Radiologic evaluation of penetrating aortic atherosclerotic ulcer

Patients with penetrating atherosclerotic ulcers of the aorta present with back or chest pain that mimics classic aortic dissection. The pathologic findings, however, are distinctly different from those of aortic dissection in that an atherosclerotic lesion with ulceration penetrates into the internal elastic lamina, allowing hematoma formation within the media of the aortic wall. This may lead to false aneurysm or, rarely, transmural rupture of the aorta. Imaging findings of penetrating aortic atherosclerotic ulcers are also different from those of classic aortic dissection. We have found computed tomography to be especially useful in differentiating between these entities and present several illustrative cases.     

Thoracic aortic disease: Spectrum of multidetector computed tomography imaging findings

The clinical presentation of diseases involving the thoracic aorta ranges from a large number of asymptomatic patients with clinically undetectable thoracic aortic aneurysm to patients with symptoms of severe chest pain as a result of acute aortic dissection. Thoracic aortic disease often remains undiagnosed until a life-threatening complication occurs or the disease is discovered serendipitously on imaging studies performed for other purposes. Multidetector row computed tomography (MDCT) imaging of the aorta is used to diagnose various acute and chronic conditions, including aortic aneurysms, aortic dissection, intramural hematoma, penetrating atherosclerotic ulcer, traumatic injury, rupture, inflammatory disorders, and congenital malformations. This review illustrates the wide range of MDCT imaging findings of thoracic aortic disease.     

Aortic branch artery pseudoaneurysms accompanying aortic dissection. Part I. Pseudoaneurysm anatomy

PURPOSE: Small areas of blood flow are sometimes seen within an otherwise thrombosed false lumen on computed tomography (CT) scans of intramural hematomas of the aorta. These are blood-filled spaces that, although they have no apparent communication with the true lumen, appear isodense with the aorta on contrast-enhanced CT scans. The purpose of this report is to describe angiographic and autopsy studies that establish the nature of this entity and describe the principal CT features distinguishing it from a penetrating ulcer. MATERIALS AND METHODS: Conventional angiographic and CT aorta findings in two cases with small collections of contrast material within an otherwise thrombosed false lumen of an aortic dissection are discussed. Also examined is another case with pathologic and histologic findings in addition to those of small collections of contrast material within an otherwise thrombosed false lumen of an aortic dissection, which illustrate the pathoanatomy of these lesions. RESULTS: Angiographic and necropsy evidence shows that some of these lesions represent branch artery pseudoaneurysms and, as such, are secondary to an intramural hematoma, not the primary cause of it. CONCLUSIONS: Difficulty in demonstrating communication between these collections of contrast material and the adjacent true lumen of the aorta on helical CT examinations and the characteristic location of these lesions along the nonpleural portion of the aortic circumference distinguish them from penetrating ulcers and should suggest the diagnosis of branch artery pseudoaneurysm. Demonstration of a branch artery originating from the contrast collection confirms the diagnosis. These branch artery pseudoaneurysms should be distinguished from penetrating atherosclerotic ulcers.     

多层螺旋CT造影在主动脉病变腔内修复术后随访的价值

目的:探讨多层螺旋CT血管造影(multi-detector rowspiral computed tomography angiography,MDCTA)及后处理技术在主动脉覆膜支架腔内修复术(transluminal stent-graft placement,TSGP)术后随访的临床应用价值。方法:21例接受TSGP主动脉疾病患者,包括:Stanford B型夹层13例,真性动脉瘤3例,假性动脉瘤2例,弓降部穿透性溃疡1例,胸主动脉瘤合并局限性夹层1例,胸主动脉瘤合并Stanford B型夹层1例,术后采用MDCTA进行随访,平均随访13个月(1~24个月)。采用轴位图像与多种重建图像相结合来显示支架形态、术前术后主动脉管腔情况的变化和有无并发症。结果:13例主动脉夹层覆膜支架置入后:所有患者均真腔扩大,假腔减小或消失并伴血栓形成,支架未发现移位或断裂;共3例(14%)随访中发现内漏,1例Ⅱ型内漏,建议随访观察;1例术后8个月复查新发现支架近端Ⅰ型内漏,密切随访2个月后患者出现胸痛,复查CT内漏增多,转外科治疗。1例腹主动脉瘤术后1月复查发现Ⅲ型内漏。所有患者介入术后CT随访图像均满足临床诊断需要。结论:MDCTA对主动脉覆膜支架置入术后随访较其他检查手段具有多方面的优越性,能及时观察术后疗效、发现并发症,对主动脉疾病覆膜支架腔内修复术后随访具有重要价值。     

