The Jarvik 2000 Heart. Clinical validation of the intraventricular position.

OBJECTIVE: Heart failure is now a public health epidemic. Donor hearts are severely restricted in availability. Permanent mechanical circulatory support or bridge to myocardial recovery are emerging alternatives. After extensive laboratory experience we sought to evaluate the intraventricular Jarvik 2000 Heart in patients with endstage heart failure. METHODS: The Jarvik 2000 Heart is a novel thumb-sized left ventricular assist device (LVAD) which is fitted within the apex of the native left ventricle. A vascular graft off loads this to the descending thoracic aorta. The pump rotor spins at between 8000 and 12,000 rpm providing 5-6 litres blood flow per minute. We have used the device with skull-mounted power delivery for seven permanent implants and trans-abdominal drive line for ten bridge-to-transplant patients. RESULTS: All patients survived the operation. Three died from non-device related complications. Survivors had early resolution of heart failure with return to NYHA I/II. All had pulsatile circulation. The device was user-friendly and imperceptible to the patient. Both the pump and native left ventricle contributed to the cardiac output during exercise. Seven patients have been transplanted successfully. All explanted devices were free from thrombus formation. Two permanent implant patients left hospital as early as 3 weeks postoperatively. CONCLUSIONS: The Jarvik 2000 is an effective user-friendly LVAD which allows early discharge from hospital. The intraventricular position has distinct advantages especially through absence of an inflow cannula. Synergy develops between the LVAD and native left ventricle. Early experience suggests that this may be a realistic LVAD to treat heart failure routinely in the outpatient setting.     

Initial experience with Impella RP in a quaternary transplant center

Right ventricular failure is one of the most common complications encountered after left ventricular assist device implantation and heart transplantation. It has been reported to have an incidence up to 30%. It increases morbidity and short-term mortality. Impella RP is a small pump that can provide up to 4L/min of flow. We analyzed all the patients with right ventricular failure that were treated with Impella RP in our institution. The Impella RP was implanted percutaneously in the catheterization laboratory guided by fluoroscopy. Overall, 7 patients required the implantation of an Impella RP due to right ventricular failure: 2 after long-term LVAD, 3 presented with acute right ventricular failure immediately after LVAD implantation, and 2 needed it after heart transplantation. Regarding complications, we report 2 patients with hemolysis. Hemodynamic parameters as well as end-organ perfusion and inotropic requirements improved after the insertion of the Impella. Overall, 30-day survival is 58%. Median time of support was 9 (5–19) days. RV failure is one of the most challenging complications after LVAD implantation and heart transplantation. The major challenge is the timing of implantation. The minimally invasive nature of the Impella RP facilitates de-escalation of treatment and paves the road to recovery. Impella RP proved useful in facilitating ECMO wean. Used in a prompt manner alongside the ease of implantation and the minimal rate of complications, Impella RP seems to be an appropriate device to tackle RV failure providing enough flow to allow for recovery or escalation decision-making.     

Left ventricular function during support with an asynchronous pulsatile left ventricular assist device.

BACKGROUND: Left ventricular assist devices (LVADs) are frequently used to maintain patients with severe heart failure until heart transplantation becomes possible. Some patients may experience recovery of LV function during such support. Therefore, it is essential to be able to monitor changes in LV function in this setting. METHODS: We studied LV function in 10 patients (median age 34 years, 9 male) who had LVADs implanted because of severe heart failure due to dilated cardiomyopathy a median of 4 months previously. Median pre-implant ejection fraction was 27% and all patients had been on maximal medical therapy, including intravenous inotropic support, prior to insertion of the LVAD. RESULTS: During LVAD support there were cyclical variations in LV dimensions, fractional shortening (FS) and transmitral flow, related to changes in the phase relationship of the LV and the LVAD. The "best" FS occurred when LV systole coincided with device filling and the "worst" FS when LV systole coincided with device ejection. Median FS with the pump switched off was 18% (10% to 32%). Pump-off FS was significantly greater than the "worst" FS with the pump on (5%, p = 0.002), and similar to the "best" pump-on FS (19%, p = NS). CONCLUSIONS: LV function could be studied echocardiographically during LV support and brief periods of interruption in support. Function varied according to the phase relationship of the LV and LVAD. The "best" FS measured during LVAD support was more closely related to the FS with the device switched off than the "worst" pump on FS. The "best" pump-on LV function is therefore most representative of intrinsic LV performance and can be used as a guide to recovery and the potential need for pump-off studies.     

