Discussion
Earlier reports on the feasibility of the newly invented Inoue balloon
for retrograde BAV is scarce. Moriki et al. reported the hemodynamical
stability during inflation of the Inoue balloon as pre-dilatation for
TAVR4; however, there are no available reports
regarding retrograde use of the Inoue balloon as a bridge BAV to TAVR.
Generally, the Inoue balloon is extensively used for percutaneous
transcatheter mitral commissurotomies or antegrade BAVs and has numerous
advantages, including stable fixation, multistage inflation, and no
requirements for rapid ventricular pacing, compared with conventional
balloons. The antegrade BAV using the Inoue balloon reportedly resulted
in a greater increase in the postprocedural valve area and a reduction
in vascular complications and the risk for stroke, compared with the
retrograde BAV using the conventional balloon.5However, the antegrade approach itself is a more technically complicated
and demanding procedure because it requires septal puncture and
antegrade passage of a wire loop through the circulation. In addition,
antegrade approach via femoral vein had lower accessibility to rescue
TAVR than retrograde approach via femoral artery. Recently, the new
Inoue balloon, which has a longer and thinner shaft, and a more
elliptical tip, has invented and utilized for retrograde BAV in Japan.
In our case, we decided to urgently perform the retrograde BAV procedure
with the Inoue balloon for three reasons. First, the patient was
hemodynamically unstable owing to the severe AS and ongoing bacterial
infection despite of the intensive medical therapy. Although there are
no guidelines on TAVR for patients with bacterial infection, sepsis
during the index TAVR hospitalization was reported to be associated with
significantly higher rates of prosthetic valve endocarditis
(PVE).6 BAV without the need for prosthetic
implantation is a reasonable choice in our case in order to avoid
subsequent PVE. Second, the patient’s severe calcified aortic valve was
risky for acute, significant aortic regurgitation post-BAV which could
be resolved by rescue TAVR. Thus, we selected retrograde BAV with higher
accessibility to transfemoral-TAVR than antegrade BAV. Third, the
patient’s LVEF was significantly reduced. Previous studies reported that
a longer ventricular pacing duration was associated with morbidity and
mortality, particularly in patients with low LVEF.7, 8To avoid rapid ventricular pacing, the Inoue balloon rather than the
conventional balloon was utilized in retrograde BAV for our case.
We describe a feasible and safe retrograde BAV case using the newly
invented Inoue balloon in a hemodynamically unstable patient having AS
with reduced LVEF complicated with bacterial infection.