Reconstruction of the right ventricle with diaphragm driven right ventricular wall device

For the treatment of congenital cardiac anomalies associated with hypoplastic right ventricle such as tricuspid atresia, various methods have been used in clinical and experimental studies. Though these methods were effective, there remained still some problems such as postoperative right heart failure or restriction of indications for the cases associated with high pulmonary vascular resistance. In order to solve these problems, diaphragm driven right ventricular wall device (RVWD) was newly developed. The device is composed of hard outer housing and soft diaphragm made of polyurethane and actuated pneumatically triggered to R wave of ECG or left ventricular pressure. Characteristics of RVWD were checked using a mock circulation to find optimal driving condition for animal experiments. Acute experiments were carried out using 15 mongrel dogs. Right ventricular free wall was excised as wide as possible under hypothermic inflow occlusion and RVWD was sutured to the edges of right ventriculotomy. Hemodynamics were investigated with and without driving of RVWD for 6 to 24 hr. RVWD was able to maintain hemodynamics efficiently during immediate postoperative period. After body temperature and cardiac function returned to normal, systemic circulation could be maintained without driving of RVWD. From the results of this study, possibly of surgical correction of hypoplastic right ventricle using RVWD was presumed.