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Circulatory Support (circulatory + support)
Kinds of Circulatory Support Terms modified by Circulatory Support Selected AbstractsExtended Mechanical Circulatory Support With a Continuous-Flow Rotary Left Ventricular Assist DeviceCONGESTIVE HEART FAILURE, Issue 2 2010Scott Harris DO Background LVAD therapy is an established treatment modality for patients with advanced heart failure. Pulsatile LVADs have limitations in design precluding their use for extended support. Continuous-flow rotary LVADs represent an innovative design with potential for small size and greater reliability by simplification of the pumping mechanism. Methods In a prospective multicenter study, 281 patients urgently listed (United Network for Organ Sharing status 1A or 1B) for heart transplant underwent implant of a continuous-flow LVAD. Survival and transplant rates were assessed at 18 months. Patients were assessed for adverse events throughout the study and for quality of life, functional status, and organ function for 6 months. Results Of 281 patients, 222 (79%) underwent transplant or LVAD removal for cardiac recovery or had ongoing LVAD support at 18-month follow-up. Actuarial survival on support was 72% (95% confidence interval, 65%,79%) at 18 months. At 6 months, there were significant improvements in functional status and 6-minute walk test results (from 0% to 83% of patients in New York Heart Association functional class I or II and from 13% to 89% of patients completing a 6-minute walk test) and in quality of life (mean values improved 41% with Minnesota Living With Heart Failure and 75% with Kansas City Cardiomyopathy questionnaires). Major adverse events included bleeding, stroke, right heart failure, and percutaneous lead infection. Pump thrombosis occurred in 4 patients. Conclusions A continuous-flow LVAD provides effective hemodynamic support for at least 18 months in patients awaiting transplant, with improved functional status and quality of life. [source] Myocardial Perfusion As Assessed by Positron Emission Tomography During Long-Term Mechanical Circulatory SupportCONGESTIVE HEART FAILURE, Issue 2 2006George V. Letsou MD Although mechanical circulatory support (MCS) can improve myocardial function in patients with advanced heart failure, its effects on relative myocardial perfusion are unclear. Using positron emission tomographic imaging techniques, the authors assessed relative myocardial perfusion in patients with ischemic or idiopathic cardiomyopathy who were receiving chronic MCS with a left ventricular assist device (pulsatile HeartMate [n=2] [Thoratec Corporation, Pleasanton, CA] or nonpulsatile Jarvik 2000 [n=4] [Jarvik Heart, Inc., New York, NY]). Relative myocardial perfusion was compared at lower and higher levels of MCS (50 vs. 100,110 ejections/min for the HeartMate and 8000 vs. 12,000 rpm for the Jarvik 2000). The size and severity of perfusion defects at rest and after dipyridamole stress were measured objectively and subjectively by computer algorithms and visual inspection, respectively. Relative myocardial perfusion increased >5% from baseline in only one of six patients when MCS was increased. No change in relative myocardial perfusion of >5% was seen in any of the other five patients, even after subsequent dipyridamole stress positron emission tomographic imaging. These pilot study findings suggest that the decreased metabolic requirements induced by ventricular unloading correspondingly decreased blood flow requirements to physiologically inactive myocardium. [source] Mechanical Circulatory Support for AMI and Cardiogenic ShockJOURNAL OF CARDIAC SURGERY, Issue 4 2010Yasir Abu-Omar D.Phil. The dismal prognosis associated with post-MI cardiogenic shock, allied with surgical and technological advancements, has shifted the treatment paradigm toward wider use of mechanical circulatory support devices (MCSD). Current experience demonstrates that better outcomes may be achieved with early MCSD deployment (prior to the onset of end-organ dysfunction). However, perceived limitations with existing devices mean that they remain infrequently applied. There is an urgent need for increased awareness of MCSD options among clinicians treating post-MI shock patients. (J Card Surg 2010;25:434-441) [source] Myocardial Failure Caused by Traumatic Dissection of Left Coronary System,Ventricular Recovery with Temporary Circulatory SupportJOURNAL OF CARDIAC SURGERY, Issue 3 2007Alexander Lauten M.D. The dissection involved the left coronary artery including peripheral segments of the coronary circulation. The patient was revascularized; however, she could not be weaned from cardiopulmonary bypass thereafter. An Impella microaxial hemopump was implanted and the patient's left ventricular function markedly improved during the following days. Eight days later hemodynamics