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.