Extracorporeal membrane oxygenation and Thoratec pneumatic ventricular assist devices as double bridge to heart transplantation

Introduction

Ventricular assist devices have benefited patients with end-stage heart failure as a bridge to heart transplantation (HTx). We present our experiment of HTx using extracorporeal membrane oxygenation (ECMO) with Thoratec pneumatic ventricular assist device (TpVAD).

Methods

From May 1996 to June 2011, among 410 patients who underwent HTx 23 required mechanical circulatory support (MCS) with implantation of the TpVAD and 15 (65%) of them received grafts.

Results

The 23 patients included 4 female and 19 male patients of age range 10 to 80 years. Eighteen (78%) of them needed ECMO before TpVAD implantation. Twelve (67%) were implanted with a TpVAD double bridge to HTx. The demand for MCS among patients with acute hemodynamic collapse has led to major improvements in the existing systems such as ECMO with double bridge to TpVAD.

Conclusion

We used ECMO as a rescue procedure for acute hemodynamic deterioration. However, during ECMO support, left ventricular afterload increased. If prolonged support is required, TpVAD might be required: 15 (65%) of patients supported by ECMO with TpVAD needed to a wait a suitable donor. We recommend the application of ECMO for short-term support (within 1 week), and TpVAD as a bridge for medium- or long-term support.     

Extracorporeal membrane oxygenation bridge to adult heart transplantation

Chung JC, Tsai PR, Chou NK, Chi NH, Wang SS, Ko WJ. Extracorporeal membrane oxygenation bridge to adult heart transplantation.
Clin Transplant 2010: 24: 375–380. © 2009 John Wiley & Sons A/S. Abstract: Extracorporeal membrane oxygenation (ECMO) can rescue some critical patients with circulatory collapse when intra‐aortic balloon pump (IABP) and ventricular assist devices (VAD) are not suitable. A subset of these patients can use ECMO for direct bridging, or indirect double bridging via VAD to heart transplantation (HTx). For these patients, we identified risk factors for unsuccessful ECMO bridging, with survival to receiving either HTx or VAD as the measure of success. The characteristics evaluated were age, sex, body mass index, pre‐ECMO cardiopulmonary resuscitation (CPR), IABP use, dialysis use, sequential organ failure assessment (SOFA) score, and the etiology of cardiomyopathy. From January 1995 to August 2007, there were 70 adult ECMO patients with the intent to bridge to HTx (male: 55, age: 46 ± 14 yr). Thirty‐one patients (44%) were successful in bridging. A stepwise multivariate logistic regression analysis found that age > 50 yr (p = 0.003), pre‐ECMO CPR (p = 0.001) and SOFA score > 10 at ECMO initiation (p = 0.018) were significant independent predictors of unsuccessful bridging. Direct VAD implantation, if possible, is preferable to double bridging in patients over 50 yr. Also, elective ECMO support before hemodynamic deterioration to cardiac arrest or multiple organ dysfunction would improve rates of successful ECMO bridging.     

Mechanical bridge with extracorporeal membrane oxygenation and ventricular assist device to heart transplantation

The aim of this study was to evaluate the effect of double bridges with extracorporeal membrane oxygenation (ECMO) and ventricular assist devices (VADs) in clinical heart transplantation. Between May 1994 and October 2000, 134 patients underwent heart transplantation at the National Taiwan University Hospital. Ten patients received ECMO or VAD support as bridges to transplantation. The ages ranged from 3 to 63 years. The indications included cardiac arrest under cardiopulmonary resuscitation in 2 and profound cardiogenic shock refractory to conventional therapy in 8 patients. Usually ECMO was first set up as rescue therapy. If ECMO could not be weaned off after short-term (usually 1 week) support, suitable VADs (HeartMate or Thoratec VAD) were implanted for medium-term or long-term support. Five patients received ECMO support as emergency rescue for 2 to 9 days, and then moved to Thoratec VAD for 8, 49, and 55 days, respectively, or centrifugal VAD for 31 days, or HeartMate VAD for 224 days. They all survived. The survival rate of double bridges with ECMO and VAD was 100%. In postcardiotomy cardiogenic shock, circulatory collapse from acute myocardial infarction or myocarditis, ECMO is the device of choice for short-term support. If heart transplantation is indicated, VADs should replace ECMO for their superiority as a bridge to heart transplantation. Our preliminary data of double bridges with ECMO and VAD revealed good results and were reliable and effective bridges to transplantation.     

Extracorporeal membrane oxygenation as a direct bridge to heart transplantation in adults

Objectives

Venoarterial extracorporeal membrane oxygenation (ECMO) use as a bridge to transplant is extremely infrequent in adults. We investigated patient outcomes of the use of ECMO as bridge to transplant.

