Acute and chronic aortic dissection

Each year acute aortic dissection is diagnosed in 2,000 individuals in the United States. Acute aortic dissection is no longer a catastrophic event because this problem can be rapidly diagnosed with current medical technology, and therefore promptly treated with medication and surgery. Consequently, patients with aortic dissection can survive for 10 to 20 or more years after the initial event. However, there is considerable current debate regarding the most optimal technique(s) for the diagnosis of aortic dissection. Moreover, little information is available on the best methods for the long-term assessment and treatment of patients who have been successfully treated for acute aortic dissection. This report reviews the current techniques that are available for the diagnosis of aortic dissection and discusses the important issues regarding the acute and long-term treatment of patients with this problem.     

Stenting of the aortic arch and the supra-aortic vessels,in a patient with DeBakey type I dissection

BackgroundAortic dissection (AD) is a medical condition which requires emergent surgical intervention for dissection type I and II DeBakey. Despite advances in diagnostic and therapeutic modalities, mortality is still high. Additional tears, critical true lumen compression and obliteration with end-organ ischemia can compromise acute and chronic clinical outcomes after surgical intervention of AD. Endovascular treatment with non-covered stent implantation can be the treatment of choice for these cases. Thus the purpose includes closure of the proximal entry tear, depressurization of the false lumen, leading to its thrombosis, redirection of the blood flow toward the true lumen and induction of “aortic remodeling” process.     

Diagnosis and Management of Acute Aortic Syndromes: Dissection,Intramural Hematoma,and Penetrating Aortic Ulcer

Acute aortic syndromes constitute a spectrum of conditions characterized by disruptions in the integrity of the aortic wall that may lead to potentially catastrophic outcomes. They include classic aortic dissection, intramural hematoma, and penetrating aortic ulcer. Although imaging studies are sensitive and specific, timely diagnosis can be delayed because of variability in presenting symptoms and the relatively low frequency with which acute aortic syndromes are seen in the emergency setting. Traditional classification systems, such as the Stanford system, facilitate early treatment decision-making through recognition of the high risk of death and major complications associated with involvement of the ascending aorta (type A). These patients are treated surgically unless intractable and severe co-morbidities are present. Outcomes with dissections that do not involve the ascending aorta (type B) depend on the presence of acute complications (e.g., malperfusion, early aneurysm formation, leakage), the patency and size of the false lumen, and patient co-morbidities. Patients with uncomplicated type B dissections are initially treated medically. Endovascular techniques have emerged as an alternative to surgery for the management of complicated type B dissections when intervention is necessary. Patients with acute aortic syndromes require aggressive medical care, risk stratification for additional complications and targeted genetic assessment as well as careful long-term monitoring to assess for evolving complications. The optimal care of patients with acute aortic syndrome requires the cooperation of members of an experienced multidisciplinary team both in the acute and chronic setting.     

Acute aortic dissection developing acute myocardial infarction diagnosed by accidentary inserting the catheters into the false lumen during catheterization: a pitfall and rare image

A case of acute aortic dissection complicating acute inferior myocardial infarction diagnosed by accidentally inserting the catheters into the false lumen during the emergency cardiac catheterization is reported. Although the incidence of acute aortic dissection developing acute myocardial infarction is not very rare, an aortogram and coronary angiogram via the false lumen has never been seen before. This case also illustrates how myocardial infarction can mask aortic dissection. Cardiologists should pay more attention to this severe complication of acute aortic dissection and perform transthoracic echocardiography prior to catheterization or fibrinolysis.     

