Imaging of thoracic aortic dissection

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.     

老年主动脉瓣闭锁不全的彩色多普勒超声心动图研究

报告接受彩色多普勒超声心动图检查的老年患者162例，其中75例有不同程度的主要动脉瓣关闭不全（Ar)。老年（Ar)的病因构成与中，老年前期者明显不同，主动脉，瓣钙化及原因不明者的比例占多数（67％）。主动脉瓣钙化者Ar程度多较重。主动脉瓣钙化及原因不明Ar患者的其他三个瓣膜返流检出率及和程度均明显高于无Ar的老年患者。表明多瓣膜退行性病变是此类Ar患者的原因之一。     

淫羊藿总黄酮对肾上腺素β_1受体的特异性阻断作用

为探讨淫羊藿总黄酮（ＴＦＥ）对肾上腺素受体的作用，本实验用离体兔心房肌、主动脉及豚鼠气管观察了ＴＦＥ对肾上腺素全体的作用，结果ＴＦＥ（０．１３ｇ／Ｌ）抑制心房肌肌力和频率，并使异丙肾上腺素（ＩＳＯ）对心房肌正性频率作用的量效曲线平行右移，但无钙拮抗作用及Ｍ受体激动效应，且不影响ＩＳＯ对豚鼠气管条的负性肌力作用及去甲肾上腺囊（ＮＥ）对兔主动脉条的收缩作用。提示ＴＦＥ选择性阻断肾上腺素β_１受体。     

慢性夹层动脉瘤的磁共振检查

本文对6例慢性夹层动脉瘤的MR所见进行分析。对真腔、假腔、“双腔主动脉”、左室形态和信号对比进行了描述。强调MR非侵袭性检查的重要意义。     

Combined mortality and morbidity of direct surgical treatment of abdominal aortic aneurysm

Two hundred aneurysms of the abdominal aorta were treated surgically from 1980 to 1987 by the same surgeon. There were 187 men and 13 women whose mean age was 66.1 years. Nine patients were 80-years-old or more. Eighty-seven percent of patients had preoperative risk factors, 30% of which were coronary artery disease. The operative approach was through a transverse laparotomy in 188 patients compared to 11 midline incisions and one lumbotomy. An aortoaortic tube was inserted in 87 patients, a bifurcated prosthesis in 99, and a tube bypass in 14. Five patients (2.5%) died within the 30 day perioperative period. Death was due to colonic necrosis, right heart chamber thrombosis, renal failure after repeat operation for acute lower limb ischemia, and myocardial infarction associated with renal and respiratory failure. The morbidity rate was 15.7% (31 patients) and included seven neurologic accidents, four respiratory complications, five ischemic events of the lower limbs requiring reoperation and one amputation, four cardiac complications, two renal failures, one reversible colonic ischemia, one revision for incomplete hemostasis, one phlebitis, one sliding syndrome, and five minor infections or cutaneous complications. Mean duration of hospital stay was 10.9 days. These results confirm that direct operation on aortic aneurysms can be performed in patients from all age groups and even with associated diseases. A rapid, simple technique based on a transverse approach, minimal dissection and insertion of aortoaortic tubes, whenever feasible, appears to reduce combined mortality-morbidity.Presented at the Annual Meeting of the Societé de Chirurgie Vasculaire de Langue Française, May 20–21, 1988, La Grande Motte, France.     

芝麻素对代谢综合征大鼠主动脉内皮功能损伤的保护作用及机制

目的:观察芝麻素对代谢综合征大鼠主动脉内皮功能损伤的保护作用,探讨其可能机制。方法:高脂高糖诱导大鼠代谢综合征24周,于第9周开始连续口服芝麻素(120,60,30mg.kg^-1·d^-1)16周。测血压、血脂、血糖、血清过氧化氢和硝酸盐/亚硝酸盐含量;采用离体灌流系统,观察大鼠主动脉环对累积浓度去氧肾上腺素的收缩反应和对乙酰胆碱及硝普钠诱发的舒张反应;免疫组织化学法观察主动脉内皮型一氧化氮合酶(eNOS)表达和硝基酪氨酸(NT)含量。结果:芝麻素明显降低代谢综合征大鼠血压、血脂、血糖;提高主动脉环对乙酰胆碱诱导的舒张反应;上调主动脉eNOS表达,降低NT含量;升高血清硝酸盐/亚硝酸盐和减少过氧化氢含量。结论:芝麻素具有改善代谢综合征大鼠的内皮功能障碍,其机制可能与其降低氧自由基生成,上调主动脉eNOS表达,增加和(或)恢复NO的生物活性有关。     

Peripheral Seeding of Mycotic Aneurysms from an Infected Aortic Stent Graft

Aortic stent graft infection is rare and there are no reported cases of seeded peripheral mycotic aneurysms complicating this condition. We describe the case of a 54 year old man who developed a late stent graft infection at three years, resulting in the peripheral seeding of three mycotic aneurysms with two incidents of rupture. He was successfully treated with extra-anatomic bypass of the aorta and both surgical and endovascular repair of his peripherally seeded mycotic aneurysms.     

胆汁对豚鼠离体胆囊肌条收缩影响的实验研究

目的：观察不同浓度的胆汁对胆囊平滑肌运动的影响并初步探讨其作用机理。方法：将肌条置于离体平滑肌灌流肌槽内，用生理记录仪记录肌条的收缩活动。结果：(1)胆汁可降低离体胆囊肌条张力，减慢收缩频率，减小收缩波平均振幅。(2)心得安、L—NNA、六烃季胺可部分阻断胆汁对脂囊肌条的作用。结论：胆汁对豚鼠胆囊肌条的作用与肾上腺素能β受体、胆碱能N受体和N0有关。     

主动脉内球囊反搏改善冠状动脉旁路移植术预后

目的：探讨主动脉内球囊反搏（IABP）在冠状动脉旁路移植术的应用效果。方法：对7例冠状动脉旁路移植术围术期应用IABP的患者,监测使用IABP前和使用后2h、撤机前的血流动力学变化。结果：使用主动脉内球囊反搏后,收缩压（SBP）、平均动脉压（MAP）、中心静脉压（CVP）、心排指数（CI）和每小时尿量均有明显改善（P〈0.05）。结论：在冠状动脉旁路移植术中及时进行主动脉内球囊反搏,能够帮助高危患者平稳度过围术期。     

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.