Painless dissection of the thoracic aorta

A 64-year-old man presented to an emergency department with a two-week history of intermittent, bilateral lower extremity paralysis without associated chest, abdominal, or back pain. He subsequently deteriorated and died as a result of a thoracic aortic dissection. This unusual case is reported, and the pathophysiology, diagnosis, and management of aortic dissection are discussed.     

Cocaine-associated dissection of the thoracic aorta

Patients present to emergency departments with a variety of complications related to cocaine abuse. Emergency physicians must be aware of the life- and limb-threatening complications to avoid undue mortality and morbidity. We present the case of a patient with aortic dissection who developed the acute onset of abdominal pain 5 minutes after subcutaneous cocaine use. Four previous reports of cocaine-associated aortic dissection are reported in the literature. These cases and other reports of intra-abdominal vascular injuries related to cocaine use are reviewed. Cocaine's mechanism of action as it relates to aortic dissection and some of the pharmacologic agents available for treatment are discussed.     

急性胸降主动脉夹层的管腔内支架人工血管治疗

目的：评价管腔内支架人工血管替代传统外科手术治疗急性期胸降主动脉夹层动脉瘤的可行性和治疗效果。方法：自2000年3月至2002年1月，采用管腔内支架人工血管治疗急性胸降主动脉夹层动脉瘤患者20例，术前行胸部增强CT扫描。所用支架材料为国产形状记忆镍钛合金。结果：在20例患者共放支架血管22只，支架人工血管成功隔绝夹层原发破裂口19你（成功率为95％），胸降主动脉受压夹层真腔全部恢复正常内径，无支架治疗导致的死亡。1例病人手术后6h因严重再灌注损伤死亡（死亡率5％），转手术1例（转手术率5％）。术后1个月之内行增强CT复查，并在术后3月、6月和12月以及每年1次CT随访，未发现与支架人工血管有关的并发症。结论：管腔内支架人工血管治疗急性期胸降主动脉夹层动脉瘤具有良好的近期治疗效果，长期效果还有待进一步的研究。     

Asymptomatic dissection of the ascending aorta: diagnosis by transesophageal echocardiography

A young man with marfanoid habitus underwent transesophageal echocardiography to evaluate an aortic root abnormality visualized on transthoracic echocardiography. Transesophageal echo demonstrated a type A aortic dissection traversing across the right sinus of Valsalva but not involving the aortic valve, right coronary artery, or pericardial sac. The aorta was not dilated. This is apparently the first reported case of an asymptomatic and uncomplicated aortic dissection localized to the sinus of Valsalva.     

Factors influencing the mechanical behaviour of healthy human descending thoracic aorta

In recent times, significant effort has been made to understand the mechanical behaviour of the arterial wall and how it is affected by the different vascular pathologies. However, to be able to interpret the results correctly, it is essential that the influence of other factors, such as aging or anisotropy, be understood. Knowledge of mechanical behaviour of the aorta has been customarily constrained by lack of data on fresh aortic tissue, especially from healthy young individuals. In addition, information regarding the point of rupture is also very limited. In this study, the mechanical behaviour of the descending thoracic aorta of 28 organ donors with no apparent disease, whose ages vary from 17 to 60 years, is evaluated. Tensile tests up to rupture are carried out to evaluate the influence of age and wall anisotropy. Results reveal that the tensile strength and stretch at failure of healthy descending aortas show a significant reduction with age, falling abruptly beyond the age of 30. This fact places age as a key factor when mechanical properties of descending aorta are considered.     

Painless limited dissection of the ascending aorta presenting with aortic valve regurgitation

Aortic dissection is a medical emergency carrying high morbidity and mortality. Prompt diagnosis is sometimes difficult because of its varying presentations, but it is critical to the achievement of good clinical outcomes. This report describes 2 cases of painless aortic dissection that presented with aortic valve regurgitation. In both, the dissection was limited to the ascending aorta just distal to the aortic valve. These dissections were diagnosed by transthoracic and transesophageal echocardiography.     

Plaque and structural characteristics of the descending thoracic aorta using transesophageal echocardiography

The in vivo acoustic and structural characteristics of atherosclerosis in the descending thoracic aorta have not been well delineated. We prospectively evaluated the descending thoracic aorta of 147 patients (35 women and 112 men; age, 61 +/- 14 years) who underwent clinically indicated transesophageal echocardiography. Patients with suspected disease of the aorta were excluded. Thirty-eight patients (26%) had protruding plaques (men, 25%; women, 29%). Six patients had mobile intimal densities with the mobile area ranging up to 1 cm2. As expected, aortic lumen area was decreased (plaque-free, 3.53 cm2; plaque, 3.19 cm2; p less than 0.05) and wall area was increased (plaque-free, 1.51 cm2; plaque, 1.92 cm2; p less than 0.05) in the regions of the plaque. However, total arterial area was not increased (plaque-free, 5.04 cm2; plaque, 5.09 cm2; difference not significant) in a compensatory manner as observed in other arterial beds. Plaque gray scale was less than the gray scale of plaque-free wall (plaque-free, 141.2; plaque, 122.7; p less than 0.05) when compared at the same level of the descending thoracic aorta or with a second aortic plaque-free level (plaque-free, 150.4; plaque, 122.7; p less than 0.05). Standard deviation of gray scale level was similar between plaque and normal regions. Unsuspected protruding plaques in the descending thoracic aorta occurred in one quarter of the patients referred for routine transesophageal examination. Plaques tended to have lower echogenicity and were differentiated from plaque-free walls within patients. Plaque formation did not result in increased total arterial area. These data suggest that the degree or character of compensatory atherosclerotic remodeling in the highly elastic descending thoracic aorta may differ from other arterial beds.     

