Cocaine mediated apoptosis of vascular cells as a mechanism for carotid artery dissection leading to ischemic stroke

In arterial dissection, blood may enter the arterial wall through an intimal tear, splitting the arterial wall and activating the coagulation cascade at the site of endothelial damage. Dissection of extracranial and intracranial vessels may lead to ischemic stroke through thromboembolic or hemodynamic mechanisms. Major blunt trauma or rapid acceleration-deceleration may cause dissection, but in patients with inherent arterial wall weakness, dissection can occur spontaneously or as a result of minor neck movement. Cocaine use has been associated with dissection of the aortic arch and coronary and renal arteries through cocaine-mediated hypertension. Recent preclinical studies have suggested, however, that cocaine may cause apoptosis of cells in the vascular wall. In this article, we postulate that cocaine may cause apoptosis of vascular endothelial and/or smooth muscle cells, thus weakening the vascular wall and resulting in a dissection-prone state. We review the literature and propose a biological basis for vasculopathy, vascular dissection, and ischemic stroke in the setting of cocaine use. Further research studies on vascular cells, as well as focused analysis of human pathological material, will be important in providing evidence for or against our hypotheses.     

D-二聚体与超敏C反应蛋白在急性主动脉夹层诊断中的研究

目的 分析D-二聚体(D-D)与超敏C-反应蛋白(hs-CRP)在急性主动脉夹层(AAD)早期诊断中的应用价值.方法2014年3月至2015年3月,分别检测105例AAD患者,其中典型主动脉夹层59例和非典型主动脉夹层46例,选择同期健康体检结果正常者44例(对照组)的血清D-二聚体和hs-CRP水平变化.结果 AAD发生后患者D-D和hs-CRP水平均不同程度升高.AAD组超敏C-反应蛋白和D-二聚体水平明显高于对照组(P<0.05);典型组与非典型组主动脉夹层患者血清D-dimer 水平比较差异具有统计学意义(P<0.05),而血清hs-CRP 水平则差异无统计学意义(P>0.05).结论在AAD早期诊断中,D-二聚体与超敏C-反应蛋白是有效、重要的筛选指标.     

Inflammatory response is associated with aortic dissection

Aortic dissection is an age-dependent life-threatening cardiovascular disease with high mortality rates. Recent research has shown that inflammation plays an important role in aortic dissection. Inflammatory cells, such as lymphocytes and macrophages, not only increase the expression of proteases and cell adhesion molecules but also release reactive oxygen species. These cells also contribute to apoptosis of smooth muscle cells in the aortic artery, and finally lead to medial degradation. This process has been considered to be the principal mechanism for aortic dissection. Furthermore, changes in systemic inflammatory biomarkers are associated with acute-phase reactions and complications in aortic dissection. These biomarkers are also used to predict the prognosis of aortic dissection and to distinguish acute aortic dissection from other chest pain diseases. In addition, elevated inflammatory cell activity in aortic wall, identified by positron emission tomography/computed tomography, is associated with serious clinical symptoms and leads to a poor clinical outcome in aortic dissection. Such observations may provide us with new sights into the mechanism of aortic dissection. In this review, we discuss the role of inflammation in the development and progression of aortic dissection. Understanding this inflammatory process may provide us with new strategies for pharmacological treatment of aortic dissection.     

Aortic dissection and bicuspid aortic valve: an autopsy study

Medico-legal post-mortems referred to the Department of Pathology, for the histopathological examination, revealed six cases of acute aortic dissection--two in isolation, three in combination with congenital bicuspid aortic valve; and one isolated case of congenital bicuspid aortic valve. One case of isolated aortic dissection was associated with Marfan's syndrome; and one case of aortic dissection with bicuspid aortic valve was associated with polycystic kidneys. History of hypertension could be elicited in two cases. Cystic medial degeneration of aorta was seen in three cases; one of which was associated with Marfan's syndrome. All five cases of aortic dissection belonged to type II of DeBakey classification.     

