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BYPASS SURGERY


(surgical bypass-revascularization of the myocardium)

If the findings of a coronarography show that the character of a coronary disease is such as requiring cardiac surgery, you will be offered a bypass surgery  as a treatment modality. An evaluation of revascularization is provided by an interventional cardiologist, and in some cases by an interventional cardiological consultation team. An additional consultation of the cardiac surgeon is occasionally necessary, if there are dilemmas about the technical possibilities of performing the surgery.

After admission to the hospital and placement in the hospital room, you will be subjected to a pre-surgery preparation. It implies the extraction of a blood sample for insight into certain laboratory findings, and, if necessary, consultative examinations of doctors of other specialties (neurologists, pneumophysiologists, etc.), mandatory pre-surgery ultrasound of the heart (and pre-surgery preparation in the narrow sense, which implies (before the day of surgery) hygienic preparation (washing, shaving) and bowel discharge, most often with laxative syrup.

On the day of surgery, you will be taken to the cardiac surgery room, where you will be subjected to general anesthesia (you will be put asleep). Then the surgery will begin. The surgery implies opening of the chest by a cut through the middle of the chest bone (longitudinally) and a procedure on the heart itself (more information later). Once the surgery is complete, you will be transported to the unit of postoperative intensive care from the surgery room. There,  waking and first rising is done, and you will remain on the observation for 24-48 hours. After extracting the drains (plastic tubes placed over the skin in the chest during surgery) and other preparations, you will be transferred to the cardiovascular department. There, an early postoperative hospital care is done, which involves moving around, taking appropriate medications, physical exercise, breathing exercises, taking blood samples for laboratory findings, postoperative ultrasound examination of the heart, etc. In about seven days after surgery you will be released for home treatment.

Control examinations are planned, the first control within seven days of discharge, the second control one month after the first, the third three months after the second one, and so on. If necessary, a competent doctor may modify and recommend a second regime of control examinations. The first control examination includes an examination by a cardiologist and a surgeon. An examination by the cardiologist includes physical examination and anamnesis (conversation with a patient), ECG and arterial pressure control. If there is a need, a control ultrasound examination of the heart will be performed. Your cardiologist will give you further instructions on therapy, i.e. about medicines that you need to take up to the next control. He will also suggest you when to come to the next examination, and what blood findings you need to bring with you.

The cardiac surgeon will perform a basic physical examination and examination of the surgical wounds and give advice on the hygienic and diet regimen related to the rehabilitation of surgical cuts. There is usually one control with the cardiac surgeon (it is performed at the first post-release control) and, if everything is all right with surgical cuts and wounds heal well, no further cardio surgery controls are required. If there is a problem in the surgical wound (infection, wound leakage, etc.), your cardiosurgeon will give you recommendations for control in our institution or control of a surgeon at a relevant healthcare institution in your place, with written instructions for you and your competent doctor  (bandaging wounds, medicines and other forms of treatment).

Controls with the cardiologist, however, will continue over a longer period of time, as some mediciness may need to be used for life, it will be necessary to periodically perform control ultrasound examinations of the heart, control laboratory findings, dose corrections and medicinescompositions that you take, etc. After stabilizing the condition and after the first 2-3 controls, your cardiologist will program your control examinations, most likely for 6 months, unless there is a need for more frequent controls.

Why is the bypass surgery performed?

If there are contractions or blockages on coronary arteries that are not possible, or it is not advisable, to treat by implantation of one or more stents, and revascularization is considered necessary, it is resorted to bypass surgical revascularization. Bypass  is an English term that means a bypass, a link, a bridging, and so on. The principle of bypass surgery is to ensure the bypass  of narrowing (or blockage) of the coronary artery by another blood vessel, so that the blood has a possibility to flow to the heart muscle by alternative way and without obstructions. The bypass is connected at one end to the aorta (or is a direct branch of another nearby artery), and in the other end end it merges ‘downstream’ from the point of narrowing or blockage. If we assume that the narrowing or blockage of the coronary artery looks like a slope on the road, with which the road is partially or completely blocked, then the bypass corresponds to the new road-bypass, which literally bypass the congestion. As the traffic in the bypass would take place normally and without delay, regardless of the blockage, so the blood is also allowed to flow to the heart normally and without obstruction, bypassing the way, regardless of the blockage of the cardiac artery.

There are two basic types of bypass grafts: arterial and venous. Venous bypasses are less quality conducting channels. In order to make venous bypasses, a large vein is taken from the inside of the leg (vein saphena magna). At the beginning of the surgery it is taken out and cut into segments. These segments look like a slight thin pipes. At one end, they are sewn on the aorta (a small opening has previously been made on it, so that blood may flow into the vein), and the other side is laterally on the heart artery, downstream from the place of blockage. This creates a venous bypass. This is why patients after a bypass surgery, apart from the scar on the skin above the chest bone, also have a scar on the leg. Venous bypass grafts are grafts of lesser quality and are susceptible to the creation of narrowing or blockages on the bypass itself. This can cause angina pain after bypass surgery, and in some cases it will be necessary to perform a control coronarography to assess the bypass state.