Aortic dissection: a 250-year perspective

Two hundred fifty years have passed since Frank Nicholls' history-making, accurate observations on the anatomic findings and cause of death of King George II were published. Several decades later, the disease was named, using--for the first time--the terms dissection and dissecting attached to an aortic disease process. Another century went by before effective surgical treatment was developed. In sharp contrast, the evolution of the last 20 years has been nothing short of amazing. Our understanding of AD, while not yet complete, has improved dramatically. In addition, the introduction of nonsurgical endovascular therapy has had a profoundly transformative impact--and we are just at the beginning! It would not be unreasonable to predict that stent-graft repair will likely replace (or nearly replace) open surgery in the treatment of complicated type B dissection in the near future, especially as technologies continue to improve and indication-specific designs are developed and tested in the clinical setting. Moreover, it is predictable that endovascular solutions for some patients with type A aortic dissection will become available in the years to come as surgical results continue to be suboptimal. Finally, and amidst this plethora of “good news,” it is appropriate to reflect on the formidable challenge that endovascular therapies face as they gear to “compete” with optimal medical therapy in the management of patients with acute uncomplicated type B dissection, because it will obviously be difficult (if not impossible) to improve on the already-achieved 30-day mortality rate of less than 10%. Long-term gains may well become the winning card when and if the late results of TEVAR can be shown to improve on the rather compromised outlook of medically treated dissection patients. Stay tuned.     

Transcatheter Inoue endovascular graft for treatment of canine aortic dissection

Summary We examined whether the Inoue endovascular graft could be used as a device for the treatment of aortic dissection. This graft consists of a cylinder made from a thin Dacron sheet suspended by several extra-flexible wire rings. Aortic dissections were experimentally created in 11 dogs. Using aortography and intravascular ultrasound imaging (IVUS), we selected the size of the graft diameter according to the diameter of the normal descending aorta (distal to aortic dissection) in 5 dogs (group I) and according to the diameter of the true lumen of the aorta within the aneurysm in 6 dogs (group II). The graft was deployed transfemorally through a 15-F long sheath into the aneurysm to close the entry site, immediately after creation of the aortic dissection. The entry was completely closed in all dogs after immediate implantation. All 5 dogs in group I died within 11 days (mean, 7 days) after graft deployment. However, all grafts in group II were tolerated very well and followed up for as long as 5 months. After the follow up, IVUS and aortography showed no rupture of the aortic aneurysmal wall and no migration, leakage, or damage to the graft in any of the 6 dogs. These 6 dogs were sacrificed and autopsy showed that the graft was covered by a thin, translucent, neointima, effectively recreating a new aortic lumen and completely closing the entry of the aneurysm. The Inoue endovascular graft proved to be effective in the long-term treatment of aortic dissection without surgery, when the size of the graft was selected according to the diameter of the true lumen of the aorta within the aneurysm.     

Intraoperative echocardiography for diagnosis and treatment of aortic dissection. Utility of color flow mapping for surgical decision making in acute stage.

In the past eight years until July 1992, 92 patients were admitted in the acute state of aortic dissection within two weeks from the onset of symptoms. 41 were diagnosed as Stanford type A and 51 were type B by transthoracic and transesophageal echography, computer tomography, and surgery. Sensitivity of transesophageal echography to detect the intimal flap and the false lumen was 97.6% in patients with Stanford type A and 100% in patients with Stanford type B. The surgical decision making has been mostly depending on the transesophageal echographic diagnosis. When the intimal flap was detected in the ascending aorta (Stanford type A) surgery was performed in emergency regardless of any evidence of rupture, cardiac tamponade, and severe aortic regurgitation. When the aortic dissection was detected only in the descending aorta (Stanford type B) the main course of therapeutic strategy in our institute was medical treatment. Surgery was performed on 37 patients of type A and nine patients of type B with mortality of 18.9% and 55.5% respectively. Four patients of type A and 42 patients of type B were treated medically with a mortality of 75.0% and 2.2% respectively. The relatively large leakages from the anastomosis of the aortic clamp site were repaired secondarily in two patients, and fenestration of the superior mesenteric artery was performed on one patient due to ischemia of the small intestine depending on the intraoperative direct scanning of color flow mapping. Coronary artery involvement of dissection was strongly suspected in two patients by intraoperative transesophageal echography and aortocoronary bypass grafting was performed on these patients. Perfusion problems was encountered in five of 37 patients with type A aortic dissection (13.5%) during cardiopulmonary bypass. Intraoperative transesophageal echography could clearly detect the hemodynamic changes in the descending aorta resulting from inadequate perfusion which was useful for the management of perfusion control during cardiopulmonary bypass. Secondary repair of the aortic arch was required due to ischemia of the aortic arch vessels in two patients after the primary surgery. The extension of the dissection into the aortic arch vessels can be promptly diagnosed with the combination of transesophageal echography and transcutaneous echography. In conclusion, transesophageal Doppler echography is the most rapid diagnostic tool for decision making in acute aortic dissection, and intraoperative transesophageal echo can provide useful information to resolve the perfusion difficulties during cardiopulmonary bypass.(ABSTRACT TRUNCATED AT 400 WORDS)     