主动脉壁内血肿的多层面螺旋CT诊断

目的:评价多层面螺旋CT诊断主动脉壁内血肿的价值.材料和方法:对23例怀疑主动脉病变的患者进行多层面螺旋CT扫描并诊断为主动脉壁内血肿.两名有经验的心血管放射医师按照CT标准做出诊断.使用16排多层面螺旋CT获得1.25mm层厚(1mm重建间隔)图像,应用多平面重建、曲面重建、最大密度投影和容积重建等方法显示壁内血肿及穿透溃疡.结果:23例主动脉壁内血肿中,1例A型,22例B型;B型壁内血肿中,仅累及降主动脉的8例,胸腹主动脉受累11例,局限于腹主动脉3例;11壁内血肿伴主动脉穿透溃疡,其中2例行带膜内支架治疗.结论:多层面螺旋CT能为主动脉壁内血肿的诊断、鉴别诊断和治疗提供重要信息.     

Inflammatory aneurysm of aorta: development documented by computed tomography

Aortic aneurysmal disease appears to be the central focus of the inflammatory process resulting in inflammatory aneurysm formation. Some authors believe that inflammatory aortic aneurysm disease is a distinct clinicopathologic entity; however, others have included it with retroperitoneal fibrosis. The histologic features of inflammatory aneurysm suggest an immunologic basis for the lesion, with the atherosclerotic aorta as a possible source of the allergen.     

多层螺旋CT血管成像在主动脉壁间血肿的临床应用

目的探讨主动脉壁间血肿（IMH）MSCT表现和诊断价值。方法10例经多层螺旋CT诊断及临床证实的IMH,男6例,女4例。使用16层螺旋CT检查,应用多平面重建、最大密度投影和容积成像等后处理方法显示壁间血肿及穿透性溃疡。结果10例IMH中,A型2例,B型8例,其中2例局限于胸主动脉,6例累及胸腹主动脉（止于肾动脉上方2例,髂总动脉分叉上方2例,2例累及双侧髂总动脉）。MSCT表现为主动脉腔内新月形或环形充盈缺损,内壁较光整,钙化内膜片内移及局灶性尖角样穿透溃疡形成,主动脉腔内无明确内膜片显示。结论多层螺旋CT能为主动脉壁间血肿的诊断、鉴别诊断和治疗提供准确的信息。     

Placement of endovascular stent-grafts for emergency treatment of acute disease of the descending thoracic aorta

