Discussion
Although the patient met class I indications for aortic and pulmonic
valve replacement, we instead proceeded with an endovascular approach to
address both valvular pathologies given his high risk for repeat
traditional surgery given his multiple previous sternotomies and
surgical complications. We elected to proceed with intervention for
pulmonic stenosis first given that right ventricular dysfunction is
typically more recalcitrant to reversal than is left ventricular
dysfunction due to limited medical therapies; and due to concern for
potential worsening of left sided output due to inadequate preload
should right ventricular dysfunction develop.
Ideal transcatheter pulmonic intervention involves implanting a valve
large enough to eliminate the hemodynamic stress placed on the right
ventricle while simultaneously avoiding catastrophic rupture of the
stenotic pulmonic conduit and/or coronary artery compression. In this
case, we were unable to obtain surgical records confirming the original
pulmonic conduit size. Therefore, we proceeded with serial balloon
dilation to determine the maximal feasible neoconduit size. Because of
the risk of coronary compression, it is critical to perform coronary
angiography during each balloon inflation to assure that coronary
compression is not occurring. The maximal allowable size of the
neoconduit is therefore typically limited by the largest diameter
balloon used that does not lead to coronary compression.
In this case, balloon dilatation lead to a small contained perforation
of the surgical pulmonic conduit, and thus a CP covered stent was
deployed to seal the contained perforation. Although the CP stent sealed
the perforation, it does not have adequate structural radial support to
resist elastic recoil. Therefore, the addition of the Palmaz stent was
necessary to add structural integrity to the neoconduit. With the proper
scaffolding in place, the Edwards valve could then be deployed.
The Aortic valve intervention presented the challenge of treating
bioprosthetic valve stenosis with concomitant moderate to severe PVL.
After valve deployment, post-dilation bioprosthetic valve fracture (BVF)
and enlargement of the surgical valve lead to sealing of the PVL and
improvement in overall hemodynamics. Given the patient’s young age, we
prioritized treatment of PVL at the LVOT level by placing a Sapien Ultra
valve slightly more ventricular than would be typical, followed by BVF.
This strategy avoided placement of a vascular plug which can increase
the risk of complications with future TAVR in TAVR procedures by
deforming during valve expansion leading to ostial right coronary artery
(RCA) obstruction or migration.