管腔内支架人工血管治疗急性胸降主动脉夹层动脉瘤

目的 探讨管腔内支架替代传统手术治疗急性胸降主动脉夹层动脉瘤的可行性及效果.方法 从2003年6月至2005年6月,12例急性胸降主动脉夹层动脉瘤患者接受管腔内支架人工血管治疗.结果 12例患者无死亡.共放支架12支,胸降主动脉受压夹层真腔全部恢复正常管径,无中转手术.术后3个月、1年随访,行CTA检查未发现与支架有关的并发症.结论管腔内支架人工血管治疗急性胸降主动脉夹层动脉瘤是一种有效的治疗方法.     

B型主动脉夹层累及肠系膜上动脉缺血侧支循环通路开放的初步研究

目的:探讨B型主动脉夹层累及肠系膜上动脉缺血灌注不良时侧支循环形成的临床意义。方法:回顾性分析2015年9月至2018年10月,就诊于我科的B型主动脉夹层累及肠系膜上动脉缺血灌注不良的15例患者影像学资料,男性14例,平均年龄51.4岁(38~66岁)。分析患者腔内修复手术前后主动脉CTA图像,测量肠系膜上动脉水平主动脉真腔和假腔面积,分别对肠系膜上动脉缺血灌注不良的类型、侧支循环通路开放情况及术后肠系膜上动脉灌注归转状况进行评估。结果:术前主动脉CTA显示,7例肠系膜上动脉属动力型缺血,其中3例侧支循环通路开放(2例腹腔干-肠系膜上动脉循环通路、1例肠系膜下动脉-肠系膜上动脉循环通路);8例肠系膜上动脉属静力型缺血,其中7例侧支循环通路开放(5例肠系膜下动脉-肠系膜上动脉循环通路、2例为腹腔干-肠系膜上动脉循环通路)。15例患者均成功行腔内修复术。术后主动脉CTA显示,肠系膜上动脉开口水平主动脉真腔面积占比增加(52.5%vs.33.4%,P<0.005)。7例属动力型缺血和6例属静力型缺血患者灌注改善且侧支循环通路未再开放。另2例属静力型缺血患者肠系膜上动脉灌注类型维持不变且侧支循环通路仍开放。结论:对于B型夹层累及肠系膜上动脉缺血灌注不良患者,侧支循环通路的开放缓解肠系膜上动脉缺血灌注不良状况。主动脉腔内修复术不仅可以有效隔绝夹层原发破口防止破裂而且能改善肠系膜上动脉缺血灌注情况。     

Recognition and management of thrombosed type of aortic dissection with long-term follow-up results

In a previous report we have stated that two distinct types of aortic dissection exist, namely the opened-communicated type (O-type) which demonstrates communication between the true lumen and the false lumen, and the thrombosed type (T-type, also known as aortic dissecting hematoma or as intramural hematoma). The latter, in its acute phase, shows no opacification of the false lumen through medical imagings such as CT scans or angiography. In previous studies we analyzed the long-term follow-up results of consecutive patients with aortic dissections at our hospital.During the past 14 years a study has been conducted of a total of 466 consecutive patients including 371 who were classified O-type and 95 who were classified as T-type. In 18 T-type patients (19%), complications such as cerebral ischemic episodes were observed. These were, however, transient and not serious, sometimes indicating only minor surgery. Only three T-type patients were indicated for surgery in the follow-up period, two because of the extension of a protruded lesion, and one because of the occurrence of redissection. Three of these died, but the actuarial survival rate of the T-type group was significantly higher than that of the O-type group. In conclusion, it can be stated that at the acute phase, a differentiation between the two types of dissection, ie, T-type and O-type, is important in the deciding of treatment.     

