Extracorporeal membrane oxygenation (ECMO) as lung or heart assist

Extracorporeal membrane oxygenation (ECMO) may serve as extracorporeal lung assist (ECLA) in patients with acute respiratory failure (ARF) or as extracorporeal heart assist (ECHA) in patients with low output syndrome (LOS) after open heart surgery. From 1988 to 1992 seven patients underwent ECMO in our hospital; four suffered from ARF and three from LOS. Various bypass techniques were employed. Two ARF patients, aged 58 and 18 years, had veno-venous bypass; in the latter, ECMO was reinstituted as a veno-arterial bypass one week after weaning. In a three-year-old boy, the ECMO outflow tubing was primarily connected to the pulmonary artery, and shortly afterwards relocated to the common carotid artery. In a 31-year-old man with ARF, and three LOS patients, a 56-year-old woman, and two men aged 68 and 70 years, ECMO was veno-arterial with direct access to the ascending aorta. A heparin-coated system was used, and all but one patient, who was treated with warfarin, received a daily low dose of heparin, which was withdrawn after from one to nine days.
Six patients were weaned off ECMO after 4.5 to 21 days. Three ARF patients recovered completely; the child died. In one LOS patient, ECMO was withdrawn due to a poor general condition. Two others were weaned off ECMO and the intra-aortic balloon pump, and the inotropic support was significantly reduced, but both died of multiple system organ failure. Although no firm conclusions can be drawn from these few case reports, the heparin-coated system used as ECLA appears promising, whereas ECHA seems to imply a poor prognosis in patients who are not candidates for cardiac transplantation.     

Clinical Application of the Ellipsoid Left Heart Assist Device

The ellipsoid left heart assist device (E-LVAD) was implanted in eight patients suffering from intra-operative heart failure. It was not possible to remove these patients from extracorporeal circulation following an intracardiac procedure; therefore, implantation of the E-LVAD was performed during extracorporeal circulation. The inflow connector was pushed forward from a purse-string suture on the right superior pulmonary vein, across the mitral valve and into the left ventricle. The outflow connector was joined to the ascending aorta. In two patients, the artificial heart chamber was removed after complete recovery of the circulation; these patients, however, later died. In six other patients, untreatable right heart failure developed and these patients died with the pump in place. It is concluded, therefore, that the right heart must also be mechanically supported during postoperative heart failure.     

Experimental and Clinical Ventricular Bypass During Acute Heart Failure

Mechanical support of the failing heart in the form of bypass of the left and right ventricles by roller pumps was used in 25 dogs with model cardiogenic shock. Early application of left ventricular bypass in acute heart failure normalizes the myocardial bioenergy state and promotes reversible changes in myocardial infrastructure as demonstrated by an increased surface area of mitochondrial cristae. On the basis of hemodynamics and morphology, we conclude that pump-aided bypass of ventricles without synchronization is a simple and effective method of circulation assistance. Mechanical support duration from 1 to 138 hours has been used in 10 patients following corrective heart surgery.     

CardioWest total artificial heart in a moribund adolescent with left ventricular thrombi

Bridge to transplant is a well-known strategy to enable patients with congestive heart failure to live until transplant. A 15-year-old boy with Beckers' muscular dystrophy and cardiomyopathy was accepted for heart transplantation. He suffered a cardiac arrest and was placed on extracorporeal membrane oxygenator. A paracorporeal biventricular assist device and a total artificial heart were considered for bridge to transplant. A CardioWest total artificial heart was chosen because of the patient's size. Multiple left ventricular thrombi were identified at the time of the ventriculectomy. The patient did well with the total artificial heart was transplanted and discharged home. The unknown presence of significant left ventricular thrombi raises the question of outcome with a paracorporeal ventricular assist device.     

Centrifugal Pumps as Left Ventricular Assist for Coronary Revascularization on a Beating Heart

During recent years, coronary bypass surgery has progressed toward minimizing invasiveness. One important feature of this approach is performing surgery on a beating heart. During the crucial phase of such surgery, the mechanical support of the heart with a left ventricular assist device (LVAD) is a possible option. During the period from October 1, 1994 until June 30, 1997, we employed a centrifugal pump system in 118 cases of coronary artery bypass graft (CABG) procedures with LVAD support (mechanically supported CABG [SUPPCAB]). A total of 179 distal anastomoses with an average of 1.5 ± 0.5 coronary anastomoses per patient was performed. Three types of pumps were used: 23 BioPump, 87 Isoflow, and 8 Capiox systems. The median time on mechanical support was 44 min (range, 16–116 min). The mean flow rate during support time was 3.5 ± 0.8 L/min, which results in a calculated flow of 1.7 ± 0.6 L/min/m² body surface area (BSA). The average flow was 3.2 ± 0.8 L/min with the BioPump and 3.7 ± 0.8 L/min with the Isoflow pump, respectively (p < 0.01). The mean arterial pressure during mechanical support was 75 ± 12 mm Hg. In 2 patients, the pump system was kept running postoperatively in the ICU. Eight of the patients received operations under resuscitation or in cardiogenic shock. Nine (7.9%) of the patients did not survive the early postoperative phase. For coronary revascularization of the anterolateral and diaphragmatic parts of the heart, the SUPPCAB procedure is feasible with excellent mechanical support of the heart by centrifugal pumps. Especially in high risk cases, this procedure can be recommended.     

