title: Assessing Endothelial Responsiveness After Cardiopulmonary Bypass: Insights on Different Perfusion Modalities.
abstract: OBJECTIVE
  Cardiopulmonary bypass (CPB) exerts several deleterious effects on inflammatory pathways. Most of these can be related to an endothelial insult leading to endothelial dysfunction. To date, the degree of endothelial damage only has been evaluated on a cellular and molecular level, but no studies exist looking at the functional effects of CPB on the endothelium.
  
  
  METHODS
  Previous studies hypothesized a negative effect of continuous flow as opposed to the physiologic pulsatile flow. The aim of the present retrospective study was to investigate how different perfusion modalities during CPB (ie, continuous v pulsatile flow) or its avoidance differently impact endothelial function.
  
  
  METHODS
  Cardiovascular operating room and intensive care unit of a large tertiary University Hospital in Monza, Italy.
  
  
  METHODS
  Flow-mediated dilatation (FMD) of the brachial artery was assessed in 29 patients undergoing elective myocardial revascularization. Ten patients receiving continuous-flow CPB, 10 receiving pulsatile-flow CPB, and 9 scheduled for beating-heart revascularization were studied.
  
  
  METHODS
  Patients were studied at baseline (after induction of general anesthesia), after CPB upon intensive care unit (ICU) admission after surgery, and on the first postoperative day before discharge from the ICU (on average, 24 hours after CPB discontinuation).
  
  
  RESULTS
  The continuous-flow CPB group demonstrated a significant reduction in FMD after CPB, (12.8% ± 9.7% v 1.6% ± 1.5%, p<0.01), which lasted up to the first postoperative day (5.9% ± 4.1%). On the other hand, FMD did not change in the pulsatile-flow group (12.5% ± 10.5%, 11.0% ± 7.2%, and 16.6% ± 11.7%, respectively). FMD also was unaffected in the beating-heart group, thus suggesting a direct effect of CPB itself on endothelial function.
  
  
  CONCLUSIONS
  In conclusion, in this study population of adult patients undergoing elective coronary revascularization, continuous-flow CPB markedly impaired endothelial function, although this was not the case with pulsatile-flow CPB. This study posed the rationale for further investigations on the potential value of FMD to predict cardiovascular events in these patients.
authors: Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital, Monza, Italy. Electronic address: f.sangalli@hsgerardo.org.
authors: Fabio
authors: F
authors: Sangalli
authors: Cardiopulmonary Unit, San Paolo Hospital, University of Milan, Milan, Italy.
authors: Marco
authors: M
authors: Guazzi
authors: Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital, Monza, Italy.
authors: Silvia
authors: S
authors: Senni
authors: Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital, Monza, Italy.
authors: Wilma
authors: W
authors: Sala
authors: Clinical Perfusion Service.
authors: Rosa
authors: R
authors: Caruso
authors: Clinical Perfusion Service.
authors: Maria Cristina
authors: MC
authors: Costa
authors: Cardiac Surgery Unit San Gerardo Hospital, Monza, Italy; University of Milan-Bicocca.
authors: Francesco
authors: F
authors: Formica
authors: Department of Anesthesia and Intensive Care Medicine, San Gerardo Hospital, Monza, Italy.
authors: Leonello
authors: L
authors: Avalli
authors: University of Milan-Bicocca; Department of Anesthesia and Intensive Care Medicine, Niguarda Ca' Granda Hospital, Milan, Italy.
authors: Roberto
authors: R
authors: Fumagalli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity / Q000502:physiology*; D001916:Brachial Artery / Q000502:physiology; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000639:trends*; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009204:Myocardial Revascularization / Q000009:adverse effects / Q000639:trends*; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D012189:Retrospective Studies
keywords: cardiopulmonary bypass; continuous flow; endothelial function; flow-mediated dilatation; pulsatile flow