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.     

Usefulness of postoperative percutaneous cardiopulmonary support using a centrifugal pump: retrospective analysis of complications

Between January 1992 and December 1997, we employed percutaneous cardiopulmonary support (PCPS) using a centrifugal pump in 25 patients. In 21 of them, PCPS was used postcardiotomy. These patients could not be weaned from cardiopulmonary bypass due to profound ventricular failure. As for the other 4 patients, PCPS was used preoperatively for profound cardiogenic shock, a thrombosed valve, a stuck valve, and pulmonary embolization. Nine patients (43%) were weaned from PCPS (Group 1), and 3 (14%) were discharged from the hospital. The other 12 patients (57%) had perioperative extensive myocardial infarction and could not be weaned (Group 2). The causes of death were bleeding and multiple organ failure (MOF) associated with ventricular failure. The reasons for MOF were perioperative massive transfusion and hepatic congestion caused by sustained ventricular failure. To increase the survival rate, complete hemostasis and prevention of increased central venous pressure by early use of PCPS are necessary.     

Acute and temporary ventricular support with BioMedicus centrifugal pump.

BACKGROUND: Short-term ventricular and pulmonary support can be provided by the Medtronic BioMedicus (Eden Prairie, MN) centrifugal pump, which is available in most cardiovascular surgery centers. This versatile pump can provide support during cardiopulmonary resuscitation, cardiopulmonary bypass, extracorporeal membrane oxygenation, and ventricular assistance. A common use of the pump is to provide ventricular assistance for patients after cardiotomy or cardiogenic shock. METHODS: From January 1986 to September 1995, 141 patients at The Methodist Hospital in Houston, Texas were placed on the BioMedicus centrifugal pump after postcardiotomy cardiac failure. Patient treatment and postimplant complications are discussed. RESULTS: Fifty-four percent of the patients were weaned; however, only 22% survived to discharge. There was a very high mortality rate in the early stage after support was discontinued, after weaning, and after device removal. CONCLUSIONS: A high incidence of complications and death is likely related to the period of attempted weaning from cardiopulmonary bypass before the initiation of ventricular support. When weaning a patient from the pump during cardiopulmonary bypass or during ventricular assistance, it is important to optimize preload, after-load, ventricular function, and cardiac rhythm. In patients who have had postcardiotomy support, avoiding fluid overload, low colloid oncotic pressure, hypoperfusion, and use of excessive inotropic and vasoactive medications improve results.     

Strategy of circulatory support with percutaneous cardiopulmonary support

We evaluated the efficacy and problems of circulatory support with percutaneous cardiopulmonary support (PCPS) for severe cardiogenic shock and discussed our strategy of mechanical circulatory assist for severe cardiopulmonary failure. We also described the effects of an alternative way of PCPS as venoarterial (VA) bypass from the right atrium (RA) to the ascending aorta (Ao), which was used recently in 3 patients. Over the past 9 years, 30 patients (20 men and 10 women; mean age: 61 years) received perioperative PCPS at our institution. Indications of PCPS were cardiopulmonary bypass weaning in 13 patients, postoperative low output syndrome (LOS) in 14 patients, and preoperative cardiogenic shock in 3 patients. Approaches of the PCPS system were the femoral artery to the femoral vein (F-F) in 21 patients, the RA to the femoral artery (RA-FA) in 5 patients, the RA to the Ao (RA-Ao) in 3 patients, and the right and left atrium to the Ao in 1 patient. Seventeen (56.7%) patients were weaned from mechanical circulatory support (Group 1) and the remaining 13 patients were not (Group 2). In Group 1, PCPS running time was 33.1 +/- 13.6 h, which was significantly shorter than that of Group 2 (70.6 +/- 44.4 h). Left ventricular ejection fraction was improved from 34.8 +/- 12.0% at the pump to 42.5 +/- 4.6% after 24 h support in Group 1, which was significantly better than that of Group 2 (21.6 +/- 3.5%). In particular, it was 48.6 +/- 5.7% in the patients with RA-Ao, which was further improved. Two of 3 patients with RA-Ao were discharged. Thrombectomy was carried out for ischemic complication of the lower extremity in 5 patients with F-F and 1 patient with RA-FA. One patient with F-F needed amputation of the leg due to necrosis. Thirteen patients (43.3%) were discharged. Hospital mortality indicated 17 patients (56.7%). Fifteen patients died with multiple organ failure. In conclusion, our alternate strategy of assisted circulation for severe cardiac failure is as follows. In patients with postcardiotomy cardiogenic shock or LOS, PCPS should be applied first under intraaortic balloon pumping (IABP) assist for a maximum of 2 or 3 days. In older aged patients particularly, the RA-Ao approach of PCPS is superior to control flow rate easily, with less of the left ventricular afterload and ischemic complications of the lower extremity. If native cardiac function does not recover and longer support is necessary, several types of ventricular assist devices should be introduced, according to end-organ function and the expected support period.     