had stabilized far enough to explant the device, after explantation the patient remained hemodynamically stable and free of inotropic support. The report intends to emphasize the potential of the myocardium to recover even after extensive infarction under temporary ventricular support and takes the Impella microaxial hemopump into consideration as a device that is technically easy to implant with no injury to the ventricle and thus associated with good properties for weaning. Surgeons should consider the device as short-term support in borderline indications. [source] Physiologic Benefits of Pulsatile Perfusion During Mechanical Circulatory Support for the Treatment of Acute and Chronic Heart Failure in AdultsARTIFICIAL ORGANS, Issue 7 2010Yulong Guan Abstract A growing population experiencing heart failure (100 000 patients/year), combined with a shortage of donor organs (less than 2200 hearts/year), has led to increased and expanded use of mechanical circulatory support (MCS) devices. MCS devices have successfully improved clinical outcomes, which are comparable with heart transplantation and result in better 1-year survival than optimal medical management therapies. The quality of perfusion provided during MCS therapy may play an important role in patient outcomes. Despite demonstrated physiologic benefits of pulsatile perfusion, continued use or development of pulsatile MCS devices has been widely abandoned in favor of continuous flow pumps owing to the large size and adverse risks events in the former class, which pose issues of thrombogenic surfaces, percutaneous lead infection, and durability. Next-generation MCS device development should ideally implement designs that offer the benefits of rotary pump technology while providing the physiologic benefits of pulsatile end-organ perfusion. [source] Prognostic Factors for Adult Patients Receiving Extracorporeal Membrane Oxygenation as Mechanical Circulatory Support,A 14-Year Experience at a Medical CenterARTIFICIAL ORGANS, Issue 2 2010Chinchun Lan Abstract Extracorporeal membrane oxygenation (ECMO) is a resource-consuming and highly invasive treatment. There were 1100 ECMO cases at the National Taiwan University Hospital between August 1994 and November 2008. Of these, 607 were adults (>18 years old) who received ECMO as mechanical circulatory support. In this study, patient characteristics and complications during the ECMO course were evaluated for their correlation with prognosis. The following factors were significantly different between survivors and nonsurvivors: age, coronary artery disease, diabetes mellitus, brain death, stroke during ECMO, the need for dialysis during ECMO, pre-ECMO infection, hypoglycemia, acidosis, alkalosis, the need for a distal perfusion catheter, and the amount of red blood cells transfused. Six independent predictors of mortality were identified: age, stroke, the need for dialysis during ECMO, pre-ECMO infection, hypoglycemia, and alkalosis. Our institution has comparatively extensive experience with adult patients, which may be quite different from other medical centers with respect to distribution of patient age. The findings should lead to better utilization of ECMO for adult patients in the future. [source] A Mathematical Model to Evaluate Control Strategies for Mechanical Circulatory SupportARTIFICIAL ORGANS, Issue 8 2009Lieke G.E. Cox Abstract Continuous flow ventricular assist devices (VADs) for mechanical circulatory support (MCS) are generally smaller and believed to be more reliable than pulsatile VADs. However, regarding continuous flow, there are concerns about the decreased pulsatility and ventricular unloading. Moreover, pulsatile VADs offer a wider range in control strategies. For this reason, we used a computer model to evaluate whether pulsatile operation of a continuous flow VAD would be more beneficial than the standard constant pump speed. The computer model describes the left and right ventricle with one-fiber heart contraction models, and the systemic, pulmonary, and coronary circulation with lumped parameter hemodynamical models, while the heart rate is regulated with a baroreflex model. With this computer model, both normal and heart failure hemodynamics were simulated. A HeartMate II left ventricular assist device model was connected to this model, and both constant speed and pulsatile support were simulated. Pulsatile support did not solve the decreased pulsatility issue, but it did improve perfusion (cardiac index and coronary flow) and unloading (stroke work and heart rate) compared with constant speed. Also, pulsatile support would be beneficial for developing control strategies, as it offers more options to adjust assist device settings to the patient's needs. Because the mathematical model used in this study can simulate different assist device settings, it can play a valuable role