Percutaneous mitral balloon valvuloplasty. Difficult mitral valve crossing

Introduction

Percutaneous mitral balloon valvuloplasty (PMBV) is the treatment of choice for significant mitral stenosis (MS). The inability to cross the mitral valve accounts for a non-negligible rate of unsuccessful PMBV. This may be caused by unfavorable septal puncture or extensive enlargement of the left atrium (LA), both resulting in insufficient support. Advanced valvular and subvalvular degeneration may further impede valve crossing.
Surprisingly, only a few reports focus on this problem. In a study by Feldman, failure to cross the mitral valve occurred in 1.7% of cases [1]. Cribier et al. reported the occurrence of this failure at 2.6% [2].
We present a case of a successful re-attempt of PMBV done with the support of a veno-arterial loop after an unsuccessful mitral valve crossing with an Inoue balloon in the first procedure.

Case report

A 38-year-old woman with significant MS, history of ischemic stroke, and hypertension was admitted for PMBV.
In echocardiography LA enlargement to 30.0 cm2, thickening of mitral leaflets and subvalvular apparatus, fusion of posterior commissure were observed. Mitral valve area (MVA) was 0.8 cm2 by the pressure half-time (PHT) formula. Trans-mitral gradient was 21.7/10.5 mm Hg maximum and mean, respectively. The standard PMBV with the Inoue balloon was initiated via the right femoral vein. Atrial septum puncture was performed under transesophageal echocardiography (TEE) guidance. In the case of LA enlargement the right atrium is pushed to the front. So, as in the typical place of puncture the ascending aorta might be present, we usually puncture the atrial septum slightly posteriorly. Then hemodynamic measurements were made. After having placed the balloon in the LA, all of the maneuvers aiming to cross the mitral valve orifice with the balloon failed. During the second approach, a modified PMBV technique was used with a transseptal veno-arterial loop serving as a rail for the balloon’s entry into the LV (Figure 1). The TEE-guided atrial septum puncture was performed again. The dedicated 6 Fr Swan-Ganz catheter, with 0.035 mm lumen, was introduced to the LA and next to the left ventricle (LV), through which a 300 mm long, 0.035 inch wire was advanced from the LA into the LV. Using the arterial access, a Multi-snare loop (PFM Medical, Germany) was advanced in a retrograde fashion through a 6 Fr-JR guide catheter into the ascending aorta and directed into the LV. Then the wire...


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