Transmyocardial Laser Revascularization (TMR) is a new and promising therapy for patients with endstage coronary artery disease. Despite the success of current medical and surgical management of ischernic heart disease, such as coronary angioplasty, and bypass grafting, a significant number of patients suffer from diffuse coronary artery disease that is not amenable to these modalities. It is estimated that 10%20% of patients referred with coronary artery disease for either angioplasty or coronary artery bypass grafting are not adequately treated because of the severity of their disease and the limitations of these treatments. These patients are frequently hospitalized with angina and consume significant resources. Their angina and the failure of current therapy is of great concern to both the patients themselves and to their referring physicians. Until recently, these patients have had few treatment options.

Transmyocardial Laser Revascularization, or TMR, is a surgical procedure during which tiny, 1 mm in diameter laser channels are created in ischernic regions of the heart muscle in order to relieve anginal symptoms. The TMR procedure targets the muscle and not the blood vessels, which themselves are not suitable for any form of therapy.

TMR is indicated for patients with chronic, severe angina. They must have evidence of reversible myocardial ischernia and have an ejection fraction of at least 25%30%. TMR may be performed as initial therapy on patients who have had no previous surgery, or on patients who have failed previous coronary artery bypass grafting or angioplasty. It is performed under general anesthesia and can be done either on a beating or a nonbeating heart. Typically, patients who have no surgical options and are not going to receive coronary artery bypass grafting will be approached through a small left anterolateral thoracotomy, or incision under the left breast. The left side of the heart is exposed and the laser energy is delivered directly into the tissue creating channels through the ventricular wall. If the patient is undergoing coronary artery bypass grafting, then the bypass grafts will be constructed first, and then the areas of the heart that cannot be bypassed will then undergo the TIVIR procedure. Approximately 30channels are created per procedure. The average length of hospital say following TMR is approximately 5 days.

The clinical trial results to date cover over 5,000 TMR procedures performed worldwide. The results have been quite impressive when comparing TMR verses medical management alone. TMR has been shown to significantly improve angina, increase exercise tolerance, and improve the patient's quality of life. The initial studies have shown that 80% of patients with the most severe form of angina are rendered painfree within 612 months of the TMR procedure (compared to medical management). Furthermore, TMR patients underwent significantly fewer hospitalizations and consumed significantly fewer medications than the medically managed patients. There was no significant difference in mortality between the two groups.

The potential mechanisms of action of how TMR works are several, including (1) patent endocardial channels; (2) Denervation; (3) Placebo Effect; and (4) Neoangiogenesis. After careful studies, it appears that the most probable mechanisms of action are Angiogenesis or the formation of new small blood vessels surrounding the zone of the transmyocardial laser channel. This appears to increase the number of blood vessels, which increases blood flow capacity during stress in the heart.

In conclusion, TMR significantly reduces angina symptoms, reduces treatment failure, reduces rehospitalizations, reduces medications, and increases eventfree survival without significantly changing mortality compared to continued medical therapy or coronary bypass graft alone. For a growing population of patients with severe angina despite previous CABG and PTCA procedures, and despite maximum medical therapy, TMR may be a form of therapy to provide relief from their chronic chest pain.

Home I Heart Attack I Diet I Excercise I Risk Factors I Valve Symptoms I Heart Disease Symptoms
Warning Signs I Bypass Surgery I Questions & Answers

The content on this web site is intended to provide you and your family with a better understanding of cardiothoracic and vascular surgery including coronary artery disease, beating heart bypass surgery and endoscopic vein harvesting. This information is not intended as a substitute for an informed discussion with your physician.  We encourage you to maintain an open dialogue with you and your primary care physician.  Please feel free to print the information contained on this web site and share this information with your family and physician(s).

Select a Condition then Click to proceed to your area of interest!

©2001 Cardiothoracic and Vascular Surgical Associates, PA
  All Rights  Reserved
Web master: webmaster@fltca.com
Last Updated: Tuesday, November 20, 2001 Rev A

FastCounter by bCentral