title: The off-pump implantation of an apicoaortic valved graft is safe and has no negative impact on coronary flow and hemodynamics.
abstract: OBJECTIVE
  : To determine the hemodynamic effect of an off-pump apicoaortic valved graft (AAVG) implantation, we performed a quantitative coronary flow analysis in a swine model of severe aortic stenosis.
  
  
  METHODS
  : In 10 swine, cardiac output, coronary flow, right common carotid artery flow, and internal mammary artery flow were measured along with left and right ventricular pressures and aortic and pulmonary artery pressures. A novel AAVG was implanted off-pump on the left ventricular (LV) apex using a specially designed implantation tool and anastomosed to the descending thoracic aorta. Aortic flow was measured proximally and distally of the AAVG-to-descending thoracic aorta anastomosis. After AAVG implantation, epicardial echo confirmed occlusion of the LV outflow tract by a valvuloplasty balloon. Baseline simultaneous measurements of all parameters were repeated after AAVG implantation and intravenous Dobutamine administration.
  
  
  RESULTS
  : The AAVG was implanted without any blood loss. After AAVG implantation and LV outflow tract occlusion, the aortic flow proximal to the AAVG-to-descending thoracic aorta anastomosis changed from antegrade (1508 ± 435 mL/min) to retrograde (-529 ± 241 mL/min, P < 0.001). All other measured parameters remained unchanged compared with baseline. After intravenous Dobutamine administration, LV pressure increased from 88 ± 20 to 184 ± 36 mm Hg (+209%, P < 0.0001) and coronary flow increased from 75 ± 34 to 193 ± 90 mL/min (+257%, P = 0.001).
  
  
  CONCLUSIONS
  : The off-pump implantation of an AAVG is bloodless, safe, reproducible and has no negative impact on coronary flow and hemodynamics. In addition, to the best of our knowledge, this is the first study where blood flow in all coronary arteries was measured simultaneously during an AAVG implantation.
authors.affiliation: From the *Division of Cardiovascular Surgery and †Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN USA.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Tsirikos Karapanos
authors.forename: Scott H
authors.initials: SH
authors.lastname: Suddendorf
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Li
authors.forename: Marianne
authors.initials: M
authors.lastname: Huebner
authors.forename: Soon J
authors.initials: SJ
authors.lastname: Park
authors.forename: Lyle D
authors.initials: LD
authors.lastname: Joyce
authors.forename: Richard C
authors.initials: RC
authors.lastname: Daly