- Grasp internal thoracic fascia at the level of the second or third interspace below the Angle of Louis using a Mills ringed tissue forcep[^a] - Incise the fascia on top of the medial internal mammary vein - You want to eliminate all possible overhang of tissue so you will be able to easily visualize the top of the mammary - The maximum setting of the [[Harmonic Scalpel]] using the hook portion of the blade is excellent for clearing overhang. This setting is otherwise hardly ever used. - Switch to a Metzenbaum scissors with nicely rounded tips - A single rounded tip can be pushed inside the - Continue the incision cephalad - Past the level of the Angle of Louis, extend the incision in the fascia directly on top of the mammary artery as far as possible - Extend the incision from the initiation point in a caudal direction, through the transverse internal thoracic muscular fibers using a left-handed grip on the Metzenbaum scissors - Using Mills forceps, grasp the adventitia of the mammary artery, or with further progress, use a single tip of the spread Mills on top of the artery, to gently pull the artery away from the chest wall - Use the minimal setting of the [[Harmonic Scalpel]] to apply the blunt tip to the tissue above the artery in an area with no visible branches - A smooth painting motion is used that allows the extremely narrowly generated vibrational heat of the tip to vaporize the tissue, but does not allow the tip to spend more than a two second count directly on the artery. - Adipose tissue will render into a murky fluid that is best sopped up with the corner of a lap sponge - The unlit tip of the harmonic scalpel is occasionally used to gently dissect away the artery from the chest wall - When a branch is seen, the blunt tip is gently applied the branch, as far as is reasonable from the artery itself until the branch has turned anywhere from white to black, indicating that the branch is now sealed - Smaller branches will be severed with this motion alone - Larger branches may cauterize to black and still not part. They can be encircled with the hook portion of the tip. - The narrow edge at the hook focuses the vibrations and cuts the branch easily - Patients will vary in the quality of their tissue. Some will have delicate branches that easily tear before the harmonic can seal them. - If there is enough of a stump, and it can be quite small, a small clip can be applied with easy and effective hemostasis, then control the chest wall end with a little zetz from the 20 bovie. - The narrowly focused vibrational heat of the harmonic scalpel isn't ideal to cauterize a freely bleeding source, as the blood heat sinks the energy away. - If the stump is too small, a 7-0 prolene figure-of-eight adventitial stitch, with a small bite on the far and near side of the branch will provide excellent hemostasis - You want to have enough mobilization on either side of the branch to facilitate this stitch - If bleeding is vigorous from the branch and obscures your view, an assistant can hold a Frazier tip suction with an unoccluded side hole a millimeter or two away from the bleeding branch to suck up the blood into the cellsaver. - If this keeps happening with certain size branches, you can always clip-clip-cut the branch[^b] - Almost all mammaries harvested with harmonic will not need clips, which is very pleasant when selecting the anastomotic site. - Travel from mid-sternum cephalad, with the hook facing cephalad - Circumferential freedom of the mammary facilitates the harvest after it is achieved. - Take extra time on the large branch at the Angle of Louis - Continue until you reach the thymic branch, a small branch at about the level of the subclavian vein that is sharply medial. The medial mammary vein should be retracted medially, sometimes with a silk tie to visualize and cut this branch. Make sure it is not the pericardiophrenic branch, since the Phrenic will not be far away. - Continue the harvest at least to the xyphoid bifurcation - The back end of the hook blade has a narrow section similar to that inside the hook, and can be very useful when harvesting in this direction - The blunt end should still be used to seal branches - Ask anesthesia to give heparin - It is a common variation to give the heparin well after the mammary has been cut, and this usually works out fine, and is certainly compatible with harvesting both mammaries, then giving the heparin. Others go to the extreme of leaving the IMA's hanging from the chest wall until the time that the heparin is given, just before going on pump. Infrequently, but with regularity, one will see a thin strand of clot that has formed inside the mammary when one is preparing the tip for anastomosis. This thin strand will be pulled out, and have a distressing length, and one will wonder how often this is happening, and we never know about it. For this reason, it seems a happy compromise to give the heparin before clipping the mammary. Moreover, if the heparin is given at this point, enough time will have typically passed before aortic cannulation that an ACT is available before putting a plastic tube in the largest artery as it travels in the direction of the brain.[^c] - When heparin is given, clip each terminal branch with three medium clips - Cut terminal branches of mammary with tonotomy scissors - Inspect caliber of mammary, strength of bleeding, then clip the bifurcated terminal branches with medium clips - What to do if the mammary is small - The mammary may be small because of conduit spasm, and may look better after it has had some time to soak in papaverine. But what if it isn't going to get better? You will need another length of vein for grafting, or if arterial conduit is desperately required, you may have to consider the RIMA or a radial. Is there a diagonal it can be sewn to? Is the mammary better more proximally? Can the portion that is better be stretched to reach the target by partially or completely skeletonizing it? If it is used to the mammary, it may grow with time, but you may not want to leave it as the only conduit going to the LAD. As the saying goes, "a good vein is better than a bad mammary". - Is flow through the mammary inadequate?[^d] - Lay out mammary on a ray-tech sponge opened lengthwise - Spray mammary and sponge with papaverine - Inspect carefully for any missed branches to be clipped - Fold ray-tech sponge over mammary, tuck into chest - Announce that one ray tech is going into the left chest, in a voice that can be heard by the circulator. - Bovie all bleeding points on interior chest wall except veins injured during harvest - Bovie will only temporarily cowe these into submission - Find the ends and clip them - Obviously, injury to the veins should be avoided to preserve circulation to the sternum, but it is not a powerful negative if it occurs. - Remove laparatomy sponge packing from left pleura - Count them out, as you counted them in, in a voice that the circulator can hear. - Remove RULtract retractor [^a]: [[Tissue Forceps Tradeoffs]] [^b]:"One quickly learns the tissues of a patient," says Dr. Kieser in her excellent surgical videos on mammary skeletonization. https://youtu.be/PezIaOpvaKg and https://youtu.be/WjjZPzKMxOw [^c]:[[Philosophies in the Timing of Heparin Administration]] [^d]:[[What to Do If Mammary Flow is Inadequate]]