title: Factors associated with thrombotic complications in pediatric patients with vascular malformations.
abstract: OBJECTIVE
  Thrombosis is an uncommon disorder in children. Patients with slowflow vascular malformations have higher risk of developing localized intravascular coagulation, which is closely related to the presence of thrombotic events. These episodes cause pain, can be recurrent and determine a clear deterioration in the quality of life. Moreover, serious complications such as pulmonary thromboembolism and eventually death have been described. The aim of the present study is to identify clinical and laboratory risk factors associated with thrombotic events in pediatric patients with vascular malformations.
  
  
  METHODS
  Case-Control study. Clinical records of patients who consulted the vascular anomalies study group (VASG). This group carries out interdisciplinary assessment of patients with vascular malformations. From June 2008 to December 2014, 110 patients were assessed of whom 46 patients met the inclusion criteria, with half of them presenting a thrombotic complication and the others not, these latter serving as controls. Statistical analysis included multivariate logistic regression analysis to determine major risk factors for thrombosis.
  
  
  RESULTS
  In the bivariate analysis we found a significant association between increased levels of Ddimer and thrombotic complications (OR 17.1 [95% CI 3.95-73.95; p<0.01]). In addition, a surface area≥10cm2(OR 6.18 [95% CI 1.59-23.99; p<0.01]) and the presence of palpable phleboliths (OR 20.17 [95% CI 2.32-165.77; p<0.01]) were associated with a significant higher risk of thrombosis. Multivariate analysis identified older age (OR 1.33; p=0.013), a surface area≥10cm2(OR 8.19; p=0.042) and palpable phleboliths (OR 85.29; p<0.01) as significant risk factors.
  
  
  CONCLUSIONS
  Our study suggests the existence of clinical factors associated with higher risk of thrombotic complications, such as the extent of the malformation, palpable phleboliths and increased age among children with vascular malformations.
authors.affiliation: Pontificia Universidad Católica de, Chile. Electronic address: pdsepulveda@uc.cl.
authors.forename: Pablo
authors.initials: P
authors.lastname: Sepúlveda
authors.affiliation: Departament of Surgery, Pediatric Surgery Unit, Pontificia Universidad Católica de, Chile.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Zavala
authors.affiliation: Departament of Pediatrics, Pediatric Hematology-Oncology Unit, Pontificia Universidad Católica de, Chile.
authors.forename: Pamela
authors.initials: P
authors.lastname: Zúñiga
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D006801:Humans; D007223:Infant; D008297:Male; D015999:Multivariate Analysis; D011655:Pulmonary Embolism / Q000209:etiology; D011788:Quality of Life; D012307:Risk Factors; D013927:Thrombosis / Q000209:etiology*; D054079:Vascular Malformations / Q000097:blood / Q000150:complications* / Q000473:pathology
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: Children; Localized intravascular coagulation; Thrombosis; Thrombotic complications; Vascular malformations