风湿性瓣膜病合并冠心病的外科治疗

报告１９９１年１月至１９９５年１１月期间１５例风湿性瓣膜病合并冠心病病人瓣膜替换及冠脉桥术（ＣＡＢＧ）的体会。手术均在低温体外循环下进行。其中二尖瓣替换＋ＣＡＢＧ６例，主动脉瓣替换＋ＣＡＢＧ６例、双瓣替换＋ＣＡＢＧ３例，术后死亡３例，其余治愈出院，作者强调了术前明确诊断的重要性，并就冠脉搭桥、心肌保护、主动脉气囊反搏（ＩＡＢＰ）及药物的应用加以讨论。     

成人先天性心脏病合并冠心病的外科治疗

目的探讨年龄>40岁的先天性心脏病合并冠心病手术治疗的安全性和有效性。方法 2002年2月～2009年5月,26例先天性心脏病(房间隔缺损18例,室间隔缺损4例,房室管畸形3例,三心房1例)合并冠心病(冠状动脉造影显示:单支病变10例,双支病变9例,三支病变7例)接受心脏畸形矫治联合冠状动脉搭桥手术,22例体外循环下行心脏畸形矫治和冠状动脉搭桥术,4例食管超声引导下行房间隔缺损术中伞堵(intraoperative device closure,IODC)及非体外循环冠状动脉旁路移植术(off-pump coronary artery bypass,OPCAB)。冠状动脉旁路移植共完成46处远端吻合,同期行二尖瓣置换术2例,二尖瓣成形术3例,三尖瓣成形术5例,房颤射频消融术2例。结果 1例房室管畸形因肺部感染和多器官衰竭死亡,其余25例康复出院,无手术并发症。术后随访17～105个月,(57.6±24.7)月:1例术后18个月再发心绞痛,未接受再次医疗干预;术后患者心功能和肺动脉高压情况改善;4例杂交手术随访中未发现残余分流、血栓和封堵装置移位等并发症。结论外科治疗成人先天性心脏病合并冠心病效果良好。IODC联合OPCAB治疗房间隔缺损安全、有效。     

Intraoperative and Immediate Postoperative Management of Calves Undergoing Valve or Total Artificial Heart Implantation

The intraoperative and immediate postoperative management data were recorded in a series of twelve artificial device implantation operations in calves. Nine of these were valved conduit experiments not requiring cardiopulmonary bypass, and three were total artificial heart implantations in which bypass was needed. The intraoperative and immediate postoperative management procedures of this laboratory are described including anesthesia, respiratory and drug therapy, and cardiopulmonary bypass management. This paper shows how these procedures may aid in reducing the recovery times of research animals.     

Paracorporeal Assistance System for Restoring Cardiac Activity

Two series of experiments were conducted to assess the potential of artificial ventricular bypass in restoring cardiac activity. One series evaluated use of a paracorporeal left ventricle in 17 calves; the other evaluated biventricular bypass in 11 calves. Module pumps with a seamless blood chamber of polyurethane were used. Pump function and system parameters were controlled by a Sinus VK-2 control system. Assisted perfusion began with the induction of ventricular fibrillation. The experiments showed that left ventricular bypass was an effective method for long-term maintenance of the hemodynamics during fibrillation, leading to certain biochemical corrections and restored electrical activity and myocardial contractile function. The hemodynamic state was maintained at a higher level with biventricular bypass and was accompanied by a greater percentage of restored myocardial function. Uneven restoration of contractile activity in the left and right ventricles points to the need for adequate support of both ventricles.     