Continuous axial-flow left ventricular assist device (Jarvik 2000) maintains kidney and liver perfusion for up to 6 months

BACKGROUND: The Jarvik 2000 axial flow left ventricular assist device (LVAD), under development for the past decade, has the potential to support patients temporarily until cardiac transplantation or as a permanent circulatory support, without the size limitations of other implantable systems. METHODS: To assess its ability to perfuse the kidneys and liver, we monitored renal and hepatic function in 10 patients who received the Jarvik 2000 LVAD as a bridge to transplantation. Left ventricular assistance was maintained for up to 214 days (> 6 months), and renal and hepatic function were monitored at least weekly. RESULTS: Renal function before LVAD implantation in these patients was normal in 7 (creatinine, < 1.5) and moderately impaired in 3 (creatinine, 1.2 to 2.0). Hepatic function was normal in 7 patients before LVAD implantation (total bilirubin< 1.2; serum glutamic-oxaloacetic transaminase (SGOT), < 40; serum glutamic-pyruvic transaminase (SGPT), < 50) and normal at the time of transplantation in all 10 patients. Of the 3 patients with abnormal hepatic function before LVAD implantation, 1 patient had also had moderate renal dysfunction. CONCLUSIONS: Despite reduced pulsatility, the Jarvik 2000 LVAD improves or maintains excellent renal and hepatic function during periods of circulatory assistance in patients awaiting transplantation.     

Right ventricular support after implantation of a Novacor Left Ventricular Assist Device

The objective was to determine which factors might help to predict the need for mechanical right ventricular support following insertion of a left ventricular assist device (LVAD). A retrospective analysis was performed on 24 patients with cardiomyopathies who had insertion of a LVAD as a bridge to heart transplantation at Presbyterian University Hospital during the period 1987 to 1991. Group 1 consisted of 18 patients who could be adequately supported with the LVAD alone, while Group 2 consisted of 6 patients who required additional support with a right ventricular assist device. Group 2 exhibited longer periods of hypotension on cardiopulmonary bypass, increased inotropic support and decreased right ventricular ejection fraction at time of chest closure post-LVAD.     

Initial experience with miniature axial flow ventricular assist devices for postcardiotomy heart failure

BACKGROUND: The recently introduced Impella Recover (Impella CardioSystems AG, Aachen, Germany) microaxial flow left and right ventricular assist devices (LVAD/RVAD) were evaluated as they provide circulatory support in the setting of postcardiotomy heart failure refractory to high-dose inotropic and intra-aortic balloon pump (IABP) support. METHODS: Between May 2002 and November 2002, the Recover LVAD was implanted in six patients (64 +/- 11 years) with acute left heart failure following coronary artery bypass procedures. Preoperative left ventricular (LV) ejection fraction was compromised (28% +/- 12%, 12% to 45%). Three patients presented with unstable circulation or cardiogenic shock following acute myocardial infarction, with a predicted mortality rate of 44% +/- 11% (EuroSCORE). Intraoperatively, severe heart failure was present with a more than 70% mortality rate predicted by the IABP score. The Recover RVAD and LVAD were combined to provide biventricular assist device (BVAD) support in one case of post-transplant graft failure. RESULTS: The Recover LVAD delivered blood flows of up to 5 L/min. A moderate degree of hemolysis and a reduction in platelet count were noted. Four patients were weaned from the LVAD after 169 +/- 34 hours, two of whom remain long-term survivors. Full recovery of graft function allowed weaning of the patient from BVAD support after six days. CONCLUSIONS: The initial experience with the Impella Recover VADs proved the new systems to be advantageous regarding the ease of implantation and device removal, low anticoagulation requirements, and advanced weaning features. In cases of severe heart failure, survival was improved by using LVADs when compared to that predicted by solely continuing IABP and drug support.     

