Total Arterial Revascularization (TAR)

Overview

Few things in life are as important as heart health when it comes to living a healthy lifestyle and having the best quality of life achievable. In addition to a healthy diet and regular exercise, visiting a cardiology clinic is essential.

However, genetics and family history are important predictors of whether or not you may develop heart disease. As a result, despite your best efforts, you may still have cardiac problems. It is critical to understand the differences between various forms of cardiac care.

Because of its higher patency compared to saphenous vein grafts, arterial grafts are preferred for coronary artery bypass grafting surgery (CABG). However, in fact, the use of total arterial revascularization (TAR) falls behind these guidelines.

Even in stable patients, there is reluctance to do complete arterial CABG because to higher technical demand, increased operation duration, and risk of bleeding problems and poor wound healing.

 

Benefits of Total Arterial Revascularization (TAR)

Aside from high success rates, invasive cardiology provides other advantages to heart patients, including:

• Less pain and scarring: When compared to regular surgery, invasive cardiology is less intrusive. Normally, the catheter is inserted by a single, small incision. The treatment is completed in about 30 minutes, resulting in reduced discomfort.
• Faster recovery: Recovery time is shorter than for other surgical procedures. Patients are not required to stay in the hospital following the procedure.
• Reduces the risk of a heart attack: Invasive cardiology not only treats symptoms such as chest discomfort and shortness of breath, but it also opens the arteries and restores blood flow, lowering the chance of a heart attack.
• Ideal for infants and children: Invasive cardiology, particularly balloon valvuloplasty, is recommended by cardiologists for infants and children with heart issues since it is minimally invasive, less unpleasant, and extremely successful.
• More inexpensive: In terms of cost, invasive cardiology is less expensive than typical cardiac surgery operations.

 

What are Your Heart Structures?

Heart walls

The heart wall is made up of connective tissue, endothelium, and cardiac muscle. The cardiac muscle permits the heart to contract and the heartbeat to be synchronized. The heart wall is separated into three layers: epicardium, myocardium, and endocardium.

• Epicardium: the outer protective layer of the heart.
• Myocardium: muscular middle layer walls of the heart.
• Endocardium: the inner layer of the heart.

 

    1. Epicardium

The outer layer of the heart wall is known as the epicardium (epi-cardium). It is also known as visceral pericardium since it constitutes the pericardium's inner layer. The epicardium is mostly made up of loose connective tissue, such as elastic fibers and adipose tissue. 

The epicardium protects the inner heart layers and contributes to the formation of pericardial fluid. This fluid fills the pericardial cavity and helps to minimize pericardial membrane friction. The coronary blood arteries, which provide blood to the heart wall, are also located in this cardiac layer. The epicardium's inner layer is in direct touch with the myocardium.

    2. Myocardium

The myocardium (myo-cardium) is the heart's middle layer. It is made up of cardiac muscle fibers that allow the heart to contract. The myocardium is the thickest layer of the heart wall, ranging in thickness across the heart. The myocardium of the left ventricle is the thickest because it generates the power required to pump oxygenated blood from the heart to the rest of the body. Cardiac muscle contractions are controlled by the peripheral nervous system, which also controls involuntary activities such as heart rate.

Specialized myocardial muscle fibers provide for cardiac conduction. These fiber bundles, which include the atrioventricular bundle and Purkinje fibers, transport electrical impulses from the heart's center to the ventricles. These impulses cause the ventricular muscle fibers to contract.

    3. Endocardium

The endocardium (endo-cardium) is the heart's thin inner layer. This layer borders the inner chambers of the heart, covers the heart valves, and connects to the endothelium of big blood vessels. Smooth muscle and elastic fibers make up the endocardium of the cardiac atria.

 Endocarditis is a disorder caused by an infection of the endocardium. Endocarditis is often caused by a bacterial, fungal, or other microbe infection of the heart valves or endocardium. Endocarditis is a potentially deadly disease.

    4. Blood supply

The 2 main coronary arteries are the left main and right coronary arteries.

   1. Left main coronary artery (LMCA). The left main coronary artery supplies blood to the left side of the heart muscle (the left ventricle and left atrium). The left main coronary divides into branches:

• The left anterior descending artery branches off the left coronary artery and supplies blood to the front of the left side of the heart.
• The circumflex artery branches off the left coronary artery and encircles the heart muscle. This artery supplies blood to the outer side and back of the heart.

   2. Right coronary artery (RCA). The right coronary artery transports blood to the right ventricle, right atrium, and the SA (sinoatrial) and AV (atrioventricular) nodes, which control heart rhythm. The right coronary artery is divided into smaller branches, the right posterior descending artery and the acute marginal artery. The right coronary artery, together with the left anterior descending artery, helps provide blood to the heart's center or septum. The coronary arteries' smaller branches include the obtuse marginal (OM), septal perforator (SP), and diagonals.

