Transmyocardial Laser Revascularization (TMR)

Transmyocardial laser revascularization (TMR) is a type of surgery that uses a laser to make tiny channels through the heart muscle into the lower-left chamber of the heart to improve oxygen-rich blood flow.

TMR can do the following:

• Improve myocardial oxygenation
• Eliminate or reduce angina
• Improve the cardiovascular function
• Relieve chest pain
• Improve the quality of life
• Reduce the frequency of hospital admissions

Transmyocardial laser revascularization is based on the use of a high-powered carbon dioxide laser. The laser interjects a strong energy pulse into the left ventricle, vaporizing the ventricular muscle and creating a transmural channel with a 1-mm diameter.

• This eventually improves the blood flow to the heart.
• The tiny channels act as bloodlines. The pumping of the ventricle sends oxygen-rich blood through these channels, restoring blood flow to the heart muscle.
• The procedure promotes angiogenesis (the growth of new capillaries or blood vessels that help supply blood to the heart muscle).

Although coronary artery bypass grafting is effective in most people, transmyocardial laser revascularization (TMR) is a treatment option for:

• Severe angina (that limits daily activities or causes sleep disruption despite medications)
• Ischemia (decreased blood supply to the heart muscle), which is identified using nuclear perfusion scan
• Coronary artery disease, which does respond to or is not eligible for other traditional procedures
• People with a history of bypass surgery or angioplasty

TMR is contraindicated for people with:

• Severely damaged heart muscle is due to heart attacks
• No areas of ischemia in the heart muscle
• Infarcted or scarred heart tissues
• Severe adhesions due to prior coronary artery bypass surgery

Apart from a thorough medical history and physical examination, tests required before transmyocardial laser revascularization include:

• Cardiac catheterization
• Other tests to determine the blood flow and the pumping ability of the heart
  • Echocardiogram
  • Positron emission tomography scan
  • Dobutamine echocardiography
  • Cardiac MRI

Before the procedure

• Let your cardiologist know all medications including prescription, over-the-counter, and supplements that you are taking.
• You may undergo certain tests, such as an electrocardiogram, blood tests, urine tests, and a chest X-ray, to analyze your current health condition.
• Avoid smoking at least two weeks before the surgery, which may help reduce the risk of excessive bleeding.
• Do not eat or drink anything after midnight the night before the surgery.

During the procedure

• An electrocardiogram machine monitors your heart’s rhythm and electrical activity. It is attached to your chest through small metal disks called electrodes.
• An intravenous line is established to administer anesthesia during surgery.
• A mild tranquilizer is administered to help you relax before entering the operating room.
• After you are completely asleep, a tube is inserted down the trachea and connected to a respirator, which will allow breathing.
• Another tube is inserted through the nose and throat and into your stomach to stop liquid and air from collecting in the stomach.
• The surgeon makes an incision in the left side of the chest to access the left ventricle and uses a special carbon dioxide laser to make 20 to 40 tiny channels (1 mm wide) in the heart muscle to achieve complete blood flow to the heart.
• The entire transmyocardial laser revascularization procedure typically takes about two hours.

After the procedure

• Stay in the hospital for four to seven days.
• Rest and limit your activities for at least four to six weeks.
• Though the symptoms of coronary artery disease and angina get better, it may take three months or more for complete improvement.

The potential complications of transmyocardial laser revascularization include:

• Supraventricular tachycardia
• Pleural effusion
• Incisional pain from the thoracotomy
• Postoperative myocardial infarctions