OBJECTIVE: The aim of this study was to evaluate the feasibility, safety, and effectiveness of endovascular stent-graft placement for the emergency treatment of acute descending thoracic aortic disease. MATERIALS AND METHODS: From January 1996 through November 2001, 18 patients underwent emergency endovascular stent-graft placement for various types of acute descending thoracic aortic disease. Five patients had Stanford type B aortic dissection, six had traumatic ruptures of the thoracic aorta, five had ruptured aortic aneurysms, and two had penetrating atherosclerotic aortic ulcers. All patients presented with life-threatening symptoms requiring treatment with stent-grafts from the emergency kit. All were at high surgical risk due to serious comorbidities. The efficacy of the procedure was assessed at follow-up studies before discharge and at 3, 6, and 12 months after intervention and yearly thereafter. RESULTS: The primary technical success rate was 78%. Four patients had primary perigraft leaks. The secondary technical success rate was 83%. One patient died 20 hr after intervention from stent-graft-related causes. Follow-up studies revealed stent-graft migration in one patient. Progression of disease was observed in one patient treated for dissection and in both patients treated for penetrating ulcers. One patient died 7 months after intervention of unknown reasons; all other patients are alive. The mean follow-up time was 17.4 months (range, 0-38 months). CONCLUSION: Emergency repair of acute descending thoracic aortic disease with stent-graft placement can be successfully accomplished and may be a promising alternative to open-chest surgery, especially in patients at high risk.     

Acute aortic syndromes: Role of multi-detector row CT

Acute thoracic aortic syndromes encompass a spectrum of emergencies including aortic dissection, intramural haematoma, penetrating atherosclerotic ulcer and aneurysm rupture. All these life-threatening conditions require prompt diagnosis and appropriate management. To date multi-detector row Computed Tomography represents a valuable diagnostic tool especially in the emergency setting. This paper focus on the use of multi-detector row Computed Tomography in the evaluation of acute thoracic aortic syndromes and illustrates the key imaging findings related to each disease.     

Intramural hematoma of the ascending aorta secondary to descending thoracic aortic penetrating ulcer: findings in two patients

The authors describe two cases of penetrating ulcers of the descending thoracic aorta associated with intramural hematoma of the ascending aorta. Since neither patient had evidence of diffuse thoracic aortic atherosclerosis to limit longitudinal extent of spread, it is postulated that the intramural hematoma started at the level of the penetrating ulcer and extended into the ascending aorta in a retrograde fashion. This is a potentially lethal entity, not previously described, for which the optimal clinical management is unknown.     

Penetrating atherosclerotic aortic ulcer with dissecting hematoma: control of bleeding with percutaneous embolization

A case is presented in which left subpleural hematoma and hemothorax resulted from a penetrating atherosclerotic aortic ulcer with an aortic pseudoaneurysm and intramedial hematoma. Percutaneous transfemoral embolization of the ulcer with use of coils and thrombin resulted in stabilization of the patient's hemodynamic status. The patient died 6 days later of pneumonia. In certain clinical situations, treatment of bleeding from penetrating aortic ulcers with percutaneous embolization may stabilize the patient's condition, allowing elective surgical intervention.     

Penetrating atherosclerotic ulcer of the descending thoracic aorta: Treatment by endovascular stent-Graft

Purpose: To present four cases of penetrating ulcer of the descending thoracic aorta treated by transfemoral insertion of an endoluminal stent-graft. Methods: Four patients with penetrating aortic ulcers were reviewed. Three cases were complicated by rupture, false aneurysm, or retrograde dissection. All patients were treated by endovascular stent-graft and were followed by helical computed tomography (CT). Results: Endovascular stent-graft deployment was successful in all patients. However, in one case we observed a perigraft leak that spontaneously disappeared within the first month, and two interventions were needed for another patient. Following treatment, one episode of transient spinal ischemia was observed. The 30-day survival rate was 100%, but one patient died from pneumonia with cardiac failure 34 days after the procedure. In one patient, helical CT performed at 3 months showed a false aneurysm independent of the first ulcer. This patient refused any further treatment and suddenly died at home (unknown cause) after a 6-month follow-up period. Conclusion: Transluminal placement of endovascular stent-grafts for treatment of penetrating ulcers of the descending thoracic aorta appears to be a possible alternative to classical surgery. After treatment, follow-up by CT is essential to detect possible complications of the disease.     