in developing mechanical circulatory support control strategies. [source] Toward Unification of Asian Pacific Countries for Circulatory Support: Founding of the Asian Pacific Society for Circulatory SupportARTIFICIAL ORGANS, Issue 7 2005D.MSc., Setsuo Takatani Ph.D. No abstract is available for this article. [source] Under-Utilization of Mechanical Circulatory Support in Canada: Why and What Can Be Done?ARTIFICIAL ORGANS, Issue 3 2004Tofy Mussivand Abstract:, In October of 2002, a workshop was held as part of the Canadian Cardiovascular Congress in Edmonton, Canada, entitled "Under-Utilization of Mechanical Circulatory Support in Canada. Why and What Can Be Done?" The workshop examined various issues related to the use of mechanical circulatory support devices in the Canadian context. Representatives from all Canadian centers with active mechanical circulatory support programs were invited to participate and participants included surgeons and cardiologists, as well as other affiliated health professionals. Opinions were solicited from the workshop participants and a series of recommendations were formulated. [source] Mechanical Circulatory Support and the Genomics Revolution?ARTIFICIAL ORGANS, Issue 2 2004Tofy Mussivand FRSC No abstract is available for this article. [source] Progress and Future Perspectives in Mechanical Circulatory SupportARTIFICIAL ORGANS, Issue 5 2001Yukiyasu Sezai Abstract: Progress in several types of artificial organs in the cardiovascular field has significantly contributed to advancements in cardiac surgery. Due to the progress of high technology in fields other than medicine, both cardiac surgery and artificial organs have shown rapid and remarkable advances. In recent years, several types of blood pumps have been developed that are widely used not only as the main pump of cardiopulmonary bypass but also for circulatory support of postcardiotomy cardiogenic shock. In this article, the progress and current status of percutaneous cardiopulmonary support systems and ventricular assist devices (VADs) are described. In addition, new centrifugal and axial pumps, which are compact and implantable clinical use devices, are introduced. I believe that by making developments toward the clinical application of artificial hearts or VADs, not only in Japan but also in cooperation with colleagues at various institutions throughout the world, we will be able to make some contributions to the progress in the field of cardiac surgery. In the 20th century, medical research showed remarkable advances, mainly in medical electronics and pathophysiology. However, in the next century, we have to focus on other research fields, namely artifical organs and gene technology. [source] Strategy of Circulatory Support with Percutaneous Cardiopulmonary SupportARTIFICIAL ORGANS, Issue 8 2000Mitsumasa Hata Abstract: 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. [source] Congenital Atresia of the Ostium of Left Main Coronary Artery: A Rare Coronary Anomaly, Diagnostic Difficulty and Successful Surgical RevascularizationCONGENITAL HEART DISEASE, Issue 5 2007Philip Varghese MRCS ABSTRACT We report the case of an 8-month-old infant who was referred for mechanical circulatory support (extracorporeal membrane oxygenation). Aortogram was compatible with the diagnosis of anomalous origin of left coronary artery to pulmonary trunk. A definitive diagnosis of atresia of the left coronary ostium was only established intraoperatively. Patient underwent successful surgical angioplasty with an autologous pericardial patch. [source] Myocardial Perfusion As Assessed by Positron Emission Tomography During Long-Term Mechanical Circulatory SupportCONGESTIVE HEART FAILURE, Issue 2 2006George V. Letsou MD Although mechanical circulatory support (MCS) can improve myocardial function in patients with advanced heart failure, its effects on relative myocardial perfusion are unclear. Using positron emission tomographic imaging techniques, the authors assessed relative myocardial perfusion in patients with ischemic or idiopathic cardiomyopathy who were receiving chronic MCS with a left ventricular assist device (pulsatile HeartMate [n=2] [Thoratec Corporation, Pleasanton, CA] or nonpulsatile Jarvik 2000 [n=4] [Jarvik Heart, Inc., New York, NY]). Relative myocardial perfusion was compared at lower and higher levels of MCS (50 vs. 100,110 ejections/min for the HeartMate and 8000 vs. 12,000 rpm for the Jarvik 2000). The size and severity of perfusion defects at rest and after dipyridamole stress were measured objectively and subjectively by computer algorithms and visual inspection, respectively. Relative myocardial perfusion increased >5% from baseline in only one of six patients when MCS was increased. No change in relative myocardial perfusion of >5% was seen in any of the other five patients, even after subsequent dipyridamole