Reversal of "no reflow" during vein graft stenting using high velocity boluses of intracoronary adenosine.

Slow or no reflow is a serious problem complicating catheter-based revascularization of degenerated saphenous vein bypass grafts. We examined the efficacy of rapidly delivered, high-velocity injections of intracoronary adenosine to reverse 11 slow-flow events complicating stenting of diseased bypass grafts. Ten of 11 events were rapidly improved to TIMI 3 flow by this technique within 3.8+/-1.6 min of the initial adenosine injection. In an ex vivo model, 3-ml syringes created higher peak pressures and velocities than 10- and 20-ml syringes. We conclude that rapid and repeated high-velocity intragraft administration of adenosine is a promising new approach to promptly reverse no-reflow events complicating PTCA and stenting of diseased saphenous vein grafts. Ex vivo studies demonstrate a potentially important mechanical advantage with the use of small syringes for injection. Further randomized studies will be required to better define the mechanism(s) and efficacy of this approach for treating no reflow, including its use in native vessels.