CORONARY ARTERY BYPASS SURGERY

Surgical myocardial revascularisation, popularly known as Coronary artery bypass grafting or CABG operation is done for critical coronary lesions. This means that when there are blocks in the arteries supplying the heart, we need to give blood supply to those parts. The common methods to give blood supply is either by medicines (medical management), angioplasty and stenting (PTCA or PCI) or bypass surgery.

There are clearly defined criteria upon which decisions are to be made as to which line of management the patient should follow. If there are very few blocks or if the blocks are discrete (small in length) or if there are some problems that may complicate surgery (= comorbidities) then percutaneous balloon angioplasty and stenting becomes a good option. In other cases, if the blocks are multiple or very near the origin of the main blood vessels and in diabetics (as stents block faster in diabetics), surgery is preferred.

The common method of doing CABG is the "off pump" or beating heart technique as this gives a faster recovery to the patients. However, if there are many grafts required or the patient is unstable, then we do  not hesitate to put on the heart lung machine. Studies have revealed that there is not much difference in the outcome if you use or do not use the heart lung machine except if there is some kidney or lung dysfunction.

Normally we use LIMA (left internal mammary artery) as the main artery to give long term results. We use radial artery if there is good circulation and if the vessel is not calcified and it also gives good long term results in our hands as well in recent studies. In some patients we use right internal mammary artery (RIMA) so that we can achieve total arterial revascularisation. This we avoid after the age of 70.  All other grafts are vein grafts.

What are grafts?

Grafts are conduits that are used to bypass the blocks in the blood vessels. Artificial grafts are not  available and those that are used for bypassing peripheral arteries do not have any good short term result when used for coronary bypass. We therefore use the grafts made of the patient’s own blood vessels. This means that we have to remove those arteries and veins which are expendable.  Usually we take the artery from the chest wall known as left internal mammary artery or LIMA. Sometimes we use the RIMA (right internal mammary artery), however in patient who are short, obese, severely diabetic or very old, we tend to avoid this graft if the LIMA is being taken. Additional graft may be taken from the arm (radial artery) when it is having good flow from its neighbouring artery (the ulnar artery). In case we need more grafts or we these above mentioned grafts are not good in quality, we would also take the superficial veins from the leg to act as grafts. The veins can be removed by open technique or by endoscopic (closed ) technique,  however there are reports that in the closed technique there is some chance of injury to the innermost layer (intima) and this may lead to graft failure earlier.

The order of preference for our unit is internal mammary artery followed by radial artery followed by leg veins. This is as per scientific evidence too. Radial artery has recently been reported to have very good long term results although they may not match the results of the mammary arteries. In elderly patients, we tend to use less of arterial grafts, as the arteries may be diseased themselves.

POSTOPERATIVE RECOVERY AFTER CABG

It is natural to have some doubts and questions after undergoing the CABG surgery. Most of the times the doubts would have been addressed by the surgeons, physicians and physiotherapist on the rounds before discharge. You should not hesitate to ask as many questions about the recovery and about what precautions you should take in the postoperative period so that your recovery and rehabilitation period especially after going home, would be fine and trouble free. For you, what you do during the postoperative period may help in improving your recovery back to normal life.

First you must understand that the purpose of doing surgery is primarily to prolong life and also to make you live life at its fullest potential. It is not meant to disable you nor give you an excuse from continuing an active life. There are some who believe that once a major heart surgery like CABG is over, your active life is finished and you are just existing to complete life and reach the eventual destination.

In the immediate postoperative period, you will have plenty of lines running for the delivery of medications and to give intravenous fluids. There will be usually a few tubes coming out of the chest to drain the chest collections. Naturally, despite giving adequate Pain killers, there may be some amount of pain. You must try to eat and drink when allowed although you may feel nauseous or like vomiting. Normal diet will help you recover fast and also you will be able to tolerate the medications and painkillers.

