What is Transmyocardial Revascularization?
Transmyocardial revascularization (TMR) is performed with a low powered Holmium:YAG laser that delivers precise laser energy directly to the target area(s) of the heart muscle. When performed as a sole therapy, it is done through a small incision between the ribs (thoracotomy) with the patient under general anesthesia. TMR can also be performed as a complement to bypass surgery in patients that have areas of ischemic heart disease that cannot be bypassed. The precise laser therapy is used to create small channels into the heart chamber which stimulate the heart muscle to create new blood vessels.
During transmyocardial revascularization (TMR), the surgeon uses one of the Cardiogenesis flexible, fiberoptic handpieces to deliver precise bursts of Holmium:YAG laser energy directly to an area of heart muscle that is suffering from ischemic heart disease. This condition can manifest itself with severe persistent chest pain, or chronic angina. The surgical procedure is performed through a small incision or small ports with the patient under general anesthesia. The surgeon can position the laser fiber on the surface of the beating heart. It takes approximately 6-10 pulses to transverse the myocardium and create channels one-millimeter in diameter. During a typical procedure, approximately 20-40 channels are made in the heart muscle.
The outside punctures seal over with little blood loss while the new channels allow fresh blood to perfuse the heart wall immediately, and may provide oxygen in the process. Published research shows evidence that these channels promote the growth of new blood vessels or angiogenesis over time.42 That, in turn, provides the damaged heart tissue a better supply of blood and oxygen. Angina usually subsides with improved oxygen supply to the targeted areas of damaged heart muscle.
Guidelines for Use
Specific guidelines for patient selection include the following criteria:
- Refractory chronic stable angina despite maximum medical management
- Ejection fraction >25%
- Objectively demonstrated diffuse CAD
- Region of myocardium with reversible ischemia not amenable to CABG or PTCA