stress positron emission tomographic imaging. These pilot study findings suggest that the decreased metabolic requirements induced by ventricular unloading correspondingly decreased blood flow requirements to physiologically inactive myocardium. [source] The Role of Intraoperative Transesophageal Echocardiography in Heart TransplantationECHOCARDIOGRAPHY, Issue 7 2002Paval Romano M.D. The number of centers that perform heart transplants has increased rapidly in recent years. Although transthoracic and transesophageal echocardiography (TTE and TEE) are utilized frequently to diagnose and manage cardiac complications commonly found in this population postoperatively, little has been written about the routine use of intraoperative TEE. Intraoperative echo is ideally suited to identify acute complications during cardiac transplantation. This can include immediate signs of rejection, valvular abnormalities, and mechanical complications related to the surgical procedure. Many of these patients might require ventricular assist devices (VAD) to provide circulatory support, and intraoperative TEE can be used to verify correct positioning of the VAD hardware. In addition, many of the chronic complications that patients with heart transplants are at risk for may be serious yet asymptomatic. Therefore, a high quality, complete intraoperative echocardiographic study might serve as an important baseline to compare postoperative changes. [source] The Use of the Impellaź LP 2.5 Percutaneous Microaxial Ventricular Assist Device as Hemodynamic Support During High-Risk Abdominal SurgeryJOURNAL OF CARDIAC SURGERY, Issue 2 2010Rony Atoui M.D. In cases when these patients require mechanical circulatory support while undergoing emergent or elective operations, perioparative monitoring becomes of paramount importance.,(J Card Surg 2010;25:238-240) [source] A Simple Technique of Distal Limb Perfusion During Prolonged Femoro-Femoral CannulationJOURNAL OF CARDIAC SURGERY, Issue 2 2006Navid Madershahian M.D. A serious complication of prolonged femoral cannulation remains the ischemic injury of the distal limb. Subjects: To minimize the incidence of ischemia in the cannulated leg, we have begun to provide antegrade femoral blood flow by placing a vascular introducer percutaneously distal to the arterial cannula into the superficial femoral artery and connecting it to the side port of the arterial line. Conclusion: This technique of distal limb perfusion was found to be safe and effective in preventing lower limb ischemia for patients with prolonged femoral cannulation for extracorporeal circulatory support. [source] Developing a Comprehensive Mechanical Support ProgramJOURNAL OF CARDIAC SURGERY, Issue 3 2001David N. Helman M.D. As cardiac surgery centers appreciate that ventricular assist devices (VAD) can dramatically impact patient survival as a bridge to transplant or recovery, and possibly permanent therapy, increasing numbers will desire to establish mechanical support programs. A number of vital elements must be put in place in order to operate a successful mechanical support program. Of utmost importance is the assembly of a dedicated team focused on comprehensive care of critically ill patients in need of circulatory support. An ongoing commitment from anesthesiologists, cardiologists, nephrologists, and other support staff is essential. Selection of complementary assist devices should be made to cover the spectrum of required support scenarios, both short- and long-term. Outpatient therapy has become increasingly important in mechanical cardiac assistance and establishment of an office where "LVAD coordinators" see outpatients facilitates this aspect of the program. Critically ill patients in need of cardiac assistance may benefit from specialized medical therapies such as: (1) intravenous arginine vasopressin for vasodilatory hypotonsion; (2) inhaled nitric oxide for right heart failure; (3) aprotinin to reduce hemorrhage; and (4) early enteral feeding in an effort to reduce infectious complications and improve rehabilitation following VAD implantation. A regional network with spoke hospitals centered around a hub hospital with long-term VAD and heart transplant programs can improve survival of patients with postcardiotomy cardiogenic shock via early transfer to the hub hospital. In this article, we describe the components of our mechanical support program that have allowed us to successfully support patients with heart failure in need of circulatory support. [source] IgG classification of anti-PF4/heparin antibodies to identify patients with heparin-induced thrombocytopenia during mechanical circulatory supportJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 2 2007S. SCHENK Summary., Commercial immunoassays frequently detect anti-PF4/heparin antibodies during mechanical circulatory support (MCS), but only a small