Intraoperative transesophageal echocardiography is beneficial for hemodynamic stabilization during left ventricular assist device implantation in children

Background:  Mechanical circulatory support, with a left ventricular assist device (LVAD) is used in an increasing number of children for treatment of advanced heart failure as bridge-to-transplant. To date no data are available and no studies have defined the role of intraoperative transesophageal echocardiography (TEE) for hemodynamic stabilization during Centrimag Levitronix centrifugal pump implantation in children.
Methods:  Children with therapy resistant heart failure, undergoing LVAD implantation using Berlin Heart Excor pediatric cannula connected to a Levitronix Centrifumag pump, are intraoperatively monitored using an Oldelft micromultiplane TEE. Intraoperative TEE is specially used to monitor right ventricular (RV) and left ventricular (LV) function, correct position of the cannulas and response to pharmacological treatment.
Results:  In five consecutive patients RV function was assessed by TEE after starting LVAD Levitronix centrifugal pump. Initial RV failure presents with RV dilation and LV collapse. After titration of vasopressor and inotropic agents, RV contractility improved and thereby the filling of the LV. In one child, despite those measures the RV showed no improvement by TEE and a Levitronix right ventricular assist device to support the RV function was implanted as well. All patients could hemodynamically be stabilized before transport to the intensive care unit.
Conclusion:  The complex interaction of the RV and LV function and correct positioning of the cannula, during LVAD implantation in children with end-stage cardiac failure is improved by simultaneous visualization of cardiac performance of both ventricles and cannula positioning by means of intraoperative multiplane TEE.     

Is the New Infant Jarvik 2015 Suitable for Patients<8 kg? In Vitro Study Using a Hybrid Simulator

Our aim was to study the feasibility of implanting the Infant Jarvik 2015 in patients weighing less than 8 kg. The Infant Jarvik 2015 left ventricular assist device (LVAD) was tested in a hybrid simulator of the cardiovascular system reproducing specific patients’ hemodynamics for different patient weights (2–7 kg). For each weight, the sensitivity of the pump to different circulatory parameters (peripheral resistance, left ventricular elastance, right ventricular elastance, heart rate, and heart filling characteristics) has been tested repeating for each experiment a pump ramp (10 000–18 000 rpm). The increase in the pump speed causes a decrease (increase) in the left (right) atrial pressure, an increase (decrease) in the arterial systemic (pulmonary) pressure, an increase in the right ventricular pressure, a decrease (increase) in the left (right) ventricular volume, a decrease in the left ventricular cardiac output, an increase in the LVAD output and an increase in the right ventricular cardiac output (total cardiac output). Suction was observed for lower weight patients and for higher pump speed in the case of vasodilation, left ventricular recovery, bradycardia, right ventricular failure, and left ventricular hypertrophy. Backflow was observed in the case of left ventricular recovery at lower pump speed. In the hybrid simulator, the Infant Jarvik 2015 could be suitable for the implantation in patients lower than 8 kg because of the stability of the device respect to the cardio/circulatory changes (low frequency of suction and backflow) and because of the capability of the device to maintain adequate patient hemodynamics.     

Anesthetic management for implantation of the Jarvik 2000 left ventricular assist system

The Jarvik 2000 Heart(TM) is a left ventricular assist device that produces continuous nonpulsatile axial flow by means of a single, rotating, vaned impeller. Anesthetic and perioperative considerations of the Jarvik 2000 Heart(TM) differ from those of conventional assist devices. The Jarvik 2000 is implanted within the left ventricle through a left thoracotomy, which is aided by left lung isolation. A brief period of cardiopulmonary bypass and induced ventricular fibrillation facilitate implantation. Transesophageal echocardiography is essential to assure proper intraventricular positioning of the device and aortic outflow, confirmed by observation of aortic valve opening in the presence of adequate left ventricular volume. Because continuous flow devices function best in the presence of lower systemic and pulmonary vascular resistance, milrinone was preferentially used as an inotropic drug. In the first group of 10 patients to receive the Jarvik 2000, the pump provided a cardiac output of up to 8 L/min, depending on preload, afterload, and pump speed. There were no early perioperative deaths. The average support duration was 81.2 days; the range was 13-214 days. Seven of the 10 patients survived to transplantation. Survivors underwent complete physical rehabilitation during pump support. IMPLICATIONS: The Jarvik 2000 is a left ventricular assist device that produces continuous nonpulsatile axial flow by means of a rotating, vaned impeller. Because the anesthetic considerations differ from those of conventional left ventricular assist devices, we report the perioperative management of the first 10 patients who participated in a bridge-to-transplantation feasibility study of the Jarvik 2000.     

