腹内疝影像诊断课件.ppt

1、腹内疝影像诊断课件腹内疝定义n腹内疝是指腹腔内脏器或组织通过腹膜或肠系膜正常或异常的孔道、裂隙离开原有位置而进入腹腔内的某一解剖间隙。n其发病率低(约0.2%0.9%)，为小肠梗阻一少见病因（约5.8%）。然而，腹内疝易并发肠绞窄或缺血，致死率高（75%），因此早期诊断和手术治疗至关重要，但由于缺乏特异性症状及体征，且多与性别和年龄无关，其术前诊断困难 腹内疝的分型n根据发生位置Meyers提出的腹内疝传统分型已被广泛接受，包括十二指肠旁疝（53%）、盲肠周围疝（13%）、Winslow孔(网膜孔)疝（8%）、经肠系膜疝（8%）、乙状结肠周围疝（6%）、吻合口后方疝（5%）。此外尚有较少见的经

2、网膜疝及发生在盆腔的膀胱上疝、经子宫阔韧带疝、Douglas疝、直肠旁隐窝疝等。根据发生原因n腹内疝又可分为先天性和后天性两类：n先天性：是指因胚胎发育过程中肠管旋转或腹膜附着异常等先天性因素所致腹膜隐窝大而深，腹膜、网膜或肠系膜存在缺损，或Winslow孔过大，肠管可经此疝入。包括十二指肠旁疝、Winslow孔疝、部分乙状结肠周围疝、部分盲肠周围疝、部分经肠系膜疝等 n是指后天因素如手术、外伤、炎症等所致腹膜或肠系膜的异常孔隙，肠管可经此疝入。包括部分经肠系膜疝、吻合口后疝、部分乙状结肠周围疝和部分盲肠周围疝等。根据疝的结构 n可按有无疝囊分为真疝和假疝。n脏器疝至另一个腹膜囊隐窝，具有疝囊

3、而称真疝。n先天性腹内假疝指肠管经大网膜、肠系膜裂孔疝入的内疝，而后天性腹内疝均为假疝。腹膜皱襞、隐窝和凹陷腹膜皱襞、隐窝和凹陷n 腹膜皱襞是脏器之间或脏器与腹壁之间腹膜形成的隆起，其深部常有血管走行。在腹膜皱襞之间或皱襞与腹、盆壁之间的凹陷称隐窝，较大的隐窝则称陷凹。（一）腹后襞的皱襞和隐窝 在胃后方、十二指肠、盲肠和乙状结肠系膜附近有较多的皱襞和隐窝，其大小和深浅可随年龄不同或腹膜外脂肪的多少而变化。十二指肠上囊位于十二指肠升部 左侧，相当第2腰椎平面，呈半月形，下缘游离。皱襞深面为口向下方的十二指肠上隐窝（国人50有此窝），其左侧有肠系膜下静脉通行于壁腹膜深面。此隐窝下方有三角形的十二指

4、肠下襞，其上缘游离。此皱襞深面为口向上的十二指肠下隐窝（国人75存在）。盲肠后隐窝位于盲肠后方，盲肠后位的阑尾常位于其内。乙状结肠间隐窝位于乙状结肠左后方，在乙状结肠系膜与腹后壁之间，其后壁内有左输尿管经过。肝肾隐窝位于肝右叶下方与右肾之间，仰卧时为腹膜腔最低处，是液体易于积聚的部位。在腹膜皱襞和隐窝较发达处可为内疝好发位置。腹膜皱襞、隐窝和凹陷腹膜皱襞、隐窝和凹陷n（二）覆膜陷凹 主要陷凹位于盆腔内，男性在膀胱与直肠之间有 直肠膀胱陷凹，凹底距肛门约7.5cm。女性在膀胱与子宫之间有膀胱子宫陷凹;直肠与子宫之间为直肠子宫陷凹，也称Douglas腔，较深，与阴道后穹间仅隔以薄的阴道壁，凹底距肛

5、门约3.5cm。A:paraduodenal 十二指肠旁B:foramen of winslow 网膜孔C:intersigmoid 乙状结肠间的D:pericecal 盲肠周围E:transmesenteric 肠系膜缺口疝F:retroanastomotic 吻合口后间隙不同类型腹内疝的临床和影像学表现n十二指肠旁疝此型为最常见类型，约占全部内疝的53%。与其他类型内疝不同，十二指肠旁疝的发生有性别倾向，男性发病率约为女性的3倍。包括左侧及右侧两种亚型，其中前者常见（约占3/4），二者临床表现相似，均为先天性疝，有疝囊，但胚胎学发育病理基础却不同。左侧十二指肠旁疝n为小肠肠袢经Landze

