Bypass surgery

The bypass operation is a method in vascular surgery to bypass constricted blood vessels and correct circulatory disorders in organs and tissues. In principle, the method works like a bypass, which diverts the blood around narrowed or blocked vessels.

Bypass operations are often used to bridge constrictions in the coronary arteries in the case of coronary heart disease ( CHD ) in order to ensure the blood supply to the heart . In principle, however, they can also be carried out in other parts of the body in order to avoid blocked vessels and maintain the blood supply to the tissues.

What is the bypass used for?

For the “bypass” a so-called donor vessel is necessary. This can be an endogenous vessel or a plastic prosthesis. What is suitable also depends on the location of the bypass operation. The patient’s leg veins and thoracic arteries are usually used for heart bypass operations. The left thoracic wall artery (internal mammary artery) plays the most important role, but forearm arteries are also used.

If usable endogenous material is not available in sufficient quantities, alternative materials (plastic prostheses) are used. The number of bypasses to be performed depends on the number of diseased vessels. In the case of coronary heart disease, several vessels are usually affected by life-threatening narrowing deposits. Accordingly, three to four bypasses are usually placed during a heart bypass operation.

Laying a bypass: What are the chances of success?

According to study results, blood flow to the heart muscle improves in more than 90 percent of cases after heart bypass surgery, and 65 percent of patients become completely symptom-free, with the success usually lasting for many years.

In addition, bypass-operated patients benefit from a longer life expectancy compared to patients treated only with medication. This is especially true if several or large vessels of the heart are affected by constrictions at the same time.

Due to decades of experience, the bypass operation is considered very safe . Nevertheless, heart surgery is always associated with risks and therefore requires a strict risk-benefit analysis by the doctor.

Bypass operations are now the most common heart operations and are routinely performed in many specialized clinics. The risk of dying from the operation is around one percent. Without surgery, the risk of death is much higher.

Do health insurance companies pay for bypass surgery?

Bypass surgery is superior to other treatments in certain cases. They help to avoid complications and save lives. If they are used in accordance with the applicable treatment guidelines, the public health insurance companies therefore pay for the bypass operations and all the necessary preliminary examinations and follow-up treatments.

Bypass surgery: indications

Bypass surgery is a method of treating narrowing of blood vessels and the associated circulatory disorders. Bypass operations are often considered when the coronary arteries narrow as a result of coronary heart disease ( aortocoronary bypass ) in order to ensure blood flow to the heart.

When is heart bypass surgery necessary?

If the vasoconstriction can no longer be adequately treated with medication alone and there is a risk of undersupply to the heart, an operative method should be considered. Two methods can be used here – restoring the blood flow in the coronary arteries using a stent , which is inserted into the respective vessel using a catheter, or bypass surgery to bridge the narrowed areas.

The bypass operation is considered to be less risky if there are severe constrictions in three coronary arteries or a narrowing of the main vessel of the left ventricle. In addition, new deposits form less quickly in the arteries than in the case of stents. The gentler stent method is recommended if only one or two coronary arteries are narrowed.

How many vessels are affected and where the occlusions are located is determined by the doctor in advance during a heart catheter examination. Which method is ultimately used also depends on other factors and the individual circumstances of the patient.

Always in combination with drug therapy

Both procedures are always carried out in combination with drug therapy, which must be continued even after a successful operation. Because even if the operation can restore blood flow to the heart, it does not cure the underlying vascular disease. Medication is essential to prevent reoccurrence.

Other areas of application for bypass surgery

Heart bypass surgery is certainly one of the best-known areas of application for bypass surgery. However, bypass operations can also be considered for vascular narrowing and blockages in other parts of the body. Other areas of application are, for example:

• Bypass on the leg, for example as a result of peripheral arterial occlusive disease  “intermittent claudication” (AVK)
• Bypass operations in the head and neck area: “ carotid bypass ” for plaque formation (vascular deposits) on the carotid artery (carotid artery)
• Bypass operations in the abdomen : “ aorto-renal bypass ” for constrictions and occlusions in the renal artery

This is how bypass surgery works

Before the operation, some important examinations take place. The heart, lungs and blood vessels are carefully inspected to identify risks and plan the operation accordingly.

In addition to the heart catheter examination , which reveals the extent and location of the blockages, an ECG examination ( echocardiography ), an ultrasound examination of the arteries supplying the brain and a lung function test are usually also carried out.

