OPERATIONS PERFORMED: Urgent coronary artery bypass grafting x3 with intra-aortic balloon pump support, left internal mammary artery to the left anterior descending, reverse saphenous vein aorta to the second diagonal, aorta to ramus, lysis of myocardial muscle bridge on left anterior descending, endoscopic vein harvest, and transesophageal echocardiogram.
PREOPERATIVE DIAGNOSES:
- Acute stuttering anterior myocardial infarction, severe left anterior descending disease with 50% left main stenosis, cardiomegaly, preoperative intra-aortic balloon pump support, preoperative heparinization and aspirin therapy.
- Hypertension.
- Dyslipidemia.
- Hypothyroidism, on replacement.
- Advanced age.
POSTOPERATIVE DIAGNOSES:
- Acute stuttering anterior myocardial infarction, severe left anterior descending disease with 50% left main stenosis, cardiomegaly, preoperative intra-aortic balloon pump support, preoperative heparinization and aspirin therapy.
- Hypertension.
- Dyslipidemia.
- Hypothyroidism, on replacement.
- Advanced age.
SURGEON: John Doe, MD
INDICATIONS: This (XX)-year-old lady had presented with symptoms of chest pain that were recurring with elevated troponins. It was suspected that she had an acute stuttering anterior type of infarction going on. She was catheterized last afternoon and found to have a very ulcerated, severe proximal LAD stenosis in the mid to distal LAD; however, there was a systolic constriction from a muscle bridge, it appeared, that was fairly long. At that time, it was hoped that maybe she could have an angioplasty, but things did not feel quite right on the catheter and so an intracoronary ultrasound (ICUS) was done at the left main. A 50% left main stenosis was found that was not visible in any of the usual injection views. Because of this finding, it was decided to send her to surgery and so a balloon pump was inserted and she was heparinized until she could be brought to surgery urgently this morning.
FINDINGS: Her heart was much more hypertrophied than we expected. It was above grade 4-5/6 and enlarged as well. The x-ray showed some vascular congestion as well. She had never been in the hospital before in her life. The anterior wall was somewhat hypokinetic, I thought, but in general, the function had looked good at the time of the catheterization. The pulmonary artery pressures initially had fairly average numbers with the diastolic in the upper teens. However, when we were taking down the mammary artery, they tended to go up quite high, as if she was having an acute V-wave from acute mitral incompetence. This may have been related to a higher CO2 level, however, and so we had to check this at the end.
We found out her mammary was very small because of her small stature, at only 112 pounds. It was small distally and so we had to trim it up to where it had at least a reasonable pulse on the balloon pump. As a result of this, I had to dissect out her LAD and lyse the systolic muscle bridge, so I could graft just above it. Here, the mammary artery length was just enough. The size of the mammary was able to be shortened enough to where she had average size and flow and it worked out fairly well. The LAD was about 1.4 to 1.5 vessel with mild disease at this level where grafted. Beyond this, it was getting a lot smaller where it had been in the muscle bridge.
We took vein from the left thigh endoscopically. She had a history of leg cellulitis, but we did not see any evidence of this whatsoever. The vein was grade C in quality, being thinner than usual and somewhat irregular. The most regular portion we used to graft was the ramus vessel. This was a high diagonal or high circumflex. It was a 1.4 vessel with mild disease where grafted. The more lateral circumflex was a little too small to graft. The second diagonal had disease in its takeoff and this was about a 1.3 to 1.4 vessel, also with mild disease where grafted. The vein grafted here was not more irregular.
DESCRIPTION OF PROCEDURE: After prepping and draping the patient, we went ahead and harvested the vein endoscopically from the left thigh. A median sternotomy was done and the heart measurements taken. We thought she tended to be a little bit more sluggish than we expected. We dissected down the left internal mammary artery and we noted that the PA pressure tended to change off and on, as detailed above. The mammary was small distally. We used papaverine and lengthened it as much as we could. We heparinized and then we cut the mammary free. We made a slit in the left pleural space and used a large silk suture to hold back the left upper lobe, so we can shorten the mammary up. This worked out fairly well at the end. We cannulated and went on bypass, cooling to 28 degrees, cross-clamping the aorta with a soft clamp and giving blood cardioplegia into the aortic root initially and up to 20 minutes. There was a little thickening in the aorta, and on a later TEE, there was found to be disease in the descending aorta as well.
We went ahead and looked at the vessels and grafted the first vein into the ramus vessel, which was really high first diagonal. We had to go high on this vessel and the second diagonal because of the fact they got small getting out farther. We had good flow in injecting through them and very good back-bleeding coming up to second diagonal at the end. This, I suspect, represents competitive flow through the 50% left main.
Next, I opened up the fatty tissue over the LAD area in the front of the heart. We tried to clip all the branches we could as we did this. We dissected the LAD out from where it came up out of the muscle and fat tunnel. We went all along it completely, dividing all of the crossing veins and opening it up completely in the muscle. It was very deep and I was concerned that we might end up in the right ventricle, but we did not. Once I got where the vessel was getting a little bit bigger more proximally, I opened it and grafted the mammary in place with 7-0 Prolene. Flow could easily start to heart to beat distally. The cross-clamp was released and a side-biting clamp used to do the two vein proximals at this point.
The heart was in a heart block rhythm at this time. This was probably the result of the very severe left ventricular hypertrophy that was present and thus having to elevate the heart against the venous cannula for some time, trying to graft the ramus vessels and the circumflex marginal region. I went ahead and placed ventricular pacer wires. I then placed atrial wires after that and we paced it AV sequentially to get her off bypass. We used Dobutrex at about 3-5 mcg. Once we came up bypass, the blood pressure was running around 100 with the balloon pump on 1:1. Cardiac index was only around 1.7 to 1.9, however, and did not improve. We gave volume, to see if that would help out, but as we did so, the PA pressures jumped up very high with a V-wave that suggested she was having an acute mitral incompetence. We added a little bit more catecholamine but things did not ever turn around very much, so we asked for TEE to be brought in. We looked at things on the TEE.
As this was being brought in, we went ahead and got some Primacor and added that as well as a little bit of Levophed. The Levophed brought the blood pressure up quite well and the Primacor helped to improve the cardiac index so it was over 2.3 or even higher. By the time we got the TEE down and looked at the heart, the PA numbers were normal and there was not any mitral incompetence to speak up. There was not any aortic incompetence hardly and the function looked fairly good with the exception of the very thick ventricle, at least 1.7 to 1.8 cm. Things were continuing to improve. We were pacing her AV sequentially and she jumped into a sinus rhythm on her own by this time, and when that occurred, the blood pressure went up 30 points and the function improved dramatically. I think a lot of the PA pressure problems were related to rhythm disturbances. We then, at this point, gave the rest of the protamine and decannulated and then closed incision as usual.
