多排螺旋CT肠系膜血管造影诊断急性肠缺血

目的 探讨多排螺旋CT肠系膜血管造影(MDCTA)在急性肠缺血(AMI)中的应用价值.方法 对43例经临床或手术、病理证实的AMI患者行全腹MDCT平扫、动脉期和门脉期扫描,准直为0.6mm,采用容积重建(VR)、最大密度投影(MIP)及薄层最大密度投影(TSMIP)技术进行肠系膜动脉和静脉成像,重点观察肠系膜血管的异常表现、肠道和肠系膜异常征象.结果 导致AMI的原因为:肠系膜上动脉(SMA)栓塞4例,SMA血栓形成6例,肠系膜上静脉(SMV)血栓形成13例,SMA夹层5例,绞窄性肠梗阻10例,血管炎5例.MDCTA可清晰地显示AMI的血管异常,如血管堵塞、狭窄或夹层的部位、形态、程度和范围;显示血管走向的异常,如聚拢、推移、扭曲或扭转等;并显示侧支血管.MDCTA可明确AMI的原因,如粥样硬化斑块、栓子、血栓形成、夹层、肿瘤血管侵犯、绞窄性肠梗阻和血管炎等.结论 MDCTA能很好地显示AMI的直接征象,结合间接征象可在病变早期诊断AMI并明确病因.     

超声检查在肠系膜上动脉栓塞性疾病诊断中的应用价值

肠系膜上动脉栓塞性疾病包括肠系膜上动脉栓塞（occlusion of superior mesenteric artery）和肠系膜上动脉血栓形成（SMA thrombosis formation），其发生率在肠系膜血管性病变中占1／3以上，占所有外科急腹症住院病人的0．9％，亦属血运性肠梗阻范畴。根据栓塞部位、大小或血栓蔓延及侧支循环情况，将会发生不同程度的肠坏死或缺血性肠病（ischemic bowel disease）。系由肠系膜血管阻塞或狭窄引起的血流灌注及供血不全，被供血区域肠襻出现缺血、肠壁营养障碍和进而发生肠梗死所最终导致的结果。     

自发孤立性肠系膜上动脉夹层CT血管造影诊断

目的探讨自发孤立性肠系膜上动脉夹层（SISMAD）的CT血管造影（CTA）特征。方法回顾性分析2011年1-7月间在深圳市南山人民医院接受腹腔动脉双源CTA检查的25例不明原因的急性腹痛患者的临床资料。结果CTA检查发现4例肠系膜上动脉夹层,均为男性,年龄（45．3±6．7）岁．2例有高血压病史。4例患者CTA检查均发现肠系膜上动脉管径增粗,2例呵见内膜瓣和真假腔．1例溃疡状破口,1例壁间血肿,近段破口均位于肠系膜上动脉近段;CTA分型：Ia型2例,Ⅱb型1例。Ⅲ型1例。2例出院时进行了DSCTA复查,出现了进行性变化。结论CTA可清晰显示肠系膜上动脉夹层的特征．并能为疾病分型和随访观察提供重要依据。     

急性肠系膜缺血的多排螺旋CT诊断

目的 总结急性肠系膜缺血（acute mesenteric ischemia,AMI）的多排螺旋计算机断层扫描（multidetector computed tomography,MDCT）表现以及MDCT对AMI预后的评估价值。方法 检索近年来AMI病理生理学、CT特征以及与它预后相关的研究并进行综述。结果 AMI的血管功能不全可由阻塞性（肠系膜动脉栓塞、动脉或静脉血栓形成）和非阻塞性病因引起。在AMI早期缺血阶段病变是可逆的，而晚期AMI的特点是发生不可逆的透壁性坏死，延迟诊断会导致病死的发生。AMI的MDCT表现可分为血管直接征象和缺血性肠损伤相关的影像学表现。气腹被视为AMI透壁性坏死的一个标志，然而由于诊断性试验的异质性，预测透壁性坏死的其他影像学特征存在争议。结论 AMI是一种危及患者生命的腹部急症，早期诊断能改善患者预后。对于放射科医生来说，识别预后相关的影像特征对于区分早期和晚期AMI至关重要。     