Surgical therapy of thoracic aortic dissection]

Considerable surgical progress of treating aortic dissection has been achieved during the past decade. The emergency indication for acute dissection of the ascending aorta (type A according to the Stanford classification) is unquestioned while surgical treatment for acute dissection of the descending aorta (type B dissection) is mainly reserved for complicated cases. The major complication of acute operations--fatal hemorrhage from the suture line and secondary multi-organ failure--have been successfully reduced by a progress of cardiopulmonary bypass techniques, the introduction of cold cardioplegic myocardial protection, the development of modern suture materials and glues and last not least by a continuous intensive monitoring. Especially the introduction of the so-called french glue safely enabled both the closure of the false lumen as well as the strong reinforcement of the diseased aortic wall and seems to offer a reliable alternative to the application of multi-layered teflon strips. Since the principle of all reconstructive approaches in case of dissection consists of closure of dissected layers and the limited replacement of the segment that is susceptible to a rupture the exact readaptation and reinforcement of the diseased aortic wall represents a fundamental operative step. In type A operations the supracoronary aortic prosthetic replacement or the combined replacement of ascending aorta plus aortic valve followed by the reattachment of coronary arteries has become the standard operative technique. In fact, independently from the location of the primary intimal tear the operation has been traditionally limited to replace the ascending aorta in order to remove an aortic segment that is most likely to rupture. Yet an increasing number of follow-up investigations has demonstrated recurrence of dissection or an aneurysmatical dilatation of the false lumen in about 20% of patients treated with ascending aortic replacement. Consequently, repair of the aortic transverse arch and the radical elimination of the intimal entry is now favoured by an increasing number of surgeons. In addition to these various perioperative and intraoperative adjuncts the introduction of new imaging techniques, especially computerized tomography, magnetic resonance imaging and transesophageal echocardiography allowed to establish adequate therapeutical concepts on a more rational basis. Transesophageal echocardiography as a mobile diagnostic device enables investigators to perform a bed-side dynamic visualization of both the location and extent of a dissection, the evaluation of ventricular performance and aortic competence. Treatment of acute type B dissection is mainly conservative unless complications like intractable pain, aneurysmatic enlargement of the false lumen, ischemia of visceral organs or even rupture occur.(ABSTRACT TRUNCATED AT 400 WORDS)     

非编码RNA在主动脉夹层中的研究进展

主动脉夹层是指主动脉内膜由自身或外界因素导致内膜撕裂,腔内血液经内膜破口进入动脉壁中层形成的夹层血肿。主动脉夹层是一种危险的急性病,如果主动脉夹层完全撕裂,将会迅速失血导致循环衰竭而立刻死亡。尽管如此,目前对主动脉夹层的机制研究还知之甚少。非编码RNA是一种独立存在的RNA转录本,占人类基因组RNA的90%以上,通常不编码蛋白质,而是作为维持正常生理功能的重要调控因子。迄今为止,已有多项研究证明非编码RNA参与心血管疾病的调控。因此,对于主动脉夹层中非编码RNA的研究引起了人们的广泛关注。本文综述了非编码RNA在主动脉夹层中的作用机制,并强调了非编码RNA作为主动脉夹层的生物标志物以及靶向主动脉夹层潜在的预防与治疗手段,为将来开发以非编码RNA为载体的靶向药物提供广泛的思路。     

Emergency surgical management of acute aortic dissection: role of transesophageal echocardiography.

