President Boris Yeltsin is unlikely to be an exception. Any major operation under general anaesthetic poses risks, and the risks are higher the older and more fragile the patient. His underlying state of health is a factor and Mr Yeltsin's bon viveur excesses which have contributed to the narrowed coronary arteries now depriving his heart of blood, will also have been taken into account.
However, he is undoubtedly a strong man, and comments by Dr Michael DeBakey, the American heart surgeon who has been consulted by the President's doctors, suggests that his chances of recovery are 95 per cent or higher.
A coronary bypass is essentially a mechanical diversion of blood from the narrowed or blocked coronary arteries supplying the heart, by grafting on to the organ additional "new" blood vessels. The operation is a treatment of last resort for patients in whom weight loss, dietary changes, stopping smoking, drugs and other medical interventions, such as balloon angioplasty to unblock the artery, have failed.
The operation requires a minimum of two surgeons and takes five hours or more. Initially, an incision is made in the patient's chest and the tissues parted to reveal the breastbone which is then split using a power saw. This action takes about 10 seconds. The heart is then revealed and the surgeon will open the pericardium, the membrane surrounding the pulsating muscle. A length of vein is removed from the leg, which will be used for the bypass procedure.
Before any further incisions are made, the patient will be connected to a heart-lung machine which takes over the function of these organs. Theheart is then temporarily stopped with an injection of potassium solution, and its temperature reduced with ice-cold, saline solution to protect the cells from damage.
One end of the section of leg vein is sewn on to the aorta, the main artery transporting oxygenated blood away from the heart, and the other end to a point below the site of the blockage in the coronary artery. If more than one artery is blocked, then other sections from the leg vein will be used.
Once the plumbing is in place, the patient is disconnected from the heart-lung machine, and his own heart given an electrical jump-start. As the blood starts flowing through it again, the surgeon will watch to see if the grafts are leaking. If all is well he will wire up the breastbone, and suture the chest.
The next 24 hours are critical as the patient is susceptible to haemorrhaging and the heart may go into "shock". Most patients spend two to four days in intensive care, another 10 to 12 on a ward. Some are back at work within six weeks.Reuse content