儿童先天性支气管动脉-肺动脉瘘的影像学评价:MSCTA与DSA对比

目的评价MSCT与DSA对儿童先天性支气管动脉-肺动脉瘘显示的一致性。方法先天性支气管动脉-肺动脉瘘患儿16例,其中6例因不明原因每日反复咯血200～400ml而接受多层螺旋CTA及DSA检查以及选择性支气管动脉栓塞治疗;其余10例因先天性心脏病就诊,均诊断为动脉导管未闭（PDA）,接受多层螺旋CTA及DSA检查。结果 DSA显示16例患儿共20支支气管动脉,均存在支气管动脉-肺动脉瘘。CTA显示20支支气管动脉,与DSA的显示率（20/20,100%）一致;其中13支呈增生性改变,管腔内径2～4mm,11支可见支气管动脉-肺动脉瘘。6例大咯血患儿经选择性支气管动脉栓塞治疗后效果良好,咯血症状消失。所有患儿随访平均时间为165天（1～12个月）,均未发现复发咯血。结论多层螺旋CTA能够显示部分支气管动脉-肺动脉瘘的直接及间接征象,但对于观察肺内支气管动脉-肺动脉瘘以及隐匿的支气管动脉-肺动脉瘘有一定局限性,诊断仍需借助DSA检查。     

Riolan动脉弓的MSCT血管成像表现

目的探讨MSCT血管成像（MSCTA）Riolan动脉弓的影像表现。方法收集6例Riolan动脉弓病变患者,3例男性患者为高血压动脉粥样硬化性疾病,3例女性患者均为多发性大动脉炎。采用16层（4例）、64层（2层）螺旋CT扫描行腹部CTA检查,对病变血管行VR、MIP和MPR重建。结果 6例Riolan动脉弓血管直径为3.5～10.0mm,平均（6.7±0.4）mm。3例腹主动脉粥样硬化性病变中,肠系膜上动脉（SMA）近端闭塞2例,远端与肠系膜下动脉（IMA）形成Riolan动脉弓,其中1例伴有腹主动脉瘤,同时SMA、IMA与腹腔动脉干形成动脉吻合弓;IMA近端闭塞1例,远端与SMA形成Riolan动脉弓。3例多发大动脉炎中,2例SMA狭窄,SMA与IMA间形成Riolan动脉弓,1例SMA、IMA同时与腹腔动脉干形成动脉吻合弓;1例IMA近端狭窄,IMA与SMA间形成Riolan动脉弓。结论 MSCTA可以显示SMA与IMA间Riolan动脉弓结构,其特征性影像表现是SMA与IMA间的纡曲扩张的血管弓。出现Riolan动脉弓提示SMA或IMA管腔闭塞或狭窄。     

尿激酶在治疗SMA栓塞时的作用

近来的研究表明经静脉或动脉应用尿激酶能起到溶栓作用，如对急性心肌梗塞、深静脉血栓、下肢远端动脉栓塞及肺动脉栓塞均有效。然而对于动脉内输入尿激酶治疗肠系膜血管栓塞尚缺乏临床经验。本文报告二例肠系膜上动脉（SMA）血栓应用尿激酶治疗成功的经验。例1为65岁男性患者，既往有高血压及反复栓塞史，为此他服用抗凝剂。8小时前突感中腹部疼痛伴腹泻。查体：血压130／70mmHg，脉不规则。腹部有压痛，无肌紧张。肛查有血便。血白细胞（WBC）25600，前凝血酶活动度60％。因怀疑肠系膜血管栓塞行SMA造影。从SMA开口下2～3cm处有一柱…     

多层CT血管成像诊断肠系膜上动脉病变

目的回顾性分析45例肠系膜上动脉（SMA）病变的多层CT血管影像,探讨肠系膜上动脉多层CT血管成像的临床应用和价值。方法怀疑SMA病变的45例患者,男30例,女15例,平均年龄50岁。使用GE16层CT机,探测器1.25mm×8,重建间隔1.0mm,重建层厚1.3mm。增强用对比剂优维显（300mgI/L）80～90ml,流速3.5ml/s。对SMA进行MPR、MIP、VR图像重组,最佳角度显示SMA的病变。结果SMA病变的类型：SMA动脉粥样硬化斑块形成、管腔狭窄16例;SMA近段管腔血栓性栓塞5例,3例有Riolan动脉弓形成,IMA近段管腔血栓性栓塞1例;＂胡桃夹＂征7例;SMA和腹腔动脉干共干2例;主动脉夹层动脉瘤累及SMA近中段管腔4例;多发性大动脉炎5例;SMA近段内支架术后1例;SMA管壁及管腔未见明显异常4例。多层CT图像后处理图像情况：MPR、MIP均清楚显示SMA管腔壁的增厚、斑块情况、管腔狭窄程度;MIP对SMA的显示范围较MPR大,随着MIP显示厚度及角度的变化,可以对SMA的部分管腔或整体管腔情况进行最佳角度显示;VR对SMA与周围血管结构的关系显示较MPR及MIP佳。结论16层CT肠系膜上动脉血管成像检查,可以明确观察SMA各类病变情况和周围血管结构的情况,有广泛的临床应用价值。     