The accuracy of transesophageal echocardiography in the diagnosis and surgical management of acute aortic dissection was determined in 54 patients who underwent surgery for acute aortic dissection. Results of the investigations were compared to the surgical assessment. From April 1993 to November 1997, we operated 54 patients (44 male and 10 female) for acute aortic dissection. Mean age was 60 +/- 9 years. At surgery, a De Bakey type I aortic dissection was diagnosed in 30 patients, type II in 23 and type III retrograde in 1. Operating procedures were: replacement of ascending aorta (24 cases), replacement of ascending aorta and aortic arch (17 cases), replacement of ascending aorta and aortic valve replacement (2 cases), Bentall procedure (6 cases) and end-to-end anastomosis of the ascending aorta (4 cases). Initial diagnosis, performed in emergency wards, was done on a clinical basis in 6 patients, on CT scan in 19, on transthoracic echocardiography in 14, and on TEE basis in 12. Three patients underwent angiography before our evaluation. As per our protocol, all patients underwent confirmation of the diagnosis by TEE. Seven patients needed additional instrumental investigations, 2 with CT scan and 5 with angiography. TEE confirmed the diagnosis of aortic dissection in all cases but one. Moreover, it described the site of the intimal tear, the extension of the dissecting process and accessory findings, such as pericardial effusion, aortic incompetence and left ventricular function. The interval between patient presentation and skin incision was a maximum of 70 minutes. At surgery, diagnosis of De Bakey classification was confirmed in 98% of cases; in 90.7% of cases exact location of the entry site was confirmed. In one case, an entry site in the arch diagnosed by TEE but not recognized at surgery, was observed at necropsy. Intraoperatively, we routinely used TEE to monitor retrograde systemic perfusion and correct implant of the vascular prosthesis. One case of malperfusion of the thoracic aorta through the false lumen was observed and managed. In one case we diagnosed acute obstruction of the prosthesis by bleeding in the wrapped aorta, which required reoperation. Assessment of ventricular function was obtained in all patients: in two cases, observation of low right ventricular function led us to perform aortocoronary by-pass to the right coronary artery. In conclusion, the high level of correspondence between TEE diagnosis and surgical anatomy prompted us to perform transesophageal echocardiography as the primary and often sole diagnostic procedure in acute aortic dissection. TEE, in experienced hands, has proven to be a highly reliable, safe and low-cost diagnostic tool. It can be performed at the patient's bedside within just a few minutes of the suspected diagnosis, thereby lowering the mortality rate of the natural history. Again, it can also be used in the operating theatre as an "on-line examination" as well as for assessment of correct surgical repair. Other diagnostic procedures do not yield more information and can cause dangerous delays in intervention.     

Simultaneous endovascular stent and renal stent placement for acute type B aortic dissection with malperfusion of kidney

Acute aortic dissection frequently causes life-threatening organ ischemia. The optimal therapy for acute type-B aortic dissection is still controversial. Surgery for acute dissection with organ malperfusion is known to carry a high morbidity and mortality; however endovascular treatment is becoming an alternative form of treatment. We report a clinical case of emergency percutaneous thoracal aorta endovascular stenting and renal artery stenting in a patient who had renal malperfusion and acute renal failure due to acute type-B dissection. The present case is a fundamental examples of collaboration between the cardiologist and cardiovascular surgeon in a hybrid procedure.     

分站式杂交手术治疗老年StanfordA型主动脉夹层

目的总结分站式一期杂交手术治疗老年StanfordA型急性主动脉夹层的临床经验及教训,探讨其可行性及适应证。方法2010年4月至2012年1月,广东省人民医院共8例老年（60岁以上）StanfordA型急性主动脉夹层患者接受分站式一期杂交手术治疗。8例患者均正中开胸,在中低温体外循环下以四分支人工血管行“升主动脉置换加主动脉弓去分支技术”。外科手术完成后送介入手术室逆行置入主动脉腔内覆膜支架。观察住院期间康复指标．定期复查全主动脉计算机断层扫描。观察人工血管通畅情况和夹层真假腔情况。结果本组患者无围术期死亡。体外循环时间（70．8_＋13．2）rain;主动脉阻断时间（37．8±6．5）min。患者术后呼吸机使用时间为2~16h,中位时间5h,住重症监护病房时间2—20d,中位时间2d。所有患者全部接受随访,随访时间3～27个月,中位时间13个月,所有患者均生存。术后3个月复查全主动脉增强计算机断层扫描,结果满意。结论分站式一期杂交手术处理老年StanfordA型急性主动脉夹层安全、有效,能明显缩短手术时间、术后呼吸机辅助时间和住院时间．减轻患者的创伤和痛苦,避免深低温停循环的风险,取得满意的近期效果。     

Percutaneous balloon-expandable stents for sealing of acute aortic dissection

Acute aortic dissection is a highly lethal disease. When dissection involves only the descending aorta and there are no ischemic complications, medical management may be the treatment of choice. However, a high risk of expansion or rupture of the dissection remains. When renal or limb ischemic complications do appear, surgery has been the only option, despite high mortality and morbidity. Percutaneous placement of stents for sealing an acute aortic dissection might be an alternative to surgical treatment. We treated 2 patients with acute type B aortic dissection by stent-fixation of the proximal and distal descending aorta. In both patients, there was evidence of persistent flap fixation at midterm follow-up.     

