title: Can visual assessment of flow waveform morphology detect anastomotic error in off-pump coronary artery bypass grafting?
abstract: OBJECTIVE
  Flow probes are being used for intraoperative assessment of anastomotic quality during off-pump coronary artery bypass grafting (CABG). We conducted a survey with the cooperation of 19 international surgeons to assess the ability of surgeons to detect anastomotic errors by evaluating mean flow and flow waveform morphology.
  
  
  METHODS
  Mongrel dogs underwent mammary to left anterior descending (LAD) grafting. Mean graft flow and flow wave morphology for varying degrees of anastomotic stenoses were recorded using transit-time flow probes. A questionnaire consisting of ten different recorded flow tracings and the corresponding mean flows were given to 20 surgeons from around the world. The surgeons were asked to determine the degree of stenosis and whether they would re-do the anastomosis based upon the mean flow and the flow tracings.
  
  
  RESULTS
  All of the 19 surgeons that responded were able to clearly identify a highly stenotic graft (>90% stenosis). However, 24% would re-do a fully patent anastomosis, 58% accepted an anastomosis with moderate stenosis, and 72% accepted anastomoses with severe stenosis.
  
  
  CONCLUSIONS
  Evaluation of flow tracing morphology and/or mean flows can be used to reliably detect nearly occluded anastomoses (>90% stenosis). However, surgeons should be cautious in assessing anastomoses with lesser degrees of stenosis, as they may be more difficult to reliably interpret.
authors.affiliation: Jewish Hospital Cardiothoracic Surgical Research Institute, Department of Surgery, University of Louisville, KY 40202, USA.
authors.forename: S F
authors.initials: SF
authors.lastname: Jaber
authors.forename: S C
authors.initials: SC
authors.lastname: Koenig
authors.forename: B
authors.initials: B
authors.lastname: BhaskerRao
authors.forename: D J
authors.initials: DJ
authors.lastname: VanHimbergen
authors.forename: P A
authors.initials: PA
authors.lastname: Spence
mesh_terms: D000714:Anastomosis, Surgical / Q000009:adverse effects; D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D001026:Coronary Artery Bypass / Q000379:methods; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000175:diagnosis*; D004285:Dogs; D007431:Intraoperative Complications / Q000175:diagnosis*; D016343:Monitoring, Intraoperative; D012212:Rheology / Q000295:instrumentation