胸降主动脉瘤伴主动脉右弓右降手术的护理配合

目的探讨临床少见的右位主动脉弓、右位降主动脉、胸降主动脉瘤外科手术中的护理配合,以提高手术配合质量,减少手术相关并发症的发生。方法针对8例行右弓、右降胸降主动脉瘤手术的病例进行术前准备、麻醉配合、体位管理和皮肤保护、术中配合、术后交接等护理配合。结果8例患者于术后4～7h清醒,无左上肢缺血、无皮肤压伤感染等护理问题。结论术前心理护理、麻醉配合、正确的体位摆放以及充分显露术野和娴熟的手术配合是确保手术顺利进行的关键因素之一。     

Spontaneous retropharyngeal hematoma: an unusual presentation of thoracic aortic dissection

A 78-year-old woman presented to the Emergency Department with spontaneous ecchymosis and swelling of the neck. Ecchymosis was also evident on the posterior pharyngeal wall. A lateral soft tissue radiograph demonstrated a retropharyngeal hematoma, which was confirmed by computed tomography (CT). At this time there was no evidence of airway obstruction and she was admitted for observation. One week after admission she became acutely short of breath, and a chest radiograph at this time showed a large pleural effusion. Pleural drainage confirmed this to be a hemothorax. Subsequent CT revealed a thoracic aortic dissection with blood communicating into both the retropharyngeal space and the pleural cavity. The case highlights both an unusual presentation of thoracic aortic dissection, and also the potential for occult hemorrhage in cases of spontaneous retropharyngeal hematoma.     

Traumatic rupture of the thoracic aorta: a review

The frequency of traumatic injuries to the thoracic aorta has increased in recent years, paralleling the upward trend in the number of vehicular accidents. Blunt trauma is the predominant mechanism. In dealing with the survivors of the immediate impact, a high index of suspicion for aortic tears will allow the radiologist to recognize important signs on the chest roentgenogram; he will be able to direct further necessary steps and secure the diagnosis of an aortic tear. The following article will review the pertinent recent literature on the subject and emphasize a practical approach to the diagnosis of this not uncommon but life-threatening lesion.     

Spontaneous multiple cervical artery dissection: two case reports and a review of the literature

Although spontaneous cervical artery dissection (CAD) is an uncommon cause of stroke in the general population, it accounts for 10-25% of cerebrovascular events in young to middle-aged patients. Two or more vessels are involved in fewer than 15% of dissections, but multiple spontaneous CADs are likely to be underestimated owing to frequent spontaneous recanalization and the possible oligo-symptomatic presentation. An extensive review of the literature shows that in the last 30 years only 28 cases of multiple CADs have been reported, and that in half of these patients symptoms were minor and transient. We describe two cases of multiple spontaneous CADs presenting as transient ischemic attack (TIA), in which only a specific diagnostic flow-chart allowed us to recognize multiple vessel involvement and start the appropriate therapy.     

Epicardial adipose tissue thickness predicts descending thoracic aorta atherosclerosis shown by multidetector computed tomography

Human epicardial adipose tissue (EAT) is a type of visceral adipose tissue functioning as an endocrine organ by secreting hormones and adipocytokines which have an important role in the atherosclerotic process. In this study, we aimed to assess the relationship between EAT measured by dual source multidetector computed tomography (MDCT) and descending thoracic aorta (DTA) atherosclerosis. A total of 148 patients who underwent MDCT for the evaluation of coronary artery disease were enrolled in this study. Thickness of the EAT was measured on contrast enhanced multiplanar reformat images with parasternal short axis view at basal, mid-ventricular and apical levels and horizontal long axis view. The atherosclerotic plaque was scored from 0 to 4 points by the percentage of the luminal surface at the cross sectional area of proximal, mid and distal segments of descending aorta. Among the study population, 84 (56.8%) were male and age was (mean ± standart deviation) 56.9 ± 11.7 years. In patients with critical coronary atherosclerosis, DTA atherosclerosis had a significant relationship with EAT (P = 0.012). Multivariate linear regression analysis revealed that in addition to critical coronary stenosis, age and total epicardial fat thickness were associated with aortic atherosclerosis (β value, 0.058 and 0.035; t value, 4.74 and 2.28, respectively; P < 0.05) after adjustment for traditional cardiovascular risk factors. In this study we demonstrated that atherosclerotic plaque burden of DTA was associated with the amount of EAT thickness among patients with suspected CAD shown by MDCT. Further large scale prospective studies are needed to address the interaction of EAT as well as the mediators of inflammation and adipocytokines with the development of atherosclerotic plaques in aorta and effects on cardiovascular outcomes.     

