Stent-based approach for ventricle-to-coronary artery bypass.
BACKGROUND
Ventricle-to-coronary artery bypass (VCAB) is an experimental revascularization procedure that provides predominantly systolic instead of diastolic blood flow to a coronary artery.


RESULTS
In a pig model, a stent-based procedure (VSTENT) was developed to create a VCAB. After thoracotomy, a covered VSTENT was implanted between the left ventricle and the left anterior descending coronary artery (LAD). Distal LAD flow, regional myocardial function, and intracoronary pressures were determined at different degrees of LAD stenosis and during complete LAD occlusion. During 3 hours of LAD occlusion, VSTENT preserved net forward flow at 70+/-6% and regional myocardial function at 71+/-8% of baseline. Preservation of net flow was influenced by the positioning of the VSTENT, with higher preservation also under conditions of increased oxygen demand if a "valve-like mechanism" was present during diastole. At a hemodynamically relevant level of LAD stenosis (>70%), systolic inflow was predominant after VSTENT implantation. Changes in mean diastolic intracoronary pressure that resulted from different degrees of LAD stenosis were linearly correlated to net flow after VSTENT implantation (r=0.88; P<0.001).


CONCLUSIONS
VSTENT for ventricle-to-coronary artery bypass was feasible and preserved 70+/-6% of baseline flow during complete LAD occlusion. The degree of preservation was dependent on the position of the VSTENT creating a valve-like mechanism during diastole. Residual diastolic blood flow through a high-grade LAD stenosis influenced net flow favorably, because diastolic backflow decreased with increasing mean diastolic intracoronary pressure.
Department of Internal Medicine I, Grosshadern University Hospital, Munich, Germany. boekstegers@med1.med.uni-muenchen.de
Peter
P
Boekstegers
Philip
P
Raake
Rasul
R
Al Ghobainy
Jan
J
Horstkotte
Rabea
R
Hinkel
Torleif
T
Sandner
Reinhard
R
Wichels
Franz
F
Meisner
Eckehard
E
Thein
Keith
K
March
Dieter
D
Boehm
Hermann
H
Reichenspurner
D000818:Animals; D017023:Coronary Angiography; D001026:Coronary Artery Bypass / Q000379:methods*; D003326:Coronary Circulation; D023921:Coronary Stenosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D003331:Coronary Vessels / Q000473:pathology / Q000503:physiopathology; D005240:Feasibility Studies; D006352:Heart Ventricles / Q000601:surgery*; D006439:Hemodynamics; D012039:Regional Blood Flow; D015607:Stents; D013552:Swine