Left ventricular outflow tract obstruction after bioprosthetic mitral valve replacement with preservation of the anterior leaflet

Congenital, acquired, or both? The only two congenitally based, acquired heart diseases

Discrete subaortic stenosis (DSS) is a type of left ventricular outflow tract obstruction whereas double-chambered right ventricle is a form of right ventricular outflow tract obstruction. Both of these cardiac malformations share lots of similar characteristics which classify them as acquired developmental heart diseases despite their congenital anatomical substrate. Both of them are frequently associated to ventricular septal defects. The initial stimulus in their pathogenetic process is anatomical abnormalities or variations. Subsequently, a hemodynamic process is triggered finally leading to an abnormal subaortic fibroproliferative process with regard to DSS or to hypertrophy of ectopic muscles as far as double-chambered right ventricle is concerned. In many cases, these pathologies are developed secondarily to surgical management of other congenital or acquired heart defects. Moreover, high recurrence rates after initial successful surgical therapy, particularly regarding DSS, have been described. Finally, an interesting coexistence of DSS and double-chambered aortic ventricle has also been reported in some cases.

Neo-LVOT and Transcatheter Mitral Valve Replacement: Expert Recommendations

With the advent of transcatheter mitral valve replacement (TMVR), the concept of the neo-left ventricular outflow tract (LVOT) was introduced and remains an essential component of treatment planning. This paper describes the LVOT anatomy and provides a step-by-step computed tomography methodology to segment and measure the neo-LVOT while discussing the current evidence and outstanding challenges. It also discusses the technical and hemodynamic factors that play a major role in assessing the neo-LVOT. A summary of expert-based recommendations about the overall risk of LVOT obstruction in different scenarios is presented along with the currently available methods to reduce the risk of LVOT obstruction and other post-procedural complications.

Comparison of modified total leaflet preservation, posterior leaflet preservation, and no leaflet preservation techniques in mitral valve replacement - a retrospective study

Background

Mitral valve replacement with the total leaflet preservation technique can yield good results; however, its development is limited by patient-valve mismatch. Therefore, we compared the efficacies of the modified total leaflet preservation technique, posterior leaflet preservation technique, and no leaflet preservation technique in mitral valve replacement.

Methods

Clinical records and echocardiographic data of 180 patients who underwent mitral valve replacement for rheumatic mitral valve disease between 2009 and 2017 were analysed retrospectively to summarise the operative experience and short-term (six months) results. The patients were divided into three groups: group A (n = 62), treated with the modified total leaflet preservation technique; group B (n = 80), treated with the posterior leaflet preservation technique; and group C (n = 38), treated with the no leaflet preservation technique.

Results

No significant difference in the preoperative clinical data was noted between the groups (p > 0.05). The clamp and recovery times of group A were longer (p < 0.05) and shorter (p < 0.05), respectively, than those of groups B and C. The postoperative left ventricular end-diastolic diameter, left ventricular end-systolic diameter, and left ventricular ejection fraction of group A were significantly better than those of groups B and C. The incidence of low cardiac output syndrome in group A was lower than that in group C (p < 0.05). There was no postoperative left ventricular posterior wall rupture or mechanical valve dysfunction in group A.

Conclusions

The short-term results of the modified total leaflet preservation technique were better than those of the other techniques. This technique is also suitable for patients with rheumatic mitral valve stenosis.

Acquired discrete subaortic stenosis late after mitral valve replacement

Although acquired left ventricular outflow obstruction has been reported in a variety of conditions, there are scant reports of its occurrence following mitral valve replacement (MVR). This study describes two female patients, who developed severe discrete subaortic stenosis, five years following MVR. In both cases, the mitral valve was replaced by a porcine Carpentier-Edwards 27-mm bioprosthesis with preservation of mitral valve leaflets. The risk of very late left ventricular outflow tract obstruction after bio-prosthetic MVR with preservation of subvalvular apparatus needs to be kept in mind in symptomatic patients.

Obstruction of mechanical mitral valves by preserved posterior leaflet remnants

We report two cases of mechanical prosthetic mitral valve obstruction caused by remnants of the mitral valve posterior leaflet tissue preserved from the previous surgery. Both patients had rheumatic mitral stenosis causing New York Heart Association class III symptoms prior to mitral valve replacement.