Timely use of a CentriMag heart assist device improves survival in postcardiotomy cardiogenic shock

Abstract Background: Postcardiotomy cardiogenic shock (PCS) is often fatal despite inotropic and circulatory support. We compared our experience with the CentriMag left ventricular assist device (LVAD) for patients with PCS at two time periods: in the operating room (OR) after unsuccessful weaning from cardiopulmonary bypass (CPB) and after transfer to the intensive care unit (ICU). Methods: We reviewed 22 patients’ records (13 men, nine women; age, 65 ± 12 years) who underwent open heart surgery (January 2004 to September 2009) and required LVAD support for PCS despite maximal inotropic and intra‐aortic balloon pump (IABP) support. In ten patients who could not be weaned from CPB despite high‐dose inotropic therapy (≥ 3 agents) and IABP support, the CentriMag was implanted in the OR (immediate group). The other 12 patients were weaned from CPB with high‐dose inotropic therapy and IABP but became increasingly unstable or had a cardiac arrest in the ICU, and the CentriMag was implanted for circulatory support (delayed group). Results: Preoperatively, the average ejection fraction was 40%± 12%, the creatinine level was 1.6 ± 0.6 mg/dL, and the European Systematic Coronary Risk Evaluation was 13.1 ± 4.6. The duration of CentriMag support was 5 ± 3 days. The immediate group had significantly better survival (7/10 vs. 2/12, p = 0.027), higher cardiac index (2.4 ± 0.3 L/min/m² vs. 1.7 ± 0.3 L/min/m², p = 0.001), and lower pulmonary capillary wedge pressure (20 ± 6 mmHg vs. 29 ± 8 mmHg, p = 0.024) than the ICU group. No perioperative complications related to device implantation occurred. Conclusion: In patients with PCS, timely placement of a CentriMag LVAD may increase the chance of eventual recovery. (J Card Surg 2011;26:548‐552)     

Experimental study of optimal driving mode in biventricular assist device

It has been known that the ventricular assist device (VAD) is effective in profound ventricular failure refractory to conventional drugs and the intra-aortic balloon pumping. The patients with biventricular failure required biventricular mechanical support for survival. Until recently, biventricular assist device (BVAD) were applied in a few instances unfortunately. In this experimental study biventricular failure was induced by pulmonary artery banding and ligation of left anterior descending coronary artery in 20 pigs, and the BVAD was operated and the optimal driving mode was examined on the flow ratio of the right and left pumps. Group I animals were treated with BVAD, in the condition pump flow ratio right ventricular assist device (RVAD): left ventricular assist device (LVAD) = 1: less than 0.5 (4 pigs), group II were RVAD:LVAD = 1:0.5 less than or equal to less than 1 (8 pigs), and group III were RVAD:LVAD = 1:1 less than or equal to (8 pigs). CVP and RVEDP were decreased by operating the BVAD in all groups. In the group I, the flow of LVAD was less than a half of that of RVAD and the condition of excess left ventricular preload was elicited, and left ventricular failure was accelerated and it was difficult to maintain the systemic circulation. In contrast, in group II and III, the left ventricular preload was decreased, and left ventricular failure improved, and it was maintain the systemic circulation. PCWP/CVP was calculated as a method to determine clinically the right and left pump flow.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preconditioning With Levosimendan Before Implantation of Left Ventricular Assist Devices

In this retrospective study, we investigated the impact of preconditioning of the right ventricle with the calcium sensitizer levosimendan immediately before left ventricular assist device (LVAD) implantation on outcome and survival. Nine consecutive LVAD patients (seven suffering from dilative cardiomyopathy and two from ischemic cardiomyopathy) with echocardiographic and invasive evidence of right heart insufficiency received levosimendan with 0.1 μg/kg body weight/min for 24 h before implantation of the assist device (seven HeartWare and two Jarvik 2000). Administration of levosimendan was safe and had not to be discontinued in any patient. We observed no relevant side effects. Twelve‐month survival after implantation of the LVAD was 89% representing a superior outcome compared with the fifth INTERMACS registry data with 75% survival. Two temporary extracorporeal membrane‐oxygenation implantations were necessary due to intraoperative right ventricular dysfunction. Only one patient died 5 weeks after LVAD implantation of multiorgan failure, five patients were successfully transplanted, and three patients underwent LVAD implantation for destination therapy. Levosimendan might improve clinical outcome and survival when used as pretreatment in patients with right heart insufficiency prior to LVAD implantation. However, we recommend a larger controlled trial in the future to confirm our preliminary results.     

