ABSTRACT
To overcome the problems of classical pulmonary banding procedure, we developed a percutaneously adjustable pulmonary artery banding device. The banding device consists of banding portion of zig-zag shaped self-expandable stainless steel wire, shaft portion made by a polyvinyl catheter and a screw adjuster which includes a bolt and a nut. As the screw moves, the diameter of banding portion changes. Four Mongrel dogs ranging from 15 kg to 20 kg in weight underwent the banding of the mid portion of descending aorta with this devices through the left thoracotomy. One month after operation, we evaluated the pressure changes by controling the banding with the devices and then the dogs were sacrificed to study the microscopic changes in the aorta. The diameter and circumference of the band could be easily and finely adjustable by the screw control. The pressure recordings revealed a linear increase and decrease in pressure gradient according to percutaneous adjustment of the banding device. Since the banding device can be easily placed and simply adjusted percutaneously, we hope the banding device may be applicable clinically to improving the safety of pulmonary artery banding and debanding procedures in the future.
Subject(s)
Animals , Dogs , Aorta , Aorta, Thoracic , Catheters , Hope , Nuts , Polyvinyls , Pulmonary Artery , Stainless Steel , ThoracotomyABSTRACT
To understand the local fluid dynamics for different designs of Fontan operation, five models were made of Pyrex glass to facilitate in vitro study. Models I, II and III had the same position as the center of the anastomosis of the IVC (inferior vena cava) with that of the SVC (superior vena cava), but Models IV and V had 10 mm offset between them. As well, the anastomotic junction angles were different (Models I and IV: 90 degrees, Models II and V: 70 degrees, Model III: 45 degrees). These models were then connected to a flow loop for flow visualization study. In Model I, no dominant vortex was seen in the central region of the junction, but a large unstable vortex was created in Models II and III. In Models IV and V, a significant stagnation region was created in the middle of the offset region. It also showed that the flow distribution from the IVC and SVC to the LPA (left pulmonary artery) and RPA (right pulmonary artery) depends more on the offset of the junction than on the anastomotic junction angle. Generally, as the total flow rates increased, the pressures in the models increased.
Subject(s)
Humans , Blood Pressure , Hemodynamics , Models, Cardiovascular , Regional Blood Flow , /physiologyABSTRACT
Acute renal failure is a serious complication after open heart surgery which involve total body perfusion but the reported incidence of the complication has varied widely. We have experienced a case of acute renal failure with hemoglobinuria following an open heart surgery for correction of ventricular septal depect, which was comfirmed by cardiac catheterization. Kidney biopsy shows a typical change of acute tubular necrosis. A brief review of literature was also presented.