How is heart bypass surgery performed? How long can the newly constructed blood vessels last?

Author: Wang Huaibin, Chief Physician, Beijing Hospital

Reviewer: Zhang Haicheng, Chief Physician, Peking University People's Hospital

The results of the coronary angiography showed severe stenosis in multiple coronary arteries. After comprehensive evaluation, the location, severity, diffuseness of the lesions, degree of sclerosis and calcification, degree of vascular tortuosity, and whether there is a coronary artery aneurysm were considered to be ineffective. In this case, the doctor would recommend coronary artery bypass surgery to improve blood flow.

1. How is heart bypass surgery performed?

After the anesthesiologist administers general anesthesia, the doctor will then strictly disinfect the skin of the surgical area and prepare the vascular materials needed for coronary artery bypass grafting. Usually, these materials are taken from the patient's own body, such as the great saphenous vein in the leg, the radial artery in the upper limb, or the internal mammary artery in the chest.

Figure 1 Original copyright image, no permission to reprint

Using autologous blood vessels as bypass materials has significant advantages. For example, after removing the great saphenous vein in the lower limb, the blood circulation in the leg can be effectively compensated by the deep venous system to ensure that the blood supply is not affected. Similarly, if the radial artery in the upper limb is used, it can be fully compensated by the ulnar artery and the deep palmar arch, superficial palmar arch and other vascular networks, and the blood supply can still remain stable.

After the vascular materials are prepared, an extracorporeal circulation system needs to be established, that is, an extracorporeal circulation machine is used to temporarily replace the patient's cardiopulmonary function, so that the heart is in a relatively static state, which facilitates the precise construction of a vascular bridge on the surface of the heart. The core of bypass surgery is not to directly intervene in the narrowed blood vessels, but to build a bypass channel through autologous blood vessels to bypass the diseased area, thereby restoring the blood supply to the distal myocardium.

Once the vascular bridge is built, the cardiopulmonary bypass machine will gradually reduce its support and eventually stop working, allowing the patient's cardiopulmonary function to recover on its own. The surgical team will then suture the skin incision, marking the successful completion of the operation. Usually, it takes about 4-6 hours to build 3-4 vascular bridges.

2. What medications should I take after heart bypass surgery?

After surgery, doctors usually recommend taking medications, not because of the bypass surgery itself, but because of the need to treat coronary heart disease. The medications used mainly include the following categories:

The first are antiplatelet drugs, such as aspirin, clopidogrel or ticagrelor, which are used to prevent thrombosis and protect the coronary arteries and bypass vessels; the second are lipid-lowering drugs, such as statins, which help stabilize atherosclerotic plaques in blood vessels; then there are beta-blockers, which can slow down myocardial contraction, lower blood pressure, and reduce myocardial oxygen consumption; in addition, there are nitrates, which can dilate blood vessels, reduce the amount of blood returning to the heart, and reduce ventricular wall tension, thereby reducing the burden on the heart.

Patients with hypertension or diabetes also need to take antihypertensive and hypoglycemic drugs to control blood pressure and blood sugar levels. These measures help delay the progression of coronary atherosclerosis and maintain the long-term patency of the vascular graft.

The doctor will prescribe the specific types of drugs required, combination medication regimen and duration of medication based on the patient's specific situation, and the patient should take the medication as ordered by the doctor.

Figure 2 Original copyright image, no permission to reprint

3. How long can the newly created blood vessels from coronary heart bypass surgery be used?

It is usually recommended to return to the hospital for a comprehensive review 3 months after surgery to assess general condition and wound healing. The review includes cardiac ultrasound to assess cardiac function, heart size and contraction strength; in addition, blood tests, electrocardiograms and chest X-rays are required, and coronary artery CT imaging is performed as much as possible to check the status of the bypass vessels.

A follow-up examination should be conducted 3 months after surgery. Provided that the medication is taken on time and the overall condition is good, it is usually recommended to have a follow-up examination once a year. The main purpose is to monitor whether the newly grafted blood vessels are restenotic or whether the blood vessels in other parts are stenotic.

It is worth noting that the blood vessels used in bypass surgery are all derived from the patient's own body, so they are highly compatible with the patient. During the operation, the doctor uses very fine sutures to perform meticulous vascular anastomosis, which results in a high long-term patency rate for the bypass vessels. In particular, the commonly used internal thoracic artery or internal mammary artery has a 10-year patency rate of more than 90%.