Preoperative Assessment For Surgical Intervention

Surgical treatment of mitral valve stenosis can be a closed commisurotomy, open commisurotomy or mitral valve replacement. Closed commisurotomy, which was very popular in the beginning of the 20lh century is now replaced by open commisurotomy and mitral valve replacement. The success of surgical commisurotomy depends on the underlying morphology of the mitral valve apparatus. Optimal results can be achieved in patients with a pliable, non-calcified valve with minimal fusion of the sub-valvular apparatus. Transthoracic and transesophageal echocardiography can determine the suitability of the patient for surgical commisurotomy and may guide the surgeon in the assessment of valvuloplasty34. Those patients with heavily calcified valves and more than grade 2 mitral insufficiency have to undergo mitral valve replacement.

GUIDELINES FOR TREATMENT OF MITRAL VALVE STENOSIS29.

Asymptomatic patients

In the a-symptomatic patient, the severity of the stenosis measured with Doppler echocardiography determines the further steps to be taken. If the mitral valve area is > 1.5 cm2 and the mean gradient < 5 mmHg, no further evaluation is needed. It takes decades before progression occurs requiring intervention35. Follow-up consists of a yearly visit with a history and physical examination. A new echocardiogram is required if symptoms develop or the physical exam changes (fig 4).

If mitral valve area is < 1.5 cm2 and gradient > 5 mmHg, the decision to proceed should be based on valve morphology and the effect of mitral stenosis on the pulmonary circulation. If the valve morphology is suitable for commisurotomy and there is a systolic pulmonary artery pressure > 50 mmHg, percutaneous balloon valvulotomy should be considered. If valve morphology is suitable for commisurotomy and pulmonary pressure is low, pulmonary pressures should be measured again after stress testing. If patients are not able to achieve adequate work load, become symptomatic and show elevation of the transmitral gradient or and a pulmonary artery pressure > 60 mmHg, further intervention should be considered.

Edio-Doppler

Figure 4: Algorithm for the evaluation ofpatients with a-symptomatic mitral stenosis.

PMVB = Percutaneous mitral balloon valvulotomy; MVA = mitral valve area;

PAP = pulmonary artery systolic pressure (From ACC/AHA Guidelines for Valvular Heart Disease29.

Figure 4: Algorithm for the evaluation ofpatients with a-symptomatic mitral stenosis.

PMVB = Percutaneous mitral balloon valvulotomy; MVA = mitral valve area;

PAP = pulmonary artery systolic pressure (From ACC/AHA Guidelines for Valvular Heart Disease29.

Patients with class II symptoms

In patients with class 2 symptoms, a mitral valve area < 1.5 cm2 and a gradient > 5 mmHg, the decision to proceed has to be based on mitral valve morphology (fig 5). If patients have a valve suitable for commissurotomy, percutaneous mitral balloon valvulotomy has to be performed. If the mitral valve area is > 1.5 cm2 and the mean gradient < 5 mmHg exercise testing should be performed to determine if symptoms are due to the mitral stenosis.

Those patients, who have a significant rise in mean gradient with exercise and a pliable valve are candidates for mitral valve valvuloplasty.

Figure 5/ Algorithm for the evaluation ofpatients with mitral stenosis and NYHA class 11 symptoms. PMVB = Percutaneous mitral balloon valvulotomy; MVA = mitral valve area; PA WP = pulmonary artery wedge pressure; PAP = pulmonary artery systolic pressure (From ACC/AHA Guidelines for

Patients with class III- IV symptoms

Patients with mitral stenosis and class III - IV symptoms have a poor prognosis if left untreated4. Therefore these patients have to be treated with either percutaneous balloon valvulotomy, mitral valve repair or mitral valve replacement.

Figure 6.1 Algorithm for the evaluation of patients with mitral stenosis and NYHA class III -IV

symptoms. PMVB = Percutaneous mitral balloon valvulotomy;

MVA = mitral valve area; PA WP = pulmonary artery wedge pressure;

PAP = pulmonary artery systolic pressure; MVR = mitral valve repair or mitral valve replacement. (From ACC/AHA Guidelines for Valvular Heart Disease29.

Figure 6.1 Algorithm for the evaluation of patients with mitral stenosis and NYHA class III -IV

symptoms. PMVB = Percutaneous mitral balloon valvulotomy;

MVA = mitral valve area; PA WP = pulmonary artery wedge pressure;

PAP = pulmonary artery systolic pressure; MVR = mitral valve repair or mitral valve replacement. (From ACC/AHA Guidelines for Valvular Heart Disease29.

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