Coronary arteries are the vessels branching from the aorta to the heart and supply the heart muscle. In the case of deposits on their inner wall plaques and clinically significant overlap of the lumen to restore blood flow to the myocardium is possible with stenting or coronary artery bypass grafting (CABG). In the latter case, to the coronary arteries during surgery, a shunt (a workaround), bypassing the area of blockage of the artery, whereby blood flow is disturbed and the heart muscle gets enough blood. As the shunt between the coronary artery and aorta, usually used internal thoracic or the radial artery, and saphenous vein of the lower limb. The internal thoracic artery is considered the most physiological autocustom, and its wear is extremely low, and functioning as a shunt for many decades.
An operation like this has the following positive aspects — increased life expectancy in patients with myocardial ischemia, reducing the risk of myocardial infarction, improving the quality of life, increase exercise capacity, reduce the need to use nitroglycerin, which is often very poorly tolerated by patients. About coronary bypass the lion’s share of patients responds more than good, as they are almost not bothering chest pain, even when significant load; there is no need the constant presence of nitroglycerine in his pocket; fade fears of emergence of heart attack and death, as well as other psychological nuances that are typical of persons with angina pectoris.
Indications for CABG are identified not only by clinical signs (frequency, duration and intensity of chest pain, having suffered myocardial infarction or the risk of acute myocardial infarction, reducing the contractile function of the left ventricle according to echocardiography), but according to the results obtained during the coronary angiography (CAG) is an invasive diagnostic method with the introduction of radiopaque substances into the lumen of the coronary arteries, most accurately showing the location of occlusion of the artery.
The main indications identified during coronary angiography are the following:
- The left coronary artery impassable for more than 50% of its lumen,
- All coronary arteries impassable for more than 70%,
- Stenosis (narrowing) of the three coronary arteries, clinically manifested by attacks of angina.
Clinical indications for CABG:
- Stable angina functional class 3-4, poorly amenable to medical therapy (repeated during the day, attacks of retrosternal pain, not stoped taking nitrates short and/or long-acting),
- Acute coronary syndrome, which may stop at the stage of unstable angina or to develop into acute myocardial infarction with lifting or without lifting of ST segment in ECG (history of large or small,respectively),
- Acute myocardial infarction not later than 4-6 hours from start nekupirutayasa pain attack,
- Reduced exercise tolerance revealed by a sample with a stress — treadmill test, Bicycle ergometry,
- Expressed painless ischemia identified during the daily monitoring of AD and ECG by Holter
- The need for surgical intervention in patients with valvular heart disease and concomitant myocardial ischemia.
Contraindications for bypass surgery include:
- Reducing the contractile function of the left ventricle, which is determined according to echocardioscopy as a decrease in ejection fraction (EF) of less than 30-40%,
- The General severe condition of the patient, due to renal or hepatic failure, acute stroke, lung diseases, cancer,
- Diffuse lesions all coronary arteries (when plaque is deposited on the entire vessel, and to draw a shunt is not possible because in arteries there is not affected area),
- Severe heart failure.
Bypass surgery can be performed in a planned or emergency basis. If the patient enters the vascular or cardiac surgery Department with acute myocardial infarction, immediately after a short preoperative preparation is performed coronary angiography, which can be expanded up to surgery, stenting or bypass surgery. In this case run only the necessary tests — definition of blood group and blood coagulation, as well as ECG in the dynamics.
In the case of a planned admission of a patient with myocardial ischemia in the hospital carried out a full survey:
- Echocardioscopy (ultrasound of the heart),
- Roentgenography of organs of a thorax,
- General clinical blood and urine tests,
- Biochemical blood analysis with determination of the coagulation capacity of blood,
- Tests for syphilis, hepatitis, HIV infection,
- Coronary angiography.
After the preoperative preparation, including intravenous sedatives and tranquilizers (phenobarbital, phenazepam, etc.) to achieve the best effect from the anesthesia, the patient was taken to the operating room where the surgery will be performed in the next 4-6 hours.
Bypass surgery is always performed under General anesthesia. Earlier, surgical access was performed via sternotomy — incision of the sternum, in recent years more operations from mini-access in the intercostal space left in the projection of the heart.
In most cases, during the operation, the heart connected to the machine extracorporeal circulation (AIK), which in this period of time provides blood flow through the body instead of the heart. It is also possible to conduct bypass surgery on a beating heart, without connecting the AIC.
After aortic cross-clamping (usually 60 minutes) and connect heart-to-device (in most cases an hour and a half), the surgeon selects a vessel that will be the shunt and leads it to the affected coronary artery, hemming the other end to the aorta. Thus, the blood flow to the coronary arteries will be carried out from the aorta, bypassing the area where the plaque is. Shunts can be multiple, from two to five, depending on the number of affected arteries.