Acute aortic syndromes

The term acute aortic syndrome comprises in addition to classic dissection also two recently described entities--penetrating ulcer and intramural haematoma. Forty-two necropsy cases of acute aortic syndrome were encountered during the last six years--41 dissections and one penetrating ulcer; the intramural haematoma was not seen. According to the DeBakey classification, there were 26 dissections of type I, 8 of type II, 1 of type IIIA, and 4 of type IIIB; in 2 cases the dissection was confined to the abdominal aorta. The dissection had a chronic character in four cases. Aortic rupture was found in 24 cases (59%), most frequently (19x) into the pericardial cavity. The aortic dissection continued into aortic branches in 25 patients (61%), causing stenosis/obstruction of coronary arteries in 7, of branches of the arch in 20, of abdominal arteries in 12, and of renal arteries in 17 patients, respectively. Histologically, there were degenerative lesions of the Erdheim type in the media of 10 aortas (from 21 completely examined). As possible risk factors for aortic dissection there appeared hypertension in 32 patients, anuloaortic ectasia in 11, saccular aneurysm ot the abdominal aorta in 6, family history of dissection in 2, Marfan syndrome in 2, prolaps of the mitral valve in 2, and bicuspid aortic valve in 2 patients, respectively. The aortic dissection was iatrogenic in 7 patients, presenting as a complication of a cardiosurgical or invasive cardiological procedure.     

Acute ischemic stroke in aortic dissection: Case report and review of literature

The estimated incidence of aortic dissection ranges from 5 to 30 cases per million per year. Nearly 38% of cases are missed at an initial presentation due to the wide range of clinical symptoms. We report a survivor of an inadvertent thrombolysis in acute ischemic stroke, secondary to aortic dissection.     

Familial aortic dissection in absence of ascending aortic aneurysms: a lethal syndrome associated with precocious systemic hypertension

The interaction of elevated blood pressure and aortic metabolism in the genesis of aortic dissection is uncharacterized. A kindred with fatal familial aortic dissection in association with precocious systemic hypertension and in absence of a definable connective tissue syndrome has undergone genealogical, clinical, pathological, and biochemical evaluation. Six family members spanning three generations have died of acute dissection. Five men died at a mean age of 28 years (range 22-34), while the proband's paternal grandmother died at 62 years of age. All were hypertensive. A constellation of subtle clinical features points toward deficient integrity of connective tissues; however, major hallmarks of known connective tissue syndromes including aortic root ectasia or aneurysms are absent. Studies of cultured dermal and aortae fibroblasts of two of the proband's brothers mitigate against Ehlers-Danlos IV syndrome. This family's susceptibility to aortic dissection reflects the synergistic liability of coexistent elevated blood pressure and metabolic abnormalities in the genesis of aortic degeneration.     

Endovascular stent-graft placement for the treatment of acute aortic dissection.

BACKGROUND: The standard treatment for acute aortic dissection is either surgical or medical therapy, depending on the morphologic features of the lesion and any associated complications. Irrespective of the form of treatment, the associated mortality and morbidity are considerable. METHODS: We studied the placement of endovascular stent-grafts across the primary entry tear for the management of acute aortic dissection originating in the descending thoracic aorta. We evaluated the feasibility, safety, and effectiveness of transluminal stent-graft placement over the entry tear in 4 patients with acute type A aortic dissections (which involve the ascending aorta) and 15 patients with acute type B aortic dissections (which are confined to the descending aorta). Dissections involved aortic branches in 14 of the 19 patients (74 percent), and symptomatic compromise of multiple branch vessels was observed in 7 patients (37 percent). The stent-grafts were made of self-expanding stainless-steel covered with woven polyester or polytetrafluoroethylene material. RESULTS: Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months. CONCLUSIONS: These initial results suggest that stent-graft coverage of the primary entry tear may be a promising new treatment for selected patients with acute aortic dissection. This technique requires further evaluation, however, to assess its therapeutic potential fully.     

急性DeBakey I型主动脉夹层手术的围麻醉期管理

目的回顾总结深低温停循环下DeBakeyI型主动脉夹层血管置换手术38例,探讨其围麻醉期管理方法。方法 38例急性DeBakeyI型主动脉夹层患者,全身麻醉深低温停循环（DHCA）下完成手术,术中实施多脏器保护。结果该组患者均顺利完成手术,麻醉诱导、维持平稳;平均体外循环时间（192.39±29.76）min,深低温停循环时间为（48.2±13.5）min,选择性脑灌注时间为（46.42±11.25）min;30例病人8～24h完全苏醒,顺利脱机拔管,8例出现短暂神经功能异常,通过术后脑保护措施,72h完全苏醒拔管,1例病人双下肢肌力减退,5d后完全恢复;肾功能衰竭6例;手术3d后死亡4例,2例死于肾功能衰竭,1例死于肺栓塞,1例死于呼吸功能衰竭,死亡率为10%;全部患者无麻醉死亡。结论充分的术前准备、术中麻醉管理、重要脏器的保护是提高主动脉弓动脉瘤血管置换手术成功率的关键。     

