Shinya Yagi

Evaluation of valve sound and its effects on ATS prosthetic valves in patients’ quality of life

BACKGROUND We interviewed patients and carried out frequency analyses to compare the closing sounds of ATS and St. Jude Medical (SJM) prosthetic valves. METHODS Forty-five patients undergoing valve replacements using ATS valves were investigated. We interviewed patients at 1 month and 1 year after the operation, and carried out frequency analysis to investigate the prosthetic valves closing sound. RESULTS According to the results of the interviews, 84.4% of patients with ATS valves were not aware of the valve sounds. ATS valves scored significantly lower than SJM valves on audibility of the valve sound, disturbance during daytime, sleep disturbance, request for replacement with a soundless prosthetic valve, audibility to others, and noise index. According to the frequency analysis on the prosthetic valves closing sound, the sound peak of the ATS valves was around 1.2 kHz, and the sound pressure of the ATS valves was significantly lower than that of the SJM valves. CONCLUSIONS Though a further long-term observation on thromboembolism and hemolysis is needed for evaluation of prosthetic valves, the ATS valve is presently considered to impart a better quality of life.

Experiences of Postcardiotomy Assist: Pneumatic Ventricular Assist Device or Venoarterial Bypass with Percutaneous Cardiopulmonary Support

From October 1982 to the present, 16 patients have been supported by a pneumatic ventricular assist device (VAD). Since April 1990, we have introduced a venoarterial bypass (VAB) with percutaneous cardiopulmonary support (PCPS) system. This PCPS system was used in 12 patients. The long-term survival rate of PCPS cases (41%) was much better than that of VAD cases (19%). The main cause of death in VAD cases was multiple organ failure (MOF). Although VAB was initiated more recently than VAD, the duration on support was longer in the VAD group than in the VAB group. Because of the longer support duration and the presence of many patients with MOF, coagulopathy deteriorated more readily in the VAD group than in the VAB group. In the case of postcardiotomy cardiopulmonary bypass weaning or low-output syndrome (LOS), the VAB with PCPS system should be applied first under intraaortic balloon pumping assist because of its simplicity and low cost. Thereafter, VAD should be applied in cases refractory to VAB support.

EFFECTS OF CONCOMITANT USAGE OF MILRINONE AND CATECHOLAMINE FOR WEANING FROM CARDIOPULMONARY BYPASS

To estimate the effectiveness of concomitant usage of milrinone and catecholamine for weaning from cardiopulmonary bypass (CPB), a clinical study was made, in elective coronary artery bypass grafting (CABG) cases. 24 consecutive patients underwent elective CABG in our institute. In all cases, moderate hypothermia and cardioplegic(St. Thomas solution) cardiac arrest were performed. In 12 cases, continuous intravenous 0.25 microgram/kg/min of milrinone, 3 micrograms/kg/min of dobutamine (DOB) and dopamine (DOA) as the initial doses, were used concomitantly as inotropic agents (Group-I). The same initial doses of catecholamine (DOB and DOA) as the Group-I were administered in another 12 patients (Group-II). When the pump flow of CPB decreased to a half, these drugs were administered in both groups. Hemodynamic data were measured before CPB, just after operation, 3, 6, 12, 24, 48, and 72 hours after operation. There were no significant differences in aortic and pulmonary artery pressure between both groups. However, cardiac index (CI) of the Group-I demonstrated significantly (p < 0.01) higher values than that of Group-II until 24 hours after surgery. Systemic vascular resistance index (SVRI) of the Group-I demonstrated significantly (p < 0.01) lower value than that of Group-II from 3 to 12 hours after operation. There were no significant differences in oxygen delivery (DO2) and oxygen consumption (VO2) between both groups. These results suggested that concomitant usage of milrinone and low dose catecholamine increased CI and decreased SVRI, and made weaning from CPB very easy, demonstrating excellent hemodynamics. This high potential phosphodiesterase inhibitor may be suitable for not only weaning from CPB but also post-cardiotomy cardiogenic shock.

Clinical evaluation of the Gyro Pump C1E3 as a cardiopulmonary bypass pump.

The Gyro Pump C1E3 is a new centrifugal pump with numerous features, including a ceramic pivot bearing system, secondary vanes, and an eccentric inlet port. To evaluate its biocompatibility, antithrombogenicity, and produced hemolysis, we used the Gyro Pump during cardiopulmonary bypass (CPB) for coronary artery bypass grafting (CABG) cases to compare it with the BioMedicus pump. From September 1998 to February 1999, 30 consecutive patients underwent CABG under conventional CPB. Fifteen patients were supported by the Gyro Pump C1E3 (Group G), and the remaining 15 patients, by a BioMedicus BP-80 pump (Group B). In both groups, flow rate was equivalent. Blood samples were taken as follows: preoperative, 60 minutes after the end of the procedure, and at postoperative days (POD) 0, 1, and 2. We evaluated the plasma free hemoglobin (free Hb) as an indication of hemolysis; beta-thromboglobulin (beta-TG) and platelet factor four (PF-4) as an indication of platelet deterioration; C3, C4, CH50 for complement activation; coagulation parameters, fibrinolytic factor, thrombomodulin, nitric oxide (NO), and endothelin as an indication of endothelial deterioration. This was the first clinical sized Gyro Pump CIE3. De-airing from the pump was easily accomplished via the eccentric oblique inlet port. The system, including its console, was easily and simply controlled. Perioperative laboratory data were not markedly changed in either group with demonstrated equivalence for biocompatibility and hemolysis. After pumping, no thrombus formation or pivot wear were observed inside the pump. This atraumatic, small centrifugal pump appears well suited not only for CPB but also for circulatory support.

