Passive graft perfusion in off-pump coronary artery bypass grafting

Myocardial protection during off-pump coronary artery bypass grafting (OPCABG) is a multifactorial problem in which maintaining stable systemic hemodynamics is very important. In this study passive graft perfusion (PGP) was applied to investigate the effect during and after OPCABG as evaluated by cardiac troponin I (CTnI) and hemodynamic indexes.

Thirty first-time patients underwent OPCABG under one surgeon. They were randomly divided into two groups: The passive graft perfusion group (PGP, n = 15) received distal coronary perfusion during the anastomosis and immediate graft perfusion after the distal anastomosis. The control group, no graft perfusion group, (NGP, n = 15) received no graft perfusion after the distal anastomosis. The results of the two protocols were evaluated by concentration of CTnI and hemodynamic indexes before induction and after operation.

There were no statistically significant differences between these two groups in their perioperation parameters. The level of CTnI increased postoperatively, reached its peak at 6 hours (P < 0.05) and recovered by the 6 days postoperative. Compared with the control group the concentration of CTnI in the PGP group was significantly lower at 6 and 24 hours (P < 0.01). Compared with the NGP group, cardiac index (CI) in the PGP group was higher at 12 and 24 hours after operation (P < 0.05). The period of mechanical ventilation was significantly shorter in the PGP group than in the NGP group (P < 0.05).

PGP can increase the flow to the myocardium and shorten the heart ischemia time, thus maintain stable systemic hemodynamics, supply a satisfactory CI after surgery and improve surgery outcome.