ABSTRACT
A case is presented of vascular ring caused by right aortic arch with mirror-image branching and left ductus arteriosus. In this case, the descending aorta was located right of the tracheoesophagus and the left ductus arteriosus connected to the descending aorta far below the arch, producing compression of the esophagus only. Through median sternotomy, the ligation and division of the ductus was performed with concomitant repair of ventricular septal defect.
Subject(s)
Aorta, Thoracic/abnormalities , Ductus Arteriosus, Patent/diagnosis , Heart Defects, Congenital/diagnosis , Aorta, Thoracic/surgery , Ductus Arteriosus, Patent/surgery , Esophageal Stenosis/congenital , Esophageal Stenosis/diagnosis , Esophageal Stenosis/surgery , Heart Defects, Congenital/surgery , Heart Septal Defects, Ventricular/diagnosis , Heart Septal Defects, Ventricular/surgery , Humans , Infant , MaleABSTRACT
In this report, we describe an operative procedure for our implantable 1 piece biventricular assist device (BiVAD) based on a moving actuator mechanism, using an ovine model. Our implantable BiVAD is a volumetric coupled 1 piece unit including right and left blood sacs and an actuator assembly based on the moving actuator mechanism. The BiVAD was controlled by fixed rate control with 75 bpm for the most part. Both the left and the right full ejection modes with the maximum stroke angle were selected to minimize blood stasis in the blood sacs because of low assist flow condition. Three Corriedale sheep were used for the device implantation by a left thoracotomy incision. Cannulation was successfully performed in all cases. Although exposability of the right atrial appendage varied from animal to animal, the insertion of the cannula was easily performed. The cannulas were connected to the pump-actuator assembly in the preperitoneal pocket. All 3 animals survived the experimental procedure. During implantation of the device, in the 1 month survival animal, pump flow was maintained between 2.0 L/min and 2.5 L/min, mean aortic pressure was 90-110 mm Hg, and mean pulmonary artery pressure was 20-30 mm Hg. The left and right atrial pressure were maintained between 0 and 5 mm Hg. In conclusion, this ovine model for implantation of the 1 piece BiVAD can be an effective alternative for testing in vivo biocompatibility of the device although it needs more consideration for anatomical fittability for future human application.
Subject(s)
Heart-Assist Devices , Thoracotomy/methods , Animals , Aorta/physiology , Atrial Function , Biocompatible Materials , Blood Pressure/physiology , Cardiac Catheterization/instrumentation , Cardiac Output/physiology , Disease Models, Animal , Equipment Design , Heart Atria/surgery , Heart Rate/physiology , Humans , Peritoneum/surgery , Pulmonary Artery/physiology , Sheep , Stroke Volume/physiology , Survival RateABSTRACT
Mainly because of technical problems, the use of rabbits as a cardiopulmonary bypass (CPB) animal model with direct cannulation of the ascending aorta is known to be extremely difficult. The objectives of this study were the establishment of a CPB model in rabbits with direct cannulation of the ascending aorta, and the evaluation of the protective effect of steroid on the development of brain edema during circulatory arrest (CA) in an established rabbit CPB model. Fifteen New Zealand white rabbits were divided into three groups; control CA group, CA with Trendelenberg position, and CA with Trendelenberg position and steroid administration. After anesthetic induction and tracheostomy, median sternotomy was performed. An aortic cannula (3.3 mm) and a venous cannula (14 Fr) were inserted into the ascending aorta and the right atrium, respectively. The CPB circuit consisted of a roller pump and a bubble oxygenator. With 120-150 ml of blood, the priming volume of the circuit was approximately 450 ml, and CPB at a flow rate of 80-85 ml/kg/min was initiated. Blood in the priming solution was obtained from donor rabbits through cardiac puncture. Ten minutes later, CA with cessation of CPB was established for 40 min at 20 degrees C (rectal temperature). After CA, CPB was restarted with a 20 min period of rewarming. Ten minutes after weaning, the animal was sacrificed. Between 1 and 2 g of the brain was removed and the water content was determined and compared between groups. CPB with CA was successfully performed in all cases, with a flow rate of 60-100 ml/kg/min maintained throughout the CPB procedure. At that time, blood gases were reasonably maintained and aortic pressure ranged from 35 to 55 mmHg. After weaning from CPB, all hearts resumed beating spontaneously. Among the three groups, there were no statistically significant differences in the water content of the brain. These results indicate that: (1) if the proper technique is used, CPB in rabbits with direct cannulation of the ascending aorta is a reliable procedure, and (2) the effect of steroid on the prevention of brain edema related to the Trendelenburg position during CA is not established within the scope of this study.