Transesophageal echocardiographic evaluation in mechanically assisted circulation

Transesophageal echocardiography (TEE) has assumed an increasing importance in cardiothoracic surgery, but its use in patients with mechanically assisted circulation is unclear. We performed TEE in 11 patients: total artificial heart (TAH) 2, right ventricular assist device (RVAD) 2, left ventricular assist device (LVAD) 6, biventricular assist device (BVAD) 1. TEE was helpful in three areas. (1) selection of the assist device (AD): evaluation of left and right ventricular function allows differentiation of left, right or biventricular failure. (2) management of patient and optimization of pump performance: in all patients, correct cannula position and pump flow could be identified. Right ventricular failure in the presence of LVAD was found to cause hemodynamic instability in 4 patients. In 1 patient with repeated RV dilation and hypotension despite RVAD, TEE allowed optimal pump settings to be determined. (3) weaning from AD: Recovery of ventricular function can be assessed prior to weaning and repeatedly monitored during weaning. TEE in TAH is limited to problems such as identification of atrial thrombus or inflow valve dysfunction. We conclude that TEE is useful in the setting of mechanically assisted circulation for AD selection, improvement of patient management, optimization of pump performance and during weaning from AD.     

Successful experience in bridging patients to heart transplantation with the MicroMed DeBakey ventricular assist device

BACKGROUND: Pulsatile left ventricular assist devices are used with increasing frequency to bridge patients with end-stage heart failure to heart transplantation (HTx). Implantation of pulsatile devices is a cumbersome surgical procedure that is associated with major complications, such as bleeding, thromboembolism, and infection. Recently, a continuous axial flow left ventricular assist device (DeBakey ventricular assist device) has been introduced with the goal of reducing the incidence of major complications. METHODS: We reviewed our experience with 11 patients who received a DeBakey ventricular assist device axial flow pump for bridge to HTx from April 2000 through November 2001. RESULTS: Two patients (18.2%) died of multiple-organ failure while on left ventricular assist device support. Bleeding requiring thoracotomy occurred in 2 patients (18.2%). One patient had a minor neurologic event, and one patient developed left ventricular assist device thrombosis, which was successfully treated without pump exchange. Renal failure developed in 1 patient and hepatic dysfunction in 2 patients. There were no instances of right heart failure. No device, pocket, or drive-line infections occurred. Nine patients (9 of 11, 81.8%) had HTx within 51 +/- 49 days (range, 11 to 141 days) after left ventricular assist device implant. One patient died 29 days after HTx because of acute rejection. CONCLUSIONS: The continuous axial flow DeBakey ventricular assist device had reliable features, including a high rate of bridge to HTx. This device had low complication and system failure rates. We consider the DeBakey ventricular assist device a favorable alternative to pulsatile heart assist devices as a bridge to HTx.     

Preexisting mitral valve prosthesis in patients undergoing left ventricular assist device implantation

Experience with patients undergoing left ventricular assist device (LVAD) implantation with preexisting mitral valve prostheses is limited. Patients with mechanical heart valves might have an increased risk of thromboembolism; in patients with biologic valves, there might be a risk of structural deterioration of the leaflets. Out of 597 patients supported with a LVAD system between 2000 and 2009, 18 patients had mitral valve surgery prior to implantation. We excluded all patients below 18 years of age, those with postcardiotomy failure, and patients who had had mitral valve reconstruction. Only 1% of the studied patient population (n= 6) had mitral valve replacement. The mitral valve implantation has been performed 7.4 ± 9.4 years prior to LVAD insertion. None of the valves (one biologic, five mechanical) were exchanged or explanted. LVAD implantation was done either with left lateral thoracotomy (n= 5) or with midline resternotomy (n= 1). Temporary right ventricular assist device support was necessary in one case (16.6%); 30-day mortality was 16.6% (n= 1). Median support time was 14 ± 15 months. Two patients received heart transplantation after 6 and 26 months on the device; four patients died on mechanical circulatory support after 1, 2, 5, and 40 months. No valve or pump thrombosis or other clinically relevant thromboembolic events were observed. Only a small number of patients (1%) had a preexisting mitral valve prosthesis prior to LVAD implantation. No severe adverse events were observed when the prosthesis was left in place. Attention should be paid to the anticoagulation regime.     

