title: Hemodynamic effects of left pulmonary artery stenosis after superior cavopulmonary connection: a patient-specific multiscale modeling study.
abstract: OBJECTIVE
  Currently, no quantitative guidelines have been established for treatment of left pulmonary artery (LPA) stenosis. This study aims to quantify the effects of LPA stenosis on postoperative hemodynamics for single-ventricle patients undergoing stage II superior cavopulmonary connection (SCPC) surgery, using a multiscale computational approach.
  
  
  METHODS
  Image data from 6 patients were segmented to produce 3-dimensional models of the pulmonary arteries before stage II surgery. Pressure and flow measurements were used to tune a 0-dimensional model of the entire circulation. Postoperative geometries were generated through stage II virtual surgery; varying degrees of LPA stenosis were applied using mesh morphing and hemodynamics assessed through coupled 0-3-dimensional simulations. To relate metrics of stenosis to clinical classifications, pediatric cardiologists and surgeons ranked the degrees of stenosis in the models. The effects of LPA stenosis were assessed based on left-to-right pulmonary artery flow split ratios, mean pressure drop across the stenosis, cardiac pressure-volume loops, and other clinically relevant parameters.
  
  
  RESULTS
  Stenosis of >65% of the vessel diameter was required to produce a right pulmonary artery:LPA flow split <30%, and/or a mean pressure drop of >3.0 mm Hg, defined as clinically significant changes.
  
  
  CONCLUSIONS
  The effects of <65% stenosis on SCPC hemodynamics and physiology were minor and may not justify the increased complexity of adding LPA arterioplasty to the SCPC operation. However, in the longer term, pulmonary augmentation may affect outcomes of the Fontan completion surgery, as pulmonary artery distortion is a risk factor that may influence stage III physiology.
authors: Mechanical and Aerospace Engineering Department, University of California, San Diego, San Diego, Calif.
authors: Daniele E
authors: DE
authors: Schiavazzi
authors: Mechanical and Aerospace Engineering Department, University of California, San Diego, San Diego, Calif.
authors: Ethan O
authors: EO
authors: Kung
authors: Mechanical and Aerospace Engineering Department, University of California, San Diego, San Diego, Calif.
authors: Alison L
authors: AL
authors: Marsden
authors: Great Ormond Street Hospital for Children and Great Ormond Street Hospital for Children, NHS Foundation Trust, London, United Kingdom.
authors: Catriona
authors: C
authors: Baker
authors: Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, Milano, Italy.
authors: Giancarlo
authors: G
authors: Pennati
authors: Great Ormond Street Hospital for Children and Great Ormond Street Hospital for Children, NHS Foundation Trust, London, United Kingdom.
authors: Tain-Yen
authors: TY
authors: Hsia
authors: Department of Pediatrics, Medical University of South Carolina, Charleston, SC.
authors: Anthony
authors: A
authors: Hlavacek
authors: Department of Pediatrics, University of Michigan Medical School, Ann Arbor, Mich. Electronic address: adamdorf@med.umich.edu.
authors: Adam L
authors: AL
authors: Dorfman
mesh_terms: D001157:Arterial Occlusive Diseases / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D002648:Child; D002675:Child, Preschool; D003198:Computer Simulation; D003251:Constriction, Pathologic; D005060:Europe; D018729:Fontan Procedure / Q000009:adverse effects; D018610:Heart Bypass, Right / Q000009:adverse effects*; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008953:Models, Anatomic; D008955:Models, Cardiovascular; D009716:Numerical Analysis, Computer-Assisted; D018579:Patient Selection; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000503:physiopathology / Q000601:surgery*; D011652:Pulmonary Circulation; D012039:Regional Blood Flow; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014481:United States; D066253:Vascular Remodeling