In the postoperative period, you may be asked to some exercises. One of the most important ones is the breathing exercise called spirometer. In this you have to inhale in a device and raise an indicator like a ball and this show you as to how much effort you make. Gradually you must try to raise the ball higher or increase the number of balls if there are more than one. This is very important as it increases your respiratory capacities and one of the most common complications of the surgery is postoperative atelectasis and pneumonias. The rib cage is more or less not very compliant due to the incision and the splitting of the muscles due to pain. This is the reason that we should try to improve the lung capacities by this exercise. Besides this, the physiotherapist may ask you to do some more exercises and also the nurse may give you nebulisation or steam inhalation so that your Lung secretions will become loose and you can cough them out.

Arm exercises and walking exercise will usually be started in the intensive care unit itself. Once you are fit to be transferred out, then you can be sent to the wards. In the ward, your near relatives/attendants may be asked to stay with you. You must be knowing that all the relatives are not medically trained and hence it is sometimes very difficult for them to comprehend As to what is going on. They may be frightened of your condition. Only those relatives that are used to see patients in postoperative phase will understand. Sometimes the fear and anxiety may be so much that it might border on a panic reaction in susceptible people. You might have to reassure them. If you are having any pain or any other problem, please call the nurse or the duty doctor and tell it to them so that action can be taken. There is no need to suffer silently just because you have a nervous attendant sitting nearby.

Gradually the pain will subside and the other symptoms like nausea, malaise and lack of appetite will go away.

Once you are discharged and go home or to a place where you are planning ambulatory care, you will have to be as independent as possible. This will aid your recovery. Try to get up on your own by turning to one side and not just getting up straight. Also mobilise yourself as much as possible in order to reduce joint stiffness. The physiotherapist must have given you a plan of exercises and you should follow that.

Normalise your diet pattern and eat the allowed foods depending on your diabetic status, your heart function and blood pressure and your lipid profile level. Increase the exercise distance and the speed of walking till you reach a level of at least walking 20 minutes a day with a brisk rate. Bathing and shower are good for health as that reduces the skin wound infection. Use sponge bath only if specially instructed (in those cases where the wound is to be seen/revised again). Do not lift heavy objects nor drive a car or scooter for a month. If you are sexually active, it is better to wait for a month. Please do not use medications for sexual activity like Sildenafil without the knowledge of your physician as there may be drug-drug interactions.

At the end of one month, you can go back to all normal activity. It is better to have an exercise protocol that will be suited to you. “Cardio” exercises like walking, running, cycling or swimming are good. Also mobility exercises such as Yoga, Taiji and others are good. If you are following prayers by “Namaz” technique, it can also be done. People who are doing “Suryanamaskar” should restart their routine.

Your medications will reduce sequentially. Initially, the antibiotics get shed out followed by painkillers and other supportive medications. Certain medications such as blood thinners (anti-platelets) and some medications to prevent atherosclerosis (blood vessel hardening) May have to be taken lifelong. When you come for review, please do not hesitate to ask any doubts so that your recovery can be maximised.

At the time of review, you will be requested to get some tests. This will help in assessing your clinical condition and advising you on secondary prevention.







OFF PUMP CORONARY ENDARTERECTOMY

Coronary Endarterectomy is done when the bood vessel supplying the heart is so totally diseased that there is no room for either a graft or a stent. The vessel is totally sclerosed and in such a situation many physicians and even surgeons tend to deem the vessel as "inoperable" and condemn the patient to only medical management in a situation where actually much better could be done.



In Coronary Endarterectomy, we remove the total scerosis of the vessel and leave only the outer layer behind. In this way, the blood channel gets opened out and then a graft can be placed. Usually endarterectomy is done with the help of the heart lung machine and using extra-corporeal circulation, but  our unit has successfully performed many coronary endarterectomies with beating heart technique and found that the results are very encouraging. The complication rate is very low and most patients are able to go to a fully active life

Our protocol is to maintain oral anticoagulation and maintain an INR (prothrombin time) of >1.5 for over 6 weeks to 2 months period. During this period we usually give additional one antiplatelet also. After this period is over, we usually supplement with double anti-platelet regime and no anti-coagulant for a period of one year and then downgrade it after that to a baseline dose.





STAGES OF CORONARY OBSTRUCTION