血清D-二聚体测定对急性肠系膜上动脉栓塞的诊断价值

目的 评估测定血清D-二聚体（D-dimer）含量在诊断急性肠系膜上动脉（superior mesenteric artery,SMA）栓塞中的价值。方法将我院1998年6月-2006年6月入院诊断或出院诊断为急性肠系膜血管缺血性疾病的63例分为SMA栓塞（11例）和其它急腹症（52例）两组。使用ROC曲线法评价D-二聚体对SMA栓塞的诊断价值,明确D-二聚体的诊断临界点,绘制ROC曲线。结果ROC曲线下面积为0．939,并有统计学意义。通过ROC曲线确定诊断临界点为0．73mg／L,并具有较高的灵敏度和特异度。结论血清D-二聚体测定可用于急腹症中SMA栓塞的临床排除诊断。当血清D-二聚体高于0．73mg／L时,应高度怀疑为SMA栓塞。     

经腹腔干-胃十二指肠弓逆向介入治疗肠系膜上动脉开口处完全闭塞无残端病变1例

目的:探讨逆向入路支架植入治疗肠系膜上动脉(SMA)闭塞的技术。方法:回顾2017年2月1例于复旦大学附属中山医院血管外科行逆向开通SMA闭塞的患者临床资料。结果:患者为47岁女性,诊断为SMA闭塞引起的慢性肠系膜缺血(CMI),行腔内治疗再通SMA。由于SMA开口处完全闭塞性,无残端,经肱动脉和股动脉双侧入路均无法开通病变部位。利用腹腔干和SMA之间的胃十二指肠弓,通过此通路逆向开通SMA闭塞处;肱动脉入路导管和导丝对接后顺利正向通过病变,完成球囊扩张和支架植入术。术后患者CMI症状消失,3个月后随访CTA显示,支架定位良好,远端血管通畅。结论:对于常规血管内介入治疗方法失败的SMA闭塞患者,通过有效的侧支通路进行逆行开通是可行的。     

Radioxenon washout for the diagnosis of low-flow mesenteric ischemia

Angiogram is accepted as one of the investigations necessary to establish the diagnosis of acute mesenteric ischemia. Unfortunately, the changes seen in the mesenteric arteriogram of patients with low-flow intestinal ischemia are not always clear and easily interpreted. In this study the washout of an intraarterial injection of radioxenon (¹³³Xe), from nonocclusive ischemic bowel, was recorded to determine if it might aid in the diagnosis of low-flow ischemia. For these investigations, a model of low-flow mesenteric ischemia was produced by infusion of noradrenalin into the dog's superior mesenteric artery (SMA). Under experimental conditions of normal and low mesenteric blood flow, the percentage disappearance at 2 min (washout), from the bowel, of a bolus intraarterial (SMA) injection of radioxenon was recorded to determine if this gave a measure of the intestinal blood flow. It was found that Xe washout and the corresponding SMA blood flow, measured with an electromagnetic flow probe, correlated well in the normal and nonocclusive ischemic bowel (r = 0.924). Measurement of the washout of an intraarterial injection of ¹³³Xe to the bowel may be a helpful adjunct to arteriogram for the clinical diagnosis of low-flow mesenteric ischemia.     

Imaging of acute mesenteric ischemia using multidetector CT and CT angiography in a porcine model

