Morphological analysis of tricuspid valve in hearts with Ebstein disease and its implications to the Cone technique

• Grant number: 13/17219-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2014
• End date: June 30, 2015
• Field of knowledge: Health Sciences - Medicine - Pathological Anatomy and Clinical Pathology
• Principal Investigator: Vera Demarchi Aiello
• Grantee: Ana Carolina Amarante Souza
• Host Institution: Instituto do Coração Professor Euryclides de Jesus Zerbini (INCOR). Hospital das Clínicas da Faculdade de Medicina da USP (HCFMUSP). Secretaria da Saúde (São Paulo - Estado). São Paulo , SP, Brazil

Abstract

Ebstein's malformation is a rare congenital heart defect that may or may not be accompanied by cyanosis. It is the tricuspid valve anomaly which more frequently causes functional disorders, mainly valvar insufficiency. The main morphological feature of the anomaly is the anomalous insertion of the septal and inferior cusps far from the valve ring, also described as "adhesion" of one or more of the cusps to the ventricular wall, with consequent incorporation of part of the right ventricle to the atrial cavity. Thus, the functional tricuspid valve orifice moves to the right cavity towards the ventricular apex. The offsetting of the valve plane results in the materialization of the right ventricular inlet, which morphologically is part of the atrium, but works in synchronically with the ventricle, causing additional damage to the cardiac cycle. Thus, the efficient part of the right ventricle is restricted almost exclusively to its outlet and offers high resistance to the emptying of the right atrium (atrium afterload).Patients with Ebstein's anomaly not treated surgically usually die, between the second and the fourth decades of life. Recently a new surgical technique to treat Ebstein's anomaly was developed, which is obtaining success as to its good results. It is the "Cone technique", developed and published by da Silva e collaborators. Objectives: the aim of this study is to assess and quantify, in anatomical specimens, the valvular tissue area available for this surgical reconstruction, also considering other morphological characteristics as the type of chordal insertion and degree of the offsetting of the insertion of the septal and posterior cusps. Another goal will be to suggest a classification aiming at the realization of the Cone technique. Methodology: twenty-five anatomical specimens (hearts) with Ebstein's malformation will be analyzed, and as controls, five normal anatomical specimens from age-paired children. After inspection of the specimen preservation (the absence of cuts or resection to prevent quantification), measurements will be performed on the circumference of the tricuspid valve, and the length of the right ventricular inlet. A digital photo of the open valve will be taken, along with a ruler, to allow computerized measurements (planimetry). From the photo, the assessment of the dimensions of each of the cusps, including the length of the insertion line, length of each cusp from its base to the free edge, area, and distance from the true atrioventricular ring. The chords will be evaluated qualitatively on the number, type, and presence of inter-chords spaces. Measurement of the mitral valve ring and the length of the left ventricular inlet will also be obtained for comparison with the right-sided values. Statistical analysis will be made of the results obtained, always comparing the two groups of specimens (cases and controls).(AU)