[Pitfall in the choice of the in situ arterial grafts in OPCAB].

Flow capacity with arterial grafts which have been used in off-pump CABG has been discussed. To analyze the hypoperfusion syndrome when in situ arterial grafts are selected, we made the simple mathematical model which consisted of two vessels with in parallel. We speculated the flow capacity of the various grafts, and flow distribution in the distal coronary artery, based on Poiseuille's law. This theoretical model clearly demonstrated that hypoperfusion syndrome occurred in reoperative coronary bypass grafting had a close relation with the diameters and lengths of bypass grafts.