Conversion to Cardiopulmonary Bypass in Off-pump Coronary Artery Bypass Grafting: Its Effect on Outcome

The surgical outcome of patients requiring conversion to cardiopulmonary bypass (CPB) during myocardial revascularization using the less invasive surgical approach (LISA) was assessed. The LISA was recently introduced as a technique for complete myocardial revascularization without CPB. It combines avoidance of CPB with the versatility of a median sternotomy for access to all coronary vessels. We have previously demonstrated reduced risk-adjusted mortality and complications in off-CPB coronary artery bypass grafting (CABG) using LISA compared to standard myocardial revascularization. From January to December 1997, 1210 patients underwent isolated CABG at our institution. Of these patients, 832 (63%) were scheduled as on-CPB cases and 378 (37%) as off-CPB. Of the off-CPB patients, 48 were converted to CPB. Team A surgeons used LISA as their primary strategy for CABG whereas team B surgeons used off-CPB CABG in selected patients. Conversions were divided in three classes: Class I patients were converted when the surgeon considered complete revascularization impossible off-CPB; Class II patients were converted due to hemodynamic instability during the procedure; and Class III patients were converted due to graft malfunction, determined by flow measurements or clinical evidence. There were four deaths. All had perioperative infarctions and required intra-aortic balloon pump (IABP). Conversion to CPB occurred in up to 25% of patients scheduled for off-CPB CABG. When off-CPB cases are done using the comprehensive LISA technique and modern technology, conversion rates may be reduced to 11%. Conversion is in general well tolerated except when it is instituted for graft malfunction combined with hemodynamic instability or collapse.     

Cardiopulmonary bypass

The primary function of the cardiopulmonary bypass (CPB) machine is to provide oxygenated blood flow to the systemic circulation while providing the surgeon with a motionless, bloodless surgical field. The CPB circuit consists of a reservoir, blood pump, oxygenator, heat exchanger, arterial filter, cardioplegia delivery device and cannulae, interconnected by various sized tubing. The venous cannula directs blood away from the heart and lungs via the CBP circuit and the arterial cannula returns the oxygenated blood to the systemic circulation. A blood pump propels the blood volume forward through a membrane oxygenator and allows rapid transfusion of oxygenated blood back into the systemic circulation. The CPB flow needs to be enough to maintain an adequate cardiac output, therefore a flow of 1.8–2.2 litres/minute/m² is recommended when at normothermia, although these flows can be reduced if the temperature is less than 28°C. The mortality and neurological complications after cardiac surgery are similar using either normothermic or hypothermic CPB. Maintenance of anaesthesia on CPB is often achieved with a propofol infusion (sometimes with the addition of remifentanil), but the use of volatile anaesthetic is also possible through the CPB machine. A vaporizer can be attached to the CPB circuit and volatile anaesthetic delivered into the sweep gas passing through the oxygenator. A safety checklist before separation from bypass is essential, and it may include: optimal temperature, heart rhythm, de-airing, acid-base status, ventilation, electrolytes and patient position. If heparin was used to maintain anticoagulation, it should be reversed with protamine after the patient is stable off-CPB. Some patients require inotropic or mechanical support to facilitate ‘weaning’ from CPB.     

Aorto-pulmonary bypass shunt for intraoperative right ventricular support during LVAD implantation

We describe a simple modification of the cardiopulmonary bypass (CPB) circuit that allows selective intraoperative circulatory support of the right ventricle during left ventricular assist device (LVAD) implantation. The addition of a side branch to the arterial line and an intermediate line connector allows selective venting and perfusion through a cannula inserted in the main pulmonary artery. This modification of the CPB circuit allows for selective evaluation of right ventricular function, titration of inotropic support, and early identification of patients that require right ventricular assist device (RVAD) support.     

