A 79-year-old woman with degenerative mitral regurgitation and secondary tricuspid regurgitation underwent mitral and tricuspid repair. Massive and intractable endobronchial hemorrhage occurred during weaning from cardiopulmonary bypass (CPB). Bronchoscopic examination during CPB revealed that the right distal bronchus was the probable bleeding point. We then performed a double-lumen endotracheal tube and a bronchial blocker in the distal portion of the right main bronchus. In addition, extracorporeal membrane oxygenation (ECMO) with a heparin-coating system was performed for 11 h, without extra heparinization because of severe hypoxia. The bronchial blocker was removed 14 h later, and the patient was weaned from ECMO 19 h after admission into ICU. Postoperative computed tomography (CT) revealed a pseudoaneurysm of the right pulmonary artery (A⁵b) corresponding with the probable site of bronchial bleeding (B⁵). We speculate that a pulmonary artery catheter induced this endobronchial hemorrhage. At 3 months after surgery the patient was doing well with no symptoms of airway bleeding, and her abnormal CT findings had disappeared.

A 47 year-old man with frequent attacks of ventricular tachycardia (VT) due to arrhythmogenic right ventricular dysplasia (ARVD) developed severe right heart failure following cryoablation of the multiple VT focuses. Inotropic support and intraaortic balloon pumping failed to maintain the systemic circulation, so that we performed the right heart bypass (RHB) using a heparin-coated tube and roller pump. With the use of RHB, systemic circulation improved. We attempted to wean the patient off after 14 days RHB support. However this was unsuccessful because of poor RV function, and RHB was recommenced. The patient finally died of multiple organ failure on the 21st postoperative day, but the major organ function was well maintained for at least two weeks. The heparin-coated tube and roller pump system is easy to handle, and is suitable as a short term lifesaving adjunct for severe right ventricular failure.

We applied a new circulatory support system to three patients with descending aortic operation between 1989 and 1990. The new system consisted of a polyvinylchloride tube coated with hydrophilic heparinized polymer and a roller pump. Low doses of heparin (0.5mg/kg) were administered in two patients and none in one patient before aortic bypass. The aortic crossclamping time ranged between 52 and 64 minutes. In two patients, whose inflow cannulae were 18Fr. or 20Fr., successful bypass flow exceeded 2l/min and optimal distal aortic pressure were maintained during aortic cross-clamping. The postoperative courses of these patients were uneventful, free from thromboembolic episodes and subsequently discharged from hospital. Furthermore, postoperative careful examination revealed no thrombus formation occurred in the three devices. In conclusion, our new simple, antithrombogenic circulatory system is extremely useful for descending aortic operations.

A minimally invasive approach to coronary artery revascularization without cardiopulmonary bypass has been performed recently and its feasibility and effectiveness have been proved. However, occlusion of the coronary artery during anastomosis in the beating heart is liable to cause myocardial ischemia or infarction. To prevent these and to perform minimally invasive coronary artery bypass on the beating heart safely, intra-coronary shunt was developed and applied in animal experiments. Materials and methods: The left internal mammary artery was harvested endoscopically and anastomosed to the left anterior descending coronary artery in the beating heart without cardiopulmonary bypass in seven pigs. Three of them utilized intracoronary shunt tubes (group S) and the other did not (group C). Results: Use of an intracoronary shunt tube facilitated non-blood exposure of the coronary artery during anastomosis. In group C, three pigs out of four had ventricular fibrillation during occlusion for the anastomosis. In group S the anastomosis was accomplished without change of ECG except one case and without any elevation of CPK-MB and Troponin T during and after the anastomosis. Conclusion: These results showed that an intra-coronary shunt can prevent myocardial ischemia and may be very useful especially to those who do not develop collateral branches from other coronary arteries.

To estimate the blood compatibility during extracorporeal circulation, we designed mock circulation system consisted of a membrane oxygenator and vinyl circuit with roller pump. Primed with 200ml Ringer's acetate and 200ml of fresh whole human blood, mock circulation was worked at flow rate 0.5l/min for 6hr. Heparin was not primed, oxygenator did not fill any gases and circulation was keeping at 37°C. The thrombin-antthrombin complex and fibrinopeptide-A showed progressive increase and fibrinogen correspondingly decrease. Nevertheless, the plasmin α2 plasmin inhibitor complex and D-dimer showed minimal changes within normal range in spite of increasing fibrinopeptide B β 15-42. We can not find any signs of secondary fibrinolytic activity. On the other hand, the platelet was persistently activated as shown statistically significant increase in β-thrombogloblin and platelet factor IV. Significant elevations of complement 3a and 4a were seen with increase of complement 5a and activated oxygen productivity by neutrophilic leucocytes. In conclusion, moderate and limited blood alterations occurred in mock cardiopulmonary bypass circuit.

A case of 65-year-old man of aorto-caval fistula induced by ruptured abdominal aortic aneurysm is reported. The symptoms were hematuria and chest pain, and an emergent operation was performed. In the operation, Fogarty's balloon occlusion catheter was used to reduce bleeding from inferior vena cava, and to prevent pulmonary embolism. The fistula was 3cm in size, and abdominal aorta was replaced with a low porosity polyester Y-graft. The symptoms of pulmonary congestion and hematuria were improved after operation. The balloon occlusion catheter was effective for reducing bleeding from IVC, and prevention from pulmonary embolism after operation.