Letter to the Editor
Dear Editor,
Karel Van Praet et al. recently published the interesting “RALT
approach” (1) for minimally invasive aortic valve replacement.
As stated by the authors in the abstract, the CT scan ismandatory for planning a MiAVR. We have treated more than 1200
patients with a total central cannulation MiAVR approach (2,3) and in
our opinion this message is misleading: the non-invasive anatomical
assessment might be useful in the beginning of the experience to rule
out difficult cases, especially the ones who have got a longmini-thoracotomy to aortic annulus distance; moreover, the
surgical access site selection does not require a CT scan, the third
being the right intercostal space (rarely if not, the surgeon can easily
change it to the second from the same skin incision). In the real world,
a dedicated CT scan means technological skills, time and financial
resources and they might not be found at once in every Center who wants
to start a MiAVR program; on the contrary this surgical approach has to
be direct and simplified, made suitable for everyone (4). The video
assistance, the peripheral cannulation and the transcutaneous clamping
allow to avoid any need of costal spreading and occasional rib injuries:
the camera should be the surgeon’s eyes and the mini-thoracotomy only
the access to bring the valve in. Minimally invasive surgery is a skill
to reduce the surgical burden: the use of central cannulation reduces
surgical trauma and avoids potential complications due to femoral
cannulation such as dissection of the femoral vessel and the aorta,
ischemia of the ipsilateral limb, cerebrovascular and renal events (5),
allowing a more physiological perfusion flow. Furthermore, in our
experience, the venous central cannulation optimizes the exposure
(simply with a wire which gently pull away to right auricula from the
aortic root) and also it reduces the shear stress, since that does not
require a vacuum assistance in most cases; we came up with a slightly
modified cannula, which can be shaped to engage easily the inferior cava
vein. The Authors refer to a SLL-PEEP technique to inflate the left lung
and push the aorta towards the surgical access, in case of suboptimal
exposition: we rely on pericardial stitches rather than inflating the
left lung, in order to avoid any risk of barotrauma.
In our opinion, MiAVR has to reproduce the gold-standard conventional
procedure in terms of safety, effectiveness and especially operative
times through a more respectful approach; the non-invasive CT-scan
assessment might be helpful, especially in the beginning of the
experience.