minority of patients develops heparin-induced thrombocytopenia (HIT). Whereas platelet functional tests can distinguish between platelet-activating and non-platelet-activating antibodies, commercial PF4-dependent immunoassays do not. Between 2003 and 2004, 113 patients were placed on MCS. Blood samples were obtained on postimplant day 5,7 for analyses by antibody assays and the functional heparin-induced platelet activation (HIPA) assay. Three distinct groups of patient sera were identified: platelet-activating anti-PF4/heparin antibodies (n = 10), non-platelet-activating anti-PF4/heparin antibodies (n = 53), and anti-PF4/heparin antibody negative (n = 50). Patients with platelet-activating antibodies had the highest risk for thromboembolic events (P < 0.005), whereas those with non-platelet-activating antibodies did not differ from antibody negative patients (P = 0.369). The enzyme-immunoassay and column agglutination assays, which cover all immunoglobulin classes, demonstrated adequate sensitivity and negative predictive value; yet, both lacked specificity with respect to the platelet-activating antibodies. If all antibody positive patients were further classified by an IgG-specific anti-PF4/heparin enzyme-immuno assay, specificity for platelet-activating antibodies increased. Whereas IgG-specific optical density (OD) values below 1.0 were likely for non-platelet-activating anti-PF4/heparin antibodies, higher values were progressively predictive for pathogenic platelet activation. The probability of the development of clinical HIT also increased steeply. In conclusion, platelet-activating anti-PF4/heparin antibodies are relatively common (about 9%) in patients on MCS and are associated with significantly higher thrombotic event rates. Low IgG-specific OD values (< 1.0) in the enzyme-immunoassay indicate low likelihood for the presence of platelet-activating antibodies. These results justify further validation so that anticoagulation during MCS becomes safer and adequate. [source] Evaluation of Repatriation Parameters: Does Medical History Matter?JOURNAL OF TRAVEL MEDICINE, Issue 1 2009Sjoerd Greuters MD Background Aeromedical repatriation of patients is an expanding service due to the growing number of travelers worldwide. Of these repatriated patients, a small number require specialized transportation due to severe medical complications. We evaluated the medical in-flight records of Dutch patients with severe disease or polytrauma who were repatriated by air from 1998 to 2002 via one of the largest Dutch alarm centers. We questioned how this Dutch population of repatriated patients is demographically distributed and whether this population is a priori at high risk for acute medical complications that need specialized medical attention. Results Seventy-seven of 115 repatriated patients were 50 years and older, of which most were male (73%). Fifty patients had no significant medical history, whereas the remaining 65 patients suffered from comorbidities such as cardiovascular disease or cancer. In patients aged 18 to 49 years, one third of all patients were repatriated due to traumatic fractures. In the older age category, the main reasons for repatriation were cardiopulmonary incidents. There was an equal distribution in the primary medical reason for repatriation as defined by need for trauma/neurological support and ventilation or circulatory support. Of note, 82% of the 65 patients who traveled with a chronic disease condition were repatriated due to worsening of this particular condition. Conclusions The present study shows that an aeromedical repatriation service is frequently employed by travelers with a history of chronic disease who develop medical complications. The growing number of repatriated elderly patients and/or patients with preexisting comorbidities requires development of secure pretravel risk assessment and adaptation of the medical service level in foreign countries. [source] Heart Transplantation in the United States, 1998,2007AMERICAN JOURNAL OF TRANSPLANTATION, Issue 4p2 2009J. D. Vega This article highlights trends in heart transplantation from 1998 to 2007, using data from the Organ Procurement and Transplantation Network (OPTN) and the Scientific Registry of Transplant Recipients (SRTR). The number of candidates actively awaiting heart transplantation has declined steadily, from 2525 in 1998 to 1408 in 2007, a 44% decrease. Despite this decline, a larger proportion of patients are listed as either Status 1A or 1B, likely secondary to increased use of mechanical circulatory support. During this time, the overall death rate among patients awaiting heart transplantation fell from 220 to 142 patients per 1000 patient-years at risk; this likely reflects better medical and surgical options for those with end-stage heart failure. This trend was noted across all racial groups, both