Successful Percutaneous Transluminal Angioplasty and Stenting in Acute Mesenteric Ischemia

Acute mesenteric ischemia (AMI) is a life-threatening emergency. The complications are high by the time of diagnosis in most cases and therefore only few data on primary percutaneous intervention with percutaneous transluminal angioplasty (PTA) and stenting in AMI are available. We present the case of an 84-year-old woman who presented to our emergency department complaining of an acute worsening of pre-existing abdominal periumbilical pain, nausea, vomiting, and diarrhea. She had previously undergone percutaneous transluminal embolectomy for an acute occlusion of the left common femoral artery. Due to suspicion of intestinal infarction, conventional angiography of the aorta and the superior mesenteric artery (SMA) was performed and confirmed a proximal occlusion of the SMA. Percutaneous SMA recanalization with balloon dilation and subsequent stent implantation was carried out successfully. The abdominal symptoms subsided after this procedure. In AMI that is diagnosed early, endovascular stenting should be considered as an alternative treatment to the surgical approach that avoids the need for surgical bowel resection.     

Mechanical Thrombectomy Using the Solitaire AB Device for Acute Embolic Mesenteric Ischemia

Purpose

To review preliminary efficacy and safety outcomes of mechanical thrombectomy using the Solitaire AB device combined with thromboaspiration for treatment of acute embolic occlusion of the superior mesenteric artery (SMA).

Spontaneous Dissection of Superior Mesenteric Artery: Long-Term Outcome of Stent Placement

Stent placement was performed in 10 patients with symptomatic spontaneous dissection of the superior mesenteric artery (SMA). A stent was placed as first-line treatment in 7 patients and as second-line treatment in 3 patients in whom conservative treatment had failed. Abdominal pain completely resolved within 2 days after stent placement, and follow-up (median 53 months; range, 11–99 months) CT angiography revealed complete obliteration of the false lumen and good stent patency in 9 patients. One patient showed asymptomatic stent occlusion at 99-month follow-up. Long-term patency of stent placement in patients with symptomatic SMA dissection seems to be acceptable.     

Coexistence of superior mesenteric artery syndrome and nutcracker phenomenon

Superior mesenteric artery (SMA) syndrome is a rare cause of upper gastrointestinal obstruction. Nutcracker syndrome occurs as the result of external compression of the left renal vein. Although they share a similar pathophysiology, SMA and nutcracker syndrome occurring simultaneously is rare. In this case report, we discuss the pathophysiology and unique computed tomography findings in a 25-year-old female patient diagnosed with SMA syndrome who was also incidentally found to have a coexisting nutcracker phenomenon. Due to similar pathogenesis, radiologists should consider the possibility of coexistence of these rare syndromes in appropriate patients.     

Nutcracker and SMA syndromes: What is the normal SMA angle in children?

Objective

The nutcracker and superior mesenteric artery (SMA) syndromes are rare conditions where the left renal vein or duodenum may be compressed by an unusually acute angle between the SMA and aorta, although the normal angle in children is unknown. We measured the SMA angle to define the normal range in children.

Methods

We retrospectively measured SMA angles, left renal vein (LRV) distance, and duodenal distance (DD) in 205 consecutive pediatric abdominal CT. Total and visceral intra-abdominal fat at the level of the umbilicus were also assessed.

Results

Mean SMA angle was 45.6 ± 19.6° (range 10.6–112.9°), mean LRV distance was 8.6 ± 3.9 mm (range 2.0–28.6 mm) and mean DD was 11.3 ± 4.8 mm (range 3.6–35.3 mm). There was a significant but weak correlation between %visceral fat volume (%VF) and SMA angle (R = 0.30; p < 0.001), LRV distance (R = 0.37, p < 0.001) and DD (R = 0.32; p < 0.001).