After all the grafts were sutured in the desired location, on the edge of the sternum, superimposed brackets of metal wire sewn with a soft cloth and superimposed aseptic bandage. Also displayed drainages, which follows hemorrhagic (bloody) fluid from the pericardial cavity. After 7-10 days, depending on the rate of healing of postoperative wounds, sutures and the bandage can be removed. During this period, performed daily dressings.
Operation CABG refers to high-tech types of medical care, so the cost is quite high.
Currently, these operations are performed by the quota allocated from means of regional and Federal budget, if the operation will be carried out in a planned manner to persons with coronary artery disease and angina, and free medical insurance for if the surgery is performed urgently in patients with acute myocardial infarction.
If the patient is not going to wait for the quota and can not afford the operation of toll services, it may apply to any state (in Russia) or private (abroad) clinic practising such operations. The approximate cost of bypass surgery ranges from 45 thousand RUB over itself without surgical intervention cost of consumables up to 200 thousand rubles with the cost of materials. In a joint heart valve replacement with bypass price is respectively from 120 to 500 thousand rubles depending on the number of valves and shunts.
Postoperative complications may develop heart and other organs. In the early postoperative period of heart complications presented perioperational acute necrosis of the myocardium, which may develop into acute myocardial infarction. The risk factors of heart attack are mainly in time of the functioning of the extracorporeal circulation – the longer the heart does not perform its function during the operation, the greater the risk of myocardial damage. Postoperative infarction develops in 2-5% of cases.
Complications from other organ systems are rare, and are determined by the patient’s age and presence of chronic diseases. Complications include congestive heart failure, stroke, exacerbation of asthma, decompensation of diabetes. and Prevention of occurrence of such conditions is a complete examination prior to bypass and comprehensive preparation of the patient for surgery with correction of the function of internal organs.
Postoperative wound already beginning to heal after 7-10 days days after bypass surgery. Sternum is a bone, it heals much later – after 5-6 months after surgery.
In the early postoperative period with the patient carried out the rehabilitation measures. These include:
- Breathing exercises – the patient is offered a semblance of a balloon, inflating which, the patient straightens his lungs that prevents the development of venous congestion in them
- Physical exercises, at first lying in bed, then walking along the corridor – at present, patients tend to intensify if it is not contraindicated because of the General severity of condition, to prevent stagnation of blood in the veins and thromboembolic complications.
In the late postoperative period (after discharge and subsequent) execution continues with the exercises recommended by the doctor of physical therapy (doctor of physical therapy) to strengthen and train the heart muscle and blood vessels. Also the patient for rehabilitation must follow the principles of a healthy lifestyle, which include:
- Complete cessation of Smoking and alcohol consumption,
- Adherence to the basics of healthy eating – exclusion fatty, fried, spicy, salty food, more consumption of fresh vegetables and fruits, dairy products, lean meats and fish,
- Adequate exercise – walking, light exercise,
- Achievement of target blood pressure levels is carried out using antihypertensive drugs.
After bypass surgery of heart vessels temporary disability (sick list) issued for a period up to four months. After that, patients are forwarded to the MSE (mediko-social examination), which decides on the award of the patient of a particular disability group.
Group III is assigned to patients with uncomplicated postoperative period and 1-2 classes (FC) of angina and no heart failure or her. Allowed to work in the field of professions that do not carry the threat of cardiac activity of the patient. Prohibited occupations include — working at height, toxic substances, the field, the profession of the driver.
Group II is assigned to patients with complicated postoperative period.
Group I is assigned to persons with severe chronic heart failure, maintenance by unauthorized persons.
The prognosis after bypass surgery is determined by a number of indicators such as:
- The duration of the operation of the shunt. The long-term is the use of the internal mammary artery, since its value is determined five years after surgery in more than 90% of patients. The same good results are observed when using the radial artery. Greater saphenous vein has less durability, and the viability of the anastomosis after 5 years is less than 60% of patients.
- The risk of myocardial infarction is only 5% in the first five years after surgery.
- The risk of sudden cardiac death is reduced to 3% in the first 10 years after surgery.
- Improves exercise tolerance, reduces seizure frequency of angina, and in the majority of patients (about 60%) angina not returned at all.
- Statistics mortality postoperative mortality is 1-5%. Risk factors include preoperative (age, number of transferred heart attacks, ischemic zone of the myocardium, number of diseased arteries, anatomic features of the coronary arteries before the intervention) and postoperative (for shunt and artificial circulation).
Based on the foregoing, it should be noted that the operation CABG is a perfect alternative to continued medical treatment of coronary artery disease and angina, as it significantly reduces the risk of myocardial infarction and risk of sudden cardiac death and significantly improve the patient’s quality of life. Thus, in most cases, bypass surgery the prognosis is favorable, and live patients after bypass surgery of heart vessels more than 10 years.