Clinical effects of percutaneous cardiopulmonary support in severe heart failure: early results and analysis of complications.

Between January 1993 and December 2001, we employed percutaneous cardiopulmonary support (PCPS) in 35 patients. PCPS was used for postcardiotomy in 25 of these patients who could not be weaned from cardiopulmonary bypass (CPB) because of severe cardiogenic shock. In the other 10 patients, PCPS was used for a non-surgical disease. Twenty-nine patients (82.9%) were weaned from PCPS, and 28 (80.0%) survived. The other 7 patients (20.0%) died due to postoperative complications. The causes of death were multiple organ failure (MOF) due to wound bleeding, low cardiac output syndrome (LOS), myonephropathic metabolic syndrome (MNMS) with severe lower limbs ischemia, cerebrovascular accident (CVA), and sepsis. The first cause for the complications was postoperative sustained severe heart failure. To improve the survival rate, it was necessary to prevent bleeding and begin PCPS at an earlier stage.     

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

Abstract: 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.     

Outcome of the perioperative use of percutaneous cardiopulmonary support for adult cardiac surgery: factors affecting hospital mortality

Percutaneous cardiopulmonary bypass support (PCPS) has become a widespread standard modality for the treatment of circulatory collapse; however, its clinical use for postcardiotomy low cardiac output syndrome (LOS) has been reported to be unsatisfactory. We reviewed the clinical outcomes of twenty-three patients undergoing cardiac surgery and treated with PCPS. Solitary coronary artery grafting was undertaken for nine patients, while three had concomitant procedures. The remaining patients underwent valvular surgery. The indications for PCPS were preoperative shock in two patients and postcardiotomy LOS or shock in twenty-one patients. All patients except one underwent an intraaortic balloon pump. Sixteen of the twenty-three patients (69.6%) were weaned from PCPS and twelve patients (52.2%) reached hospital discharge. A univariate analysis revealed that risk factors for hospital mortality were age older than seventy years (P = 0.05), PCPS running time (P = 0.017), low cardiac function at the institution of PCPS (P = 0.004), and urine output within the initial 24 h (P = 0.041). The cardiac index (CI) in survivors was improved within 24 h, and eleven of the twelve survivors were weaned off PCPS within 48 h, whereas ten of the twelve nonsurvivors required PCPS for more than 48 h (P = 0.0006). There is little possibility of weaning patients from PCPS who do not show any signs of hemodynamic recovery within 48 h after its institution. Limited use of PCPS within 48 h may be applicable for postcardiotomy patients, but other cardiopulmonary support, such as a left ventricular assist device, may be required when hemodynamic recovery is not obtained within 48 h.     

Clinical experience of a percutaneous ventricular support for profound heart failure following acute myocardial infarction--a case report]

Percutaneous biventricular support with centrifugal pump was applied to a 59-year-old man with profound heart failure following acute myocardial infarction. Direct coronary angioplasty was performed under percutaneous cardiopulmonary support (PCPS). After angioplasty, he could not be weaned from PCPS under IABP. We used percutaneous left ventricular support (PLVS) with transseptal left atrial cannulation. PLVS could not maintain effective assist flow and he developed a cardiogenic shock again. PCPS was added to PLVS, and percutaneous biventricular support was started. Assist flow ranged 1.7-3.0 L/min in PLVS, and 1.7-2.0 L/min in PCPS, and total assist flow was 3.4 L/min. Pulsatile pressure was obtained by adding IABP. The patient was successfully weaned from PCPS in 26 hours and PLVS in 118 hours. Patient is alive and well one year after PLVS. Combination of PLVS and PCPS is an effective ventricular support system, being less invasive than conventional method with thoracotomy, and may be useful for profound heart failure.     

