Segmental arterial mediolysis: a precursor to fibromuscular dysplasia?
Segmental arterial mediolysis: a precursor to fibromuscular dysplasia?
复制标题
节段性动脉中溶解症：纤维肌性发育不良的前兆？
作者：
R. Slavin;K. Saeki;B. Bhagavan;A. Maas
我们描述了五例节段性动脉中溶解(SAM)，以前被称为节段性中溶解动脉炎。SAM见于心外膜冠状动脉和腹部内脏动脉。腹腔型SAM患者多为老年人，而冠状SAM多见于新生儿、儿童和年轻人。SAM是通过外部介质的介质分解而启动的，这种介质可以扩展到包括中间介质和内部介质。伴随的改变包括内侧外膜交界处的纤维素线状沉积和溶解的肌肉纤维被纤维蛋白、红细胞和肉芽组织取代。穿壁介质溶解导致动脉壁缝隙，常合并夹层血肿和动脉瘤。腹部出血是由这些并发症引起的。累及腹部内脏动脉的SAM临床表现为腹痛、腹胀、红细胞压积下降和休克。同时累及一条以上的腹主动脉是常见的，最常累及的是腹主动脉的分支。在SAM患者的直接临床背景中，各种疾病状态都会引起内皮细胞介导的血管收缩的病理刺激。SAM的某些形态特征表明，这种动脉病变是由于血管痉挛引起的，我们推测这是局灶性内皮旁分泌功能障碍所致。非复杂性SAM病变的组织可能类似于某些类型的纤维肌肉发育不良，提示此类动脉病变的发生与血管痉挛有关。
We describe five cases of segmental arterial mediolysis (SAM), formerly known as segmental mediolytic arteritis. SAM occurs in epicardial coronary arteries and in the abdominal splanchnic arteries. Patients with abdominal SAM are generally elderly, whereas coronary SAM presents in neonates, children, and young adults. SAM is initiated by mediolysis of the outer media, which can expand to involve the mid- and inner media. Accompanying alterations include fibrinous linear deposits at the medial adventitial junction and replacement of the lysed muscle fibers by fibrin, erythrocytes, and granulation tissue. Transmural mediolysis results in arterial wall gaps frequently complicated by dissecting hematomas and aneurysms. Abdominal hemorrhages stem from these complications. SAM involving abdominal splanchnic arteries clinically presents with abdominal pain and distension, falling hematocrit, and shock. Simultaneous involvement of more than one abdominal artery is frequent, and branches of the celiac axis are most commonly affected. Various disease states that provoke pathologic stimuli for endothelial mediated vasoconstriction occur in the immediate clinical background of patients with SAM. Certain morphologic features of SAM suggest that this arterial lesion is due to vasospasm, which we putatively ascribe to focal endothelial paracrine dysfunction. Organization of uncomplicated SAM lesions could resemble certain types of fibromuscular dysplasia, suggesting that the genesis of such arterial lesions is related to vasospasm.