6、rts陷窝（十二指肠旁隐窝）向后下疝至十二指肠升段的左侧，可达左侧结肠系膜深面。nLandzerts陷窝位于十二指肠升段的左后方，前界为覆盖走行于陷窝左侧的肠系膜下静脉及左结肠动脉升支的腹膜皱襞，认为其形成与发育中降结肠系膜的先天性缺损有关 左侧十二指肠旁疝n临床表现：慢性食后腹痛、恶心，症状可追溯至儿时。十二指肠旁疝易自行缓解，症状间断发作。n消化道造影检查：左上腹十二指肠升段左侧的小肠肠袢聚集成团，可致远端横结肠、十二指肠空肠曲向下移位，压迫胃后壁使其呈锯齿状。n CT：疝入肠袢的位置，可位于Treitz韧带左侧、胃与胰腺之间，或胰腺后方，或横结肠及左侧肾上腺之间，肠系膜血管的改变包括供应

7、疝入肠段的肠系膜血管向疝口处拉伸、纠集、扩张充血，肠系膜下静脉及左结肠动脉升支位于疝囊颈前界并可向左侧移位。左侧十二指肠旁疝示意图nLeft-sided paraduodenal hernian42-year-old woman with left-sided periumbilical pain and a palpable mass.n SBFT image:a saclike mass of mildly dilated jejunal loops(solid arrows)to the left of the ligament of Treitz.Mass effect is note

8、d and causes displacement of the greater curvature and posterior wall of the stomach(open arrow).nLeft-sided paraduodenal hernia in a 55-year-old man with chronic abdominal pain.(a)Transverse CT scan through the upper abdomen shows a saclike mass of jejunal loops(arrows)in the left upper quadrant in

9、terposed between the pancreas(P)and stomach(S).(b)CT scan at a lower level shows that the encapsulated cluster of jejunal loops(arrows)causes indentation of the posterior wall of the stomach(S).The mesenteric vessels within the hernia appear somewhat crowded and engorged.A:axial contrast-enhanced CT

10、 scan in 11-year-old boy shows small-bowel loops(arrow)between stomach and pancreas.B:A:axial contrast-enhanced CT scan in 28-year-old man shows small-bowel loops behind pancreas black arrow indicates stomach.C:axial contrast-enhanced CT scan in 36-year-old man shows small-bowel loops(arrow)displayi

11、ng inferior mesenteric vein(arrowhead)to left.D:coronal construction of contrast-enhanced CT deta set in 28-year-old man shows small-bowel loops between transverse colon(T)and left adrenal gland(arrow).A:contrast-enhanced CT scan of the upper abdomen shows a saclike mass of dilated jejunal loops bet

12、ween the pancreatic head(P)and stomach.The descending mesocolon(D)and stomach are displaced laterally.The dilated inferior mesenteric vein is located at the anterior border of the encapsulated loops.B:CTscan obtained 20mm a shows crowed and engorged mesenteric vessels(arrow)at the fossa of Landzert(

13、L)。J(jejunal loops),S(stomach),arrowhead(the inferior mesenteric vein)E:unenhanced axial CT scan in 35-year-old men show envidence of small-bowel obstruction of herniated contents as multiple loops of dilated small bowel(arrow)with fluid-fluid levels noted.D:缆绳征右侧十二指肠旁疝 n为小肠肠袢经Waldeyers陷窝（十二指肠结肠系膜隐窝

14、）疝至十二指肠降段后下方，可达右侧结肠系膜深面。n该陷窝位于十二指肠降段下方、肠系膜上动脉后方，回结肠系膜动脉分支位于疝囊表面，疝囊一般较大，而且位置比较固定，可以向外、向下扩张。n临床表现与左侧十二指肠旁疝相似，可表现为慢性食后痛。n消化道造影显示位于十二指肠降段后下方的由小肠肠管聚集而成的较大且固定的卵圆形团块。nCT表现：右中腹部一簇小肠肠袢被膜性结构包绕所形成的团块，可见肠梗阻表现右侧十二指肠旁疝示意图 nRight paraduodenal hernia in a 23-year-old man without significant clinical symptoms.n A,B,

15、Contrast-enhanced CT：the clustered and collapsed ileal loops(arrowheads)in the right upper quadrant abdomen,located laterally and inferiorly against the third portion of the duodenum(open arrow).These herniated bowel loops protrude toward the right abdomen through the space between the portal vein a