Implantable left ventricular assist devices can successfully bridge adolescent patients to transplant.

BACKGROUND: Left ventricular assist devices (LVAD) have been used successfully as a life-sustaining bridge to transplantation in adults with end-stage heart failure. Long-term implantable cardiac assist devices for smaller adolescent patients are not yet available in the United States. METHODS: This study reviews the experience with patients less than 21 years old that received HeartMate LVADs (TCI) at our institution. Twelve patients were implanted with 13 LVADs. The patients ranged in age from 11 to 20 years (mean 16 years). Body surface area ranged from 1.4 to 2.2 m2 (mean 1.8 m2). Patients were selected for LVAD placement based on eligibility for heart transplant and evidence of end-organ dysfunction. Device placement in small patients was facilitated with prosthetic graft abdominal wall closure. No patient received systemic anticoagulation. RESULTS: The duration of LVAD support ranged from 0 to 397 days (mean 123 days). Seven of the 8 patients eligible for discharge from the hospital with a vented-electric LVAD were supported at home while awaiting transplantation. Outcomes of LVAD support were: LVAD explantation in 2 cases (15%), expiration with LVAD in place in 3 cases (23%), and successful transplantation in 8 cases (62%). Complications included 4 patients with systemic infection, 3 re-operations for hemorrhage, 1 embolic event, and 1 intraoperative air embolus that proved fatal. One explanted patient required a subsequent LVAD and the other expired 4 months after explantation. Six of the 8 transplanted patients are alive and well with follow-up ranging from 8 to 43 months. CONCLUSIONS: Adolescent patients with heart failure can be successfully supported on a long-term basis to heart transplantation with the HeartMate LVAD. The wearable device allows for discharge home while awaiting transplantation. Device explantation without subsequent transplantation can be unpredictable. The incidence of thromboembolism remains low despite the absence of systemic anticoagulation. The technique of prosthetic graft closure of the abdominal wall facilitates the use of this device in smaller patients.     

Right ventricular dysfunction and organ failure in left ventricular assist device recipients: a continuing problem

BACKGROUND: Although right ventricular assist device (RVAD) use has declined with the introduction of inhaled nitric oxide and phosphodiesterase inhibitors (type III), right ventricular dysfunction (RVD) is still a serious problem in patients receiving left ventricular assist devices (LVAD). METHODS: We retrospectively analyzed Thoratec Vented Electrical LVAD recipients between June 1996 and September 1999. RVD was defined as inotropic requirement 14 days or more or need for RVAD postoperatively, or both. RESULTS: Sixty-nine LVAD recipients were analyzed. Twenty-one patients (30.4%) had RVD, with 1 patient requiring RVAD insertion, and there were 48 non-RVD patients. There were no significant differences between both groups for age, sex, etiology of congestive heart failure, days of support, and preoperative hemodynamics. Preoperative right ventricle stroke work index (mm Hg x m(-2) x L(-1)) had a trend toward being lower in the RVD group (4.1+/-3.2 versus 6.1+/-3.7, p = 0.06). A higher preoperative total bilirubin (mg/dL) was noticed in the RVD group (4.0+/-5.2 versus 2.1+/-1.7). The RVD group had a higher postoperative creatinine (2.2+/-1.4 mg/dL versus 1.5+/-0.8 mg/dL), incidence of continuous venovenous hemofiltration dialysis (73% versus 26%), transfusion of packed red blood cells (43.2+/-28.6 units versus 24.7+/-18.9 units), platelets (58.6+/-46.1 units versus 30.2+/-20.4 units), with longer intensive care unit length of stay (33.6+/-34.7 days versus 9.1+/-6.9) and higher mortality (42.8% versus 14.5%). When deaths were excluded, both intensive care unit and postoperative length of stay were significantly longer in the RVD group. CONCLUSIONS: RVD in LVAD recipients remains poorly identified and is associated with a high transfusion rate and end organ failure that results in increased intensive care unit and hospital length of stay, and a high mortality rate. Preoperative identification of risk factors for RVD may select patients who would benefit from a biventricular assist device and prevent the subsequent end organ failure.