Glove retractor for left circumflex coronary artery bypass grafting

During off-pump coronary artery bypass grafting (OPCAB), displacing the heart to expose the left circumflex artery (LCX) results in hemodynamic disturbance. The objective of this study was to evaluate, in a canine model, the hemodynamic impact on the beating heart of using a glove retractor instead of conventional retraction to expose the LCX.

Six mongrel dogs ranging in weight from 19.7 to 25 kg were used. Hemodynamic parameters were continuously monitored at a fixed rate of 80 beats/min. After the baseline data had been obtained, the LCX was exposed by applying an Octopus system. Each dog was then placed in the Trendelenburg position. Subsequently, the glove retractor was applied and its effects were examined both with and without the Trendelenburg position.

LCX exposure decreased aortic flow to 35.2 +/- 12.8% of the baseline value (p< 0.001 vs. baseline), and this decrease was not fully reversed even by the Trendelenburg position (67.6 +/- 14.3%). Glove retractors tend not to interfere with right ventricular expansion so that hemodynamic disturbance is mild, and in the Trendelenburg position aortic flow (88.9 +/- 9.9%) and mean aortic pressure (95.0 +/- 5.1%) during LCX exposure were completely maintained with the glove retractor in place.

Glove retractors can be used to displace the canine heart to expose the LCX, minimizing hemodynamic impairment, with normalization of hemodynamic parameters by the Trendelenburg position. This technique may offer an alternative hemodynamic support method in some patients undergoing OPCAB.