Home Therapies Bypass: When to use it and how the surgery works

Bypass: When to use it and how the surgery works

by Josephine Andrews
Published: Last Updated on 393 views

In medicine, a bypass is an operative circumvention of constricted blood vessels. Bypasses are mainly applied to the heart, but also to other blood vessels if diseased vessels are no longer sufficient for the blood supply. Here you can read when and how a heart bypass operation is performed and what needs to be considered afterwards.

What is bypass?

Bypass means “bypass”. In medical terms, this means bypassing blood vessels that are restricted in their function. With certain diseases, such as claudication (peripheral arterial occlusive disease in the leg arteries), an artificial vascular bypass may be necessary, as well as narrowing of the vessels in the heart ( coronary heart disease ).

A cardiac bypass improves or completely restores the oxygen supply to the heart muscle. The bypass is sewn there behind narrowed or occluded vessel sections and bypasses them. If doctors use vessels from the arm or leg for this purpose, one end is sewn to the main artery ( aorta ), the other behind the coronary artery (coronary artery). Therefore, this bypass is called aortocoronary bypass, ACB for short.

When is bypass surgery performed?

There are various reasons for a bypass. At heart they are often needed when

  • in the context of a heart catheter examination , the widening or reopening of a coronary artery was unsuccessful
  • one or two coronary arteries are affected and the left coronary artery (LAD) is narrowed or blocked at its base, a so-called main-stem stenosis
  • all three main branches of the coronary arteries are affected at the same time (“three-vessel disease”)
  • there are several narrowings over long sections of the artery and the patient is diabetic
  • several coronary vessels are affected and the pumping function of the left ventricle is restricted due to the lack of oxygen and nutrients
  • if the anterior artery between the two ventricles (RIVA, coming from the left coronary artery) is severely narrowed at its beginning

But there are also some reasons that speak against bypass surgery. One of these contraindications is when life expectancy is greatly reduced, for example due to other diseases. In any case, severe comorbidities may prevent the procedure.

What do you do with bypass surgery?

The operation takes place under general anesthesia. The patient’s body is often cooled slightly for the operation. This slows down metabolic processes and reduces the need for oxygen during bypass surgery. The duration and exact course of the operation are not always the same, but on average the operation takes about three to four hours.

In classic bypass surgery, the sternum is split along its entire length (median longitudinal sternotomy) to gain access to the heart and surrounding structures. After the pericardium has been opened, the large vessels (aorta/large veins ) are connected to the heart-lung machine. This now takes over the supply of oxygen to the body and the removal of carbon dioxide. The heart is stopped for further steps with a special, cold electrolyte solution (cardioplegic solution), so that the surgeon can begin to lay the actual bypass.

Arteries as well as veins (usually the vena saphena magna, alternatively parva) can be used as bypass material. However, we now know that veins are more quickly affected by renewed narrowing or occlusion than arteries. The thoracic artery (Arteria thoracica interna) is used most frequently, since its anatomical position in relation to the heart is favorable and the outlet from the collarbone artery (Arteria subclavia) can remain unchanged. In this case, only the heart-side connection to the coronary vessel has to be created.

By the way: the internal thoracic artery is also known as the internal mammary artery. Surgeons therefore like to refer to this bypass as an IMA bypass (internal mammary artery bypass). Since they usually use the left IMA as a bypass, this bypass is also known as a LIMA bypass (L for left).

Rarely, an artery of the arm (arteria radialis) is used for the bypass. In this case, the piece of vessel must be sutured to both the aorta and the respective coronary artery (beyond the narrowing) so that the desired bypass is created. In addition, it must be ensured beforehand that the blood circulation in the hand is guaranteed even without a radial artery (Allen test).

If the bypass is successfully placed, the right atrium and right ventricle are temporarily connected to a pacemaker and the heart-crippling electrolyte flushed out. Now the heart can take over the supply of the body again. The heart-lung machine is then no longer necessary after a short time and is separated again from the large blood vessels.

Finally, a few suction drains are placed in the chest, which drain blood and wound secretions to the outside in the first few days after the operation. Finally, the chest is closed again. Doctors use wires to hold the bony breastbone together.

After the bypass operation, the patient is closely monitored

Intensive observation of the patient is essential after major operations, even after a bypass operation. Heart, circulation, respiration and organ functions are continuously measured, monitored and evaluated in the intensive care unit for at least one day.

Other variants of bypass surgery

In addition to the classic procedure, there are other variants of the bypass operation. The process and procedure vary according to individual requirements: For example, in suitable patients – for example if only one vessel needs to be bypassed – minimally invasive surgical methods (without complete splitting of the sternum) can be considered – e.g. an incision on the left chest wall (anterolateral mini-thoracotomy). ). The so-called “off-pump coronary artery bypass” is performed without a heart-lung machine, so the heart pumps itself. Bypass operations of this type are often referred to by physicians as the MIDCAB technique (“minimally invasive direct coronary artery bypass”).