Extracorporeal membrane oxygenation as a bridge to lung transplantation

The occurrence of severe graft failure after lung transplantation which appears refractory to conventional treatment represents a difficult situation with regard to the therapeutic strategies available. Of 17 patients undergoing single lung transplantation at our center, 2 developed early graft failure. In both, temporary artificial cardiopulmonary support by means of extracorporeal membrane oxygenation became necessary as a bridge to retransplantation. Both patients were successfully retransplanted after 8 h and 232 h, respectively, of extra-corporeal support. Postoperatively, there was a variety of complications. The first patient completely recovered from temporary severe cerebral dysfunction diagnosed as "locked-in syndrome". She was discharged from hospital on the 93rd postoperative day and remains alive and well 10 months after her operation. The other patient recovered well early after retransplantation. Later, however, airway problems developed, requiring the implantation of endotracheal stents. Cachexia and several episodes of viral pneumonia contributed to the progressive deterioration of her clinical status. She finally died after being hospitalized for 5 months after the original operation. These two cases illustrate the feasibility of using extracorporeal membrane oxygenation as a bridge to pulmonary transplantation.     

Left ventricular assist devices as bridge to heart transplantation: The Niguarda Experience

BACKGROUND: Congestive heart failure is the leading cause of death in Western countries. Heart transplantation currently is the only accepted therapy for patients with end-stage heart failure, but the supply of donor hearts is inadequate, and different mechanical circulatory support systems have been investigated as bridges to heart transplant. METHODS: Since April 1992, 53 patients (47 men, 6 women, aged 12 to 61 years) received left ventricle mechanical circulatory support as bridge to heart transplant. The two principal devices used were: the Novacor LVAS in 31 patients and the DeBakey VAD in 11 patients. RESULTS: All patients survived the operation. Mean duration of LVAD support was 2.8 +/- 5.6 months. Thirty-seven patients (71.1%) underwent heart transplantation. Twelve major bleeding episodes occurred in nine patients (16.9%). Globally, major and minor neurologic events occurred in 13 patients (24.5%). Ten patients (19.9%) assisted with the Novacor Wearable LVAS device were discharged at home while waiting for heart transplant (HTx). The mean follow-up of the 34 discharged transplanted patients was 45.3 +/- 37 months. Actuarial survival of transplanted patients while on LVAD was 91.0 +/- 4.9% and 83.4 +/- 8.5% at 1 and 5 years, respectively. No differences in post-transplant long-term survival and rejection and allograft vasculopathy occurred between patients transplanted with or without LVAD implanted. CONCLUSIONS: LVAD therapy proved to be effective in bridging patients with end-stage heart failure to HTx. While on LVAD support, patients assisted with implantable wearable devices could be discharged at home, ameliorating their quality of life. The excellent survival rate after HTx is concomitant with a low incidence of rejection and cardiac allograft vasculopathy.     

Extracorporeal membrane oxygenation is superior to right ventricular assist device for acute right ventricular failure after heart transplantation

Background

Acute right ventricular failure after heart transplantation is a life-threatening condition, and sometimes the use of mechanical circulatory support is inevitable. The aim of this retrospective study was to investigate the effectiveness of two different mechanical circulatory support systems for this indication.

Methods

From 1984 to 2003, 28 heart transplant recipients exhibited right ventricular failure resistant to drug therapy. Right ventricular assist device (n = 15) or extracorporeal membrane oxygenation (n = 13) was implanted to support the failing heart.

Results

Overall in-hospital survival was 43%. In the right ventricular assist device group, only 2 patients (13%) could be weaned from mechanical circulatory support compared with 10 patients (77%) in the extracorporeal membrane oxygenation group (p = 0.001). Retransplantation was necessary in 6 patients in the right ventricular assist device group and in 1 patient in the extracorporeal membrane oxygenation group (p = 0.049). There was no difference in patient survival between groups, but graft survival was significantly better in the extracorporeal membrane oxygenation group (p = 0.005).

Conclusions

In view of these results, extracorporeal membrane oxygenation seems to be the better option as mechanical circulatory support for right ventricular failure in heart transplantation.     

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.     

Extracorporeal membrane oxygenation as a bridge to pulmonary endarterectomy

Untreated severe chronic thromboembolic pulmonary hypertension has a poor prognosis ending with right heart decompensation and multiorgan failure. This case report demonstrates that it is possible to intervene in the terminal stages of chronic thromboembolic pulmonary hypertension and bridge patients to surgery and recovery using various forms of extracorporeal membrane oxygenation support.     