Conclusion

There is a wide range of SMA angle, LRV and DD in normal children, which correlated weakly with visceral fat volume. Using a definition of SMA angle <25° would diagnose 9.3% of asymptomatic children with nutcracker syndrome, and using a DD definition of <8 mm would diagnose 20% with SMA compression. Our findings suggest exercising caution when attributing these rare syndromes to an absolute SMA angle.     

Bare Stent Implantation in Iatrogenic Dissecting Pseudoaneurysm of the Superior Mesenteric Artery

Iatrogenic arterial dissection leading to the development of dissecting pseudoaneurysms of the superior mesenteric artery (SMA) is a rare complication of angiography. Surgical and endovascular treatment options exist for this important condition. We report a case of bare stent implantation in dissecting pseudoaneurysm of the SMA that developed after angiography in a patient with acute mesenteric ischemia. Although it is rarely published, iatrogenic arterial dissection causing pseudoaneurysm can occur after diagnostic and interventional angiography. Bare stent implantation in dissecting pseudoaneurysm of the SMA could be an advantageous endovascular treatment option in selected cases due its to potential preservation of important side branches of the SMA.     

Usefulness of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI): Assessment of morphology and diameter of the superior mesenteric artery (SMA) on multi-planar reconstructed (MPR) images

Objective

The purpose of this study was to assess the efficacy of multidetector-row CT (MDCT) for the diagnosis of non-occlusive mesenteric ischemia (NOMI) by analyzing morphology and diameter of superior mesenteric artery (SMA). We assessed whether MDCT was as useful as angiography for the diagnosis of NOMI.

Materials and methods

Four patients who were diagnosed with NOMI were retrospectively analyzed. All patients had 8-row MDCT followed by laparotomy. Two of them underwent angiography after MDCT. The morphology and diameter of SMA of these cases was analyzed on multi-planar reconstructed (MPR) images. The mean diameter of SMA of NOMI cases was compared to that of 13 control cases.

Results

MPR images of all NOMI cases showed irregular narrowing of the SMA, spasm of the arcades of SMA, and poor demonstration of intramural vessels. MPR images of two patients who had angiography were concordant with their angiograms. The mean diameter of SMA of NOMI patients was 3.4 ± 1.1 mm, which was statistically smaller than that of 13 control patients, 6.0 ± 1.5 mm (P < 0.05, Wilcoxon rank sum tests).

Conclusion

Angiography has been recognized essential for the diagnosis of NOMI. This study shows the possibility of MDCT to be an equivalently useful modality compared to angiography for the diagnosis of NOMI by interpreting morphologic appearance and diameter of SMA. Introduction of MDCT in the decision tree of NOMI treatment may bring the benefit of prompt diagnosis and subsequent early and efficient initiation of therapy, which may improve the mortality.     

肠系膜上动脉病变 MSCTA 诊断价值

目的：探讨多层螺旋 CT 血管成像(MSCTA)诊断肠系膜上动脉(SMA)病变临床价值。方法回顾性分析40例 SMA病变患者 MSCTA 图像特点,运用容积再现(VR)、多平面重组(MPR)、曲面重组(CPR)及最大密度投影(MIP)等多种后处理重建技术。结果SMA 缺血16例,包括 SMA 急性闭塞8例,其中并发小肠缺血性坏死1例并行坏死小肠切除术。SMA 慢性闭塞8例;孤立性 SMA 夹层10例;SMA 真性动脉瘤7例,感染性心内膜炎相关假性动脉瘤1例;SMA 溃疡3例,其中1例合并肠系膜下动脉(IMA)重度狭窄;腹腔干重度狭窄2例;IMA 闭塞1例。本组40例患者可见 SMA 疾病相关侧支循环13例,4例见于 SMA 慢性闭塞,3例见于 SMA 急性闭塞,1例见于孤立性 SMA 夹层,1例见于 SMA 假性动脉瘤,2例分别见于 IMA 狭窄和闭塞。2例见于腹腔干重度狭窄。其中包括胰十二指肠前、后动脉弓3例,胰背动脉侧支2例、Riolan 弓10例。结论MSCTA 可以清晰观察SMA 各类病变、侧支循环开通情况以及评估肠腔缺血状态。     

