Objective To assess clinical results of three different conduit materials （Gore-Tex synthetic graft，bovinejugular vein and autologous pericardium）for palliative right ventricle-to-pulmonary artery （RV-PA） shunt，and explore the correlation between suitable conduit size and patients’ body weight and McGoon ratio. Methods We retrospectively analyzed clinical data of 24 patients with congenital heart diseases who underwent palliative RV-PA shunt in Department of Pediatric Cardiovascular Surgery of Fu Wai Cardiovascular Hospital from July 2010 to July 2012. There were 11 males and 13 females with their age ranging from 60 days to 6 years and body weight of 10.22±7.41 kg. There were 22 patients with pulmonary atresia and ventricular septal defect （PAVSD），1 patient with tetralogy of Fallot （TOF） and 1 patient with doubleoutlet right ventricle （DORV）. Among different conduit materials，autologous pericardium was used for 17 patients，Gore-Texsynthetic graft was used for 5 patients，and bovine jugular vein was used for 2 patients. Conduit size and children’s body weight were analyzed with linear regression，then the equation was corrected with McGoon ratio. Results There was no perioperative death. Postoperative percutaneous saturation （SpO2）of the 24 children was 20.37%±28.33% higher than preoperative SpO2 . Electrocardiogram showed sinus rhythm in all the patients. Twenty-three patients were NYHA classⅡ，and 1 patient was NYHA classⅢ. Postoperative mechanical ventilation time of patients with autologous pericardium were significantly shorter than those of patients with other 2 materials （P=0.017）. Sixteen patients were followed up from 10 months to 2 years after discharge，including 12 patients with autologous pericardium，3 patients with Gore-Tex synthetic graft and 1 patient with bovine jugular vein. During follow-up，McGoon ratio of patients with autologous pericardium，Gore-Tex synthetic graft and bovine jugular vein were 1.98±0.46，1.83±0.33 and 1.68 respectively，all of which weresignificantly higher than preoperative McGoon ratio （P＜0.05）. Six patients underwent radical corrective surgery，including5 patients with autologous pericardium and 1 patient with Gore-Tex synthetic graft. There was no complication directly related to surgery during follow-up. Linear regression was performed to form an equation between suitable conduit size and patients’ body weight：conduit diameter （mm）=0.327×body weight （kg）＋4.599. McGoon ratio，conduit size and equationresult were compared to find a practical choice of conduit size. If McGoon ratio＜0.8，the first integer greater than the equation result could be chosen. If McGoon ratio＞1.2，the first integer less than the equation result could be chosen. If 1.2＞McGoon ratio＞0.8，the first integer either less or greater than the equation result could be chosen. Group analysis showed that patients who recovered better postoperatively were those whose conduit sizes were closer to equation results as well as equation results corrected with McGoon ratio. Conclusion All the 3 materials can be conventionally chosen for RV-PA shunt. Appropriate conduit size can be decided upon patients’ body weight and McGoon ratio for RV-PA shunt.
Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.
Objective To investigate the hemodynamic performance of valved bovine jugular vein conduits (BJVC) for right ventricular outflow tract reconstruction in canine model. Methods The BJVC that were treated with the glutaraldehyde were implanted between the pulmonary artery and right ventricle in seven young canines. Right ventricular and pulmonary artery pressures were measured directly before and after the implantation. Hemodynamic evaluations were carried out by echocardiography and cardiac catheterization after the implantation. Results Seven canines were survival one year after the implantation. The pulmonary artery pressures (including systolic pressure, diastolic pressure and mean pressure) had not significantly changed after reconstruction with the conduits. The right ventricular diastolic pressures had not increased after the reconstruction, but the right ventricular systolic pressure and mean pressure had increased. One year later, the echocardiography showed valve motion with no obvious thickening of the leaflets. No graft kinking or obvious regurgitation of the valve was observed. Cardiac catheterization and angiography showed that the pressure gradients between the right ventricle and the conduits varied from 3 to 19mmHg, the diastolic pressures in the conduits were higher than that of right ventricle((Plt;)0.01), and the conduits and pulmonary arteries had no obvious obstruction. Conclusion The glutaraldehyde-fixed bovine jugular vein conduit has good hemodynamic performance in the pulmonary circulation.