心脏移植前采用体外膜肺氧合循环支持过渡二例

目的：探讨等待心脏移植患者发生心源性休克时采用体外膜肺氧合（ECMO）循环支持过渡的可行性和有效性。方法：2例患者在等待心脏移植期间发生心源性休克，1例为限制型心肌病，另1例为扩张型心肌病，并发肝功能异常，药物治疗均无法控制心力衰竭和呼吸衰竭，遂紧急使用ECMO支持，等待心脏移植。使用Medtronic成人ECMO系统，采用股动脉、股静脉插管，ECMO系统使用肝素涂层表面和离心泵，流量30～50ml·kg^-1·min，激活全血凝固时间维持在160s左右，血温维持在36～37℃。流量随心肺功能改善情况进行调整，支持期间监测动脉血气、血浆游离血红蛋白、血小板、出血及凝血指标，以及股动脉插管侧下肢血液循环情况。结果：经ECMO支持后，患者的血流动力学稳定，血气各指标改善，循环、呼吸平稳，X线显示双肺清晰，肝功能异常的1例肝功能好转。ECMO支持期间未发生严重的并发症。2例患者分别支持了5d和3d，均顺利过渡到心脏移植，术后心功能Ⅰ级，未发生排斥反应，患者痊愈出院。结论：等待心脏移植患者发生心源性休克时，可采用ECMO循环支持过渡，安全、有效。     

Isolated left ventricular assist as bridge to cardiac transplantation

The electrically driven Novacor implantable left ventricular assist device has been implanted in six patients (four men and two women) since Sept. 7, 1984. In four of the six patients (67%) the device was a successful bridge to cardiac transplantation. One patient died of multiple organ failure and Candida sepsis after 16 days of support with the device. One patient died in the operating room of uncontrollable hemorrhage and biventricular failure caused by severe cardiac rejection. Three patients are alive with cardiac transplants 38, 17, and 10 months after transplantation. One patient died after cardiac transplantation of presumed sepsis. The Novacor left ventricular assist device performed in all cases without mechanical or electrical failure. Excluding the intraoperative death, assist duration ranged from 2 to 16 days. The cardiac index (synonymous with device output) ranged from 2.4 to 3.4 L/min/m2. No embolic events (cerebrovascular or systemic) occurred during assistance with the device. Minimal red cell hemolysis was documented during the period of support. The Novacor left ventricular assist device is a safe and effective bridge to cardiac transplantation in patients with refractory cardiogenic shock.     

Diaphragmatic hernias associated with ventricular assist devices and heart transplantation

BACKGROUND: Diaphragmatic hernias in heart transplant recipients with prior left ventricular assist device (LVAD) placement are a potentially life-threatening complication. This review examined the incidence, diagnostic strategies, surgical management, and prevention of diaphragmatic hernias in these patients. METHODS: A retrospective review of patients receiving a Thoratec HeartMate (Thoratec Laboratories Corp, Pleasanton, CA) LVAD who developed a diaphragmatic hernia after VAD explantation and orthotopic heart transplantation (OHT). Two groups were identified and their results compared. In the early group, the diaphragmatic defect was not closed at the time of OHT and VAD explantation, while in the late group the defect was closed. RESULTS: In the early group, between September 1995 and November 1999, a total of 61 HeartMate LVADs were placed intraperitoneally as a bridge to transplantation, and 44 of those patients went on to OHT. Of these patients, 7 of 44 (15.9%) developed a diaphragmatic hernia after transplantation. Five of the patients underwent successful surgery by laparotomy without recurrence. Two patients with asymptomatic diaphragmatic hernia await repair. After a modification in diaphragmatic closure after VAD explantation at the time of OHT, in the late group between November 1999 and July 2002, 29 HeartMate LVADs were placed and 23 patients went on to OHT. There has been one diaphragmatic hernia (1 of 23, 4.3%) in this group. CONCLUSIONS: Diaphragmatic hernia following VAD placement and heart transplantation requires an aggressive diagnostic and therapeutic approach in this immunosuppressed patient population. We recommend primary closure of all diaphragmatic defects at the time of OHT and VAD explantation to reduce the incidence of this complication.     

Ventricular assist devices as a bridge to heart transplantation or as destination therapy in pediatric patients

Purpose

Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report on our experience in the pediatric population.

Methods

Retrospective review of 27 consecutive children offered mechanical support with Berlin Heart as a bridge to heart transplant, and Jarvik 2000 as a destination therapy from February 2002 to October 2011.