急性肠系膜上动脉血栓形成的螺旋CT诊断

目的:分析急性肠系膜上动脉血栓形成的临床特点及螺旋CT表现,提高认识水平.方法:回顾性分析7例经手术证实为肠系膜上动脉血栓形成的螺旋CT表现.7例均行平扫加增强扫描,及最大密度投影图像后处理重建.结果:7例增强均显示肠系膜上动脉血栓形成的直接征象为肠系膜上动脉管腔充盈缺损.螺旋CT平扫5例出现肠系膜上动脉密度增高,4例肠系膜上静脉与肠系膜上动脉管径比例<1,4例肠系膜上动脉壁斑片状钙化,2例肠腔淤积扩张,2例薄纸样肠壁及腹腔积液等征象.7例最大密度投影重建显示肠系膜上动脉血管内不同程度充盈缺损、管腔狭窄.结论:螺旋CT检查对于早期诊断肠系膜上动脉血栓形成是一种有价值的方法.对于不明原因所致腹痛及临床怀疑肠系膜缺血的患者均应及时行螺旋CT检查.     

介入取栓术治疗急性肠系膜上动脉栓塞临床研究

目的评价经皮肠系膜上动脉吸栓和(或)溶栓治疗急性肠系膜上动脉栓塞的疗效。方法34例急性肠系膜上动脉栓塞的患者(房颤14例;左房黏液瘤2例;血栓形成15例;慢性缺血性肠病急性发作3例),行经皮动脉长鞘吸栓术和(或)溶栓术。结果34例患者均成功的去除栓子,动脉开通。31例痊愈;2例行开腹探查;1例24h后死亡。结论经皮介入取栓术对于治疗急性肠系膜上动脉栓塞,是一种简便有效的方法。准确地判断病因是提高疗效,避免合并症的关键。     

Stenting of the Superior Mesenteric Artery as a Preoperative Treatment for Total Pancreatectomy

The patient was a 58-year-old male with mucinous cyst adenocarcinoma of the pancreas. Prior to total pancreatectomy, preoperative CT and angiography showed a high-grade arteriosclerotic stenosis of about 1.0 cm in length in the ostium of the superior mesenteric artery (SMA), as well as the development of collateral vessels in the area around the head of the pancreas. A stent was placed in the SMA stenosis to preserve the intestinal blood flow in the SMA region after total pancreatectomy, which was performed 25 days after stent placement. The postoperative SMA blood flow was favorable, with no postoperative intestinal ischemia, and the patient had an uneventful postoperative course.     

Intracerebral hemorrhage after transcatheter thrombolysis of non-occluding superior mesenteric artery thrombosis

We performed transcatheter thrombolysis on a 64-year-old man with non-occluding superior mesenteric artery (SMA) thrombosis because his severe symptoms could not be controlled with medication. An enhanced computed tomography (CT) scan revealed intramural thrombosis in the SMA. We were concerned that the narrowing of the SMA lumen might progress to complete occlusion, resulting in a high likelihood of mortality. After dissolution of the SMA thrombosis, the original symptoms almost completely disappeared. However, intracranial hemorrhage occurred 8 hr after thrombolysis, requiring surgical intervention. Transcatheter thrombolysis is thought to be a useful treatment for SMA thrombosis, especially in elderly patients with a high operative risk; however, the possibility of intracerebral hemorrhage must be taken into consideration.     