In addition to a vein, it is also possible to take an arterial bypass. The most often taken artery is the thumb artery (arteria radialis) – a radial bypass graft. By the same principle, one end is connected to the aorta, and the other on the cardiac artery, lower from the place of blockage. Results regarding emergence of new narrowings on bypasses are better than on venous bypasses.

The highest quality bypass is the so-called LIMA-bypass. LIMA is an abbreviation for Left Interior Mammarian Artery. Equally high quality is RIMA bypass (Right Interior Mammarian Artery). LIMA is more commonly used, because it is on the left side closer to the heart and easier to connect. This is the artery (present, of course, on both sides – left and right) that separates from the arterial arteria (arteria subclavia) and descends on the inside of the chest wall. This artery practically does not suffer from atherosclerosis, i.e. it does not develop narrowings and blockages, unlike other arterial bypass grafts, and in particular venous. LIMA bypass graft is not cut off at the upper end, but is left at its source – subclavian artery. At the lower end, this artery separates from the chest muscle and connects to the cardiac artery. Since this is the highest quality bypass graft, it is used only for the most important cardiac artery – the front descending coronary artery. On other arteries, radial arterial or venous bypass grafts are connected. LIMA or RIMA bypass, if performed technically correctly during the surgical procedure, remains in function the longest of all bypasses and has the best long-term results. Problems with LIMA-bypass grafts are most likely the result of manipulation of this extremely narrow and sensitive artery, and, if they occur, thez are manifested shortly after surgery. Since the LIMA artery supplies blood to the largechest muscle (musculus pectoralis maior), after its ‘turning’ to the heart, patients in the first months feel numbness in the area of ​​the left breast until an alternative (so-called collateral) circulation develops for the area. So, the numbness on the left side of the chest after the bypass surgery is normal.

MID-CAB or LAST bypass operation

If the patient has a narrowing or blockage of the left anterior descending coronary artery (the most important coronary artery), which it  is not possible or not safe for the patient to treat with stenting, and revascularization is necessary, the patient is directed to the MID-CAB operation. MID-CAB is an English abbreviation for the term Minimally Invasive Direct Coronary Artery Bypass. Unlike the classic bypass surgery, a chest is not opened here by the longitudinal cutting of the chest bone. The term ‘minimally invasive’ means a significantly smaller surgical incision, which is performed on the left side of the chest, below the breast, usually in the fifth left intercostal space. Therefore, this abbreviation is often used by the English abbreviation LAST (Left Anterior Small Thoracotomy, a chest cut). Through this opening, the LIMA bypass graft described above is installed on the front descending coronary artery. The surgical wound on the chest is much smaller than in the classic bypass, and there is not a big scar on the leg from taking venous grafts. This reduces the incidence of complications of the chest bone cutting, as well as the cut on the leg. This method is particularly good for diabetic patients with single-vessel coronary disease on the front descending coronary artery, which is not for treatment with stenting. Numbness to the left of the chest after surgery is normal.

When is a patient sent ton a bypass surgery?

Patients-diabetics, due to changes in the immune system, metabolism and reactions of the organism, specifically react to the inserttion of a foreign body. Thus, when stenting, these patients are more likely to develop new narrowings within the stents (so-called in-stent restenosis). This adverse effect is far less pronounced if the drug-eluting stent is inserted to those patients. On the other hand, the same adverse effect is more pronounced if longer stents are inserted or more stents (more inserted foreign material provokes a stronger reaction of the organism). It has therefore been shown that for coronary disease in diabetics, which is with multiple narrowings and blockages, a better prognosis is if they undergo a bypass surgery, than the inserttion of multiple stents.

Narrowings of the main tree of the left coronary artery is extremely risky for stent insertion, although in some cases it can be directed to the stent for this type of disease. As a rule, it is safer to treat the patient in this case with a bypass surgery.

An extremely large number of narrowings of the coronary arteries (the so-called diffuse coronary disease), which require the insertion of a large number of stents, even in non-diabetic patients, in some cases have better results with a bypass surgery.

Solid total blockages of coronary arteries that can not be ‘opened’ by stenting, or a very high proportion of calcium in narrowings that make them non-dilaitable (impossible to expand by a balloon or stent) can be treated bypass surgery.

As a rule, patients are not directed to bypass surgery unless they have narrowing/blockage on the front descending coronary artery (the most important of the three present). Bypass surgery in these patients is done only exceptionally, if narrowing/blockage on other arteries is not possible (or is not safe) to be successfully treated otherwise (stents or medications), and if the patient in these circumstances has extremely pronounced anginous problems.