Results

The median patient age was 4.8 years (range = 75 days to 20.5 years). The median patient weight was 18.6 kg (range = 2.9-63 kg). We divided the patients in two groups, including in group I patients assisted for bridging to heart transplantation and in group II patients with Duchenne's dystrophy assisted as destination therapy. In the group I, 11 patients required biventricular mechanical support (BVAD), but in all other cases, a single left VAD proved sufficient (56%). The median duration of VAD support was 48 days (1 to 192 days). The median pre-VAD pulmonary vascular resistance index (Rpi) was 5.7 WU/m² (3.5 to 14.4 WU/m²). Twelve patients (48%) were successfully bridged to heart transplantation after a median duration of mechanical support of 63 days (range = 2-168 days). Ten deaths occurred (40%), three for neurological complications, two for sepsis, two for multiorgan failure, and three other for device malfunctioning. Since 2007, the survival rate of our patients has increased from 33% to 75%, and the need for BVAD has decreased from 89% to 23%. In the group II, two patients with mean age of 15.3 years were assisted with Jarvik 2000, and both of them are alive in a follow-up of 10.4 months. In two patients with Rpi > 10 WU/m², unresponsive to pulmonary vasodilatator therapy, Rpi dropped to 2.2 and 2 WU/m² after 40 and 23 days of BVAD support, respectively. Six patients (32%) required at least one pump change. Of 12 patients undergoing heart transplantation, five developed an extremely elevated (>60%) panel-reactive antibody by enzyme-linked immunosorbent assay, confirmed by Luminex. All of them experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow-up of 34.4 months (45 days to 8.7 years).

Conclusions

Mechanical support in children with end-stage heart failure is an effective strategy as a bridge to heart transplantation with a reasonable morbidity and mortality. BVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance. The total implantable system opens a future scenarios for patients not eligible for heart transplantation.     

Pneumatic pulsatile ventricular assist device as a bridge to heart transplantation in pediatric patients

Despite the remarkable advances with the use of ventricular assist devices (VAD) in adults, pneumatic pulsatile support in children is still limited. We report on our experience in the pediatric population. A retrospective review of 17 consecutive children offered mechanical support with Berlin Heart as a bridge to heart transplant from February 2002 to April 2010 was conducted. The median patient age was 3.9 years (75 days to 13.3 years). The median patient weight was 14.1 kg (2.9–43 kg). Before VAD implantation, all children were managed by multiple intravenous inotropes and mechanical ventilation (14) or extracorporeal membrane oxygenation (3). All patients had right ventricular dysfunction. Nine patients required biventricular mechanical support (BVAD), but in all other cases a single left ventricular assist device proved sufficient (47%). The median duration of VAD support was 47 days (1–168 days). The median pre‐VAD pulmonary vascular resistance index (Rpi) was 5.7 WU/m² (3.5 to 14.4 WU/m²). Eleven patients (65%) were successfully bridged to heart transplantation after a median duration of mechanical support of 68 days (6–168 days). Six deaths occurred (35%), three for neurological complications, one for sepsis, and two others for device malfunctioning. Since 2007, the survival rate of our patients has increased from 43% to 80%, and the need for BVAD has decreased from 86% to 30%. In two patients with Rpi >10 WU/m², unresponsive to pulmonary vasodilatator therapy, Rpi dropped to 2.2 and 2 WU/m² after 40 and 23 days of BVAD support, respectively. Seven patients (41%) required at least one pump change. Of 11 patients undergoing heart transplant, four developed an extremely elevated (>60%) panel reactive antibody by enzyme‐linked immunosorbent assay, confirmed by Luminex. All of them experienced at least one acute episode of rejection in the first month after heart transplant, needing plasmapheresis. The survival rate after heart transplantation was 100% with a median follow‐up of 25.4 months (6 days to 7.7 years). Mechanical support in children with end‐stage heart failure is an effective strategy as a bridge to heart transplantation with a reasonable morbidity and mortality. BVAD support may offer an additional means to reverse extremely elevated pulmonary vascular resistance.     

Selection of candidates for a ventricular assist device as a bridge to heart transplantation

This study was undertaken to see how many people could receive the ventricular assist device (VAD) as a bridge to heart transplantation and to get selection criteria of the recipient. From January 1984 to December 1987, 9916 patients were admitted to our institute and 399 cases of them were dead. All dead cases were examined in terms of age, heart disease, other organ function, infection, and so on. There were 42 possible candidates for VAD, 31 men and 11 women. The average age was 50 years with a range from 22 to 63 years. Ten cases (23.8%) of them had the indication for VAD bridge to transplantation. The criteria for transplantable patients included the following three categories: I) Cardiogenic shock: Irreversible left or double ventricular failure with or without life-threatening dysrhythmia during IABP therapy--4 cases. II) End-stage valvular heart disease; Operation under VAD stand-by--2 cases. III) Postoperative refractory ventricular pump failure: Failure to wean from assist circulation after IABP trial or sustained ventricular failure under IABP support--4 cases. It was indicated that continuous precise evaluation of the deteriorating hemodynamics and the intensive care for major organ functions (renal, pulmonary, neurologic, hepatic, coagulation, etc.) were important to select the candidate for VAD bridge to heart transplantation.