Percutaneous transvenous mitral commissurotomy using the Inoue balloon

The Inoue balloon catheter is unique in function as well as shape, and can be especially adapted for each patient to ensure a high success rate and low morbidity during percutaneous transvenous mitral commissurotomy (PTMC). Before transseptal puncture, right atrial angiography is performed to image the proper point of puncture to avoid not only accidental perforation but also the difficulty of balloon insertion into the mitral orifice. There are two main techniques for inserting the balloon into the mitral orifice. One is a direct method, and the other is loop formation in the left atrium. Balloon selection is basically standardized by patient height; 30 mm for a height of greater than 180 cm, 28 for greater than 160, 26 for greater than 147, 24 for less than 147. However, it should be smaller in valves with severe pathological changes, to prevent mitral regurgitation especially in valves with a mix of strong and weak echoes in the leaflets, combined with strong echo in the commissures shown on 2-dimensional echo-cardiography. For a patient at an advanced age, a smaller balloon should be chosen. A stepwise dilatation technique is effective for preventing the creation of severe mitral regurgitation. Doppler echo-cardiography should be used to decide whether further dilatation is necessary. This will estimate resultant mitral regurgitation, increased mitral valve area and degree of commissure separation. The disappearance of the balloon waist under fluoroscopy is also important in decision making. PTMC is a treatment of choice for mitral stenosis except for fresh mural thrombus and combined severe mitral regurgitation.