Development of Autonomous Paracorporeal and Implanted Artificial Heart and Circulatory Assist Systems

The development of autonomous systems for the artificial heart (AH) and for circulatory assistance (CA) has taken several directions. Studies relating to one direction--the development of paracorporeal and implanted systems based on thermal or electric motors--have been conducted at our institute in two stages, moving from stationary systems to totally implanted systems for long-term use. The development of these systems is described. Improvements in the linear solenoid motor, used in some of the first paracorporeal systems, enabled progress toward the development of implanted CA systems based on a reversing electrohydraulic actuator. Modifications were also made in the control system. Early animal testing of these systems indicated that they could be effective in unburdening the heart cavities during left and right bypasses. Full implantation, however, demanded that the devices have improved forms and dimensions and less weight. Smaller electromechanical systems are being developed, and we are experimenting with ways to increase the overall autonomy of the system. An orthotopic model of an implanted AH is promising. Experiments continue on the use of the body's own skeletal muscles to create a blood pump.     

Clinical Experience of Assisted Circulation with a Centrifugal Pump at Tokyo Women's Medical College

Abstract: In postpericardiotomy patients, the use of pulsatile pumps is limited in a semielective fashion to patients whose postoperative marginal hemodynamics are expected preoperatively. Since 1989, 25 patients have under-gone assisted circulation with a centrifugal pump: 15 (60%) were weaned from the pump, and 7 (28%) survived. In 1988, we heparin-coated the Bio-Pump using the Carmeda technique and developed a totally heparin-coated left heart bypass system together with heparin-coated cannulas and tubing. Four postpericardiotomy patients underwent left heart bypass with this system without heparin for 2 to 9 days. No thrombus was detected in the system. Left heart bypass with a centrifugal pump has been used as a supportive method in surgical repair of thoracic or thoracoabdominal aortic aneurysm. To over-come intraoperative hypothermia and hypoxia, we used a small membrane oxygenator with a heat exchanger in 11 patients, and postoperative recovery dramatically improved. We also developed a preassembled percutaneous cardiopulmonary support (PCPS) system with an automatic priming function using Terumo's straight path centrifugal pump and small membrane oxygenator in cooperation with the Terumo Corporation. This system was used in a patient with cardiogenic shock after acute myocardial infarction. The setup and priming took only 5 min, and 2.5-3.5 L/min of flow was obtained.     

Concomitant Cholecystectomy and Open Heart Surgery

Purpose Cholelithiasis may be present concomitantly with cardiac disease. We performed a retrospective study to verify the safety and efficacy of synchronous cholecystectomy and open heart surgery. Methods Between 1999 and 2004, we performed synchronous cholecystectomy and open heart surgery in nine patients (group A) and open heart surgery alone in 1248 patients (group B). Open heart surgery was performed with open cholecystectomy (OC) in seven (77.7%) patients and with laparoscopic cholecystectomy (LC) in two (22.2%) patients. One patient with unstable angina and acute cholecystitis underwent simultaneous procedures. The indications for open heart surgery were coronary artery disease in eight (88.8%) patients and severe aortic stenosis in one (11.2%) patient. Results In group A, the mean number of bypass grafts performed was 2.5 ± 0.5, the mean operative time was 348.4 min, and patients remained intubated for 25.7 ± 6.7 h. The mean intensive care unit (ICU) stay was 4.1 ± 1.6 days and the mean postoperative hospital stay was 19.2 ± 5.7 days. There was a significant difference between the two groups in these two variables. No intra-abdominal complications or mediastinitis occurred in the immediate postoperative period in the setting of concomitant procedures and the mortality rate was zero. Conclusion Synchronous cholecystectomy and open heart surgery can be performed safely in selected patients.     

Analysis of Clinical Factors for Survival After Left and Biventricular Bypass Using Centrifugal Pump Following Open Heart Surgery in Infants and Adults

A total of eight patients, including three infants, received left or biventricular assist using centrifugal pump (CFP) following open heart surgery. Three infants, aged 9-11 months and with complex cardiac lesions, were supported by left heart bypass (LHB) using pediatric type CFP for 63 h, 64 h, and 13 days. All were weaned from LHB, but long-term survival was not obtained, mainly due to complications. In five adult patients, LHB alone was used in three, and biventricular support in two for 33-240 h with three survivals. The factors related to unsuccessful recovery were delayed start of support and multiorgan failure.     

Mechanical Circulatory Support for Severe Heart Failure After Operation

To evaluate the clinical results of circulatory support for severe heart failure after operation, we examined 62 patients (39 males and 23 females) who underwent circulatory support for postoperative heart failure from 1984 to 1996. Their ages ranged from 22 to 78 (mean 52) years. In 62 patients, 35 had valvular, 25 had ischemic, and 2 had congenital heart disease. Postoperation, 29 patients underwent venoarterial bypass (VAB), 20 had biventricular bypass (BVB), and 8 had left ventricular bypass (LVB). The remaining 5 patients received a pulsatile left ventricular assist device (LVAD). The weaning and discharge rates of the patients by type of support were 51.7% and 31.0% with VAB, 75.0% and 55.0% with BVB, 87.5% and 37.5% with LVB, and 60.0% and 40.0% with LVAD, respectively. The complete results of this series (64.5% weaning rate and 40.3% discharge rate) were acceptable.     