Imaging appearances and management of isolated spontaneous dissection of the superior mesenteric artery

OBJECTIVE: The objective of our study was to report the clinical and imaging features of isolated dissection of the superior mesenteric artery (SMA) and describe our imaging classification of this disease entity. SUBJECTS AND METHODS: We retrospectively analyzed clinical presentation, imaging appearances and outcome of the 12 patients who were diagnosed as having spontaneous dissection of the SMA from 1991 to 2005 in our institution or its affiliated two hospitals. There were 11 males and 1 female with a mean age of 50 years (range, 43-61 years). The diagnosis of isolated dissection was established with CT within 24h of the onset. RESULTS: We categorized SMA dissection into the following four types based on imaging appearances: type I, patent false lumen with both entry and re-entry (four patients), type II, 'cul-de-sac' shaped false lumen without re-entry (one patient), type III, thrombosed false lumen with ulcer like projection (ULP), which is defined as a localized blood-filled pouch protruding from the true lumen into the thrombosed false lumen (five patients) and type IV, completely thrombosed false lumen without ULP (two patients). One patient with type II underwent urgent surgery because of small bowel ischemia. One patient with type III underwent urgent embolotherapy for the treatment of rupture of a branch of the SMA. The remaining 10 patients were initially managed conservatively. In one of the conservatively treated patient, ULP had progressively dilated, and it was treated with stent placement and coil packing 22 months after the onset. The remaining nine patients were conservatively managed without any event during the follow-up period of 7-72 months. CONCLUSION: Most of the patients with isolated SMA dissection can initially be managed conservatively if there are no clinical and imaging signs indicating ruptured SMA branches or bowel ischemia.     

Superior Mesenteric Artery Pseudoaneurysm Following Pancreaticoduodenectomy: Management by Endovascular Stent-Graft Placement and Transluminal Thrombin Injection

Superior mesenteric artery (SMA) pseudoaneurysm formation is a rare and potentially fatal postoperative complication. Herein we present a case of a large post-pancreaticoduodenectomy SMA pseudoaneurysm that required thrombin injection after initial stent-graft deployment to accomplish complete pseudoaneurysm occlusion.     

16层螺旋CT肠系膜上动静脉成像诊断小肠扭转的初步研究

目的探讨小肠扭转时肠系膜上动、静脉的CTA表现及其诊断价值。方法回顾性分析经手术证实的5例小肠扭转病人的肠系膜上动、静脉CTA表现。使用Siemens 16层螺旋CT,于工作站重建肠系膜上动、静脉最大密度投影(MIP)及容积再现(VR)图像。分析肠系膜上动、静脉CTA对于小肠扭转的诊断价值。结果5例病人均清晰显示肠系膜上动脉主干,但远级分支模糊。2例表现为肠系膜上静脉主干远段的扭曲,3例表现为肠系膜上静脉不同属支的扭曲及走行异常,走行异常的血管均与扩张小肠袢位置相吻合。1例见肠系膜上静脉主干的轴向扭曲。2例显示走行异常的肠系膜上静脉属支增粗。5例病人均正确诊断小肠扭转。结论肠系膜上静脉或其属支的扭曲为小肠扭转主要的CTA表现,行肠系膜上动静脉CTA对小肠扭转具有确诊价值。     

128层螺旋CTA对自发性孤立性肠系膜上动脉夹层的诊断

目的探讨64排128层螺旋CTA对自发性孤立性肠系膜上动脉夹层(spontaneous isolated superior mesen-terric artery disection,SISMAD)的显示方法及诊断价值。方法回顾性分析64排128层螺旋CTA诊断SISMAD的患者资料8例,总结及优化扫描方案,采用多种后处理方法显示。结果共诊断SISMAD 8例,SISMAD起止的长度在10～75 mm之间;夹层发生的部位7例靠近于肠系膜上动脉(SMA)近段,其中3例发生于SMA近心端距SMA开口处约10～30 mm;1例起于发出胰十二指肠下动脉后。发现3处及以上破口的SISMAD 5例,发现2处破口1例,发现1处破口2例。部分假腔内可见血栓形成。结论 SISMAD涉及的多种病理改变64排128层螺旋CTA均可清楚显示,可作为诊断SISMAD的首选影像学检查手段。     

