title: Operative classification of thromboembolic disease determines outcome after pulmonary endarterectomy.
abstract: OBJECTIVE
  We sought to determine whether type and location of thromboembolic disease in the pulmonary vascular tree predicts the hemodynamic result and clinical outcome in patients undergoing pulmonary endarterectomy.
  
  
  METHODS
  From 1998 to 2000, 202 patients with pulmonary hypertension and pulmonary vascular resistance ranging from 194 to 2950 dynes-s-cm(-5) underwent pulmonary endarterectomy. Preoperative and postoperative tricuspid valve function, pulmonary artery pressure, and pulmonary vascular resistance were determined by means of transthoracic echocardiography and measurements with a Swan-Ganz catheter (Edwards Lifesciences, Irvine, Calif), respectively. Patients underwent intraoperative classification of thromboembolism as follows: type 1 (76 patients), fresh thrombus in the main-lobar pulmonary arteries; type 2 (81 patients), intimal thickening and fibrosis proximal to the segmental arteries; type 3 (38 patients), disease within distal segmental arteries only; and type 4 (7 patients), distal arteriolar vasculopathy without visible thromboembolic disease.
  
  
  RESULTS
  Overall perioperative mortality was 4.5% (9/202 patients). By means of univariate analysis, patients with type 3 or 4 disease (distal pulmonary vasculopathy) had more residual postoperative tricuspid regurgitation (P <.0001), higher postoperative pulmonary artery systolic pressure (P <.0001), and greater postoperative pulmonary vascular resistance (P <.0001) compared with that seen in patients with type 1 or 2 disease, in whom thromboembolic disease was more surgically accessible. Factors such as severity of preoperative tricuspid regurgitation, patient age, and circulatory arrest time had no correlation with postoperative hemodynamic improvement. Patients with distal thromboembolic disease (type 3-4) had higher perioperative mortality, required longer inotropic support, and had longer hospital stays compared with patients with type 1 or 2 thromboembolic disease.
  
  
  CONCLUSIONS
  The degree of improvement in pulmonary hypertension and tricuspid regurgitation after pulmonary endarterectomy is determined by the type and location of pulmonary thromboembolic disease. Classification of thromboembolism is useful for predicting patient outcome after pulmonary endarterectomy.
authors.affiliation: Divisions of Cardiothoracic Surgery, Biostatistics, and Cardiology, University of California, San Diego, Calif. 92103-8892, USA. Pthistlethwaite@ucsd.edu
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Thistlethwaite
authors.forename: Makato
authors.initials: M
authors.lastname: Mo
authors.forename: Michael M
authors.initials: MM
authors.lastname: Madani
authors.forename: Reena
authors.initials: R
authors.lastname: Deutsch
authors.forename: Daniel
authors.initials: D
authors.lastname: Blanchard
authors.forename: David P
authors.initials: DP
authors.lastname: Kapelanski
authors.forename: Stuart W
authors.initials: SW
authors.lastname: Jamieson
mesh_terms: D004691:Endarterectomy; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000601:surgery*; D011655:Pulmonary Embolism / Q000145:classification* / Q000175:diagnosis; D016896:Treatment Outcome; D014262:Tricuspid Valve Insufficiency / Q000175:diagnosis; D014655:Vascular Resistance