 

When Total Arterial Revascularization (TAR) is Indicated?

TAR is generally recommended when there are high-grade blockages in any of the major coronary arteries and/or percutaneous coronary intervention (PCI) has failed to clear the blockages. Class 1 recommendations from the 2011 ACCF/AHA guidelines are as follows:

• Left main disease greater than 50%.
• Three-vessel coronary artery disease of greater than 70% with or without proximal LAD involvement.
• Two-vessel disease: LAD plus one other major artery.
• One or more significant stenosis greater than 70% in a patient with significant anginal symptoms despite maximal medical therapy.
• One vessel disease greater than 70% in a survivor of sudden cardiac death with ischemia-related ventricular tachycardia.

 

What Happens Before Total Arterial Revascularization (TAR)?

TAR is major surgery, and people who have this done must first undergo a wide range of tests and other preparations.

 

Imaging and lab tests

Before you can have TAR, you must first go through a series of tests to determine whether the procedure is safe for you and whether you really need it in the first place. The potential tests include, but aren’t limited to, the following:

• Electrocardiogram (ECG or EKG).
• Echocardiogram.
• Exercise stress test.
• Nuclear cardiac stress test.
• Cardiac catheterization.
• X-ray angiography or computed tomography (CT) scan angiography.
• Coronary calcium scan.
• Lab tests, such as a complete blood count, that analyze your cholesterol, blood sugar, and other factors. Other possible tests include urine tests that analyze how well your kidneys function.

 

Information and education

Preparing for TAR entails informing and educating you on what to expect and what you need to do before and after surgery to get the best possible outcome. You will learn about the following topics:

• Medications. Before the procedure, your healthcare professional will review the drugs you're taking. They will also advise you on which drugs to continue taking and which to discontinue (and when to stop them). In some situations, they may change your prescriptions or start you on new ones.
• How to Get Ready for Surgery? Your healthcare practitioner will provide you instructions and materials to help you prepare for the surgery. This includes understanding what sort of assistance you'll require at home, what you can and cannot consume following the surgery, what essentials you'll require at home, and more. It also contains instructions on how to bathe (typically with special soap) and groom yourself before to the surgery.
• What to Expect Following Surgery? Your healthcare practitioner will also offer you with information and tools outlining what to expect during your recuperation. This covers how long it will take you to heal, how you will feel, signs to look out for, and other information.

 

What Happens During this Procedure?

TAR is a time-consuming operation that requires many hours to complete (the actual time needed depends on the specific type of CABG surgery, how many bypasses you need, and more). The majority of these procedures take the following steps.

 

Anesthesia and life support

The initial stage in this procedure, as with other major surgeries, is to put you into a deep sleep. This prevents you from feeling discomfort throughout the procedure. It also helps you relax for the next phases in the preparation.

Because TAR includes cardiac surgery, different methods of life support are frequently used. These are some examples:

1. Ventilation and intubation. Intubation is a procedure in which a tube is inserted down your neck and into your windpipe. They then connect that line to a machine known as a ventilator, which does your breathing for you. Your lungs continue to process and transmit oxygen into and out of your bloodstream, but the ventilator moves the air.
2. Intravenous (IV) lines. Intravenous (IV) lines are tubes that allow doctors to directly inject drugs and fluids into your veins.
3. Urinary catheter. Before beginning surgery, physicians will put a tiny tube through your urethra and into your bladder. A catheter is a tube that permits urine to flow through it and into a bag. This allows you to "pee" unknowingly even when under anesthesia.
4. Heart-lung bypass surgery. This machine replaces your heart and lungs by pumping blood from your body into this machine, which also supplies oxygen and eliminates carbon dioxide from your blood. The blood is then pumped back into your body via an IV line by the machine. Using this equipment, clinicians may temporarily stop your heart, making some surgical procedures easier. A heart-lung bypass machine is not always required, but its usage is prevalent.

 

Blood vessel harvesting

TAR is the procedure of creating a blood bypass to allow blood to bypass blocked areas of your heart. A bypass is a path your blood takes to avoid an obstacle. To create that bypass, a blood artery from another area of your body, such as your leg, arm, or chest, is removed and redirected around the obstruction. When more than one artery is occluded, several bypasses may be necessary. These are double, triple, and quadruple bypasses.

 

Surgery

A cardiothoracic surgeon will create an incision in the middle of your chest to reach your heart and perform the procedure. They'll also divide your breastbone (sternum) down the center before spreading and lifting your rib cage to have access to your heart.