Role of Re-entry Tears on the Dynamics of Type B Dissection Flap

Mortality during follow-up after acute Type B aortic dissection is substantial with aortic expansion observed in over 59% of the patients. Lumen pressure differential is considered a prime contributing factor for aortic dilation after propagation. The objective of the study was to evaluate the relationship between changes in vessel geometry with and without lumen pressure differential post propagation in an ex vivo porcine model with comparison with patient clinical data. A pulse duplicator system was utilized to propagate the dissection within descending thoracic porcine aortic vessels for set proximal (%circumference of the entry tear: 40%, axial length: 2 cm) and re-entry (50% of distal vessel circumference) tear geometry. Measurements of lumen pressure differential were made along with quantification of vessel geometry (n = 16). The magnitude of mean lumen pressure difference measured after propagation was low (~ 5 mmHg) with higher pressures measured in false lumen and as anticipated the pressure difference approached zero after the creation of distal re-entry tear. False lumen Dissection Ratio (FDR) defined as arc length of dissected wall divided by arc length of dissection flap, had mean value of 1.59 ± 0.01 at pressure of 120/80 mmHg post propagation with increasing values with increase in pulse pressure that was not rescued with the creation of distal re-entry tear (p < 0.01). An average FDR of 1.87 ± 0.27 was measured in patients with acute Type B dissection. Higher FDR value (FDR = 1 implies zero dissection) in the presence of distal re-entry tear demonstrates an acute change in vessel morphology in response to the dissection independent of local pressure changes challenges the re-apposition of the aortic wall.     

Replacement of the aortic root in patients with Marfan's syndrome

BACKGROUND: Replacement of the aortic root with a prosthetic graft and valve in patients with Marfan's syndrome may prevent premature death from rupture of an aneurysm or aortic dissection. We reviewed the results of this surgical procedure at 10 experienced surgical centers. METHODS: A total of 675 patients with Marfan's syndrome underwent replacement of the aortic root. Survival and morbidity-free survival curves were calculated, and risk factors were determined from a multivariable regression analysis. RESULTS: The 30-day mortality rate was 1.5 percent among the 455 patients who underwent elective repair, 2.6 percent among the 117 patients who underwent urgent repair (within 7 days after a surgical consultation), and 11.7 percent among the 103 patients who underwent emergency repair (within 24 hours after a surgical consultation). Of the 675 patients, 202 (30 percent) had aortic dissection involving the ascending aorta. Forty-six percent of the 158 adult patients with aortic dissection and a documented aortic diameter had an aneurysm with a diameter of 6.5 cm or less. There were 114 late deaths (more than 30 days after surgery); dissection or rupture of the residual aorta (22 patients) and arrhythmia (21 patients) were the principal causes of late death. The risk of death was greatest within the first 60 days after surgery, then rapidly decreased to a constant level by the end of the first year. CONCLUSIONS: Elective aortic-root replacement has a low operative mortality. In contrast, emergency repair, usually for acute aortic dissection, is associated with a much higher early mortality. Because nearly half the adult patients with aortic dissection had an aortic-root diameter of 6.5 cm or less at the time of operation, it may be prudent to undertake prophylactic repair of aortic aneurysms in patients with Marfan's syndrome when the diameter of the aorta is well below that size.     

急性主动脉综合征的诊治

急性主动脉综合征包括一类严重的、危及生命的主动脉疾病,包括急性主动脉夹层(aortic dissection,AD)、壁内血肿(intramural haematoma,IMH)、主动脉穿透性溃疡(penetrating aortic ulcer,pAu),其中最常见的是主动脉夹层,其次为IMH、主动脉穿透性溃疡.先天性血管缺陷、遗传综合征和非遗传变异性综合征均是急性主动脉综合征的易患因素,可用CT、超声心动图、MRI等影像学方式来确诊.急性主动脉综合征的首要处理是控制血压以减少主动脉壁压力,其诊治往往需要一个多学科专家小组来评估并决定患者的治疗决策.急性主动脉综合征的最佳治疗方案仍然是一项具有挑战性的临床难题,需要进一步的研究来评价每种治疗方案的适用范围,制定以患者为本的精准治疗方案.     

