Correction of left ventricular outflow tract obstruction caused by anomalous papillary muscle and subaortic membrane

Abstract This paper presents a case study of a 30-year-old male patient with dyspnea on exertion had echocardiographic diagnosis of aortic subvalvar stenosis. Discrete mitral regurgitation and aortic valve dysplasia with mild to moderate insufficiency and hypertrophic cardiomyopathy were also noted. During surgery, a rare condition was identified: presence of papillary muscle anomaly associated with the subaortic membrane as a cause of obstruction of the left ventricular outflow tract. With the resection of these structures and a mitral valve annuloplasty, the patient evolved with a significant improvement of clinical condition and heart failure, with no residual mitral insufficiency.

Correction of Left Ventricular Outflow Tract Obstruction Caused by Anomalous Papillary Muscle and Subaortic Membrane.

This paper presents a case study of a 30-year-old male patient with dyspnea on exertion had echocardiographic diagnosis of aortic subvalvar stenosis. Discrete mitral regurgitation and aortic valve dysplasia with mild to moderate insufficiency and hypertrophic cardiomyopathy were also noted. During surgery, a rare condition was identified: presence of papillary muscle anomaly associated with the subaortic membrane as a cause of obstruction of the left ventricular outflow tract. With the resection of these structures and a mitral valve annuloplasty, the patient evolved with a significant improvement of clinical condition and heart failure, with no residual mitral insufficiency.

Subaortic membrane and aorto-septal angle: an echocardiographic assessment and surgical outcome.

BACKGROUND: Development of a subaortic membrane is not fully understood. Recurrence after surgical removal continues to be high. We sought to assess the differences in aorto-septal angles (AoSA) to possibly explain alterations within the left ventricular outflow tract, hence in subaortic membrane formation. METHODS: A total of 113 patients who underwent subaortic membrane resection were matched by age and sex with 113 controls. The subaortic membrane resection group included isolated subaortic membranes (n = 34, group I), associated with ventricular septal defect (n = 29, group II), or patent ductus arteriosus (n = 50, group III). RESULTS: Mean (± standard deviation) AoSA (in degrees) were not different between subaortic membrane groups I, II, and III but were steeper than their control groups (126.2 ± 9.2 vs 138.6 ± 7.0, 129.2 ± 9.9 vs 137.7 ± 10.0, and 126.2 ± 8.1 vs 135 ± 8.5, respectively; all Ps < .05). Additionally, group II had lower preoperative gradients (28.8 ± 20.7 mm Hg) compared to groups I and III (67.0 ± 32.9 and 66.2 ± 33.1 mm Hg, respectively, P < .001). Follow-up ranged from 3 to 132 months. In 22 (32%) patients, a subaortic membrane recurred. Early postoperative residual gradients and development of aortic regurgutation were associated with the need for reoperation (P < .05). CONCLUSIONS: These findings suggest a contributing role of the AoSA in the development of subaortic membrane. Further rheological experiments are warranted. Whether the steeper the angle the higher the risk of recurrence may be revealed by longer follow-up periods.

Comportamiento in vitro de un anillo mitral ajustable para cirugía de reparación mitral / In vitro behavior of an adjustable mitral ring for mitral repair surgery

Introducción. La reducción anular mitral es una de las técnicas quirúrgicas utilizadas en la reparación de la insuficiencia mitral funcional. Para su realización, se implanta un anillo protésico restrictivo para lograr la coaptación de los velos mitrales. Los anillos protésicos disponibles tienen tamaño fijo y existe el riesgo de implantar un anillo de tamaño inadecuado que resulte en una reparación imperfecta. Además algunos pacientes con disfunción ventricular severa no toleran la corrección de la insuficiencia mitral. Por esto, hemos diseñado un nuevo anillo regulable desde un dispositivo extracardíaco que podría resolver algunas deficiencias actuales en el tratamiento de dicha afección. Objetivo. Evaluar el comportamiento in vitro del anillo mitral regulable en cuanto a su capacidad de modificar sus dimensiones, corregir la insuficiencia mitral y producir voluntariamente nuevamente la insuficiencia. Material y métodos. Se utilizó un modelo de corazón porcino aislado al que se produjo insuficiencia mitral por dilatación anular. Se implantó el anillo regulable y se realizaron maniobras de reducción y dilatación observando su comportamiento y su efecto sobre la insuficiencia valvular. Resultados. Las maniobras de reducción y dilatación anular permitieron variar las dimensiones protésicas proporcionalmente sin modificar la forma anular. Se logró corregir y reproducir la insuficiencia mitral desde el control extracardíaco. Conclusión. In vitro el anillo regulable es capaz de modificar sus dimensiones proporcionalmente con el fin de corregir o reproducir la insuficiencia mitral