Clinical Experience with Percutaneous Cardiopulmonary in Postcardiotomy Cardiogenic Shock

From April 1990 to June 1996, 14 patients who had been suffering from post-cardiotomy cardiogenic shock were supported by a heparin-coated percutaneous cardiopulmonary support (PCPS) system. Of these patients, 8 (57%) (group I) could be weaned from PCPS, and 6 (group II) could not. Of the group I patients, 7 were discharged from our hospital (long-term survival rate 50%). One patient died from cardiac rupture due to severe myocardial infarction. In group II, cerebral vascular damage was recognized in two cases and renal failure in three. As for aortic crossfclamp time and cardiopulmonary bypass (CPB) time, there were no significant differences between the groups. However, the time delay from initiation of CPB to that of PCPS in group I (212 min) was significantly shorter than that in group II (390min). This heparin-coated PCPS system was very simple and easy to control. It demonstrated long-term biocompatibility without systemic heparinization. Quicker application of this system is expected to play an important role in preventing severe complications, such as multisystem organ failure, and to obtain better clinical results.

Retrospective analysis of the clinical trends and current indications for perioperative intraaortic balloon pumping in high-risk coronary artery bypass surgery

We clinically evaluated the current indications for perioperative intraaortic balloon pumping (IABP) in high-risk patients undergoing coronary artery bypass grafting (CABG). Over the past 22 years, 196 CABG patients received perioperative IABP at our institution. We divided the 22 years into periods I–IV (earliest to latest) and investigated the annual changes in the indications for and mortality from IABP. In periods I and II, IABP was mainly employed for postoperative low-output syndrome (LOS) or perioperative myocardial infarction (PMI). The hospital mortality rate was 13.2%–18.5%. In period III, the mortality rate was markedly reduced by the use of preoperative scheduled IABP. In period IV, however, scheduled IABP was used less often for high-risk CABG, and IABP was mainly employed in patients having emergency CABG for acute coronary syndrome (ACS). The hospital mortality rate was reduced to 3.7%. In the last 2 years, 19 (65.5%) of 29 patients who received preoperative IABP had emergency CABG for ACS, while 27 high-risk CABG patients with poor left ventricular (LV) function or left main trunk (LMT) disease were treated successfully without scheduled IABP. There were no significant differences between the IABP and non-IABP patients in age, sex, number of bypasses, and aortic cross-clamp time. Because of improvements in anesthesia, operative techniques, perioperative management, and cardioplegic solutions, preoperative support with IABP is less often needed for high-risk CABG, except in patients undergoing emergency surgery for ACS.

A case of coronary arterial fistula orginating from both coronary artery and draining to the right atrium

We encountered a case with bilateral fistulas of coronary arteries into the right atrium, a rare cardiac anomaly. The case was a 17-year-old woman, who visited our hospital at the age of 11 because of fever. At that time, the patient was diagnosed as having a left coronary artery-right atrial fistula through cardiac catheterization (CAG). When the patient developed staphylococcus infected endocarditis at the age of 16, a thick fistula of the coronary artery, directly running from the deformed left coronary arterial sinus, a fistula of the left circumflex branch, and also a fistula of the right coronary artery into the right atrium were detected by CAG. The outlets of these fistulas were closed from the inside of the right atrium under artificial cardiopulmonary circulation and cardiac arrest, and each fistula was ligated at the outside of cardiac chambers. At that time, we took particular care that any branch of the sinuatrial node was not injured. Although all fistulas were confirmed to be closed by postoperative CAG, and no evidence of ischemia was detected by myocardial scintigraphy, deformity of the left coronary arterial sinus remained, requiring further follow up.

Post-Cardiotomy Assist: Pneumatic VAD or PCPS-VAB?

Several types of mechanical circulatory support devices are currently available for profound heart failure in conjunction with open heart operations [1,2]. Pneumatic ventricular assist devices (VADs) have been employed postoperatively in more than 200 patients in Japan and have established a reputation as powerful assist devices in the treatment of heart failure [3]. In recent years, percutanous cardiopulmonary support (PCPS) systems have been introduced as easily used support devices in both surgical and medical fields [4]. As of September 1994, pneumatic VADs had been employed in 16 postcardiotomy patients in our department, and a PCPS system for veno-arterial bypass (VAB) had been employed in 14 postcardiotomy patients. Here, we review our experience with the pneumatic VAD system and the PCPS-VAB system and compare the results to evaluate their feasibility for post-cardiotomy mechanical support.

Clinical Applications and Problems of Pneumatic Pulsatile Ventricular Assist Devices

Since October 1982, we have employed a pneumatic ventricular assist device (VAD; Nippon Zeon, Tokyo, Japan) for profound heart failure in 16 post-cardiotomy settings. The etiology of the underlying diseases was ischemic in four patients, valvular in six, combined ischemic and valvular in four, and congenital in one, and “cardiomyopathy” in one patient. Average assist duration was 86 h, with left side assist being employed in 13 patients and right side assist in 3 patients. Weaning rate from the device was 66% and survival rate was approximately 20%. Causes of death were: multiple organ failure in 40%, ventricular failure in 25% and other causes in the remaining patients. Infection and thromboembolic complications were not observed during assistance. Optimization of assist flow was achieved by monitoring hemodynamic and echo-cardiographic data. Hemodynamic criteria for weaning from the device were also established; cardiac index (CI) > 2.51/min/m2, pulmonary capillary wedge pressure (PCWP) < 15 mmHg, etc. Monitoring of the coagulation system has also been important for avoiding multi-organ failure and achieving long-term survival. Comparisons of pulsatile and nonpulsatile devices have been considered. The results suggest that this system, which is currently available commercially, is versatile for use in profound heart failure in the postcardiotomy setting and could also be employed as a short-term or intermediate-term device in an emergency setting and in bridge-to-transplant patients.