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Palacios Mini-invasive Surg 2020;4:73 I http://dx.doi.org/10.20517/2574-1225.2020.72 Page 9 of 24

PMV is performed as previously described [1,2,5,6] . All patients should undergo diagnostic right and left,
and transseptal left heart catheterization [1,2,5,6] . Following transseptal left heart catheterization, systemic
anticoagulation is achieved by the intravenous administration of 100 units/kg of heparin. In patients older
than 40 years, coronary angiography should also be performed. Hemodynamic measurements, cardiac
output, and cine left ventriculography are performed before and after PMV. Cardiac output is measured
by thermodilution and Fick method techniques. An oxygen diagnostic run is performed after PMV to
determine the presence of significant left to right shunt across the interatrial septum after PMV.

THE ANTEGRADE DOUBLE-BALLOON TECHNIQUE
PMV using the antegrade double-balloon technique [Figure 5] is performed as previously described [1,2,5,6] .
A 7F flow directed balloon catheter is advanced through the transseptal sheath across the mitral valve into
the left ventricle [1,2,5,6] . The catheter is then advanced through the aortic valve into the ascending and then
the descending aorta. A 0.889 mm or 0.9652 mm, 260 cm long Teflon coated exchange wire is then passed
through the catheter. The sheath and the catheter are removed leaving the wire behind. A 5 mm balloon
dilating catheter occasionally is used to dilate the atrial septum. A second exchange guide wire is pass
parallel to the first guide wire through the same femoral vein and atrial septum punctures using a double
lumen catheter. The double lumen catheter is then removed leaving the two guide wires across the mitral
valve in the ascending and descending aorta. During these maneuvers care should be taken to maintain
large and smooth loops of the guide wires in the left ventricular cavity to allow appropriate placement
of the dilating balloons. If a second guide wire cannot be placed into the ascending and descending
aorta, a 0.9652 mm Amplatz type transfer guide wire with a preformed curlew at its tip can be placed at
the left ventricular apex. In patients with aortic valve prosthesis, two Amplatz type transfer guide wires
with preformed curlew tips should be placed at the left ventricular apex. When one or both guide wires
are placed in the left ventricular apex, the balloons should be inflated sequentially. Care should be taken
to avoid forward movement of the balloons and guide wires to prevent left ventricular perforation. Two
balloon dilating catheters, chosen according with the patient’s body surface area, are then advanced over
each one of the guide wires and positioned across the mitral valve parallel to the longitudinal axis of the
left ventricle. The balloon valvuloplasty catheters are then inflated by hand until the indentation produced
by the stenotic mitral valve is no longer seen. Generally, one, but occasionally two or three, inflations
are performed. After complete deflation, the balloons are removed sequentially. The Multi-track system
[36]
[Figure 6] introduced by Bonhoeffer, shares the advantages of the traditional double-balloon technique .
It is safer and reduces the risk of accidental balloon displacement. The procedure is easier to perform as it
only requires the presence of a single guide wire and therefore procedure times are reduced. The system
is versatile and can be used in other indications. With this technique, two separate balloon catheters are
positioned on a single guidewire. The first catheter, with only a distal guidewire lumen, is introduced into
the vein and then advanced into the mitral orifice. Subsequently, a rapid exchange balloon catheter running
on the same guidewire is inserted and lined up with the first catheter so the two are positioned side by side.
[36]
Both balloons are then inflated simultaneously .
THE INOUE TECHNIQUE OF PMV
Nowadays, PMV is more frequently performed using the Inoue technique as previously reported
[Figure 7] [4,16,18,22,37] . The Inoue balloon is a 12 French shaft, coaxial, double lumen catheter, made of a double
layer of rubber tubing with a layer of synthetic micromesh in between. After transseptal catheterization,
a stainless-steel guide wire is advanced through the transseptal catheter and placed with its tip coiled
into the left atrium and the transseptal catheter removed. Subsequently, a 14 French dilator is advanced
over the guide wire and used to dilate the femoral vein and the atrial septum. An Inoue balloon catheter
chosen according to the patient’s height is advanced over the guide wire into the left atrium. The distal
part of the balloon is inflated and advanced into the left ventricle with the help of the spring wire stylet