The Loyola practice is for the surgeon to administer the heparin to the patient into the right atrium inside the venous cannulation stitch. The total heparin dose is in a large syringe with a generous bore needle, after aspiration shows blood flash. Bleeding from the puncture site is handled by cinching down the cannulation stitch. Because the surgeon is thereby certain the heparin has gone in, it has traditionally been possible to immediately proceed to aortic cannulation. As far as I can tell, this technique developed because of a single incident, lost in the mists of time, where anesthesia staff mistakenly failed to properly administer the heparin secondary to some stopcock mistake.[^a] It is interesting to note that this practice means that the heparin was given after preparation (including clipping and cutting from the distal extent of the artery) of one or two mammary grafts. Moreover, aortic cannulation was performed before checking ACT. In several decades, across at least a thousand patients or more per year, this practice has been followed without a remarkable event. Personally, I prefer to ask anesthesia to give the total heparin dose, which they draw up after asking the perfusionist the quantity. I like to keep all the parties involved, attentive, and invested in the case. I wait until the ACT is measured to be adequate, or heparin resistance addressed if identified before cannulation. This is the safest practice. But the above experience lets you know that you can accelerate matters if you are desperate, as in the technique of stab cannulation. I ask for heparin to be administered before severing the distal mammary in bypass grafting procedures. I dislike leaving the mammary connected to the chest wall if there is more work to be done (another mammary to be harvested, a contralateral radial, complicated and prolonged vein harvest) that requires the mammary retractor to be removed. It isn't impractical to leave it attached, but I like it out of the way and wrapped up in the vasodilatory arms of a papaverine soaked ray-tech sponge. I will clip the distal branches of the mammary, cut it with a tonotomy scissors, and lay it out in front of me, asking an assistant to occlude it gently with a finger. As quickly as possible, I cannulate the end with a 24 guage yellow angiocath catheter mounted on a five cc syringe and administer 3 ml of straight heparin, ask for the assistant to occlude once more while I rapidly clip the end of the mammary. This allows a column of heparin to rest within the mammary, as long as it isn't bleeding out through a branch. During non-bypass cases, I will get control of the periosteal and marrow bleeding from the sternotomy, then ask for the total dose to be administered while I proceed with cannulation. [^a]:So many practices are the result of gradual evolution towards simplicity and effectiveness. A substantial number, however, originate as a draconian policy because of a single mistake. There is something in our nature as cardiac surgeons that likes to hand down commandments in retribution for an isolated screw-up. It is admittedly a high-stakes game, but hard cases often make bad law.