Contained local compression on peri-ascending aortic area for postoperative bleeding control: a case report

After type A acute aortic dissection(AAD)repair or modified Bentall procedure,uncontrollable bleeding from the anastomotic sites of the fragile dissected tissues or aortic root area is a critical situation to a cardiac surgeon.For postoperative care,lots of blood transfusion with strict monitoring on the patient all night and subsequent reoperation for the bleeding control is usually needed.We managed to make contained local compression of upper half of the heart,from upper part of the right ventricle to just above the innominate vein,using bovine pericardium with closing both sides of transverse sinus in two cases of uncontrolled postoperative bleeding(bleeding from distal anastomotic site in type-A AAD and valve sitting site in modified Bentall procedure).Even though reoperations for the removal of packed gauges were done in both cases 2 days later,postoperative courses at intensive care unit were very smooth with little need for transfusion.This kind of contained local compression trial could be a useful strategy for dealing with the malignant uncontrollable bleeding from the fragile aortic tissue or root area after acute dissection or aortic root repair.     

Atypical manifestations in a patient with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is a chronic systemic inflammatory disease associated with the production of various autoantibodies and involvement of multiple organs. Necropsy findings in a 65 year old woman with SLE who had multiple aortic aneurysms and dissections, as well as other unusual manifestations, are described. The case illustrates the occurrence of and the difficulties encountered in the diagnosis of several diseases, namely aortic aneurysm, aortic dissection, acute pancreatitis, and Penicillium marneffei infection.     

Partial aortic root remodeling for root reconstruction in patients with acute type A dissection

In the present study, we reported our experience with partial aortic root remodeling for root reconstruction in patients with acute type A dissection, which involves in non-coronary sinus and/or the right coronary sinus with just one trimmed Dacron graft. Between February 2001 and May 2010, we performed partial aortic root remode-ling in 40 patients, who underwent emergency surgical intervention. The dissected sinuses were excised leaving a 3-5 mm rim of the aortic wall from the attached aortic valve cusps. A short piece (4-5 cm) of collagen coated woven polyester vascular prosthesis was trimmed with one or two "tongues" to reconstruct the non-coronary sinus and/ or the right coronary sinus, but without using separated patches. Additional procedures were including hemi-arch replacement in 11 patients, and total arch replacement plus stent-elephant trunk in 20 patients. The mean follow-up time was 36.4±3.6 months. In-hospital mortality was only 5.0% (2/40); furthermore, 3 (8.6%) patients underwent re-operation of the aortic valve and 2 (5.7%) patients died during follow-up. At the end of follow-up, trivial or no aortic regurgitation was found in 33 patients, but mild aortic regurgitation was found in 2 patients. Our data suggest that the early and mid-term results of partial aortic root remodeling were favorable, and it restored valve durability and function. Thus, the use of technique for root reconstruction in patients with acute type A dissection should be vigorously encouraged.     

Evaluation of aortic aneurysm and dissection by abdominal echography

Aortic dissection and aneurysm are related to increased vulnerability of the aortic wall due to arteriosclerosis. Echographic findings of aortic sclerosis include irregularity and strong punctate echoes in the intima and meandering of the aorta. Unruptured abdominal aneurysms are often found incidentally by routine echography. The "maximum diameter" and "increase in the size" of aortic aneurysm on echography are important information closely related to the risk of its rupture. In the evaluation of acute aortic dissection, the flap length indicates the range of dissection. The presence or absence of blood flow in the false lumen must be examined simultaneously using color Doppler echography. Some aortic dissections and aneurysms require emergency treatment on detection, and the evaluation of their images on echography, which is often performed for screening of patients with back or abdominal pain, are important for the determination of the therapeutic approach. In patients who are treated conservatively or observed, echography is very useful for the follow-up. Such patients must also be diagnosed or followed up by combining echography with other imaging techniques depending on the condition and necessary information in each patient.     