Pulmonary embolectomy for acute massive pulmonary embolism under percutaneous cardiopulmonary support

Portable percutaneous cardiopulmonary support (PCPS) with heparin-coated circuits and a biopump was employed in a patient who had a massive pulmonary embolism with circulatory collapse after stripping of varicosities of the leg. Emergency pulmonary embolectomy was successfully performed. The main pulmonary incision was facilitated by cross-clamping of the main pulmonary arterial root. The bypass circuit was kept closed, and used with the normothermic beating heart without converting to conventional total cardiopulmonary bypass. Blood flow from the lung was removed by pump suction, stored in the reservoir, and intermittently returned to the venous circulation. Heparin was added to the circuits to keep the activated clotting time greater than 300 sec. In massive pulmonary embolism, PCPS is useful for preoperative, intraoperative, and postoperative support.     

Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure.

The reported clinical use of the Sarns centrifugal pump (Sarns, Inc./3M, Ann Arbor, Mich.) as a cardiac assist device for postcardiotomy ventricular failure is limited. During a 25-month period ending November 1988, we used 40 Sarns centrifugal pumps as univentricular or biventricular cardiac assist devices in 27 patients who could not be weaned from cardiopulmonary bypass despite maximal pharmacologic and intraaortic balloon support. Eighteen men and nine women with a mean age of 60.4 years (28 to 83) required assistance. Left ventricular assist alone was used in 12 patients, right ventricular assist in 2, and biventricular assist in 13. The duration of assist ranged from 2 to 434 hours (median 45). Centrifugal assist was successful in weaning 100% of the patients. Ten of 27 patients (37%) improved hemodynamically, allowing removal of the device(s), and 5 of 27 (18.5%) survived hospitalization. Survival of patients requiring left ventricular assist only was 33.3% (4/12). Complications were common and included renal failure, hemorrhage, coagulopathy, ventricular arrhythmias, sepsis, cerebrovascular accident, and wound infection. During 3560 centrifugal pump hours, no pump thrombosis was observed. The Sarns centrifugal pump is an effective assist device when used to salvage patients who otherwise cannot be weaned from cardiopulmonary bypass. Statistical analysis of preoperative patient characteristics, operative risk factors, and postoperative complications failed to predict which patients would be weaned from cardiac assist or which would survive.     

Clinical Experience with the Sarns Centrifugal Pump

Abstract: Since October 1986, we have had experience with 96 Sarns centrifugal pumps in 72 patients (pts). Heparinless left atrial to femoral artery or aorta bypass was used in 14 pts undergoing surgery on the thoracic aorta with 13 survivors (93%). No paraplegia or device-related complications were observed. In 57 patients, the Sarns centrifugal pump was used as a univentricular (27 pts) or biventricular (30 pts) cardiac assist device for postcardiotomy cardiogenic shock. In these patients, cardiac assist duration ranged from 2 to 434 h with a hospital survival rate of 29% in those requiring left ventricular assist and 13% in those requiring biventricular assist. Although complications were ubiquitous in this mortally ill patient population, in 5,235 pump-hours, no pump thrombosis was observed. Hospital survivors followed for 4 months to 6 years have enjoyed an improved functional class. We conclude that the Sarns centrifugal pump is an effective cardiac assist device when used to salvage patients otherwise unweanable from cardiopulmonary bypass. Partial left ventricular bypass using a centrifugal pump has become our procedure of choice for unloading the left ventricle and for maintenance of distal aortic perfusion pressure when performing surgery on the thoracic aorta. This clinical experience with the Sarns centrifugal pump appears to be similar to that reported with other centrifugal assist devices.     

Percutaneous left ventricular assist system using a modification of the Dennis method: Initial clinical evaluation and results

A percutaneous left ventricular assist system (PLVAS) using a modification of the Dennis method was developed and implemented in 8 patients. Transseptal cannulation was performed under biplane fluoroscopy and/or transesophageal echocardiogram without encountering any problems. All the patients were in a state of severe cardiogenic shock, caused by acute myocardial infarction in 5, cardiomyopathy in 2, and postcardiotomy in 1, and were on intraaortic balloon pump support and/or percutaneous cardiopulmonary support (PCPS), in the form of partial cardiopulmonary bypass. Three patients who developed concomitant right heart failure required additional PCPS. All the patients were supported at 3.0 to 4.0l/min for 76–284h for an average time of 159h. Three patients were successfully weaned from PLVAS and one of these patients, who had suffered an acute myocardial infarction, was discharged from hospital. The complications directly related to this system were minimal. Our observations led to the conclusion that PLVAS using our modification of the Dennis method is a simple, easy, and safe means of maintaining adequate systemic circulation in severely ill patients. As PLVAS is particularly effective for patients in cardiogenic shock following acute myocardial infarction, we believe that it will be applied routinely by many cardiac surgeons and cardiologists in the future.     

