疽而被切除（箭头）。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.图11一78岁男性患者的网膜疝，表现为持续24小时的急性上腹部疼痛，住院时的生命体征、实验室检查结果和体格检查均正常，仅表现为中上腹疼痛。住院第二天，实验室检查发现白细胞计数20300/mm3（20.3×109/L）。（a）中腹部增强CT扫描显示闭合肠管（S）积液扩张，周围见大量腹水（短箭头）。与腹壁相邻的疝孔处可见肠系膜血管充盈拥挤（箭头）。CT检查后2小时进行了手术。（b）手术所见的示意图（冠状面）显示疝孔直径3cm（箭头），其边缘牢固呈纤维性。（c）术中图片显示距Treitz韧带120cm的空肠有约90cm发生坏疽（箭头），被手术切除。screen.width-333）this.width=screen.width-333'width=640height=576title='Clicktoviewfull11.jpg（824X742）'border=0align=absmiddle>PericecalHernia盲肠旁疝Anatomy解剖Embryologically,theanatomyofthececalandpericecalperitoneumisnotdetermineduntilthe5thfetalmonth,whenthemigrationofthemidgutiscomplete,withthececumfixedintherightcolicfossaandresorptionoftheperitonealsurfaces（39,40）.Fourdifferentpericecalrecessesformedbyfoldsoftheperitoneumhavebeenreported:thesuperiorileocecalrecess,inferiorileocecalrecess,retrocecalrecess,andparacolicsulci（Fig12）（3,39,40,42）.胚胎发育中，胎儿5个月时盲肠和盲肠旁的腹膜解剖才明确，此时中肠移位完成，盲肠固定在右侧结肠隐窝，重新附着腹膜面。据报道，根据腹膜皱襞将盲肠旁隐窝分为4个：回盲上隐窝、回盲下隐窝、盲肠后隐窝和结肠旁沟（图12）。Figure12.Drawing（coronalview）showsthelocationsofpericecalrecesses.1=superiorileocecalrecess,2=inferiorileocecalrecess,3=retrocecalrecess,4=paracolicsulci.（Adaptedandreprinted,withpermission,fromreference41.）图12示意图显示盲肠旁疝的部位。1，回盲上隐窝；2，回盲下隐窝；3，盲肠后隐窝；4，结肠旁沟。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.回盲上隐窝在盲肠血管襞前方和回肠系膜的后方。回盲下隐窝在回盲襞前方和回肠后表面及其系膜的下方，盲肠右侧，阑尾上系膜的后方。盲肠后隐窝是四个隐窝中最大的，位于盲肠后壁的前面，后腹壁的后方，覆盖盲肠后壁腹膜反折的上方，两盲肠襞的中侧方。结肠旁沟是腹膜侧方围绕盲肠的凹陷。这些隐窝不会或者很少向后延伸至盲肠，但其形成的“口袋”足以容纳数只手指。另外，根据文献报道，由于在肠管旋转和腹膜融合过程中的个体差异，一些其他的附属隐窝或陷窝可延伸到回盲区，这些结构也可变成疝孔Features特征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）.盲肠旁疝占所有腹内疝的13%，大多数病例中回肠经缺口疝出占据右侧结肠旁沟（图13）。临床的诊断有一定困难，尽管临床的症状和体格检查常可提示急性SBO，但在慢性绞窄时容易和炎性肠病、阑尾病变及其他原因引起的SBO相混淆。为了能做出准确的术前诊断，如果病人情况允许，进行小肠延迟X线检查或钡灌肠检查可能会有帮助。盲肠旁疝的特异性CT表现还没有确定，仅有几篇相关的文献报道。我们的这两例，CT扫描显示小肠堆集，肠管内液体积聚，位于盲肠的侧方和升结肠的后方。另外，还显示在腹膜隐窝裂隙处的鸟嘴征及其扩张的小肠肠管和过渡区。基于这些CT表现可以高度确定盲肠旁疝的诊断。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岁男性患者的经盲肠后隐窝的盲肠旁疝，表现为持续48小时的右下腹的疝气痛和呕吐。其54岁时曾进行过阑尾切除术。（a）中腹部的CT增强扫描显示右侧结肠旁沟侧方和升结肠（A）后方的小肠堆集包绕（短箭头），其内可见肠系膜血管扩张拉长（长箭头）。（b）下腹部CT扫描显示盲肠后隐窝（短箭头）处肠管塌陷呈鸟嘴征（长箭头）。升结肠（A）向前移位。CT扫描12小时后行剖腹术。（c）手术所见的示意图（冠状面）显示距Treitz韧带120cm的空肠和回肠（长箭头）有约230cm经盲肠后隐窝（短箭头）疝出发生坏疽。坏疽肠管被手术切除。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.图14一86岁男性患者的经结肠旁沟的盲肠旁疝，表现为持续10天的下腹疼痛和呕吐。其56岁时曾进行过阑尾切除术。（a）下腹部的增强造影CT扫描显示小肠（S）扩张积液并堆积（长箭头），升结肠（A）向前移位，在右侧结肠旁沟内可见腹水（短箭头）。（b）盆腔CT扫描显示近端肠管扩张（短箭头），远端肠管塌陷（长箭头）。CT扫描6小时后行剖腹术。（c）手术所见的示意图（冠状面）显示距回盲瓣30cm的回肠（I）有约20cm经结肠旁沟上5cm的缺口（长箭头）疝出发生绞窄，有10cm的绞窄回肠因发生坏疽被手术切除。screen.width-333）this.width=screen.width-333'width=640height=520title='Clicktoviewfull14.jpg（900X732）'border=0align=absmiddle>SigmoidMesocolonHernia乙状结肠系膜疝Anatomy解剖Thesigmoidmesocolonisaperitonealfoldattachingthesigmoidcolontothepelvicwall.Theapexisdividedneartheleftcommoniliacarteryandservesasapotentialsiteforaninternalhernia.Theintersigmoidfossa（Fig1,G）liesbehindthisapexoftheV-shapedparietalattachmentofthesigmoidmesocolon.Thispocketisfoundin65%ofautopsiesandvariesinsizefromadimpletoafossaadmittingthefifthfinger（1,3,22）.乙状结肠系膜是固定乙状结肠到骨盆壁的腹膜皱襞，其尖端在接近左侧髂总动脉处分叉，成为潜在的腹内疝的部位。乙状结肠间隐窝（图1，G）就位于乙状结肠系膜与壁附着的V形尖端的后面，尸检中65%的可以发现这种隐窝存在，其大小从小的浅窝到可容五指的隐窝不等。Features特征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）.乙状结肠系膜疝占所有腹内疝的6%，可以分为3类：（a）乙状结肠间疝；（b）经乙状结肠系膜疝和（c）乙状结肠系膜间疝。由于术前鉴别这三种累及乙状结肠系膜的疝常常很困难，因此在绝大多数的病例中只有通过手术才能确诊。乙状结肠间疝是最常见的类型，是指疝入位于乙状结肠系膜侧方的先天性隐窝―乙状结肠间隐窝。经乙状结肠系膜疝是指经乙状结肠系膜上的缺损的小肠的嵌顿，这种缺损呈口状，直径2-4cm。经乙状结肠系膜疝穿过两层乙状结肠系膜，小肠肠管向左下腹乙状结肠侧后方疝出，这种疝被认为没有急性的疝囊。乙状结肠系膜间疝是指经乙状结肠系膜仅仅只有一个叶，疝囊经过这个先天性的缺损导致的疝。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.图15一79岁男性患者的乙状结肠系膜间疝，表现为急性的下腹部疼痛3小时。经鼻胃管保守治疗4