SCTA在微小脑动脉瘤诊断中的应用

目的 探讨螺旋CT血管造影（SCTA）在直径小于10mm的脑动脉瘤诊断中的临床应用和价值。方法 选择12例直径小于10mm的脑动脉瘤患，进行SCTA，DSA或MRA检查，SCTA成像技术为表面遮盖法（SSD）和最大密度投影法（MIP）。结果 12例微小脑动脉瘤患术前均准确定性，定位，全部经神经外科手术证实。结论 SCTA是一种无创伤性血管成像方法，在诊断脑动脉瘤方面，具有分辨率高，快速，准确，经济等优点，可为临床诊断与治疗提供更多的信息。     

Effect of defective connective tissue on the formation of aneurysmal-like structures in the rat testicular artery

Microscopic aneurysmal-like structures (ALS) develop spontaneously in the convoluted rat testicular artery and have been previously proposed as a model relevant to cerebral aneurysms. The effect of defects in connective tissue fibres on ALS formation was investigated by microscopy using two approaches: (i) the study of the effect of β-aminopropionitrile (BAPN), an inhibitor of the cross-linking of elastic and collagen fibres, on the incidence, size and morphology of ALS in spontaneously hypertensive rats (SHR) and their normotensive controls (WKY). The straight spermatic artery was studied for comparison. (ii) The determination of the incidence of spontaneous ALS in Brown Norway (BN) and Long Evans (LE) rats which are highly susceptible (BN) or resistant (LE) to the spontaneous rupture of the arterial internal elastic lamina. (i) BAPN increased the number and size of ALS in SHR and WKY rats and had no effect on the straight spermatic artery and (ii) ALS were more numerous and of greater size in BN than in LE rats. Taken together, these results show that defective connective tissue fibres may favour the formation and induce the enlargement of aneurysmal-like structures. By analogy, these data suggest that a lack of connective tissue fibre integrity may be of importance in cerebral aneurysm formation and development.     

腹主动脉瘤应力模型的建立及其应用

本研究用螺旋CT扫描腹主动脉瘤获得的断层图像合成腹主动脉瘤几何模型，通过设定瘤壁组织生物力学参数和边界条件，使用有限元分析的方法分析腹主动脉瘤瘤壁的应力分布。结果标明，本例腹主动脉瘤应力峰值位于远端分叉部位，瘤体应力峰值位于后壁，均小于瘤壁的承受极限。本研究所得结果对腹主动脉瘤应力模型有助于分析个体化腹主动脉瘤的破裂部位和生长方向，对研究疾病进程提供依据。     

Different roles of arteriosclerosis in the rupture of intracranial dissecting aneurysms

AIMS: Although intracranial dissecting aneurysm (IDA) is a newly described variant of the brain aneurysms that affects mainly the vertebrobasilar arterial system, its pathogenesis remains obscure. We aimed to clarify the role of arteriosclerosis in the pathogenesis of IDA based on histopathological findings in seven autopsy cases of IDA. METHODS AND RESULTS: All cases exhibited systemic hypertension or left ventricular hypertrophy. Macroscopically, all cases exhibited subarachnoid haemorrhage. Two types of dissection were recognized in the vertebral artery. Six of seven IDA cases showed a widespread disruption of the entire thickness of the arterial wall with the formation of a dilated pseudoaneurysm, which consisted of thin adventitia (arterial wall disruption type). Medial disruption of the arterial wall and subadventitial dissecting haemorrhage were also found, resulting in the formation of a false lumen and stenosis of the 'true' lumen of the artery. However, these lesions were connected to the site of rupture of the entire arterial wall. Within 1 day after onset of IDA, the autopsy cases showed formation of fibrin thrombus, marked leucocyte infiltration and necrosis of the arterial wall at the site of the lesion. Cases that survived more than 1 week showed smooth muscle cell proliferation, macrophage accumulation and lymphocytic infiltration in the lesions. These cases showed no atherosclerotic plaque, but non-atherosclerotic fibrocellular intima. The thickness of intima and media was significantly less in the vertebral artery of IDA patients than that of non-IDA patients with systemic hypertension. On the other hand, the remaining case showed severe atherosclerosis with haemorrhage into the lipid core without connection to the arterial lumen (intra-atheromatous plaque haemorrhage type). However, unusual arterioles and neovascularization of the intra-and peri-arterial walls were observed. CONCLUSIONS: Our results suggest that disruption of the entire arterial wall may be a critical event in the development of IDA and result in the medial disruption and subadventitial haemorrhage. Non-atheromatous intima might function as a protective factor in arterial wall disruption. On the other hand, atherosclerosis may predispose to intra-atheromatous plaque haemorrhage type of IDA through intramural haemorrhage originating from the newly formed vessels.     

