Most pathologies of the cardiovascular system pose a danger not only to health, but also to human life. If conservative methods of treatment are ineffective, the doctor evaluates the advisability of the operation. In order to restore blood supply to the affected area of the myocardium, aortocoronary or mammarocoronary bypass surgery is prescribed. The difference between the methods is that in the first case an additional vessel is created (bypassing the affected) from its own vein. During mammary coronary bypass surgery, the mammary artery (internal thoracic) is used. Like any other treatment method, this method has its own characteristics, advantages and disadvantages.
Indications
Under the influence of various adverse factors, the lumen of the vessel that feeds this or that part of the myocardium narrows. As a result, the work of the heart muscle is disrupted and the process of formation of necrotic zones is launched. In order to restore blood circulation in the affected areas, mammary-coronary bypass surgery is prescribed.
Indications for surgical intervention:
- Coronary artery disease. Most often, patients have revealed stenosis of the anterior interventricular branch (LAD). Mammarocoronary bypass surgery is prescribed to persons for whom stenting or angioplasty is contraindicated.
- Obliterating atherosclerosis.
- Running angina pectoris, practically not amenable to drug treatment.
- Narrowing the lumen of the coronary arteries by 70% or more.
- Myocardial infarction.
- Ischemic pulmonary edema.
- Postinfarction myocardial ischemia.
- Narrowing the lumen of the left coronary artery by 50% or more.
- Poor angioplasty or stent placement in the past.
This is the main list of indications for mammary coronary artery bypass grafting. It can be expanded following an individual consultation with a doctor. It is important to understand that the assessment of the feasibility of surgical intervention is carried out in each case. The doctor takes into account the age of the patient, the general state of his health, the severity of the existing pathology.
Contraindications
Like any other surgical treatment, mammary coronary artery bypass grafting has a number of limitations. The main contraindications for surgical intervention:
- Congestive heart failure.
- Diffuse lesion of the coronary vessels.
- The presence of malignant neoplasms.
- Cicatricial tissue lesions that contribute to a sharp decrease in the ejection fraction of the left ventricle (about a third).
- Renal failure.
- The presence of chronic lung pathologies of non-specific etiology.
It is worth noting that old age is not a contraindication to surgery. But in this case, the doctor must consider all possible risks.
Advantages and disadvantages
The use of the mammary artery has a number of undeniable advantages. The advantages of shunting in this case:
- This vessel is characterized by an increased degree of resistance to atherosclerosis.
- The mammary artery has no valves; it is not affected by varicose veins. In addition, it has a rather large diameter, which makes it ideal for coronary artery bypass grafting.
- The walls of the artery have an endothelial layer. It synthesizes prostacyclin and nitric oxide - substances that contribute to the combination of platelets.
- The internal thoracic artery is able to increase in diameter, which allows to increase the volume of incoming blood.
- Significantly improves the functioning of the left ventricle.
- The mammary artery as a shunt is more durable.
- High survival rate among patients.
- Significantly reduces the risk of relapse.
The disadvantage of this method is the large difference in the diameter of the internal thoracic and anterior interventricular arteries. Mammarocoronary bypass surgery is complicated by the fact that it is difficult to isolate a vessel that is planned to be used as a shunt.
Technique
In short, during the operation, myocardial revascularization is performed with the creation of an additional message between the internal thoracic and coronary arteries. The left mammary vessel is used to create an anastomosis on this side. The right one is necessary to form a connection with the anterior descending artery.
Mammarocoronary bypass surgery is performed according to the following algorithm:
- The doctor performs a median sternotomy, that is, provides access to the myocardium through dissection of soft tissues.
- After this, the surgeon secretes veins, subcutaneous tissue and the selected mammary artery. The next step is the ligation of the lateral branches.
- At the place of departure, the doctor pinches the mammary artery. This helps prevent the development of spasm.
- The surgeon inserts a weak solution of papaverine hydrochloride into the distal end. Then measured the indicator of free blood flow.
- The end of the anastomosis is freed from the surrounding tissues. Then the surgeon opens the coronary artery, making an incision from 4 to 8 mm long. The next step is the application of an anastomosis. The doctor makes it single seams or one continuous.
The final stage is tissue suturing.
Postoperative period
A few days after the intervention, the patient is in a hospital, where he is constantly monitored and regularly taken biomaterial for research. At first, strict bed rest is shown. During this period, antibiotics and pain medications are prescribed.
On the first day after surgery, the drainage system is removed. In addition, oxygen support also ceases. A prerequisite is a diet.
After a while, the patient is allowed to sit, get up and take several steps around the room. As you recover, physical activity should increase, and nutrition will become more diverse.
Finally
Mammarocoronary bypass surgery is a method of surgical intervention, during which an additional vessel is created to bypass the affected. At the same time, normal blood supply to the myocardium is restored. During the operation, mammary arteries are used, which serve as a shunt for a very long time.