sexes, all disease etiologies (retransplantation excepted) and all status groups. Recipient numbers were relatively stable over the past decade. In 2007, 2207 transplants were performed, although the proportion of patients transplanted as Status 1A shifted from 34% to 50%. A trend toward transplanting more patients above 65 years of age was seen. Adjusted patient (and graft) survival at 3 months, 1, 5 and 10 years after transplantation has gradually, but significantly, improved during the same period; current patient survival estimates are 93%, 88%, 74% and 55%, respectively. [source] Development of a Disposable Magnetically Levitated Centrifugal Blood Pump (MedTech Dispo) Intended for Bridge-to-Bridge Applications,Two-Week In Vivo EvaluationARTIFICIAL ORGANS, Issue 9 2010Eiki Nagaoka Abstract Last year, we reported in vitro pump performance, low hemolytic characteristics, and initial in vivo evaluation of a disposable, magnetically levitated centrifugal blood pump, MedTech Dispo. As the first phase of the two-stage in vivo studies, in this study we have carried out a 2-week in vivo evaluation in calves. Male Holstein calves with body weight of 62.4,92.2 kg were used. Under general anesthesia, a left heart bypass with a MedTech Dispo pump was instituted between the left atrium and the descending aorta via left thoracotomy. Blood-contacting surface of the pump was coated with a 2-methacryloyloxyethyl phosphorylcholine polymer. Post-operatively, with activated clotting time controlled at 180,220 s using heparin and bypass flow rate maintained at 50 mL/kg/min, plasma-free hemoglobin (Hb), coagulation, and major organ functions were analyzed for evaluation of biocompatibility. The animals were electively sacrificed at the completion of the 2-week study to evaluate presence of thrombus inside the pump, together with an examination of major organs. To date, we have done 13 MedTech Dispo implantations, of which three went successfully for a 2-week duration. In these three cases, the pump produced a fairly constant flow of 50 mL/Kg/min. Neurological disorders and any symptoms of thromboembolism were not seen. Levels of plasma-free Hb were maintained very low. Major organ functions remained within normal ranges. Autopsy results revealed no thrombus formation inside the pump. In the last six cases, calves suffered from severe pneumonia and they were excluded from the analysis. The MedTech Dispo pump demonstrated sufficient pump performance and biocompatibility to meet requirements for 1-week circulatory support. The second phase (2-month in vivo study) is under way to prove the safety and efficacy of MedTech Dispo for 1-month applications. [source] Physiologic Benefits of Pulsatile Perfusion During Mechanical Circulatory Support for the Treatment of Acute and Chronic Heart Failure in AdultsARTIFICIAL ORGANS, Issue 7 2010Yulong Guan Abstract A growing population experiencing heart failure (100 000 patients/year), combined with a shortage of donor organs (less than 2200 hearts/year), has led to increased and expanded use of mechanical circulatory support (MCS) devices. MCS devices have successfully improved clinical outcomes, which are comparable with heart transplantation and result in better 1-year survival than optimal medical management therapies. The quality of perfusion provided during MCS therapy may play an important role in patient outcomes. Despite demonstrated physiologic benefits of pulsatile perfusion, continued use or development of pulsatile MCS devices has been widely abandoned in favor of continuous flow pumps owing to the large size and adverse risks events in the former class, which pose issues of thrombogenic surfaces, percutaneous lead infection, and durability. Next-generation MCS device development should ideally implement designs that offer the benefits of rotary pump technology while providing the physiologic benefits of pulsatile end-organ perfusion. [source] Initial Clinical Experience With the HeartMate II Ventricular Assist System in a Pediatric InstitutionARTIFICIAL ORGANS, Issue 7 2010William R. Owens Abstract In many adult cardiac programs, intracorporeal mechanical circulatory support has become a routine treatment for end-stage cardiac failure. For the pediatric population, options are often limited by a small body habitus. Even when an adolescent's weight may suggest adequate space for device implant, most intracorporeal adult devices remain too large for adolescents. The Thoratec HeartMate II (HM II) (approved by the FDA in April of 2008) is a small, noiseless device that is easily operated and monitored. By having an uncomplicated operating system and small percutaneous drive line, the HM II provides an opportunity for these patients to aggressively rehabilitate to become a better transplant candidate and also provides the potential to be discharged home. The two youngest patients