Acute mesenteric ischemia, a frequently lethal disease, requires prompt diagnosis and intervention for favorable clinical outcomes. This goal remains elusive due, in part, to lack of a noninvasive and accurate imaging study. Traditional angiography is the diagnostic gold standard but is invasive and costly. Computed tomography (CT) is readily available and noninvasive but has shown variable success in diagnosing this disease. The faster scanning time of multidetector row CT (M.D.CT) greatly facilitates the use of CT angiography (CTA) in the clinical setting. We sought to determine whether M.D.CT-CTA could accurately demonstrate vascular anatomy and capture the earliest stages of mesenteric ischemia in a porcine model. Pigs underwent embolization of branches of the superior mesenteric artery, then imaging by M.D.CT-CTA with three-dimensional reconstruction protocols. After scanning, diseased bowel segments were surgically resected and pathologically examined. Multidetector row CT and CT angiography reliably defined normal and occluded mesenteric vessels in the pig. It detected early changes of ischemia including poor arterial enhancement and venous dilatation, which were seen in all ischemic animals. The radiographic findingsd—compared with pathologic diagnosesd—predicted ischemia, with a positive predictive value of 92%. These results indicate that M.D.CT-CTA holds great promise for the early detection necessary for successful treatment of acute mesenteric ischemia. Presented at the Forty-Sixth Annual Meeting of The Society for Surgery of the Alimentary Tract, Chicago, Illinois, May 14–18, 2005 (oral presentation). Supported by the Karin Grunebaum Research Fellowship, Harvard Medical School (D.E.R.), the German Research Fellowship, German Research Foundation STR 690/1-1 (O.S.), and the Phillip H. Meyers Grant from the Society of Gastrointestinal Radiologists (S.P.T.).     

The effect of glucose infusion on survival after acute mesenteric ischemia/reperfusion

Perfusion of ischemic tissue with glucose has been shown to be deleterious to heart, spinal cord, and kidney. Observations that glucagon improves survival after acute mesenteric ischemia, however, suggest that hyperglycemia may not be deleterious during bowel ischemia. This experiment examined the effect of glucose infusion on survival in an established rat model of acute mesenteric ischemia. The superior (cranial) mesenteric artery (SMA) was occluded for 85 min in 36 anesthetized Sprague-Dawley rats. Animals were randomized to receive 5% glucose in normal saline (n = 15; 16.5 mL/kg.min iv), normal saline alone (n = 13; 16.4 mL/kg.min iv), or no intravenous fluid (n = 8). Ninety-minute intravenous infusions were initiated 10 min after SMA occlusion. Survival to 48 h was 47% in glucose-saline-treated rats, 31% in saline-only-treated rats, and 12.5% in control rats. These results demonstrate no deleterious effect of glucose infusion on mortality after acute mesenteric ischemia in this model.     

Technique of hybrid retrograde superior mesenteric artery stent placement for acute-on-chronic mesenteric ischemia

Revascularization for acute mesenteric ischemia can be challenging in patients with bowel gangrene, peritoneal contamination, and no good source of inflow for a bypass graft. A 70-year-old female patient presented with acute-on-chronic mesenteric ischemia, flush superior mesenteric artery (SMA) occlusion, and diffuse aorto-iliac occlusive disease. This study describes the technique of hybrid retrograde SMA recanalization and stent placement using a midline laparotomy is described. The mid-portion of the SMA was exposed and jejunal branches were controlled with silastic vessel loop. Retrograde access was established under direct vision and the occluded SMA segment was crossed, pre-dilated, and stented using a balloon-expandable stent. The SMA was flushed through a longitudinal arteriotomy, which was closed using a saphenous vein patch. Retrograde hybrid SMA stenting is an expeditious option to revascularize patients with acute on chronic mesenteric ischemia who have peritoneal contamination and no other good source of inflow to the mesenteric arteries.     

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??3D-CTA for diagnosis of mesenteric arterial disease XIAO Liang, MU Xiao-lin. Department of Radiology, First Affiliated Hospital of China Medical University, Shenyang 110001,China
Corresponding author??XIAO Liang, E-mail??xiaoliang1972@126.com
Abstract Mesenteric artery CTA, displaying not only the luminal structures of the lesions but also the anatomy of the outer lumen and the luminal structures of the segment beyond occlusive lesion, has become an important diagnostic tool of mesenteric artery disease. Correct interpretation of the mesenteric artery CTA images should know something as following: (1) Familiar with mesenteric artery anatomy and important communicating branches, such as the communicating branch between celiac artery and SMA, jejuno-ileal artery anastomosis, the communicating branch between IMA and SMA, and Riolan’s arch; (2) Understand the advantages and disadvantages of different image reconstruction: VR can display vivid anatomy and the relationships of neighbor branches, but it’s capability of displaying the arterial details is unsatisfactory; MIP displays poorer SMA spatial structure as more overlapping artifacts; TS-MIP can distinctly show the tiny blood vessels of mesenteric vascular network, but SMA spatial structure could not be displayed satisfactorily; CPR can clearly show the structural characteristics of the SMA trunk lesion, but can not show the relationship between the trunk and the branches. Integrative utilization of various reconstruction techniques and combining with window technology should overall display morphological features of mesenteric arterial disease in detail. In addition, combining clinical features of the diseases, we can make the correct diagnosis and provide a basis of the clinical therapeutic regimen.     

