What is that
That of the bypass is a delicate surgical technique, but by now consolidated, to which one recurs when the coronary arteries of the heart are narrowed, or even occlude, due to the effect of atherosclerosis or other pathologies.
Let us remember how the coronary arteries are responsible for transporting blood to the heart muscle; consequently their obstruction results in a reduced supply of blood, oxygen and nutrients to the heart muscle. The cells of the heart thus enter a state of suffering, which can result in serious cardiovascular events, such as
- angina pectoris (transient deficiency of blood flow, responsible for an overwhelming pain behind the sternum);
- or heart attack (irreversible death of heart muscle tissue, resulting from prolonged obstruction of one or more coronary arteries).
How to do it
Through the bypass operation an artificial bridge is created that allows to bypass the obstacle to the circulation. This bridge, called a bypass, consists of a section of healthy and well-functioning blood vessel that is taken by the surgeon at the moment of the operation. When possible, some segments of the patient's mammary arteries will preferably be used (which have optimal functional characteristics to best perform the bypass action); alternatively, traces of the saphenous vein (venous branch of the lower limbs) are used.
These vessel segments are then grafted upstream and downstream of the occluded coronary artery, creating the famous bypass; this expedient allows an optimal supply of blood and oxygen to flow back to the heart.
Since the early 1970s, when the technique of coronary artery bypass grafting began to take hold, surgical techniques have evolved considerably. From the traditional intervention under general anesthesia and extracorporeal circulation (the heart is stopped and an external machine is used to circulate the blood), in more recent times we have reached interventions that can be performed with a beating heart and even under local anesthesia.
Risks and Consequences
As mentioned, the choice of the vessel to be used as a bypass is very important to ensure a longer life and to reduce the risk of this degenerating process (obstructions, etc.). According to some statistical data, about 10% of venous bypasses and 95% of arterial bypasses are effective ten years after surgery.
In general, the mortality rate of the intervention is close to 1%, very little considering the high risk of myocardial infarction which patients in the operation should face.
An alternative intervention to the coronary bypass is represented by the angioplasty (dilates the occluded artery by means of an inflatable balloon introduced with catheter, then a special net called stent is applied to prevent its reocclusion). Certainly less invasive than the bypass, it is suitable for patients in whom surgery is contraindicated.
Indications
In general, bypass is used in young patients (under the age of 70), with severe occlusions of several coronary arteries and at high risk of adverse cardiovascular events, which cannot be prevented by medical therapy alone.
The latter is based on pharmacological treatments (beta-blockers, calcium antagonists, acetylsalicylic acid, etc.) and on behavioral corrections that must however be undertaken also in expectation and after bypass surgery (abolition of smoking, reduction of body weight, control of stress and motor activity aimed at improving the effectiveness of the cardiovascular system).