ever to utilize the HM II are also the first two cases of using the HM II at a freestanding pediatric hospital. A 12-year-old, 53 kg, girl with dilated cardiomyopathy was supported for 85 days before receiving her heart transplant. The second patient, a 13-year-old, 149 kg, Hispanic male suffering from morbid obesity and dilated cardiomyopathy, was supported for 128 days. The HM II allowed for rehabilitation and nutritional education, resulting in this patient losing 50 kg before heart transplant. Despite both of these patients' size, their thoracic cavities were that of a preadolescent and thus techniques were developed to avoid morbidities like chest wall abrasion and bleeding. Because of differences between adult and pediatric patients and institutions, these cases provided unique challenges. However, as pediatric device therapy is now maturing, pediatric programs such as Texas Children's Hospital have begun to develop strategies for mechanical support that factor in patient's size and need for long-term or temporary support, utilizing the growing number of devices (i.e., Jostra Rotoflow, Tandem Heart PTVA, Thoratec CentriMag, Berlin Heart EXCOR, etc.) that are now available to children. [source] Prognostic Factors for Adult Patients Receiving Extracorporeal Membrane Oxygenation as Mechanical Circulatory Support,A 14-Year Experience at a Medical CenterARTIFICIAL ORGANS, Issue 2 2010Chinchun Lan Abstract Extracorporeal membrane oxygenation (ECMO) is a resource-consuming and highly invasive treatment. There were 1100 ECMO cases at the National Taiwan University Hospital between August 1994 and November 2008. Of these, 607 were adults (>18 years old) who received ECMO as mechanical circulatory support. In this study, patient characteristics and complications during the ECMO course were evaluated for their correlation with prognosis. The following factors were significantly different between survivors and nonsurvivors: age, coronary artery disease, diabetes mellitus, brain death, stroke during ECMO, the need for dialysis during ECMO, pre-ECMO infection, hypoglycemia, acidosis, alkalosis, the need for a distal perfusion catheter, and the amount of red blood cells transfused. Six independent predictors of mortality were identified: age, stroke, the need for dialysis during ECMO, pre-ECMO infection, hypoglycemia, and alkalosis. Our institution has comparatively extensive experience with adult patients, which may be quite different from other medical centers with respect to distribution of patient age. The findings should lead to better utilization of ECMO for adult patients in the future. [source] Animal Model Development for the Penn State Pediatric Ventricular Assist DeviceARTIFICIAL ORGANS, Issue 11 2009Elizabeth L. Carney Abstract:, In March 2004, the National Heart, Lung, and Blood Institute awarded five contracts to develop devices providing circulatory support for infants and small children with congenital and acquired cardiac disease. Since 2004, the team at Penn State College of Medicine has developed a pneumatically actuated ventricular assist device (VAD) with mechanical tilting disk valves. To date, hemodynamic performance, thrombogenesis, and hemolysis have been chronically evaluated in 16 animals, including 4 pygmy goats and 12 sheep. Major complications, mainly respiratory failure, have been encountered and resolved by a multi-disciplinary team. Multi-modal analgesia, appropriate antibiotic therapy, and attentive animal care have contributed to successful outcomes. Time after implant has ranged from 0 to 40 days. Most recently, a sheep implanted with Version 3 Infant VAD was electively terminated at 35 days postimplant, with no major adverse events. This report describes a successful in vivo model for evaluating a pediatric VAD. [source] Experience With the Levitronix CentriMag in the Pediatric Population as a Bridge to Decision and RecoveryARTIFICIAL ORGANS, Issue 11 2009Peter C. Kouretas Abstract Short-term mechanical circulatory support in the pediatric population with acute cardiac failure has traditionally been limited to extracorporeal membrane oxygenation given the limited availability of pediatric-sized pumps. The Levitronix CentriMag system (Thoratec Corporation, Pleasanton, CA, USA) offers expanded options for short-term support for this population. We report our experience with the successful use of the CentriMag in the pediatric population as a bridge to decision after postcardiotomy ventricular failure and as a bridge to recovery after heart transplantation. The first patient was bridged to a long-term HeartMate II (Thoratec Corporation) as a bridge to potential recovery. The second patient was supported after severe graft failure post heart transplantation, with a full recovery. The Levitronix CentriMag has proven to be a versatile, safe, and effective short-term circulatory