Fluorescein-assisted laparoscopy in the identification of arterial mesenteric ischemia

Summary Accurate identification of acute mesenteric ischemia remains a challenge. It was hypothesized that fluorescein-assisted laparoscopy (FAL) may have a role in the identification of acute arterial mesenteric ischemia. Arterial ischemic small-bowel segments were prepared in 11 dogs. Following 2.5 h of ischemia, laparoscopy was performed with a standard light source followed by FAL with an argon laser. These two techniques were immediately compared with open inspection. Standard laparoscopy correctly identified 10 ischemic segments. FAL correctly identified 9 ischemic segments and the combination of the 2 techniques allowed laparoscopy to correctly identify all 11 ischemic segments. Standard laparotomy with and without fluorescein correctly identified 10 ischemic segments. The difference between laparoscopy and laparotomy was not significant (P>0.6, Fisher's exact test). The combination of laparoscopic evaluation with and without fluorescein allowed identification of small-bowel ischemia in all subjects in this canine model. Further studies are warranted to delineate the accuracy of laparoscopy in other patterns of mesenteric insufficiency before clinical application.     

A new model for intestinal ischemia in the rat

Many models of intestinal ischemia in the rat have been described yielding mortality rates of 8-80% following superior mesenteric artery (SMA) occlusion for periods of 1-85 min. These results have been difficult to reliably reproduce in our lab. Based on our theory that these inconsistent findings are secondary to individual variability in collateral circulation, we have developed a new model for intestinal ischemia with reproducible and consistent mortality. Male Sprague-Dawley rats weighting 300-400 g underwent celiotomy and evisceration. Occlusion of the superior mesenteric artery just distal to the right colic artery was achieved. Collateral arcades from the right colic artery and the jejunal arteries proximal to the site of occlusion were ligated and the bowel was returned to the abdomen for the remainder of the ischemic period. SMA occlusion alone and SMA occlusion with interruption of collateral flow were evaluated and compared for severity of ischemic injury reflected by mortality and for reproducibility of ischemia and mortality. Quantitative measurements of blood flow for each technique were made using radiolabeled microspheres, and a survival curve for SMA occlusion with collateral ligation was constructed. SMA occlusion alone in the rat is not a reliable model for mesenteric ischemia because the resulting ischemic injury is inconsistent and not reproducible. SMA occlusion with collateral ligation produced more severe and reproducible ischemia with greater mortality than did SMA occlusion alone. This technique produced mortality rates that were reproducible and were more consistently related to duration of ischemia.     

Superior mesenteric artery angioplasty and stenting via a retrograde approach in a patient with bowel ischemia--a case report

Acute mesenteric ischemia continues to be a highly morbid diagnosis with a high mortality rate. Percutaneous management of mesenteric ischemia is being more widely applied. Its utility is limited, though, for patients who present with an acute abdomen from ischemic bowel. The authors report a novel combination of open and endovascular techniques via a retrograde superior mesenteric artery (SMA) approach to treat acute mesenteric ischemia in the setting of an acute abdomen.     

异搏定、能量合剂对小肠缺血再灌注损伤的保护作用

目的研究不同肠系膜上动脉灌注液对缺血小肠功能改变的影响。方法制成兔小肠缺血再灌注模型。分别观察缺血即刻、完全阻断６０分钟和再灌注３０分钟时小肠组织线粒体游离Ｃａ２＋浓度和小肠组织ＡＴＰ含量结果完全阻断６０分钟时,异搏定组Ｃａ２＋浓度（２．９７６±０．４１０）ｎｍｏｌ／ｍｇ·ｐｒｏｔ及该组和能量合剂组ＡＴＰ含量（０．５６４±０．０９７,０．５９４±０．０９０）μｍｏｌ／ｇ干重明显优于生理盐水组（Ｐ＜０．０１）;再灌注３０分钟时,两组Ｃａ２＋浓度（２．４０１±０．３２３,３．８４７±０．６１０）ｎｍｏｌ／ｍｇ·ｐｒｏｔ和ＡＴＰ含量（０．８０６±０．１８４,０．７４９±０．２８０）μｍｏｌ／ｇ干重均优于生理盐水组（Ｐ＜０．０１）。结论异搏定和能量合剂可以显著改善缺血小肠的功能改变。