title: Immediate flow reserve of Y thoracic artery grafts: an intraoperative flowmetric study.
abstract: OBJECTIVE
  Use of both internal thoracic arteries in a Y graft configuration can raise concerns about the possibility of the single left internal thoracic artery being able to meet the flow requirements of two or three distal territories. We evaluated intraoperatively the flow reserve of a Y thoracic artery graft distally anastomosed to the anterior and lateral territories.
  
  
  METHODS
  In 21 patients who had Y thoracic artery grafts, the flow was measured in the main stem of the left internal thoracic artery, in the left internal thoracic artery branch, and in the right internal thoracic artery. A transit time Doppler flowmeter was used. Measurements were repeated after the injection of a bolus of 20 mug/kg dobutamine.
  
  
  RESULTS
  At baseline condition, the mean blood flow was 44.8 +/- 24.2, 23.4 +/- 11.5, and 21.4 +/- 15.3 mL/min in the main stem of the left internal thoracic artery, in the left internal thoracic artery branch, and in the right internal thoracic artery, respectively. After dobutamine injection, these values increased to 93.2 +/- 49.8, 46.1 +/- 22.6, and 42.5 +/- 31.2 mL/min, respectively. Flow reserve was 2.1 +/- 0.6, 2.2 +/- 0.9, and 2.1 +/- 0.9 mL/min, respectively.
  
  
  CONCLUSIONS
  Intraoperative injection of dobutamine increases the flow in the Y thoracic graft by more than two times, not only in the main stem but also in each branch. This finding attests to the safety of Y thoracic conduits in terms of hemodynamic potential.
authors.affiliation: Department of Cardiology and Cardiac Surgery, G. D'Annunzio University, Chieti, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Gaudino
authors.forename: Michele
authors.initials: M
authors.lastname: Di Mauro
authors.forename: Angela Lorena
authors.initials: AL
authors.lastname: Iacò
authors.forename: Carlo
authors.initials: C
authors.lastname: Canosa
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Vitolla
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Calafiore
mesh_terms: D000368:Aged; D003326:Coronary Circulation / Q000502:physiology; D004280:Dobutamine; D005260:Female; D045268:Flowmeters; D006801:Humans; D007432:Intraoperative Period; D008297:Male; D008323:Mammary Arteries / Q000502:physiology*; D008875:Middle Aged; D009204:Myocardial Revascularization
chemical_list: D004280:Dobutamine