Once they get at your heart, the surgeon will use the harvested blood artery to create the bypass. Just after it exits your heart, the upper end (beginning) of the bypass joins to your aorta, the big artery that delivers blood out of your heart and to the rest of your body. The bypass's lower end (ending) will connect to the blocked artery right past the obstruction.

Once the bypass is in place, the surgeon can restart your heart (if they stopped it) and get your blood flowing again. They’ll then lower your rib cage back into place and wire it together so it can heal. They’ll then close the incision in your chest with staples and sutures (stitches).

 

What Happens After this Procedure?

TAR patients are admitted to the hospital's intensive care unit following surgery (some hospitals use different terms like critical care unit). Staying in the intensive care unit (ICU) is required because ICU staff have specific training and expertise that is better suited for persons with unique requirements, such as those who have just had TAR.

When a patient is stable and a doctor believes they are ready, they can be transferred to a conventional medical-surgical room for the duration of their stay. The usual hospital stay is 8 to 12 days (longer for people who had TAR because of a heart attack, shorter for people who had stable ischemic heart disease or similar problems).

Most TAR patients will also undergo a cardiac rehabilitation program when they leave the hospital. These programs, also known as cardiac rehab, assist you in recovering and rebuilding your strength following intensive cardiac surgeries or incidents such as heart attacks. Cardiac rehabilitation programs use carefully trained and highly qualified personnel. Nurses, exercise physiologists, nutritionists and dietitians, counselors and behavioral health professionals, and doctors are common members.

 

What is the Recovery Time?

The majority of TAR patients will require several weeks to recover entirely. During that period, your provider will most likely advise you to avoid any strenuous activities or situations that might place excessive strain on your heart and incisions.

Your healthcare professional is the best person to tell you how long it will take to recover and what to expect. They'll also inform you when you may resume normal activities like work, exercise, driving, and so on.

During your recovery, you should also follow your provider’s guidance regarding the following:

• Take your medication as recommended. This is a vital aspect of your rehabilitation, and it's critical that you take your prescriptions exactly as your provider advises. If you have any questions regarding how to take or store your prescriptions, you should inform your physician as soon as possible.
• Attend cardiac rehabilitation. These regimens can significantly improve your overall recovery and how you feel following your treatment. They can also assist detect any issues or warning signals sooner rather than later because they are medically monitored and manned by skilled medical personnel.
• Maintain your mental health. People who have TAR may develop mental health difficulties such as anxiety or depression. These are natural and should not be embarrassed of. It is just as important to speak with mental healthcare specialists about these difficulties as it is to consult a clinician about your cardiac problems.
• Change your way of life. Though CABG can restore blood flow, the problems that caused you to require CABG can recur. It is critical to follow your healthcare provider's advice on altering your lifestyle, including food and exercise. Improving your lifestyle might help you avoid future difficulties.

 

Risks/Complications

Because CABG is a significant procedure, there are considerable risks and complications. While the majority of these risks and problems are preventable or manageable, it is still critical to be aware of them. Possible hazards include:

• Heart rhythm irregularities (arrhythmias). Atrial fibrillation, which increases the risk of stroke, is the most prevalent arrhythmia following CABG. Fortunately, it is typically only a short-term issue.
• Bleeding. This is a possibility with any major operation. To avoid this, patients who use blood thinners must discontinue them (under the supervision and direction of their healthcare professional) before to surgery.
• Infections. Infection is another possible surgical consequence. When infections spread throughout your body, they can induce sepsis, a potentially fatal immune system response. Sepsis is a medical emergency, and having two or more of its symptoms (rapid heart rate, fever, chills, disorientation, rapid breathing, or confusion) is as deadly as having a heart attack or stroke. Fortunately, due to better surgical care and methods, severe infections following CABG are uncommon.
• Confusion or delirium. These cause symptoms like agitation, trouble thinking clearly, memory problems or someone behaving unusually (where they seem like a different person).
• Kidney problems.
• Stroke.

 

When Should I Go to the Emergency Room?

You should go to the hospital right away if you have any of the following:

• Chest pain.
• Trouble breathing.
• Feeling dizzy or lightheaded.
• Passing out or fainting.
• Heart palpitations (the unpleasant feeling of your heart beating without feeling for your pulse).
• Drooping of your face or weakness on one side of your body.
• Slurred or distorted speech.
• Having a fever or chills.
• Fast heart rate or breathing.

 

Conclusion

The prevailing trend in coronary artery bypass grafting (CABG) for the treatment of coronary artery disease is total arterial revascularization (TAR). In addition to outperforming vein conduits, arteries offer more adaptability and long-term patency, reducing the need for reintervention. This is especially critical for people with multi-vessel coronary artery disease and for children.