support system for our pediatric patients. [source] Development of Mechanical Circulatory Support Devices in ChinaARTIFICIAL ORGANS, Issue 11 2009Wei Wang Abstract Myocardial dysfunction leading to low cardiac output syndrome is a common clinical pathophysiological state. Currently, the use of mechanical circulatory support (MCS) is an essential aspect of the treatment of patients with cardiac failure. Several groups in China are engaged in the design and development of MCS devices. These devices can be classified as pulsatile, rotary, and total artificial heart (TAH). There are two types of pulsatile pump, which are driven by air (pneumatic). One of these pumps, the Luo-Ye pump, has been used clinically for short-term support since 1998. The other is a push-plate left ventricular device, which has a variable rate mode. Various rotary devices are classified into axial and centrifugal pumps, depending on the impeller geometry. Most rotary pumps are based on the maglev principle, and some types have been used clinically. Others are still being studied in the laboratory or in animal experiments. Furthermore, certain types of total implantable pump, such as the UJS-III axial pump and the UJS-IV aortic valvo-pump, have been developed. Only one type of TAH has been developed in China. The main constituents of this artificial heart are two axial pumps, two reservoir tanks mimicking the right and left atria, flow meters, two pressure gauges, and a resistance adaptor. Although the development of mechanical assist devices in China is still in a nascent stage, a number of different types of MCS devices are currently being studied. [source] Computational Design and In Vitro Characterization of an Integrated Maglev Pump-OxygenatorARTIFICIAL ORGANS, Issue 10 2009Juntao Zhang Abstract For the need for respiratory support for patients with acute or chronic lung diseases to be addressed, a novel integrated maglev pump-oxygenator (IMPO) is being developed as a respiratory assist device. IMPO was conceptualized to combine a magnetically levitated pump/rotor with uniquely configured hollow fiber membranes to create an assembly-free, ultracompact system. IMPO is a self-contained blood pump and oxygenator assembly to enable rapid deployment for patients requiring respiratory support or circulatory support. In this study, computational fluid dynamics (CFD) and computer-aided design were conducted to design and optimize the hemodynamics, gas transfer, and hemocompatibility performances of this novel device. In parallel, in vitro experiments including hydrodynamic, gas transfer, and hemolysis measurements were conducted to evaluate the performance of IMPO. Computational results from CFD analysis were compared with experimental data collected from in vitro evaluation of the IMPO. The CFD simulation demonstrated a well-behaved and streamlined flow field in the main components of this device. The results of hydrodynamic performance, oxygen transfer, and hemolysis predicted by computational simulation, along with the in vitro experimental data, indicate that this pump-lung device can provide the total respiratory need of an adult with lung failure, with a low hemolysis rate at the targeted operating condition. These detailed CFD designs and analyses can provide valuable guidance for further optimization of this IMPO for long-term use. [source] Development of a Disposable Maglev Centrifugal Blood Pump Intended for One-Month Support in Bridge-to-Bridge Applications: In Vitro and Initial In Vivo EvaluationARTIFICIAL ORGANS, Issue 9 2009Takeshi Someya Abstract MedTech Dispo, a disposable maglev centrifugal blood pump with two degrees of freedom magnetic suspension and radial magnetic coupling rotation, has been developed for 1-month extracorporeal circulatory support. As the first stage of a two-stage in vivo evaluation, 2-week evaluation of a prototype MedTech Dispo was conducted. In in vitro study, the pump could produce 5 L/min against 800 mm Hg and the normalized index of hemolysis was 0.0054 ± 0.0008 g/100 L. In in vivo study, the pump, with its blood-contacting surface coated with biocompatible 2-methacryloyloxyethyl phosphorylcholine polymer, was implanted in seven calves in left heart bypass. Pump performance was stable with a mean flow of 4.49 ± 0.38 L/min at a mean speed of 2072.1 ± 64.5 rpm. The maglev control revealed its stability in rotor position during normal activity by the calves. During 2 weeks of operation in two calves which survived the intended study period, no thrombus formation was seen inside the pump and levels of plasma free hemoglobin were maintained below 4 mg/dL. Although further experiments are required, the pump demonstrated the potential for sufficient and reliable performance and biocompatibility in meeting the requirements for cardiopulmonary bypass and 1-week circulatory support. [source] | ||||||||||