TMR - The TMR Procedure

What does the TMR procedure entail?

The surgical site, near the left breast, will be shaved if necessary and an antibacterial solution will be applied to the chest. You will be given a sedative through an intravenous (IV) line, and hooked up to an electrocardiogram ( ECG) so that your heart rate and blood pressure can be monitored. For this, small sticky patches with wires attached will be taped to your body.

General anesthesia is given through a breathing tube to make sure you are asleep for the entire procedure, and it will be constantly monitored by your anesthesiologist. A tube called a catheter will be inserted in your neck and threaded into a pulmonary artery so that your physicians can measure your heart function and the pressure in your heart and lungs. A urinary catheter is also inserted.

The surgeon will first make an incision on the left side of the chest to access the heart's left ventricle. A special laser is then used to make 20 to 40 tiny channels about 1 millimeter wide (the size of the head of a pin) and about 1 centimeter apart in the heart muscle. The channels bleed for a few seconds but stop when the surgeon presses on them gently with a finger. This causes the tops of the channels to clot.

How long does the TMR procedure take?

The procedure takes between 1 and 2 hours.

What happens after the TMR procedure?

You will stay in the hospital for 4 to 7 days following TMR. Your physician will discuss with you which activities you are allowed to do after the procedure, but you will probably be told not to perform any strenuous activities. Often, chest pain symptoms get better right after TMR, but sometimes it can take 3 months or more for you to feel relief.

What does the PMR procedure entail?

During PMR, a laser-tipped catheter is inserted in the groin area into the femoral artery and threaded into the heart. The laser pulses are then delivered by the catheter, and anywhere from 8 to 30 channels are made. Chest incisions and general anesthesia are not necessary for PMR, which reduces recovery time and the chance of complications.

How long does the PMR procedure take?

The PMR procedure takes between 1 and 2 hours.

What are the risks of TMR?

The risks associated with TMR are low but, as with all surgeries, there is a small risk of complications. With TMR, these may include the return of chest pain, damage to a heart valve, heart failure, heart rhythm problems, damage to the larger blood vessels of the heart, low blood pressure, and heart attack. Also, the long-term effects of TMR are unknown. Because the majority of studies on TMR are small and not placebo-controlled, results often vary. The risk of dying after TMR is about 5%.^{2, 4, 6, 9, 11} About one-third to two-thirds of people experience problems within 30 days of surgery, but few have serious complications that require hospitalization, such as heart attack, heart failure, or unstable angina.^{2, 4-6, 9, 11}

Is TMR ever performed at the same time as bypass surgery?

Yes—currently, two-thirds of TMR surgeries are performed along with bypass surgery.¹⁰ TMR plus bypass surgery is not an alternative to bypass surgery alone. The two procedures are used together when there are one or more areas of the heart that can be treated with bypass surgery and one or more areas that cannot. People who have TMR plus bypass surgery have less severe chest pain after 5 years than eligible patients who had bypass surgery alone.¹²

References

1. Adult Cardiac Database Executive Summary: Fall 2004 Report. Society of Thoracic Surgeons. Available at: http://www.ctsnet.org/file/STS-ExecutiveSummary-Fall2004.pdf. Accessed February 28, 2005.
2. Schofield PM, Sharples LD, Caine N, et al. Transmyocardial laser revascularisation in patients with refractory angina: a randomised controlled trial. Lancet. 1999;353:519-524.
3. Jones JW, Schmidt SE, Richman BW, et al. Holmium:YAG laser transmyocardial revascularization relieves angina and improves functional status. Ann Thorac Surg. 1999;67:1596-1601; discussion 1601-1592.
4. Frazier OH, March RJ, Horvath KA. Transmyocardial revascularization with a carbon dioxide laser in patients with end-stage coronary artery disease. N Engl J Med. 1999;341:1021-1028.
5. Burkhoff D, Schmidt S, Schulman SP, et al. Transmyocardial laser revascularisation compared with continued medical therapy for treatment of refractory angina pectoris: a prospective randomised trial. ATLANTIC Investigators. Angina Treatments-Lasers and Normal Therapies in Comparison. Lancet. 1999;354:885-890.
6. Allen KB, Dowling RD, Fudge TL, et al. Comparison of transmyocardial revascularization with medical therapy in patients with refractory angina. N Engl J Med. 1999;341:1029-1036.
7. Aaberge L, Nordstrand K, Dragsund M, et al. Transmyocardial revascularization with CO2 laser in patients with refractory angina pectoris. Clinical results from the Norwegian randomized trial. J Am Coll Cardiol. 2000;35:1170-1177.
8. Leon MB. DMR in Regeneration of Endomyocardial Channels Trial (DIRECT). Paper presented at: Transcatheter Cardiovascular Therapeutics, 2000; Washington, DC.
9. Tjomsland O, Aaberge L, Almdahl SM, et al. Perioperative cardiac function and predictors for adverse events after transmyocardial laser treatment. Ann Thorac Surg. 2000;69:1098-1103.
10. Peterson ED, Kaul P, Kaczmarek RG, et al. From controlled trials to clinical practice: monitoring transmyocardial revascularization use and outcomes. J Am Coll Cardiol. 2003;42:1611-1616.
11. Hughes GC, Landolfo KP, Lowe JE, Coleman RB, Donovan CL. Perioperative morbidity and mortality after transmyocardial laser revascularization: incidence and risk factors for adverse events. J Am Coll Cardiol. 1999;33:1021-1026.
12. Allen KB, Dowling RD, Schuch DR, et al. Adjunctive transmyocardial revascularization: five-year follow-up of a prospective, randomized trial. Ann Thorac Surg. 2004;78:458-465; discussion 458-465