What is a mitral commissurotomy?
The mitral valve is the valve between the upper and lower chambers on the left side of the heart. After rheumatic fever the two leaflets of this valve can become stuck together at their edges, so that the opening narrows and blood cannot pass easily from the lungs into the heart. A balloon mitral commissurotomy, also called balloon valvuloplasty, opens that narrowing without surgery: a balloon is guided into the valve and inflated so that the fused edges split apart and the valve opens more widely.
Why is it done?
It is offered to patients with significant rheumatic mitral stenosis who are breathless, tire easily, cough up blood or have developed atrial fibrillation or raised pressure in the lung arteries. Opening the valve relieves these symptoms, often dramatically, and avoids or postpones open heart surgery. It is also used in pregnancy, when a narrowed valve becomes dangerous, because it avoids the risks of surgery to mother and baby.
Who is suitable?
Not every narrowed mitral valve can be treated this way. A detailed ultrasound of the heart, usually including a transoesophageal echocardiogram, is done first to check the shape of the valve, how much calcium and scarring there is, whether the valve also leaks, and whether a blood clot is present in the upper chamber. The best results are in younger patients with flexible, minimally calcified leaflets and no significant leak. If the valve is heavily damaged or leaking badly, surgical repair or replacement is the better option, and your cardiologist and the surgical team will discuss this with you.
What happens on the day?
The procedure is done in the catheterisation laboratory. You come in fasting, a drip is placed, and the skin over the vein in the groin is numbed with local anaesthetic; sedation keeps you comfortable, and general anaesthesia is occasionally used. A catheter is passed up the vein to the right side of the heart, a small controlled opening is made in the wall between the two upper chambers so that the left side can be reached, and a special balloon is guided across the narrowed valve. The balloon is inflated for a few seconds, sometimes more than once, while pressures and ultrasound pictures are checked to confirm that the valve has opened and is not leaking. It usually takes one to two hours.
What to expect afterwards
You lie flat for several hours so that the groin puncture seals, and your heart rhythm and blood pressure are watched. Many patients notice easier breathing within days. Most people go home after one or two nights. Avoid heavy lifting and strenuous exercise for about a week, keep the groin site clean and dry, and continue your medication, including any blood thinner or penicillin prophylaxis, exactly as prescribed. A follow-up ultrasound confirms the result, and lifelong follow-up is important because the valve can narrow again after some years, when the procedure can sometimes be repeated.
Possible complications
Most patients do well, but there are real risks. Bruising or bleeding at the groin is the most common. The valve may end up leaking, and if the leak is severe urgent surgery to replace the valve may be needed; this happens in a small percentage of cases. Other uncommon problems are a persistent hole in the wall between the upper chambers, bleeding around the heart requiring drainage, stroke caused by a clot or debris travelling to the brain, a disturbance of heart rhythm, or an incompletely opened valve requiring further treatment. Death related to the procedure is rare. Your cardiologist will discuss your individual risk, based on the appearance of your valve, before you consent.
This information does not replace a consultation. Please discuss your own risks and options with your cardiologist.