Hemolysis in Different Centrifugal Pumps

Abstract: Different types of centrifugal pumps cause different amounts of hemolysis based on shear stress and blood exposure time. However, the hemolytic characteristics of centrifugal pumps in each clinical condition are not always clear. We compared the hemolytic characteristics of one cone-type centrifugal pump (Medtronic Bio-Medicus BP-80) and 2 impeller-type centrifugal pumps (Nikkiso HMS-12 and Terumo Capiox) under experimental conditions simulating their use in cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), and percutaneous cardiopulmonary support (PCPS) as well as their use as left ventricular assist devices (LVADs). The normalized indexes of hemolysis (NIHs; grams free plasma hemoglobin per 100 L blood pumped) during use as LVADs were not significantly different among the 3 pumps. The BP-80 pump produced almost 3–fold more hemolysis than the HMS-12 and Capiox pumps during CPB, 3– to 4–fold more hemolysis during ECMO, and 5.5–fold more hemolysis during PCPS. The 2 impeller-type centrifugal pumps will therefore cause less hemolysis under high flow, high pressure difference (as in CPB) and low flow, high pressure difference (as in ECMO and PCPS) conditions than the cone-type pump.     

Clinical Experiences of Percutaneous Cardiopulmonary Support: Its Effectiveness and Limit

In recent years, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB) and postcardiotomy cardiac support. From April 1990 to March 1997, a percutaneous cardiopulmonary support (PCPS) system was used in 20 patients with an average age of 58 years (13 males and 7 females). They comprised 11 ischemic, 6 valvular, 2 aortic, and 1 congenital heart disease patients. Our PCPS system consists of a centrifugal pump (BioMedicus BP-80), an oxygenator, and a reservoir. The entire blood contacting surface, including that of the thin wall cannulas, is coated by heparin bonded materials. As a result of this new technology, this system can be used for the long term without systemic heparinization. No major critical thrombi were revealed inside the pumps or circuits. Of the 20 patients, 7 (35%) (Group 1) could be weaned from PCPS, and the remaining 13 (Group 2) could not. In Group 1 although 2 patients suffered from renal failure and pneumonia, respectively, both were discharged from our hospital. The long-term survival rate was 35%. In Group 2 cerebral vascular damage was recognized in 3 patients, renal failure in 4, multiple system organ failure in 4, bleeding in 2, arrhythmia in 1, and leg ischemia in 2. Pulse pressure was significantly elevated due to the recovery of the native heart in Group 1, 2 days after support. However, in Group 2, it did not elevate, and the left ventricular ejection fraction was less than 30 %, associated with high left atrial pressure. In conclusion, this heparin coated PCPS system was very simple and easy to control. It demonstrated long-term biocompatibility and was very effective in recovering deteriorated cardiac function. Quicker application of this system can play an important role in preventing severe complications and obtaining better clinical results. If long-term support is necessary, a ventricular assist device (VAD), which is more powerful, durable, and biocompatible, has to be applied instead of PCPS.     

Long-term application of percutaneous cardiopulmonary support system without systemic heparinization

Though the amount of systemic heparin sodium administration was reduced after the introduction of heparin sodium-coating material to percutaneous cardiopulmonary support system (PCPS), bleeding due to heparin sodium is still the one of the major complications. In 2 patients of postcardiotomy cardiogenic shock, we neutralized heparin sodium by protamine sulfate administration immediately after the institution of PCPS and did not perform systemic heparinization until hemostasis was secured. The time on PCPS without heparin sodium was 37 hours in 1 patient and 91 hours in another patient. While systemic heparin sodium was not administered, activated clotting time (ACT) ranged from 109 to 148 sec and the bypass flow rate was maintained in more than 2.5 l/min. The exchange of the devices was unnecessary during the assistance and the patients were successfully weaned from PCPS without major complications. We conclude that systemic anticoagulation can be avoided in the case of life-threatening hemorrhage.     