What are the risks of bypass surgery?

As with any major surgery, complications can arise during or after bypass surgery. They are at higher risk if the procedure is emergency, if the heart has already had surgery, or if the heart output is severely reduced. In recent decades, however, the risk of serious complications has steadily decreased. It is also significantly influenced by other diseases of the patient. These include diseases of the kidneys or lungs as well as metabolic diseases such as diabetes. The advanced age of the patient is also considered a particular risk factor.

The following complications can arise during or after bypass surgery:

  • Heart attack during and after the operation (e.g. due to the closure of the bypass)
  • Cardiac arrhythmias (usually easily treatable)
  • Circulatory weakness due to insufficient pumping capacity of the heart
  • Cardiac tamponade (post-bleeding into the pericardium, which then mechanically constricts the heart)
  • Stroke or other neurological disorders such as confusional states
  • Post myocardial infarction syndrome (Dressler syndrome, autoimmune processes trigger pericarditis, for example , generally possible with a heart attack)

Other possible complications after successful bypass surgery: Wound healing disorders or infections, bleeding and pain. They are more common in some pre-existing conditions (e.g. more wound healing disorders in diabetics). Smokers are more likely to develop pneumonia immediately after surgery than non-smokers. If the kidney function was already impaired before the bypass operation, artificial blood washing ( dialysis ) may be necessary temporarily . Blood clots are also a possible consequence of the operation. Overall, one to two percent of patients die during bypass surgery.

What do I have to consider after a bypass operation?

In a normal course, the patient is discharged about seven to ten days after a bypass operation, cardiac rehabilitation clinics then take over the so-called follow-up treatment (AHB), which lasts three to four weeks. In some cases, the patient is also discharged home and the rehabilitation treatment can be carried out on an outpatient basis.

It is very important to avoid risks after bypass surgery. These include, above all, smoking, extensive alcohol consumption and food that is too fatty or salty. A Mediterranean diet is often recommended. In combination with regular exercise, the risk factor of being overweight can be reduced, among other things. If the patients also avoid stress, they have laid another foundation stone for the long-term success of bypass surgery.

Bypass surgery follow-up

Long-term medication is usually required after bypass surgery . Above all, the long-term intake of platelet aggregation inhibitors is common, so that no new thrombi (blood clots) form in the coronary arteries or in the bypass.

As a rule, the doctor prescribes other medications in addition to a platelet aggregation inhibitor (e.g. acetylsalicylic acid, or ASA for short). This can be:

  • ACE inhibitors and calcium channel blockers (including treatment of high blood pressure)
  • Beta-receptor blockers (including against high blood pressure and arrhythmias)
  • Statins (therapy of elevated blood lipid levels )
  • Nitrates (e.g. as a spray to treat angina attacks when needed)

Some patients experience depression some time after bypass surgery . It is important to talk about the feelings and to see the surgery as a new beginning and opportunity. The doctor treating you (often the family doctor) should be informed about this and will then point out psychotherapeutic options. It can also offer advice on lifestyle changes. On the one hand, this prevents the rapid progression of cardiovascular diseases and, on the other hand, the bypass then lasts longer.

Sport after bypass surgery

In the case of an uncomplicated bypass operation, the patient can start early mobilization 24 to 48 hours after the operation. However, restrictions on physical activity are still to be expected in the first few weeks. The training should therefore start with gentle exercises.

Patients should avoid postural, tensile, and compressive loads for at least six weeks. This puts unnecessary traction on the surgical site. Patients should also avoid pressure on the chest in the first few weeks after the procedure. Jerky movements are also unfavorable. If the procedure was carried out minimally invasively, the period of time in which restrictions are to be expected can be shorter.

Discuss the start of training after a bypass operation with your doctor in advance.

Depending on their individual well-being and personal resilience, patients should initially start with a low level of exertion and then slowly increase it.

Suitable sports after the bypass

Can you ride a bike after bypass surgery? In principle, all sports are possible with a bypass operation. In the case of stressful disciplines, high-performance or competitive sports, however, you should discuss your return to the sport with your doctor in advance.

In order to become active after a bypass operation, gentle endurance sports are initially suitable. These include, for example:

In order to achieve a health-promoting effect, bypass patients should exercise about three times a week for 30 minutes at a moderate level. This is not only good for the heart, but also contributes to a healthy weight.

Warning: If you experience shortness of breath, sweating, heart palpitations or chest pains during exercise, you must stop exercising immediately. Speak to a doctor immediately.

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