Is it better to install stents or go for a bypass surgery?

For patients with acute myocardial infarction, the most effective way of treatment in general insertion of a stent. Patients with acute myocardial infarction are nowhere in the world undergoing routine bypass surgery due to general and local cardiac instability during surgery. Inserting a stent in infarct is a real revolution in medicine, especially considering that the infarct is the most common cause of death in developed and developing countries and countries in transition (and therefore in our country). Stent insertion in an acute infarct significantly reduces the mortality of these patients compared to the conditions when the stent would not inserted, but one would resort to other forms of therapy. Of course, infarction is extremely difficult and life-threatening, so despite all the efforts of an interventional cardiologist, in certain cases, some patients lives can not be saved. However, mortality is significantly reduced (and over two times less people die of infarction if treated with stenting) compared to other ways of treating this condition.

The insertion of stents for single-vessel coronary disease has been a long time established metohd of revascularization. In a large number of cases of two-vessel or three-vessel coronary diseases, it is also possible to insert stents. For patients with diabetes, drug-eluting stent can be inserted, which causes far less newly formed narrowings within the stent. And for non-diabetic patients, and who develop  narrowings within a stent, it is possible to insert these special stents as a basic treatment.

Long period of great research has shown that for patients with extremely diffuse coronary disease (a large number of narrowings and blockings of the heart arteries), especially with the narrowing of the main tree of the left coronary artery, a more secure and prognostically better way of revascularizing is a  bypass surgery. As for the risk, immediate mortality at the surgery is higher than in the stent insertion. It has also been demonstrated that these patients receive a stroke somewhat more often on bypass surgery than in stenting. On the other hand, after inserting a large number of stents into one patient, a more frequent revascularization (stents or bypass surgery) is expected, than in such patients who have undergone surgery.

Long-term prognosis regarding life expectancy in both groups (operated and stent patients) is the same.

Also, based on other tests, it is not always necessary to stent or subject to bypass surgery  all narrowings or blockages. By special testing it is possible to determine the risks and benefits of these procedures, and it is sometimes better to treat certain forms of coronary disease with medicines.

If, even after a bypass surgery, a patient has problems with coronary arteries, these problems can be resolved by medications, by stent insertion or by a new bypass surgery. Also, if after the insertion of the stents the patient has problems with coronary arteries, those problems can be solved by medications, by the insertion of new stents or bypass surgery. In the event of these problems, which manifest themselves as angina pectoris, chest pain provoked by strain, choking, fatigue, pathological result of ergotest (or scintigraphy of the heart, or stress-echocardiography), the patient first undergoes control coronarography, and then the decision is made: medicines- stent- bypass.

Today’s trend in the world is that more patients undergo stenting than surgery, because the technique and stent technology today are at a very high level, and the procedure is much more comfortable for the patient: there are no major surgical cuts, no general anesthesia, a patient much earlier goes home and returns to work and day-to-day activities. A possibility of new control coronarographies and new procedures for the insertion is also accepted, as well as possible bypass surgeries.

Risks of procedures and your consent to the procedure

In an open conversation with your intervening cardiologist, after a completed coronarography, a definitive decision will be made on continuation of treatment: medications, stent inserting, or bypass surgery. Sometimes additional consultation with a cardiac surgeon will be necessary, especially if there are dilemmas about the technical capabilities for the surgery. It is important that you know that all decisions are made in your best interest, but also that heart conditions are always more or less risky. So, by agreeing to appropriate procedures (or by rejecting them), you are also taking part of the risk outcome, whatever it may be. These risks will be explained to you in detail, and if you consent to coronarography/stent/bypass surgery, you will sign a document on accepting the procedure. The risk of all procedures at the heart implies the potential risks of local complications, stroke, cardiac infarction, procedural failure, andeven a  fatal outcome. The lowest is the risk of coronarography, higher on stent insertion, and the highest in surgery. Particularly at risk are patients with acute infarct, due to the possibility of terminal heart failure and the development of severe, lethal arrhythmias. Patients with very weakened heart muscle are also risky, as are those with severe forms of heart valve disease. Older patients are also at greater risk than younger, as well as diabetic compared to non-diabetic patients. When making a decision, your doctor, or a medical consultation team, is guided by your individual characteristics and condition, as well as clinical and statistical indicators and prognoses of the procedure. The patient is always recommended a treatment which has been shown to be associated with the best curing prognosis in the given situation. This does not mean that more or less complications, even those of a fatal outcome or disability, are not excluded. This explains in detail the risks and benefits of the procedure and the alternative method of treatment. Remember that no one can persuade you of something you do not want and that you can refuse any procedures and request alternative treatment methods, explaining to you all the deficiencies of your choice of treatment.


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