Surgical treatment with infarction exclusion technique and postoperative percutaneous cardiopulmonary support for a patient with ventricular septal perforation —A case report—

A 76-year-old woman was referred to our hospital because of postinfarction ventricular septal perforation (VSP). VSP occurred twelve days after acute myocardial infarction and resulted in interventricular shunt with Qp/Qs of 4.8. Because she suffered from pulmonary edema and oligouria, she underwent emergent surgical treatment after application of the intraaortic balloon pump. The infarction involved whole of right ventricle and the inferoposterior wall of left ventricle, and the location of the perforation was infero-septum with the size of 10 × 6 mm. A bovine pericardial patch was tailored in a triangular shape of approximately 7 × 7 × 5 cm. The base of the patch was sutured to the fibrous annulus of the mitral valve and medial margin of the patch was sewn to healthy septal endocardium. And the lateral side of the patch was sutured to the posterior wall of the left ventricle. Because of difficulty in weaning of the cardiopulmonary bypass, a percutaneous cardiopulmonary support system (PCPS) was inserted via femoral artery and vein with a flow support of 2.0 L/min. After 4 days support of PCPS, improvement of right ventricular function was detected by echocardiogram and PCPS was removed. While PCPS support, low dose heparin to maintain ACT level around 150 seconds was continuously administered. Any complication including bleeding and thrombosis was not remarkable. The patient was discharged on the 53th postoperative day, and is now doing well.     

Tamponade after open-heart surgery with percutaneous cardiopulmonary support.

A 56-year-old man presented with late cardiac tamponade appearing on 9 postoperative day after weaning from percutaneous cardiopulmonary support. He had been referred to our hospital for congestive heart failure. He underwent aortic valve replacement and fell into postcardiotomy low output syndrome. He could not be weaned from extracorporeal circulation, and we had to use an intraaortic balloon pump and percutaneous cardiopulmonary support. On postoperative day 9, percutaneous cardiopulmonary support was successfully withdrawn without problems, but he showed signs of superior vena cava syndrome after the cannulas were removed. An echocardiogram also showed cardiac tamponade. When the wound was reopened, a lot of old clots had compressed the right atrium and, after clot removal, the patient's hemodynamic state improved markedly. It is important to be aware that percutaneous cardiopulmonary support may conceal hemodynamic deterioration due to cardiac tamponade and to take care that a patient does not experience hemodynamic deterioration after percutaneous cardiopulmonary support withdrawal.     

An emergency aortic valve replacement for cardiogenic shock patient with severe aortic stenosis and regurgitaiton using percutaneous cardiopulmonary support

The percutaneous cardiopulmonary support system (PCPS) was used in a 64-year-old woman with cardiogenic shock due to sustained ventricular fibrillation (Vf) caused by severe aortic stenosis and regurgitation. The Vf attack was resistant to cardioversion and adrenaline for lack of left ventricular support by PCPS. She was transported to the operation theater with PCPS in situ and emergency aortic valve replacement was performed. Although preoperative cardiac resuscitation time was long (35 minutes), she was discharged from the hospital on foot without any neurological complications on 84th postoperative day. Because PCPS does not decrease left ventricular systolic stress in poorly contracting dilated heart, early surgical treatment is needed in patients with severely damaged heart.     

Successful repair of penetrating cardiac injury with chopstick; report of a case

We used percutaneous cardiopulmonary support (PCPS) to resuscitate a 54-year-old man who had stabbed himself in the left anterior chest with a chopstick. Chest computed tomography showed that the chopstick had penetrated the heart. As he was in shock due to the development of tamponade while waiting for emergency surgery, we immediately decided to initiate PCPS. After cardiopulmonary bypass was established through a median sternotomy replacing PCPS, the chopstick was removed and the stab wounds were closed by mattress sutures. The postoperative course was uneventful.     

Postoperative pulmonary bleeding and reperfusion pulmonary edema in an adult patient after repair of tetralogy of Fallot with pulmonary atresia--percutaneous cardiopulmonary support (PCPS) and lung protective ventilatory strategy

After total correction of tetralogy of Fallot, pulmonary atresia and major aorto-pulmonary collateral arteries, a 31-year-old man developed life-threatening pulmonary hypertension and reperfusion pulmonary edema, leading to pulmonary hemorrhage, right heart failure and hypoxia. Because of difficulty in weaning from cardiopulmonary bypass and in controlling hemorrhage from pulmonary arteries, we applied percutaneous cardiopulmonary support (PCPS) for 281 hours with strategy of delayed sternal closure (17 days) and a large quantity of transfusion. We also applied lung protective ventilatory strategy for reperfusion pulmonary edema (high PEEP, limited peak inspiratory pressure and recruitment maneuver). As the result, he was discharged alive without any major complications. We report our postoperative managements, in terms of 1) lung protective ventilatory strategy, 2) surgical control of pulmonary blood flow, and 3) evaluation of the cardiopulmonary function during PCPS for early weaning from PCPS.