Background. Mitral ring downsizing is one of the techniques used in ischemic mitral regurgitation (MR) and MR due to dilated cardiopathy. In this technique, a prosthetic ring smaller than the native one is implanted in order to achieve mitral leaflet coaptation. Mitral ring prosthesis available up to date have fixed sizes and there is a risk that the chosen size turns out to be inadequate at follow-up. Some patients with severe ventricular dysfunction dont tolerate mitral valve repair and the increase in afterload that accompanies it. In order to overcome these difficulties, we designed a new mitral ring adjustable through an extra-cardiac device and tested it in vitro. Methods. Mitral regurgitation was obtained in a porcine isolated heart after forced dilatation of the mitral annulus. The mitral ring prototype was sutured to the mitral annulus using the conventional technique. Using the extra-cardiac device, the mitral annulus could be reduced and dilated obtaining annular diameters from 24 to 32 mm. Results. Proportional modification of annulus dimensions maintaining the characteristic shape of the mitral ring and its proportions was achieved. Mitral regurgitation was corrected and the optimal annulus dimension was determined after various dilatation and reduction maneuvers. Conclusions. Through this isolated porcine heart model of MR, we demonstrated that our prototype can reduce and dilate the mitral annulus proportionately without changing the native mitral annulus shape through the use of an extra-cardiac device

Comportamiento in vitro de un anillo mitral ajustable para cirugía de reparación mitral / In vitro behavior of an adjustable mitral ring for mitral repair surgery

Introducción. La reducción anular mitral es una de las técnicas quirúrgicas utilizadas en la reparación de la insuficiencia mitral funcional. Para su realización, se implanta un anillo protésico restrictivo para lograr la coaptación de los velos mitrales. Los anillos protésicos disponibles tienen tamaño fijo y existe el riesgo de implantar un anillo de tamaño inadecuado que resulte en una reparación imperfecta. Además algunos pacientes con disfunción ventricular severa no toleran la corrección de la insuficiencia mitral. Por esto, hemos diseñado un nuevo anillo regulable desde un dispositivo extracardíaco que podría resolver algunas deficiencias actuales en el tratamiento de dicha afección. Objetivo. Evaluar el comportamiento in vitro del anillo mitral regulable en cuanto a su capacidad de modificar sus dimensiones, corregir la insuficiencia mitral y producir voluntariamente nuevamente la insuficiencia. Material y métodos. Se utilizó un modelo de corazón porcino aislado al que se produjo insuficiencia mitral por dilatación anular. Se implantó el anillo regulable y se realizaron maniobras de reducción y dilatación observando su comportamiento y su efecto sobre la insuficiencia valvular. Resultados. Las maniobras de reducción y dilatación anular permitieron variar las dimensiones protésicas proporcionalmente sin modificar la forma anular. Se logró corregir y reproducir la insuficiencia mitral desde el control extracardíaco. Conclusión. In vitro el anillo regulable es capaz de modificar sus dimensiones proporcionalmente con el fin de corregir o reproducir la insuficiencia mitral

Background. Mitral ring downsizing is one of the techniques used in ischemic mitral regurgitation (MR) and MR due to dilated cardiopathy. In this technique, a prosthetic ring smaller than the native one is implanted in order to achieve mitral leaflet coaptation. Mitral ring prosthesis available up to date have fixed sizes and there is a risk that the chosen size turns out to be inadequate at follow-up. Some patients with severe ventricular dysfunction don’t tolerate mitral valve repair and the increase in afterload that accompanies it. In order to overcome these difficulties, we designed a new mitral ring adjustable through an extra-cardiac device and tested it in vitro. Methods. Mitral regurgitation was obtained in a porcine isolated heart after forced dilatation of the mitral annulus. The mitral ring prototype was sutured to the mitral annulus using the conventional technique. Using the extra-cardiac device, the mitral annulus could be reduced and dilated obtaining annular diameters from 24 to 32 mm. Results. Proportional modification of annulus dimensions maintaining the characteristic shape of the mitral ring and its proportions was achieved. Mitral regurgitation was corrected and the optimal annulus dimension was determined after various dilatation and reduction maneuvers. Conclusions. Through this isolated porcine heart model of MR, we demonstrated that our prototype can reduce and dilate the mitral annulus proportionately without changing the native mitral annulus shape through the use of an extra-cardiac device