Aortic dissection surgery: experience of 78 cases.

From May 1990 to January 2001, 78 patients underwent surgery for aortic dissection, 68 (87%) of type A. Presentation was acute in 55 patients (71%). For type A dissection, in-hospital mortality was 13% (9 patients) and late mortality was 16%. For type B dissection, in-hospital and late mortality were both 30% (3 patients). The follow-up was complete and medical and imaging controls were performed periodically. Computerized axial tomography has shown persistence of distal aortic dissection in 18 patients, one of whom maintained dissection of the supraaortic trunks with false lumen thrombosis. Six patients maintained signs of dissection in the thoracic and abdominal aorta with patent false lumen. In another eight patients the false lumen was thrombosed. In 3 cases the dissection was located in the abdominal aorta. Two patients developed pseudoaneurysms of the thoracic aorta, one of whom was reoperated due to symptoms of dysphagia and chest pain, with angiographic signs of probable rupture of the aorta. Periodic imaging monitoring is essential, as it allows assessment of the extent of residual aortic disease and its evolution, with early detection of possible complications. This will enable prompt and safe action in those patients who may benefit from reoperation.     

Management of acute aortic syndromes

Acute aortic syndrome (AAS) describes the acute presentation of patients with characteristic "aortic pain" caused by one of several life threatening thoracic aortic conditions including aortic dissection, intramural hematoma or penetrating atherosclerotic ulcer. Recent advances in imaging and therapeutic techniques have emphasized the importance of early diagnosis of acute aortic syndrome because it is crucial for survival. Not just because the cardiovascular community knows little, the management of AAS remains a therapeutic challenge, while diverse surgical and percutaneous strategies for the treatment of aortic syndromes are continuously evolving. As a result of increasing knowledge and better management strategies in this area, the outcomes of patients treated for acute aortic syndromes have improved. This review discusses the etiology and clinical presentation, but mainly focuses on modern management and both established and emerging therapeutic approaches to acute aortic syndromes.     

Hybrid技术应用于Stanford B型主动脉夹层的近期疗效

目的探讨腔内隔绝术联合血管旁路移植术（Hybird技术）治疗破口位于弓部的StanfordB型主动脉夹层（AD）近期疗效。方法选择武汉亚洲心脏病医院2008年8月至2012年6月收治的StanfordB型AD37例,均采取腔内隔绝术,并在其术前行血管旁路移植术。其中男33例,女4例,年龄36-71（51．84±9．21）岁。主动脉夹层第一破口距左颈总动脉或左锁骨下动脉开口处均小于15mm。27例行右颈总动脉-左颈总动脉旁路移植术,2例行右颈总动脉一右锁骨下动脉旁路移植术,6例行左颈总动脉-左锁骨下动脉移植术,2例行左颈总动脉-左腋动脉移植术（左锁骨下动脉开口及近端均被夹层血肿挤压）。术后立即转人介入导管室行腔内隔绝术。共置入带膜支架42枚（双支架5例,其中4例应用带膜支架加裸金属支架）。结果（1）37例行血管旁路移植术及腔内隔绝术均顺利。术后8—24（17．97±3．88）d出院。其中1例院内死亡,近期死亡1例（随访证实出院后当日死亡,等同于近期）。其余病例均无内漏、截瘫、内脏器官缺血、脑部缺血和左上肢缺血症状,随访30d,均恢复良好。（2）术后11例出现发热,排除感染因素,考虑为腔内隔绝术后综合征,经对症处理后恢复。2例因人工血管吻合口出血再次行吻合术。2例新出现肾功能不全,分析为对比剂肾病,经治疗后恢复。术后有5例仍有胸背痛症状,复查主动脉增强CT无内漏出血,治疗后均好转出院。结论腔内隔绝术联合血管旁路移植术治疗累及主动脉弓的StanfordB型主动脉夹层是一种创伤小、疗效好的治疗方法。