Common Indications for Cardiac Bypass
Left Main Coronary Artery Occlusion >50%
Stenosis (hardening) of LAD or Proximal Circumflex >70%
3 vessel disease with or without angina, or with Left Ventricular dysfunction
The Surgical Procedure
Depending on how many arteries are occluded, a certain amount of vein/artery autograft is needed. At many hospitals the PA is primarily responsible for harvesting the vein or artery from leg or arm. Before now, this was performed in an open procedure with an incision alongside the vein to remove it. Now, most of these harvests are performed endoscopically with a scope designed specifically for vessel harvesting. With this scope, the incision in limb can be much smaller; in most cases that I was in, it was no more than two and a half inches. Once the vessel is harvested it is prepared by clipping the branches closed and repairing any possible holes/areas of potential leakage.
While the vessel is being harvested the surgeon is opening the chest and preparing for cannulation to the pump. If needed, he/she will take down the mammary artery for anastomosis. Once the PA is finished harvesting he/she returns to the chest with the surgeon and assists with cannulation. The purpose for the pump is to allow for blood distribution to the rest of the body while the heart is still. Essentially, the pump machine acts as the heart for the rest of the body. During this process the heart is cooled to allow for complete asystole and preservation during the bypass.
The bypass begins distally by attaching the autograft to the area distal to the occlusion (to allow for blood flow to the areas previously restricted due to occlusion and essentially "bypassing" the occlusion). Once all the anastomoses are attached distally, the autografts are attached to the aorta (proximally). Very small sutures are used for vessel anastomosis which requires the use of magnifying lenses worn by the surgeon and PA.
Upon completion of the bypass portion of the procedure, the pump is removed and the heart is warmed. At this point, if everything is going as planned, the chest can be closed with wires and the surgery is complete. Depending on the surgeon, number of bypasses, and other factors, the duration of the surgery varies greatly; however, typically it will be at least 3-4 hours.
This Site Was Unique
The PAs at this site were allowed to do so many more things than I have seen other PAs do in any other specialty. It was clear that this was still not even the norm for this specialty as most of these PAs have worked in this field for a long portion of their career. The three surgeons in the group were very trusting of the PAs that they have worked with for over a decade, allowing them to attach the proximals, attach the cannulation, and much more. The PAs at this site were thrilled to learn and do more every day, to them this was more than exciting, they could not get enough of procedures and took every opportunity to learn/try new things, and perfect their skills. What made me so impressed was that they were not "one trick ponies" they worked and managed their patients on the floor and knew medicine just as well as they knew surgery. Every one of them was highly admirable, they are intelligent, skilled, and still very grounded as people. I highly look up to them and hope to experience something as great as them one day. They truly have reached the ceiling of the PA profession as they are not just surgeons, they are amazing clinicians.