特殊类型主动脉夹层的电子束CT表现及诊断

目的探讨表现特殊的主动脉夹层的电子束CT(EBCT)影像特征及诊断.材料和方法20例表现特殊的主动脉夹层,其中不典型夹层13例,三腔以上夹层动脉瘤3例,合并升主动脉壁内血肿的Stanford B型夹层2例,动脉瘤样夹层1例,外伤性主动脉夹层1例.结果主动脉不典型夹层为主动脉壁新月形或环形的低密度血肿包绕,常可见穿透性溃疡或钙化内移等征象;三腔以上夹层动脉瘤有2～3个内膜片,3～4个腔,瘤体管径较大;合并升主动脉壁内血肿的B型夹层见升主动脉管壁低密度新月形或环形增厚,降主动脉则见内膜片及真假两腔形成;动脉瘤样主动脉夹层见降主动脉局限性瘤样扩张,破口大,内膜片不易发现.1例外伤性夹层于主动脉弓峡部及降部起始见破裂内膜片.结论特殊类型的主动脉夹层表现各具特征,EBCT可清晰显示,是极适用于胸部急症的快速、无创的检查方法.     

粥样硬化性主动脉溃疡的MSCTA诊断

目的 利用多层螺旋CT血管造影（MSCTA）探讨粥样硬化性主动脉溃疡的影像学表现,以期进一步提高对本病的认识.方法 回顾分析我所经MSCTA诊断的粥样硬化性主动脉溃疡患者23例,男19例,女4例,年龄44～75岁,平均（58.5±11.3）岁.图像经工作站后处理后,对病变的部位及征象进行分析.结果 23例患者共42处病灶,位于升主动脉1例（4.3％）,主动脉弓17例（73.9％）,降主动脉3例（13.0％）,腹主动脉2例（8.7％）.溃疡可表现为蘑菇形、半圆形,可见“狭颈征”.结论 MSCTA对于诊断粥样硬化性主动脉溃疡有着重要的意义,可为临床治疗提供有意义的影像学依据.     

急性壁间血肿合并穿透性主动脉溃疡的MSCTA诊断

目的评价多层螺旋CT血管造影(MSCTA)技术在急性壁间血肿合并穿透性溃疡的临床应用价值。方法对20例急性壁间血肿合并穿透性溃疡患者行MSCTA检查,结合二维和三维重建技术进行图像分析。结果按照Stanford分型,A型:5例,B型:15例。所有病例均未显示真假腔及撕裂内膜片,均合并主动脉穿透性溃疡。主动脉壁间血肿(aortic intramural hematoma,IMH)表现为主动脉壁"环"形或"新月"形增厚,伴钙化内膜内移12例,胸腔积液8例,心包积液4例。穿透性溃疡20例共28个病灶,表现为主动脉壁上的溃疡样突起(ulcerlike pro-jection,ULP),其中穿透性主动脉粥样硬化性溃疡(penetrating atherosclerotic ulcer,PAU)14例共22个(79%)病灶,6个(21%)ULP病灶均单发。结论 MSCTA是一种有效、无创的诊断急性壁间血肿合并穿透性溃疡的检查方法,能为临床诊断和治疗提供重要信息。     