Bicuspid aortic valve stenosis complicated by descending aortic dissection mimicking coarctation of the aorta.

We report a rare case of bicuspid aortic stenosis complicated by an ascending aortic aneurysm and aortic dissection of DeBakey type IIIb. A 35-year-old woman was admitted to our hospital to examine her systolic murmur identified at birth. Severe aortic stenosis, dilatation of the ascending aorta, and the narrow color flow signal in the descending aorta were detected by transthoracic echocardiography. Initially, coarctation of the descending aorta was suspected, but aortic dissection, DeBakey type IIIb, was revealed by transesophageal echocardiography. Transesophageal echocardiography is indicated when only insufficient information is available on valve and aortic morphology in patients with bicuspid aortic valve.     

Transesophageal echocardiographic detection of thoracic aorta dissection extending into the celiac artery.

Special positioning of a transesophageal echocardiography probe allows visualization of the superior portion of the abdominal aorta including the celiac artery branch. This case report describes a thoracic aorta dissection that extended into the abdomen and involved the celiac artery.     

Acute dissection of the aorta: a review for nurses

This article will review important elements involved in caring for the patient experiencing an acute dissection of the aorta. The etiology and classification system, signs and symptoms, diagnostic methods, indications for operation, circulatory arrest/deep hypothermia, surgical techniques, and complications of surgery will be discussed.     

Spontaneous spinal epidural hematoma of thoracic spine: a rare case report and review of literature

Spontaneous spinal epidural hematoma is a rare condition of spinal cord compression, and emergent decompressive surgery is strictly indicated. Early recognition, accurate diagnosis, and rapid treatment may result in decreased morbidity and improved outcome. Here, we present a case of a 50-year-old man who sustained sudden onset of severe back pain, followed by progressive weakness and numbness over bilateral lower limbs. Magnetic resonance imaging of thoracic spine demonstrated an epidural mass extending from T6 through T8, causing spinal cord compression. Emergent decompressive surgery was performed, and epidural hematoma was diagnosed postoperatively; the patient had significant improvement of neurologic deficits. The relevant literature is also reviewed.     

上下台阶方法的生物力学研究

目的：从运动学角度对不同上下台阶方法的差异进行比较分析，取得科学数值。方法：以3名健康青年男性为研究对象，利用三维动作分析系统(VICON612)及肌电图仪检测膝关节力矩和股四头肌收缩强度的变化值。结果：不同方法上下台阶时的膝关节力矩有差异，而膝关节屈曲角度未见明显不同；上台阶时的肌肉活动强度要比下台阶时大。结论：膝关节屈伸力矩、内外翻力矩以及股四头肌收缩强度均按正面一脚一阶、正面两脚一阶、横面两脚一阶、斜面两脚一阶的顺序逐渐减小。     

胸主动脉瘤破裂入左肺1例报告及文献分析

目的 对胸主动脉瘤破裂入左肺进行回顾性分析，旨在提高对胸主动脉瘤破裂入左肺的早期诊断和治疗的有效性。方法 结合1例报告，总结自1990年1月至2005年3月文献报道的胸主动脉瘤破裂入左肺16例病例。根据其有无感染、首发症状、胸主动脉瘤部位、侵入肺叶、手术方法及治疗效果进行分析。结果 胸主动脉瘤侵入左肺叶多数病程长，多合并肺部细菌和／或特异性感染，咯血是最常见的首发症状；来源于主动脉弓的瘤多侵入左肺上叶。手术多以全弓或次全弓切除及人工血管置换和左肺上叶切除术为主，而降主动脉瘤多侵入左肺下叶，手术以主动脉瘤切除及主动脉修补或血管置换术和左肺下叶切除为主；若无不可控制的大出血，预后较好。结论 胸主动脉瘤切除及人工血管置换术加侵入相应肺叶的切除术是治疗胸主动脉瘤侵入左肺的有效方法。     

肺动脉异常起源于升主动脉产前超声诊断并文献回顾

目的探讨肺动脉异常起源于升主动脉的产前超声图像特征。方法回顾性分析产前超声诊断的2例左肺动脉异常起源于升主动脉胎儿临床资料,总结肺动脉异常起源于升主动脉产前超声诊断特点,与引产后胎儿的高频超声及病理解剖结果进行对比,并对国内外相关文献进行回顾分析。结果 2例产前超声诊断左肺动脉异常起源于升主动脉均经尸体解剖证实,近端型与远端型各1例,1例合并法洛四联症,右位主动脉弓,动脉导管缺如;1例合并肺动脉瓣缺如,室间隔缺损,永存左上腔静脉,三尖瓣反流,右心增大。2例羊水染色体核型均正常。结论肺动脉异常起源于升主动脉有特征性超声表现,产前超声检查可作出诊断。