title: [Segmental arterial mediolysis: pathogenesis of aneurysms and dissections in patients younger than 60 years].
abstract: BACKGROUND
  Complications deriving from arterial aneurysm and dissection without signs of atherosclerosis are rare clinical entities. In recent literature case reports show a descriptive similarity of pathological findings summarized as segmental arterial mediolysis (SAM).
  
  
  OBJECTIVE
  The purpose of this study was to answer the question whether, among 16 patients suffering from SAM histological findings corresponded and assess causality.
  
  
  METHODS
  In a prospective prognostic trial sixteen patients were enrolled between 1st January 2008 and 31st October 2011. Inclusion criteria were a lack of atherosclerosis, age under 60 and clinical findings. Most of these sixteen patients were treated as emergency cases of life-threatening blood loss or organ system ischemia. Thirteen of the patients were male, 3 female and their average age was 44 (28-59) years. Localisation of the segmental aneurysm or dissection showed a broad variability from central to renovisceral and peripheral lesions. Imaging diagnostics (e.g., US and CT-A) were complemented by exclusion of positive family history, connective tissue diseases and autoimmune or inflammative disorders. In 8 patients with open vascular reconstructions, it was possible to obtain a biopsy from the target lesion to analyse morphological and immunochemical expression levels (e.g., MMP1-12, vWF, vSMC or CD 68).
  
  
  RESULTS
  None of the patients died nor had described familiar associations. Even the examination of twins with sCAD showed no coincidence. Differential diagnostic findings were excluded. All patients agreed to undergo human genetic screening. The 8 biopsy tissues showed homogeneously mediolysis with focal and increasingly confluent lesions. Main findings were that the vessel wall layering was destroyed and that capillarisation was initiated from the adventitial layer. Furthermore, all patients suffered from hypertension associated to the SAM, or developed it during surveillance.
  
  
  CONCLUSIONS
  SAM is a rare, life-threatening diagnosis and has to be taken into consideration in young patients with aneurysm and dissection of unusual locations. Rare vascular diseases should have a forum in future investigations which might highlight molecular genetic triggers and associated diseases, e.g., hypertension and aortic type B dissection.
authors.affiliation: CVEC, Uniklinik Münster, Deutschland. eva.schoenefeld@ukmuenster.de
authors.forename: E
authors.initials: E
authors.lastname: Schönefeld
authors.forename: B
authors.initials: B
authors.lastname: Kasprzak
authors.forename: W
authors.initials: W
authors.lastname: Völker
authors.forename: G
authors.initials: G
authors.lastname: Weissen-Plenz
authors.forename: G
authors.initials: G
authors.lastname: Torsello
mesh_terms: D000199:Actins / Q000032:analysis; D000328:Adult; D000783:Aneurysm / Q000175:diagnosis*; D000784:Aortic Dissection / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology / Q000628:therapy; D015703:Antigens, CD / Q000032:analysis; D015214:Antigens, Differentiation, Myelomonocytic / Q000032:analysis; D001706:Biopsy; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000032:analysis; D006801:Humans; D045726:Metalloproteases / Q000032:analysis; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000175:diagnosis* / Q000209:etiology / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D011446:Prospective Studies; D017540:Tunica Media / Q000473:pathology*; D014841:von Willebrand Factor / Q000032:analysis; D000097382:CD68 Molecule
chemical_list: D000199:Actins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D045726:Metalloproteases; D014841:von Willebrand Factor; C067980:CD68 antigen, human; D000097382:CD68 Molecule