Beating heart coronary surgery supported by an axial blood flow pump.

BACKGROUND: We have previously presented a method for performing coronary artery bypass graft operation on the beating heart without cardiopulmonary bypass (CPB). This method has now been explored. METHOD: Thirty-two patients were prospectively randomized. The study group was operated on using an axial blood flow pump (Hemopump; HP) as circulatory support. Operations were performed on the beating heart. The control group was operated on using CPB, aortic cross-clamping, and cardioplegic arrest. RESULTS: All patients went through the procedure without major complications, and were discharged from the hospital. No statistical differences were observed between the groups for time on support (HP, 60.5 minutes; CPB, 70.5 minutes) or total operating time (HP, 178 minutes; CPB, 162 minutes). The number of grafts was greater in the CPB group (HP, 1.8; range, 1 to 3; CPB, 2.5; range, 1 to 4; p = 0.03). Statistical differences were found for intraoperative bleeding (HP mean, 312 mL; CPB mean, 582 mL; p = 0.0003) and myocardial trauma as measured by postoperative troponin-T values (HP, 0.23 microg/L; CPB, 1.17 microg/L; p = 0.004). CONCLUSIONS: Hemopump-supported coronary artery bypass graft operation has been shown to be a safe and feasible procedure with the potential benefits of reduced operative bleeding and myocardial damage without prolonging intraoperative support or total operating time.

The Linköping-Lund surgical experience with the HeartMate left ventricular assist system.

Four transplant candidates fulfilling the Food and Drug Administration criteria for a permanent left ventricular assist device received a pneumatic HeartMate system as a bridge to heart transplantation. All patients survived and were fully rehabilitated at the time of transplantation, which was carried out 2 to 6 months after the initial operation. There were no major complications associated with the procedures. We are impressed by the effectiveness and safety of the device.

Improvement of gait following functional electrical stimulation. I. Investigations on changes in voluntary strength and proprioceptive reflexes.

Patients with central spastic paresis and equipped with peroneal stimulators sometimes experience an improvement in their gait, even when the stimulator has been switched off. The object of the present investigation was to reach a better understanding of the mechanisms operating in such cases. 7 patients were investigated on repeated occasions. It was found that some of these patients got a clear increase in isometric strength of foot dorsiflexion following 10 min of peroneal stimulation. In other cases the increase was only slight. There was an inverse relation between the increase and the strength before stimulation. The increase of strength was due, at least partly, to an increased ability to activate the foot dorsiflectors, since there was a simultaneous increase in the EMG from the anterior tibial muscle. Evidence was also obtained suggesting that the increase in strength involved not only foot dorsiflexion but also plantarflexion of the foot end extension of the knee. Following peroneal stimulation there was also a decrease of the achilles reflex and in some cases possibly also the patellar reflex. There was an inverse relation between the decrease in the achilles reflex and its strength before stimulation. It is probable that the changes in voluntary strength and reflex activity reflect conditions which can be of importance in explaining the gait improvement which is sometimes observed in patients equippped with peroneal stimulators.

Anesthetic management of patients undergoing coronary artery bypass grafting with the use of an axial flow pump and a short-acting beta-blocker.

OBJECTIVES: To describe the clinical protocol regarding monitoring, pharmacologic interventions, and postoperative care during and after coronary artery bypass grafting (CABG) on the beating heart with an axial flow pump and a short-acting beta-blocker. DESIGN: A retrospective study. SETTING: A university hospital. PARTICIPANTS: Seventeen patients scheduled for elective CABG. INTERVENTIONS: Invasive monitoring was performed with either a standard pulmonary artery catheter (PAC) or a surgically placed PAC. An axial flow pump was inserted through a graft sutured to the ascending aorta. A short-acting beta-blocker was administered to decrease the motion of the heart and make conditions for CABG adequate and safe. MEASUREMENTS AND MAIN RESULTS: Compared with baseline measurements, there were significant decreases in mean arterial blood pressure, mixed venous oxygen saturation, and right ventricular ejection fraction during maximal axial flow pump support and beta-blockade. No significant change in heart rate was observed at this time. Hemodynamic variables were normalized in the intensive care unit. All patients were separated from the Hemopump without inotropic support, and values of troponin-T, aspartate aminotransferase, and alanine aminotransferase were low postoperatively. All patients survived and were discharged from the hospital. CONCLUSION: The anesthetic protocol for patients undergoing surgery with a beating heart and the combined use of an axial flow pump and a short-acting beta-blocker is outlined. Multiple-vessel CABG on the beating heart was performed with maintenance of an acceptable hemodynamic situation.

Management of patients with end-stage heart disease treated with an implantable left ventricular assist device in a nontransplanting center.

OBJECTIVE: To describe the setup of a left ventricular assist device (LVAD) program in a nontransplanting center. DESIGN: A prospective study from February 1993 to June 1999. SETTING: A university hospital. PARTICIPANTS: Ten patients, 6 men, with a mean age of 44 years (range 16 to 63 years) and with end-stage heart failure resulting from dilated cardiomyopathy (n = 7) or ischemic heart disease (n = 3). INTERVENTIONS: The patients received the TCI (Thermo Cardiosystems Inc, Woburn, MA) Heart Mate implantable assist device. Five patients had a pneumatic device, and 5 had an electric device. All except 1 patient with an electric device had the pump for an extended period. MEASUREMENTS AND MAIN RESULTS: Median time on the ventilator was 6.2 days, and median time in the ICU was 14 days. Significant hemodynamic improvement was observed by echocardiography and invasive monitoring. Milrinone and epinephrine supplemented by prostaglandin E1 were the most commonly used drugs to avoid right-sided heart failure. Nine patients were transplanted after pump therapy of 241 days (median) (range, 56 to 873 days). One patient died because of endovascular infection and septicemia. Infectious complications were frequent, especially when the pump time was extended. CONCLUSIONS: The introduction of an LVAD program in a nontransplanting center can be achieved with good results. Intense collaboration with a transplant center is mandatory. The complication rate increased when treatment times were extended.