Constitutive activation of the PI3K‐AKT pathway and cardiovascular abnormalities in an individual with Kosaki overgrowth syndrome

Kosaki overgrowth syndrome is a recently described syndrome characterized by distinctive facial features, brain white matter lesions, and developmental delay. Germline activating heterozygous PDGFRB mutations have been reported in this condition. Systemic connective tissue‐type findings have been described in some individuals. We describe a 19‐year‐old Caucasian female with a history of hydrocephalus, Dandy–Walker malformation, cervical spine arachnoid cyst, progressive scoliosis, and overgrowth. Her physical exam included distinctive craniofacial dysmorphism, as well as soft and hyperextensible skin. Cardiovascular imaging during adolescence revealed saccular aneurysms in both coronary artery systems and subtle tortuosity of the cervical vertebral arteries. Exome sequencing trio analysis identified a de novo previously reported pathogenic variant in PDGFRB, c.1696T>C (p.[Trp566Arg]). Further functional studies included platelet‐derived growth factor cellular metabolic pathway activity that confirmed the variant causes a constitutive activation of the PI3K‐AKT pathway. This is the first report to characterize the activating nature of this PDGFRB variant. We also highlight the connective tissue findings seen in Kosaki overgrowth syndrome and recommend baseline echocardiographic evaluation in all individuals with this condition with particular emphasis on coronary arteries.     

Morphological and functional characteristics of myocytes isolated from human left ventricular aneurysms

Isolated single myocytes were prepared from myocardium of developing ventricular aneurysms and from myocardium within the scar of chronic ventricular aneurysms. The morphology and function of the individual cells were compared. The cells from developing aneurysms were rod-shaped, with a distinct sarcomeric structure, but did not contract even in the presence of high calcium concentrations. The sarcomere length was significantly higher than that of cells from chronic aneurysms and approached the theoretical point at which no contraction can occur. Cells from chronic aneurysms were either rod-shaped and contractile, or rounded due to hypercontracture of the myofilaments. Electron microscopy of cells from developing aneurysms confirmed the presence of elongated sarcomeres, a loss of the actin-myosin interdigitation, and damage to the contractile proteins which was particularly evident in the thin filaments. Cells with similar characteristics have also been isolated from a ruptured, ischaemic papillary muscle. These changes, which are due either to ischaemia or to overstretching of cells, may account for the weakness of the wall of developing aneurysms and be a cause of rupture or enlargement.     

Ectopia lentis in Loeys‐Dietz syndrome type 4

Loeys‐Dietz syndrome is a heritable disorder of the connective tissue leading to multisystem involvement including craniofacial features, skeletal abnormalities, cutaneous findings and early‐onset and aggressive disease of the aorta and its branches. There are multiple types of Loeys‐Dietz syndrome related to pathogenic variants in TGFBR1, TGFBR2, SMAD3, TGFB2, and TGFB3. Individuals with Loeys‐Dietz syndrome may be misdiagnosed as having Marfan syndrome due to shared phenotypic features and aortic root dilation. However, ectopia lentis has been an important discriminating feature, being unique to Marfan syndrome and not reported to be associated with Loeys‐Dietz syndrome. We report the case of a 46‐year‐old woman with Loeys‐Dietz syndrome type 4 due to a pathogenic variant in TGFB2 who was diagnosed with ectopia lentis at age 44. The patient underwent whole exome sequencing and no other pathogenic variants were found to explain the ectopia lentis. Our findings indicate that ectopia lentis may be an uncommon finding in Loeys‐Dietz syndrome type 4 and emphasize the importance of genetic testing in familial thoracic aortic aneurysm disease.     

Overall results in 304 consecutive patients with acute spontaneous subarachnoid hemorrhage

The results obtained in 304 consecutive patients with spontaneous subarachnoid hemorrhage are described, the majority of whom (86%) were admitted while in acute condition. Only 46% of the patients in this series were in good condition at admission. The initial management was standardized for all patients, but the protocol of "delayed surgery" was applied to patients with subarachnoid hemorrhage from aneurysmal rupture. Two hundred and twenty-two patients (73%) had intracranial aneurysms. Of these, 20 (9%) were moribund and died shortly after admission; nine (4%) underwent emergency surgery due to the coexistence of a life-threatening cerebral hematoma; seven (3%) were operated upon within 3 days of admission; 78 (35%) died after rebleeding or after steady deterioration of the patient's condition due to vasospasm while awaiting surgery. Of the remaining 108 patients ready for delayed surgery, 12 (11%) (operation refused, elderly patients in poor general condition, spontaneous thrombosis of the aneurysm) were treated conservatively, and 96 (89%), who were in various clinical conditions, were actually operated on. Of these 96 patients, 79 (82%) exhibited excellent or good results, 5 (5%) were disabled, and 12 (12%) died. In the authors' experience, the overall management of intracranial aneurysms in unselected patients according to the protocol of delayed surgery results in significant loss of patients awaiting surgery, and good surgical results in the survivors.     

Ventricular tachycardia as a complication of annular subvalvular ventricular aneurysm in a Caucasian woman

A Caucasian female patient with repetitive attacks of ventriculartachycardia and fibrillation caused by annular submitral leftventricular aneurysm is reported. During a follow-up periodof six years after aneurysmectomy, the patient remained symptom-free.     

“Cross-over” duplication of middle cerebral artery,agenesis of internal carotid artery and saccular aneurysms

Summary The authors describe a patient with anomalous branches of the left internal carotid artery, cross-over duplication of its middle cerebral artery and agenesis of the contra-lateral internal carotid artery associated with two aneurysms successfully clipped. Pertinent literature is reviewed.