Surgical pathology of chronic ascending aortic dissections

AIMS: A majority of aortic dissections affect the ascending aorta and are acute in nature. Chronic dissections in this region are uncommon. This report characterises the clinicopathological features of 15 non-iatrogenic chronic ascending aortic dissections. METHODS: Among 65 patients who had surgery for ascending aortic dissection over a period of 6 years, 15 showed morphological evidence of chronic dissection. Clinical data and morphological features of these were analysed. RESULTS: Twelve patients (80%) were over the age of 50 years, with a male predominance (11 patients, 73.33%). Exertional dyspnoea was the most common presenting symptom, while chest pain was noted in three cases. An echocardiographic diagnosis of dissection was made in six patients. The disease was restricted to the ascending aorta in nine (60%) and all had aortic regurgitation of varying severity. Areas of recent dissection were also noted in three specimens. The risk factors or pathogenetic mechanisms noted were hypertension in four and Marfan's syndrome, penetrating atherosclerotic ulcer, patent ductus arteriosus, and vehicular accident, in one patient each. The aortic segment of the latter patient had shown intimal flaps to be associated with multiple saucer-shaped depressions with thin walls. These features were also noted in two of the seven patients without risk factors and in two hypertensives. This raises the possibility of subclinical intimal injury sustained during sudden deceleration with blunt chest trauma. Significant aortopathy was seen in 10 cases. CONCLUSIONS: Chronic dissections as a cause of aortic regurgitation and aneurysmal dilatation, especially in the elderly, should be kept in mind. This may follow sudden deceleration intimal injuries, superimposed on aged-related medial degeneration.     

Small vessel avulsion and acute aortic syndrome: a putative aetiology for initiation and propagation of blunt traumatic aortic injury at the isthmus

Based on literature, clinical observation and the analysis of material properties of the aorta, we hypothesize that the aortic isthmus is intrinsically susceptible to blunt trauma because it has a higher density of tributary vessels than other elements of the aortic tree, the avulsion of which during trauma, is a contributory factor in the development of an acute aortic syndrome resulting from intra-mural haematoma, localized dissection and ultimately rupture. This hypothesis provides putative explanations for several aspects of the injury profile including: localized peri-isthmus injuries, inside out injury profiles and the concept of initiation versus propagation of blunt traumatic aortic injury.     

Chronic dissecting aneurysm of the aorta

Three observations (2 males, aged 44 and 63, and a female of 47) of chronic dissecting aortic aneurysms are described. In all the cases the patients didn't die immediately from the acute dissection, as the blood accumulated in the canal formed, broke back into the aortic lumen, thus a lower orifice of the chronic aneurysm was formed. It might be possible that in some aortic dissections the hematomas fused, forming subsequently a canal. The new canal joined the main trunk (the aorta) by 2 or 3 orifices. The duration of the dissection was not identified clearly, but the canals formed were in all cases organized and had a smooth inner surface. Histology revealed striate-like necroses in the aortic wall, as well as fragmentation, swelling and lysis of the elastic fibers, resulting in the formation of slits, cavities with accumulation of metachromatic substances, i. e. the changes, characteristic for the medianecrosis (Gsell-Erdheim syndrome). A possible primary injuring effect of xenobiotics on the aortic wall is suggested.     

Increased levels of lipoprotein(a) in non-smoking aortic dissection patients

OBJECTIVES: To investigate lipoprotein(a) (Lp(a)) serum levels in patients with aortic dissection and the influence of smoking on the level of Lp(a) in aortic dissection patients. METHODS: An age-and sex-matched case-control study was conducted. Lp(a) levels in patients with aortic dissection (n = 52) and healthy subjects (n = 104) were studied. The strength of associations between Lp(a) serum levels and aortic dissection was assessed by means of multivariate logistic regression analysis. RESULTS: Patients with aortic dissection had significantly higher Lp(a) serum levels (median, 17.6 mg/dl; range, 6.4-88.7 mg/dl) compared to healthy individuals (median, 12.4 mg/dl; range, 4.9-26.4 mg/dl) (p = 0.005). The Lp(a) concentration in non-smoking patients with aortic dissection (median, 19.1 mg/dl, range, 10.5-88.7 mg/dl) significantly surpassed that of the smoking patients with aortic dissection of comparable age (median, 10.7 mg/dl; range, 6.4-22.1 mg/dl) (p < 0.0001). Multivariate analysis confirmed an independent association between Lp(a) and aortic dissection in the non-smoking population (p = 0.001). CONCLUSIONS: Serum Lp(a) level is significantly elevated in non-smoking patients with aortic dissection independently of other cardiovascular risk factors. Therefore, determination of Lp(a) levels may be important in identifying subjects at risk of aortic dissection among nonsmokers.