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.

Value of morrow procedure in surgery of discrete membranous subaortic stenosis

Subuortic stenosis constitutes up to 20% of all farms of left ventricular outflow had [LVOT] obstruction in children. Although the resulting significant left ventricular hypertrophy and aortic insufficiency are clear indications for surgery, controversy persists whether to remove the membrane in symptom-free patients with an isolated membrane or not. In addition to the timing of surgical repair, the surgical technique remains an area of discussion. In this study, we try to evaluate the impact of early surgical interference as well as surgical technique on the early and mid-term outcome. 44 patients with a mean age of 9.26 years [range, 2.4-28 years] underwent surgical resection for discrete membranous subaortic stenosis [DMSS]. For the purpose of the study, the patients were divided into two groups. Group I consisted of 31 patients who underwent membranectomy combined with routine transoortic myectomy. Group II consisted 13 patients to whom only excision of the subaortic membrane was done [membranectomy] without any myotomy or myectomy. Group II was done in Assuit University Hospital between 2001 and 2003. Group I was done in Paediatric cardiothoracic surgery unit [Children Hospital. Assuit University] between 2009 and 2013, in early postoperative results, the mean LVOT gradient in group I was statistically significantly lower than that of group II [p=0.000]. Aortic regurge [AR] improved in all patients of group I but progressed in five patients of group H. Mid-term follow up showed better results in group I than group II early resection of DMSS, before development of significant left ventricular hypertrophy and aortic insufficiency is advisable. Resection of the obstructing membrane together with generous myectomy of the LVOT is a safe and effective treatment in terms of more significant reduction of LVOT gradient; both early and in mid-term follow up, with lower incidence of recurrence and significant improvement of associated aortic incompetence

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