Percutane hartklep implantatie bij congenitale en ... - KCE

14 Percutaneous Heart Valves KCE Reports 95
Figure 2.1: The Edwards Sapien Transcatheter Heat Valve (Edwards
Lifesciences) (side and top view)
Source: pictures received from Edwards
During the first years following the introduction of the technique, the antegrade
approach via the interatrial septum was used for PAV implantation, as discussed earlier.
Hereby, catheterization through the interatrial septum is performed from the femoral
vein. A flotation balloon catheter is used for antegrade crossing of the aortic valve, and
a guide wire is advanced through this catheter to the descending aorta. After
predilatation of the native aortic valve with a balloon catheter, the PAV is advanced
over the wire, across the interatrial septum, and within the stenotic native valve. To
improve the precision of PAV implantation, rapid cardiac pacing (180 to 220 beats/min)
of the heart up to 10 seconds decreases aortic blood flow and prevents PAV migration
during balloon inflation. 14 The disadvantage of this antegrade technique is that it is
complex and technically demanding. Moreover, there is a risk of damage to the mitral
valve which has led to a renewed interest of the retrograde technique which is similar
to the routine BAV. 24 Here, the aortic valve is reached straight against the direction of
blood flow via the ilio-femoral arteries and the descending aorta, and a guidewire is
advanced through the aortic valve orifice. After predilatation of the native aortic valve,
the PAV is advanced over a guidewire within the native valve and deployed as in the
antegrade technique. The antegrade approach of the aortic valve has been mostly
replaced by the retrograde approach. The retrograde technique however can be
hampered due to difficulties to advance large catheters through tortuous and diffusely
diseased femoral and iliac arteries, often encountered in elderly people. These
difficulties have led to the development of the transapical approach where the same
device is introduced from the cardiac apex, directly into the left ventricle via a minithoracotomy,
with or without femoral extracorporeal circulation. 33 As in the
transvascular approach, valvuloplasty is performed first, after which a 33F or 26F
delivery sheath is advanced through the left ventricular apex to insert the PAV under
fluoroscopic imaging. 34 At the end of the procedure, the apex is closed surgically with
purse-string sutures. The pericardium is closed over the apex and a left lateral chest
tube is inserted.
The first results of single-centre feasibility series, using the Cribier-PVT valve mostly via
the antegrade approach, were published in 2004 14 and 2006 35 . After the acquisition of
Percutaneous Valve Technologies by Edwards LifeSciences in 2004, there have been
continued technical improvements of the system and in the protocol for device delivery,
in order to better traverse the vascular system and the aortic arch. Moreover, a larger
caliber PAV was developed, because of the concern of valve migration and residual
paravalvular leaks. For regulatory reasons (sic), these technologic advances could not be
used in France before 2006 and were evaluated inititally by J. Webb in Vancouver,
Canada and later on in the US. 36 The antegrade and retrograde procedures have been
performed both under local or general anesthesia.
The transapical approach, including a mini-thoracotomy, obviously requires general
anesthesia. Dual antiplatelet therapy is instituted at least 24 hours before the procedure
with aspirin and clopidogrel. 24 To date, reportedly more than 1000 Edwards PAVs have
been implanted worldwide in humans, using one of these different approaches. 36