16、nd inferior vena cava and show right-sided displacement or distortion of mesenteric vessels within or near the hernial sac.Note the ileocolic branch(arrow)of the superior mesenteric artery located at the anterior margin of the hernial sac.nC,The right paraduodenal hernia due to the anomaly of intest

17、inal rotation was found at surgery.c b aa:enhanced axial CT scan of upper abdomens suggest presence or right-side paraduodenal hemia:distended small-bowel loop with air-fluidlevel protrudes behind second portion duodenum.b:arrowhead,herniated loops.c:arrow,superior mesenteric artery located at anter

18、ior margin or neck of hernial sac.右侧十二指肠旁疝 A:abdomen reveals presence of large right-side paraduodenal hemia marked by clustering encapsulation of small bowel loops in right midabdomen.B:arrowhead,superior mesenteric artery.盲肠周围疝 n约占全部内疝的13%，可为先天性或后天性。n盲肠周围的腹膜皱襞形成四个不同的隐窝，分别为位于升结肠内侧回肠上方的回盲上隐窝，回盲部下方的回

19、盲下隐窝，盲肠后下方的盲肠后隐窝，以及位于盲肠外侧的结肠旁沟，肠管可向以上4个隐窝疝入。n临床表现为反复发作的剧烈右下腹痛，易与肠炎性疾病、阑尾病变或其他原因导致的肠梗阻相混淆，临床诊断难。n此型疝常快速进展至肠绞窄，据文献报道致死率高达75。n平片示小肠梗阻及位于盲肠后外方扩张的回肠袢，消化道造影示回肠位置异常，斜位及侧位显示回肠固定在盲肠的后外方。n CT表现为盲肠及升结肠后外方的一簇固定扩张的小肠肠袢，可占据右结肠旁沟，可见肠梗阻征象，盲肠受压向前内方移位。盲肠周围疝示意图Pericecal hernia in a 73-year-old man with intense abdomin

20、al pain and nauseanCT：the counterclockwise whirling of ileal loops as well as adjacent mesentery and its vessels at ileocecal region.The ascending colon(AC)and cecum are displaced anteromedially by dilated ileal loops.nD,Intraoperative findings show herniated ileal loops through a defect of the ileo

21、cecal mesentery,which occurred through postinflammatory effects of appendicitis.盲肠周围疝A:single anteroposterior radiograph from barium enema study shows retrograde filling of herniated distalileum(arrow)as loop of ileum pass posterior to cecum(C)through defect ileocecal.B:arrowhead,small bowel loops.a

22、sterisk,cecumWinslow孔(网膜孔)疝 n为小肠或其他脏器经Winslow孔疝入网膜囊内，为先天性，约占全部内疝的8%。nWinslow孔（网膜孔）为一正常解剖结构，位于小网膜游离缘后方，上界为肝尾叶，下界为十二指肠上部，前界为肝十二指肠韧带及其内走行的胆总管、肝固有动脉及肝门静脉，后界为腹膜覆盖的下腔静脉，网膜囊借此孔与腹膜腔其余部分相通。此型疝约2/3疝内容物只包含小肠，剩余1/3尚可包括盲肠和升结肠，偶有胆囊、横结肠及网膜疝入。n临床多为中年患者，典型表现为突发的严重、进展性腹痛及肠梗阻体征，也可因疝内容物压迫胃而产生相应症状，偶见因疝内容物压迫胆总管导致的黄疸或胆囊扩张

23、。症状发作前常有腹内压增高，如分娩、排便等。nWinslow孔的扩大、小肠系膜过长或升结肠系膜未与壁腹膜融合而持续存在所导致肠管的活动度增加均为易患因素。Winslow孔疝示意图 Winslow孔(网膜孔)疝 立位平片平片典型表现为上腹胃后内方有聚集的局限性含气肠袢，伴小肠梗阻。Winslow孔(网膜孔)疝CT表现n门腔静脉间隙、胃与胰之间多发充气的肠袢，管腔内可见气液平面，朝向Winslow孔的肠袢逐渐变尖呈“鸟嘴征”，且肠系膜血管拉直、进入网膜孔内，胃受压向前移位。n如果胃结肠韧带或肝胃韧带存在缺损，疝入网膜囊内的肠管可再次疝入腹膜腔，此时易致肠绞窄、缺血。因盲肠及胆囊可疝入，所以必须确定

