title: Splenectomy and chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  An increased prevalence of splenectomy has been reported in patients with idiopathic pulmonary arterial hypertension. Examination of small pulmonary arteries from these subjects has revealed multiple thrombotic lesions, suggesting that thrombosis may contribute to this condition. Based on these findings, we hypothesised that splenectomy could be a risk factor for chronic thromboembolic pulmonary hypertension (CTEPH), a condition defined by the absence of thrombus resolution after acute pulmonary embolism that causes sustained obstruction of the pulmonary arteries and subsequent pulmonary hypertension.
  
  
  METHODS
  The medical history, clinical characteristics, thrombotic risk factors and haemodynamics of 257 patients referred for CTEPH between 1989 and 1999 were reviewed. In a case-control study the prevalence of splenectomy in patients with CTEPH was compared with that of patients evaluated during the same period for idiopathic pulmonary hypertension (n=276) or for lung transplantation in other chronic pulmonary conditions (n=180).
  
  
  RESULTS
  In patients with CTEPH, 8.6% (95% CI 5.2 to 12.0) had a history of splenectomy compared with 2.5% (95% CI 0.7 to 4.4) and 0.56% (95% CI 0 to 1.6) in cases of idiopathic pulmonary arterial hypertension and other chronic pulmonary conditions, respectively (p<0.01).
  
  
  CONCLUSIONS
  Splenectomy may be a risk factor for chronic thromboembolic pulmonary hypertension.
authors.affiliation: UPRES EA 2705, Centre des Maladies Vasculaires Pulmonaires, Service de Pneumologie et Réanimation Respiratoire, Hôpital Antoine Béclère, 157 rue de la Porte-de-Trivaux, 92140 Clamart, France. xavier.jais@abc.ap-hop-paris.fr
authors.forename: X
authors.initials: X
authors.lastname: Jaïs
authors.forename: V
authors.initials: V
authors.lastname: Ioos
authors.forename: C
authors.initials: C
authors.lastname: Jardim
authors.forename: O
authors.initials: O
authors.lastname: Sitbon
authors.forename: F
authors.initials: F
authors.lastname: Parent
authors.forename: A
authors.initials: A
authors.lastname: Hamid
authors.forename: E
authors.initials: E
authors.lastname: Fadel
authors.forename: P
authors.initials: P
authors.lastname: Dartevelle
authors.forename: G
authors.initials: G
authors.lastname: Simonneau
authors.forename: M
authors.initials: M
authors.lastname: Humbert
mesh_terms: D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D013156:Splenectomy / Q000009:adverse effects*; D013923:Thromboembolism / Q000209:etiology*