If they are needed for the bypass, the leg veins are also examined and assessed. Special procedures such as Doppler sonography and angiography are suitable for this . Blood tests and, depending on the initial findings, other tests may also take place. In a preliminary discussion, the patient is informed about the course of the operation.

Different surgical techniques

The bypass operation takes place under general anesthesia and takes about five hours. Depending on how extensive the planned operation is, different surgical techniques can be considered. It is often possible to operate with a less invasive surgical technique, the so-called “off-pump” technique .

This surgery is performed on the beating heart, so no heart-lung machine is needed. The surgeon gains access to the heart through an incision a few centimeters wide lengthways through the breastbone. The corresponding coronary vessels that need to be operated on are immobilized using special holding devices and traction sutures.

For major surgeries, the heart must be stopped while a heart-lung machine takes over. In certain cases, a so-called minimally invasive direct coronary artery bypass graft (MIDCAB) operation can also be performed. It is also performed on the beating heart without a heart-lung machine and only requires a small incision on the left side between the ribs.

Mostly arterial or vein bypass

If possible, the surgeon will use the left thoracic artery (Arteria mammaria-interna) for the most important supply vessel of the anterior heart wall. With this so-called arterial bypass , there is by far the lowest risk of a renewed occlusion. So-called vein bypasses are also possible , for which vein material is removed from the upper or lower leg. Less commonly, forearm arteries or arteries from the abdomen are used. If these options are not available either, artificial materials ( artificial bypass ) are used. However, the possibility of reclosing is greater here than with natural materials.

At the end, depending on the operation, the chest is closed again, for example with special wire loops made of stainless steel, which are usually not removed and remain in the body, the skin and tissue are sewn up. Drains are placed so that the wound secretion can drain off in the first few days.

After the operation

After the operation, the patient remains in the intensive care unit for two to three days, where specialized doctors closely monitor his state of health. From day one, he is under the care of a physiotherapist who begins rehabilitation. If there are no complications, the patient can usually leave the clinic after two to three weeks. This is usually followed by a rehabilitation treatment lasting several weeks.

In the first days and weeks after the bypass operation, pain in the chest can occur, but this can be controlled with medication.

Risks of bypass surgery

Bypass operations are now routine operations. Nevertheless, heart surgery is not trivial and involves certain risks. The risk of complications also depends on the severity of the coronary artery disease and the extent of the operation, as well as on the general condition of the patient and other existing medical conditions.

The following complications can occur, especially in the initial period after the operation:

• Cardiac arrhythmias , which may manifest as atrial fibrillation, and which require close monitoring and medication
• Wound infections , for which there is an increased risk in patients who are overweight , diabetic or smokers
• Other complications such as secondary bleeding, heart attack , stroke , narrowing or blockage of blood vessels ( embolism ) due to blood clots or other material washed up with the blood that may have been loosened during the operation
• Pericarditis can also occur due to irritation of the pericardium during the operation.
• Especially after long and complicated operations, heart failure can occur, which can be treated with medication or by temporarily inserting a special pump into the aorta.
• During operations using the heart-lung machine, blood coagulation disorders sometimes occur as a result of contact between the blood and the synthetic material .
• Artificial respiration using a breathing tube during the operation can lead to temporary hoarseness and a sore throat .
• Smokers have an increased risk of wound healing disorders . Smokers also have an increased risk of developing pneumonia .

During the operation, injuries to other organs can also occur, which can result in further risks.

In order to be able to help quickly in these cases, the patient is cared for and constantly monitored in the intensive care unit for the first few days after the operation. For patients with a known risk of these complications, treatment plans are developed before the operation, which are then used if the worst comes to the worst.

When is bypass surgery not performed?

Bypass surgery can be vital. Therefore, the doctor will carefully consider whether it is possible to carry them out. Nevertheless, in some cases the risks can outweigh the risks, for example if important organ functions of the patient are weakened. Older age does not necessarily have to be a reason not to carry out the procedure.

In the case of planned operations (not emergencies), possible risks are carefully ruled out before the operation. The bypass operation must not be performed if there are active infections or open wounds, as this can lead to serious wound healing disorders. Before the operation, the patient must therefore obtain findings from the urologist, gynaecologist, ENT doctor and dentist to ensure that there are no infections. Teeth and gums must also be cleaned before the operation.