Analysis of hemodynamic response with 1/R control on biventricular bypass goat

A conductance and arterial pressure based method (1/R control) to determine the cardiac output (CO) of a total artificial heart (TAH) was developed to provide a central nervous system with control over the output of TAH. In order to clarify the deference in hemodynamic response between natural heart and 1/R control, biventricular bypass was introduced in the goat. After 2 pneumatically driven sac-type blood pumps were connected to the natural heart, the pulmonary artery was totally clamped to acquire 100% right heart bypass, and the ascending aorta was stenosed to acquire about 60 to 90% left heart bypass; 1/R control was performed substituting the output of the right artificial heart for the CO. The results demonstrated that stable control could be achieved. A discrepancy was often seen between the pulse rate (PR) of the artificial heart and the heart rate (HR) in absolute value. However, the relative changes of PR were quite similar to that of HR for the most part, indicating that the responses of 1/R control were the duplication of natural cardiac responses in normal daily activity.     

胸部小切口心内直视手术810例临床应用

目的探讨胸部小切口在心内直视手术中的应用价值。方法1995年12月～2008年1月，经胸部小切口行心内直视手术810例，包括先天性心脏病660例，瓣膜病129例，心脏黏液瘤21例。经胸骨正中上段小切口手术36例，胸骨正中下段小切口59例，右胸骨旁小切口3例，右胸前外侧小切VI658例，右腋下小切口54例。其中382例在心脏跳动下手术。结果术后死亡12例，手术死亡率1．5％。术后呼吸机辅助（6．7±4．2）h，术后引流量（210±165）ml，术后住院时间（7．4±4．9）d，421例（52％）未输血。术后无胸骨裂开、纵隔感染。术后随访690例（85％），随访（48．2±25．3）月，无远期死亡。心功能Ⅰ级478例，Ⅱ-Ⅲ级212例，Ⅳ级0例，明显好于术前（310、438、62例，Z=-13．21，P=0．000）；心胸比率0．51±0．11（0．37～0．75），明显低于术前（0．53．4-0．08，t=4．065，P=0．000）；左心室射血分数0．63±0．11（0．36～0．75），明显高于术前（0．57±0．11，t=-10．529，P=0．000）。结论胸部小切口心内直视手术具有切口隐蔽美观、胸骨畸形及感染发生率低等优点，但必须选择适合的病例，应用必要措施改善显露，加上熟练的手术技巧，才能取得良好的手术及美学效果。     

Partial Artificial Heart (ALVAD) Use with Subsequent Cardiac and Renal Allografting in a Patient with Stone Heart Syndrome

The abdominal left ventricular assist device (ALVAD) is an order of magnitude more effective than conventional intra-aortic balloon pumping (IABP) in unloading and providing circulatory support to the failing left ventricle. This is a report of a unique case which demonstrates that in the absence of pulmonary vascular obstruction or constriction, the ALVAD can substitute for both left and right heart function. A 21-year-old patient with a congenital bicuspid aortic valve developed acute valvular endocarditis which rapidly progressed to congestive heart failure. An operation was undertaken, the mitral and aortic valves were excised and replaced by porcine heterografts, and a fistula from the right sinus of Valsalva to the right ventricle was closed. When coronary circulation was restored, irreversible ischemic contracture of the left ventricle, or "stone heart" syndrome, developed and emergency ALVAD or partial artificial heart implantation was effected. This device functioned as a total artificial heart for nearly six days, while a donor heart was sought. The patient then underwent removal of the ALVAD and cardiac and renal allografting. The transplanted heart functioned well, but the patient expired fifteen days later from gram-negative sepsis.     

Splenic injury during biventricular assist device support as bridge to transplantation

Biventricular assist device (BVAD) has been shown to be effective for bridge to heart transplantation with an acceptability low incidence of adverse effects in critically ill heart failure patients. We report the case of a 44-year-old man with severe acute ischemic heart failure who was supported with the Thoratec paracorporeal biventricular assist system. After an initial uneventful postoperative course the patient experienced a splenic rupture which required a splenectomy. The pathological mechanism of this outcome remains unclear. Two months after discharge, the patient underwent heart transplantation and had no postsplenectomy sepsis or thrombotic complications at the last follow-up.