3|DISCUSSION
For adults suffering from symptomatic AS, SAVR is recommended in those
at low risk (EuroSCORE II<4%), while the TAVI is considered to be a
choice for patients who are not suitable for SAVR, especially for those
suitable for transfemoral access2. Another traditional
therapy for symptomatic AS is balloon aortic valvotomy, which usually be
chosen for hemodynamically unstable patients in the transitional period
to SAVR or TAVI2.
However, a significant number of patients with symptomatic AS are not
referred to the three above-mentioned traditional methods for some
complexity conditions. Risk factors among them include severely
calcified aorta root or ascending aorta (porcelain aorta) and/or aortic
valve leaflet, narrow left ventricular outflow tract (<18
mm)1, small aortic annulus, ascending aorta banding,
severe left ventricular dysfunction, previous CABG3.
AVB is regarded as a good option for reducing the left ventricular
overload by connecting the left ventricular apex and descending aorta in
patients with contraindications to SAVR and TAVI.
We presented a case of AVB surgery that was conducted successfully in a
high-risk symptomatic AS patient with contraindications to methods.
Internal diameters of the aortic annulus, aortic
sinus and ascending aorta are narrow with severe calcification to the
extent that it is hard to inflate a balloon or release a transcatheter
aortic valve. Besides, there was a lack of appropriate valve in the
market we can found. Considering of the coarctated and porcelain aorta,
replacement of ascending aorta combined SAVR seemed necessary, but the
mortality risk calculated by EuroSCORE II for this operative plan was
72.04%. In this case, patient characteristics showed
contraindications to SAVR, TAVI and balloon aortic
valvotomy. To widen the total area of the left ventricular tract and
decrease the cardiac afterload, we finally performed a surgical
procedure of aortic valve bypass and aortic valvuloplasty in
consideration of the severe stenosis and moderate
regurgitation of the aortic valve.
Indication for AVB is severe symptomatic AS in high-risk patients with
contraindications to both AVR and TAVI1. The
implantation of the apico-aortic conduit relieves left ventricular
outflow obstruction by shunting blood flow. Compared with TAVI, Patients
undergoing AVB procedures have similar in-hospital mortality, lower
complication rate, and fewer hospital charges3. Even
so, AVB is seldom offered as the initially routine treatment as a result
of the technical difficulty of apical anastomosis procedure. The new
invention of an automated apical connector device would help collapse
the technical barriers4.
A theoretical risk of the AVB procedure is the possibility of flow
subtraction with cerebral hypoperfusion ascribed to the competition
between the antegrade and retrograde flow from two ventricular outputs.
In a recent study, Benevento et al.5 showed that the
blood flow distribution after AVB depends on the effective orifice area
of the stenotic aortic valve and apico-aortic valved conduit implanted.
Mantini et al.6 reported that the flow redistribution
after AVB does not compromise cerebral blood supply. Another serious
complication is aortic thrombosis at the level of flow stagnation caused
by the collision of two blood flows, which is more likely to happen when
the retrograde flow is dominant and antegrade/retrograde flows are
equivalent7. The recommendation is that patients who
underwent AVB receive long-term strict
anticoagulation7.