Long-Term Follow-Up After Endovascular Treatment of Acute Aortic Emergencies

Purpose To investigate the long-term outcome and efficacy of emergency treatment of acute aortic diseases with endovascular stent-grafts. Methods From September 1995 to April 2007, 37 patients (21 men, 16 women; age 53.9 ± 19.2 years, range 18–85 years) with acute complications of diseases of the descending thoracic aorta were treated by endovascular stent-grafts: traumatic aortic ruptures (n = 9), aortobronchial fistulas due to penetrating ulcer or hematothorax (n = 6), acute type B dissections with aortic wall hematoma, penetration, or ischemia (n = 13), and symptomatic aneurysm of the thoracic aorta (n = 9) with pain, penetration, or rupture. Diagnosis was confirmed by contrast-enhanced CT. Multiplanar reformations were used for measurement of the landing zones of the stent-grafts. Stent-grafts were inserted via femoral or iliac cut-down. Two procedures required aortofemoral bypass grafting prior to stent-grafting due to extensive arteriosclerotic stenosis of the iliac arteries. In this case the bypass graft was used for introduction of the stent-graft. Results A total of 46 stent-grafts were implanted: Vanguard/Stentor (n = 4), Talent (n = 31), and Valiant (n = 11). Stent-graft extension was necessary in 7 cases. In 3 cases primary graft extension was done during the initial procedure (in 1 case due to distal migration of the graft during stent release, in 2 cases due to the total length of the aortic aneurysm). In 4 cases secondary graft extensions were performed—for new aortic ulcers at the proximal stent struts (after 5 days) and distal to the graft (after 8 months) and recurrent aortobronchial fistulas 5 months and 9 years after the initial procedure—resulting in a total of 41 endovascular procedures. The 30-day mortality rate was 8% (3 of 37) and the overall follow-up was 29.9 ± 36.6 months (range 0–139 months). All patients with traumatic ruptures demonstrated an immediate sealing of bleeding. Patients with aortobronchial fistulas also demonstrated a satisfactory follow-up despite the necessity for reintervention and graft extension in 3 of 6 cases (50%). Two patients with type B dissection died due to mesenteric ischemia despite sufficient mesenteric blood flow being restored (but too late). Two suffered from neurologic complications, 1 from paraplegia and 1 from cerebral ischemia (probably embolic), 1 from penetrating ulcer, and 1 from persistent ischemia of the kidney. Five of 9 (56%) patients with symptomatic thoracic aneurysm demonstrated endoleaks during follow-up and there was an increase in the aneurysm in 1. Conclusion Endovascular treatment is safe and effective for emergency treatment of life-threatening acute thoracic aortic syndromes. Results are encouraging, particularly for traumatic aortic ruptures. However, regular follow-up is mandatory, particularly in the other pathologies, to identify late complications of the stent-graft and to perform appropriate additional corrections as required.     

Penetrating aortic ulcers: diagnosis with MR imaging

The authors studied seven patients with penetrating aortic ulcers with use of magnetic resonance (MR) imaging. All patients were evaluated for acute chest symptoms, and the presence of aortic ulcers was confirmed by means of angiography in all seven patients. Five patients also underwent computed tomography (CT). Three patients underwent surgical repair of the thoracic aorta. MR findings included intramural hematoma and focal aortic wall ulceration in four patients, focal ulceration in one, focal intramural hematoma in one, and focal intramural hematoma with rupture in one. The diagnosis of intramural hematoma was made by the detection of increased signal intensity on T1- and T2-weighted MR images. MR imaging was superior to angiography in depicting the extent of intramural thrombus, although one ulceration diagnosed at angiography was missed at MR imaging. MR imaging was superior to CT in differentiating acute intramural hematoma from atherosclerotic plaque and chronic intraluminal thrombus, although it did not depict displaced intimal calcification in one patient with extensive intramural hematoma.     

运动影响ApoE~(-/-)小鼠动脉粥样硬化形成的形态学研究

目的:探讨运动对动脉粥样硬化(AS)斑块和主动脉病理形态变化的影响。方法:以30只8周龄的ApoE基因敲除小鼠(ApoE-/-小鼠)建立AS模型,分为ApoE-/-小鼠安静组(n=15)和ApoE-/-小鼠运动组(n=15),15只C57BL/6J小鼠为同源对照安静组。ApoE-/-小鼠饲以"西方膳食"饲料,C57小鼠饲以普通饲料。运动组进行中等强度跑台运动,前6周由10m/min×30min渐增至13m/min×60min,后6周以稳定的运动量(13m/min,60min)进行运动,每周5次。12周实验结束后,采用光学显微镜、体视显微镜及图像分析系统,从形态学角度观察各组小鼠主动脉斑块面积,主动脉大体病理形态、组织学结构及主动脉内膜、中膜厚度。结果:ApoE-/-小鼠安静组主动脉弓、分支口和腹主动脉形成斑块,多为纤维粥样硬化期病变,弹力纤维断裂多见,中膜空泡变性。ApoE-/-小鼠运动组斑块较ApoE-/-小鼠安静组减少,多为早期脂纹脂斑病变,弹力纤维断裂和中膜病变均减轻。经图像分析,ApoE-/-小鼠运动组斑块面积,内膜(I)、中膜(M)厚度及I/M比值较ApoE-/-小鼠安静组减少。结论:运动可减少高脂饮食导致的斑块形成,减轻AS的主动脉壁组织损伤,从而抵御主动脉壁的脂质沉积,延缓AS进程。     