24、二者的位置，以防漏诊。n Winslow孔疝的影像学表现常与左侧十二指肠旁疝相似，二者之间重要的鉴别点为后者有包绕疝入肠管的膜性结构，而前者则无；此外前者疝入点相对较高，且位于脊柱的右侧，前方有肝门，而后者疝入点相对较低，且位于脊柱的左侧，前方有肠系膜下静脉及升结肠动脉左支，而横结肠受压向下移位更多见于左侧十二指肠旁疝。Winslow孔(网膜孔)疝经肠系膜疝 n为肠管经小肠系膜或结肠系膜缺孔的疝出，为后天性，无疝囊，约占全部内疝的8%。n近年来随原位肝移植及胃分流术等伴有Roux-en-Y吻合术式的广泛应用，经肠系膜疝发病率增加，在某一研究中已超过十二指肠旁疝。n在儿童中，经肠系膜疝为腹内疝的

25、最常见类型，约占35%，多起因于靠近Treitz韧带或回盲部的小肠系膜局部先天性缺损。n在成人中，病因多为医源性，与以往的腹部手术有关，尤其是RouxenY吻合术，此外还可因创伤或炎症所致。n临床多表现为肠梗阻症状和体征，包括脐周痛、腹绞痛、恶心、腹胀，因残胃分泌少且Roux肠袢可接受梗阻上方的分泌物，呕吐较少见。症状发生较其他类型内疝迅速，经肠系膜疝多数发生于术后1个月之后，而不同于术后第一个月内最常见并发症的肠粘连。经肠系膜疝影像学表现n平片可显示肠梗阻。n CT表现为疝入的肠袢紧邻腹壁，无网膜脂肪被覆，聚集成簇，位于结肠外侧，致邻近结肠向中央移位（如横结肠向背侧和/或尾侧移位，升、降结肠

26、向内侧移位）。n输入及输出段肠管在疝口处受压、拥挤、可呈“鸟嘴征”改变；并可见肠梗阻征象，近段肠管扩张，远端肠管萎陷；肠系膜血管改变包括肠系膜动、静脉主干向右侧移位，系膜血管向疝口纠集、充血、拉伸、移位。疝入的肠袢可发生扭转，形成闭袢性肠梗阻，易致肠缺血，出现相应表现。此型疝与肠管自粘连带下方脱出形成的闭袢性肠梗阻鉴别困难。经肠系膜疝示意图nTransmesenteric hernia in a 51-year-old woman with acute and chronic abdominal pain,nausea,vomiting,and prior abdominal operatio

27、ns including creation of Roux-en-Y anastomosis to bypass a partially obstructed duodenum(superior mesenteric artery syndrome).n(a)SBFT image:the abnormal position and dilatation of the jejunal loops(J).n(b)Transverse CT:through the midabdomen demonstrates a dilated small bowel(J)lateral to and media

28、lly displacing the ascending colon(AC).Transmesenteric hernia 6 years after OLT in a 56-year-oldman who had chronic intermittent abdominal pain for several years.Transverse CT scan shows a mildly dilated jejunum(J)lateral to and medially displacing the ascending colon(C).(Despite use of a large fiel

29、d of view,a portion of the herniated bowel is outside the scanningfield.)Note the stretched engorged mesenteric vessels(solid arrow),displaced duodenum(D)and duodenojejunal junction(djj),and markedrightward displacement of the superior mesenteric trunks(open arrow).Djj:十二指肠、空肠汇合点；C:升结肠；J：空肠；D：十二指肠；弯

30、箭：肠系膜血管；直箭头：肠系膜血管主干。nTransmesenteric hernia with volvulus in a 82-year-old woman with acute abdominal pain and history of resection of a jejunal leiomyoma 32 years prior.CT:a classic whirl sign(curved arrow),which is indicative of volvulus with twisting of the mesenteric root.Dilated small bowel(str

31、aight arrow)lies adjacent to the abdominal wall and medially displaces the ascending colon(AC).Other gas-distended jejunal loops(J)dorsally displace the transverse colon(TC).nTransmesenteric hernia with strangulation and ischemia 2 years after OLT in a 47-year-old man with severe abdominal pain,dist

32、ention,and nausea.n(a)CT:markedly dilated jejunal loops(J),crowded and engorged mesenteric vessels(arrow),and ascites.n(b)CT:marked ventral and rightward displacement of the mesenteric vessels(SMA,SMV).乙状结肠周围疝 n约占全部内疝的6%，分为三种类型即乙状结肠间疝、经乙状结肠系膜疝和乙状结肠系膜内疝。其中第一型最常见，是指肠管（多为回肠）疝至由相邻两段乙状结肠及其系膜之间所形成的乙状结肠间隐窝