内毒素休克后家兔血管反应性的变化规律及器官差异

目的 了解内毒素休克后血管反应性的变化规律及器官差异.方法 家兔48只,随机分为6组,依次为正常对照组、给内毒素(LPS)后0.5、1、2、4、6小时组,分别测定各组肠系膜上动脉(SMA)、腹腔动脉(CA)和左肾动脉(LRA)离体血管环对去甲肾上腺素(NE)、乙酰胆碱(Ach)的收缩和舒张反应性.结果 内毒素休克后SMA对NE的收缩反应性早期轻度升高,晚期显著下降,对Ach的舒张反应性早期显著升高,晚期显著下降;CA对NE的收缩反应性早期显著升高,晚期显著下降,对Ach反应性呈持续高反应,峰值在早期;LRA认对NE的收缩反应性早期显著升高,晚期显著下降,对Ach的反应性早期显著升高,晚期无明显变化.结论 内毒素休克血管反应性呈现一定器官差异,这种差异可能与内毒素休克血流动力学改变及血液重分布有关.     

Stent-Graft Treatment for Bleeding Superior Mesenteric Artery Pseudoaneurysm After Pancreaticoduodenectomy

We report two cases of intraperitoneal bleeding from superior mesenteric artery (SMA) pseudoaneurysm after pancreaticoduodenectomy for pancreatic head carcinoma. In both cases, a stent-graft was deployed on the main SMA to exclude pseudoaneurysm and to preserve blood flow to the bowel. Bleeding stopped after the procedure. One patient was able to be discharged but died from carcinoma recurrence 4 months later. The other patient died of sepsis and stent-graft infection 5 months later. These patients remained free of intraperitoneal rebleeding during the follow-up period.     

Superior mesenteric artery syndrome in a malnourished female: A rare cause of abdominal pain

Superior mesenteric artery (SMA) syndrome is a rare cause of duodenal obstruction that can go undiagnosed, exacerbating weight loss in an already significantly malnourished patient. Diagnosis is often challenging, however, can be made by keeping a high index of suspicion based on the clinical presentation. The pathology involves a reduction in the amount of fat pad between the abdominal aorta and superior mesenteric artery (SMA) leading to a reduction of aorto-mesenteric angle and consequent compression of mostly third part of the duodenum. Management is usually conservative, however, if conservative treatment fails, surgical intervention is warranted.Our patient was a 20-year-old female who presented to us with nausea, vomiting, weight loss, and abdominal pain. The presence of obstructive symptoms along with imaging (CT scan) lead to the diagnosis of SMA syndrome and she improved with conservative management. Informed consent was obtained for this study.     

肠系膜上动、静脉病变64层螺旋CT血管成像探讨

目的探讨64层螺旋CT血管成像在肠系膜上动、静脉病变的诊断和临床应用价值。资料与方法回顾性分析经CT增强血管造影诊断肠系膜上动、静脉病变45例。采用Philips 64层螺旋CT容积扫描,增强扫描于注射对比剂后延迟25~30 s扫描动脉期、65~75 s扫描门静脉期。在工作站采用多平面重组(multi-planar reformat-ting,MPR)、最大密度投影(maximum intensity projection,MIP)及容积再现(volumetric rendering,VR)重组肠系膜上动、静脉图像,分析肠系膜上动、静脉血管成像对肠系膜血管病变的诊断价值。结果 45例患者均清晰显示肠系膜上动、静脉主干及其分支,共发现肠系膜上动、静脉病变49处,其中累及肠系膜上动脉23处,肠系膜上静脉13处,肠系膜上动、静脉同时累及13处。结论 64层螺旋CT血管成像能清楚显示肠系膜上动、静脉解剖结构,对肠系膜动、静脉病变有确诊价值,为临床诊断和治疗节省宝贵时间。