Penetrating atherosclerotic ulcers of the descending thoracic aorta: evaluation with CT and distinction from aortic dissection.

Penetrating atherosclerotic ulceration of the aorta is a poorly understood entity that clinically mimics classic aortic dissection but has imaging features that are distinctly different. In a review of 16 patients with penetrating atherosclerotic ulceration, patients were typically hypertensive (n = 14), and they experienced chest or back pain (n = 13). All patients had an abnormal chest radiograph, with diffuse (n = 14) or focal (n = 2) enlargement of the descending thoracic aorta. Features at contrast material-enhanced computed tomography (CT) included intramural hematoma (n = 16), focal ulcer (n = 15), displaced intimal calcification (n = 13), pleural and/or extrapleural fluid (n = 7), mediastinal fluid (n = 4), and a thick or enhancing aortic wall (n = 6). The chest radiograph and CT findings were compared in patients treated conservatively (n = 9) and surgically (n = 7). These findings did not correlate with the need for surgery. Eight of nine conservatively treated patients were asymptomatic after treatment with antihypertensive medication. Contiguous dynamic contrast-enhanced CT of the aorta enables distinction of ulceration from dissection, which is particularly important in the hemodynamically unstable patient because the surgical management of ulceration is more extensive than that for aortic dissection.     

Aortic branch artery pseudoaneurysms accompanying aortic dissection. Part II. Distinction from penetrating atherosclerotic ulcers

PURPOSE: Small collections of contrast material are frequently seen within the otherwise thrombosed false lumen of an aortic dissection (AD). These collections can be divided into those without apparent communication with the aortic lumen (ie, pseudoaneurysms) and those with obvious communications (ie, ulcers). The present study was performed to test the hypotheses that pseudoaneurysms and ulcers differ in their distribution around the aorta and that the distribution of pseudoaneurysms is similar to that of small aortic branch arteries. MATERIALS AND METHODS: Computed tomography (CT) scans in 187 patients with AD and thrombosed false lumens showed 335 intramural contrast medium collections, including 128 pseudoaneurysms and 207 ulcers. CT scans in 40 control individuals without AD were reviewed to localize small aortic branch arteries. The angular distributions around the circumference of the aorta of pseudoaneurysms and ulcers and the branch artery origins were tabulated and compared. The frequency of detection of small branch arteries arising from the contrast material collections was noted. RESULTS: The angular distribution of pseudoaneurysms did not differ significantly from that of branch artery origins but did differ from that of ulcers. Pseudoaneurysms were found along the posterior, medial, and anterior walls of the aorta in the chest, sparing the lateral wall abutting the pleura. Ulcers tended to spare the arc containing branch artery origins. The composite distribution of ulcers and pseudoaneurysms appears uniform around the circumference of the aorta except at the T10-T12 levels. CONCLUSIONS: Branch artery pseudoaneurysms spare the pleural surface of the aorta and have nearly the same distribution around the circumference of the aorta as the origins of small aortic branch arteries. In contrast, ulcers tend to spare branch artery origins. The characteristic appearance and distribution of pseudoaneurysms on CT can help differentiate them from ulcers.