33、内，为先天性，有疝囊，常可自行复位。n这三型在影像学上鉴别困难，但因外科治疗术式近似，故鉴别并不重要。临床及影像学表现n临床上，这种类型疝在病史及体格检查上并无确切或特征性表现。n钡灌肠检查显示囊袋状的回肠袢占据左下腹，乙状结肠受压向右前移位。nCT可显示扩张的小肠肠管疝人乙状结肠的左后方，乙状结肠受压向右前移位，疝口多位于乙状结肠及左侧腰大肌之间，或乙状结肠肠袢之间。乙状结肠周围疝示意图乙状结肠周围疝小肠肠管突入乙状结肠旁，疝口多位于乙状结肠及左侧腰大肌之间，位于乙状结肠的后外侧吻合口后疝 n是指肠管向后疝入手术吻合口后方的间隙，约占全部内疝的5%，为后天性，无疝囊。n此型疝同样多发生于Ro

34、ux-en-Y吻合术后，近年来其发病率增加。n此型疝多发生于术后第1个月内(约占50)，25发生于手术1 a后，25发生在术后第2-12个月内，而不同于好发于手术1个月之后的经肠系膜疝。n临床表现与术式有关。若为结肠后术式，症状可有腹痛、恶心，呕吐较少见，体格检查中，有时可触及左上腹包块。若为结肠前术式，多表现为持续上腹痛及触痛，不含胆汁的呕吐，淀粉酶升高。因此型疝疝口较大，较少发生肠绞窄。吻合口后疝影像表现n因肠管多自右向左疝入吻合口后方间隙，平片可显示左上腹聚集扩张的肠袢，亦可见残胃明显扩张。胃肠道造影及CT可显示胃肠吻合口左后方异常聚集的肠袢（扭曲、环形肠管走行），多伴有一定程度的扩张及

35、积气、积液；肠系膜血管改变；肠管周边无网膜脂肪。n由于这类疝位置多变，没有疝囊，所以影像学诊断困难吻合口后疝示意图Roux-en-Y（胆管空肠空肠端-侧吻合术）吻合术后。大黑星：扩张十二指肠；白星：扩张空肠；箭头：吻合口；直肠旁隐窝疝n盆腔腹内疝很少见，包括膀胱上隐窝疝、经子宫阔韧带疝、Douglas疝、直肠旁隐窝疝；其中以子宫阔韧带疝最为多发nCT扫描表现有时难以区分a 48-year-old woman with mildabdominal painn A 10-mm thick contrast-enhanced CT scan of the pelvis shows dilatatio

36、n of small-bowel loops and a decompressed colon and rectum.n B 10-mm thick contrastenhanced CT scan obtained at the level of the pelvic floor shows an ileal loop(arrow)on the right side of the rectum(arrowhead)and behind the uterine cervix(asterisk).n C 2-mm thick contrast-enhanced CT scan obtained

37、at the level of the hilus shows proximal(arrow)and distal(arrowhead)transitional points of the herniated ileum.nA 51-year-old woman with a history of appendectomy and laparoscopic tubal ligation.nCT：an obstructive condition with a closed ileal loop:the point of junction is close to the uterus.na:axi

38、al slice:closed loop dilatation of the ileum in the pelvis,close to the uterus where there is a right latero-uterine double beak sign(*).The uterus is displaced forward(U)n b:the trapped loop is more easily seen on the coronal reconstructions.Note the very good visualisation of both parts(upstream a

39、nd downstream)of this closed loop occlusion(b1,black arrows)nthe C arrangement of the herniated loop(b2,arrowheads).The CT features implying intestinal strangulationnbowel-wall thickening(3 mm in a dilated segment);(扩张的肠壁超过3mm)nintramural hemorrhage(high attenuation of the bowel wall on unenhanced C

40、T scan)（肠腔出血）nthe presence of mesenteric infiltration;localized mesenteric fluid;engorgement of mesenteric vessels（肠系膜血管增粗、渗出、积液）n abnormal bowel-wall enhancement,including lack of enhancement,a target pattern of enhancement,or heterogeneous enhancement（异常强化，包括无强化、靶样强化、不均匀强化）nAscites（腹水）npneumatosis intestinalis（肠壁积气）nportomesenteric venous air and thrombosis（肠系膜静脉积气、血栓形成）nabscess formation（腹腔脓肿形成）nintra-abdominal free air（腹腔积气）