A method for anticoagulation of children on mechanical circulatory support.

Anticoagulation of children on mechanical circulatory support presents a challenge. We implanted 28 devices in children and infants using a consistent anticoagulation protocol. We performed a retrospective review of all children implanted in our program with mechanical assist devices since 1997. Heparin, dipyridamole, and aspirin were used for anticoagulation and antiaggregation. Coagulation monitoring included thromboelastography (TEG), platelet aggregration studies, international normalized ratio, partial thromboplastin time, and platelet count. Twenty-eight children, ages 1 month to 16 years (mean 5.3; median 2.4 years), were implanted for 3-107 days (mean 27; median 17). Eighteen received left ventricular assist devices, seven received biventricular assist devices, and three received total artificial hearts. Adverse events during the 720 days of device support included the following: six (21%) reoperations for bleeding; seven strokes (25%): two fatal, two with a mild residual deficit, and three without deficit; and three (11%) visceral emboli: two fatal and one nonfatal. There were eight deaths (29%). Causes of death were embolic (four), graft failure post-transplantation (one), preimplant anoxic brain damage (two), and postexplant heart failure (one). 24/28 (86%) survived to transplantation or weaning from device and 20/28 (71%) were discharged from the hospital, 10 after transplantation and 10 after native heart recovery. All 20 early survivors survived long term. We describe an anticoagulation protocol based upon TEG and platelet aggregation studies and using heparin, aspirin, and dipyridamole. Adequate anticoagulation is more difficult in children. However, 71% of the patients in our study survived long term.

Mechanical support and medical therapy reverse heart failure in infants and children.

Most infants and children implanted with ventricular assist devices (VADs) go on to cardiac transplantation. Recovery of dilated cardiomyopathies with the combination left ventricular decompression with a VAD and treatment with maximal medical therapy has been possible in some adults, and may be more feasible in infants and children. We used pulsatile and continuous flow VADs and the total artificial heart (TAH) as bridges to transplantation or to recovery. Candidates for native heart recovery were treated with maximal medical therapy for congestive heart failure and short-term dobutamine prior to weaning off device support. Since 1997, 28 infants and children, ages 1 month to 16 years, were implanted for durations of 3-107 days (mean 27). Eighteen received left VADs (LVAD), seven biventricular assist devices (BiVADs), and three TAHs. Device-related mortality was 7/28 (25%), leaving 21/28 (75%) surviving to transplantation or weaning from device support and 20/28 (71%) discharged from the hospital and currently surviving for 2 months to 9 years. Ten of 11 transplant recipients (90%) have survived 2 to 9 years. All 10 with recovered hearts are alive and well for 2 months to 5 years. Eight of 12 (67%) LVAD patients with dilated hearts recovered. None of the recovery patients were over 6 years old. Infants and children who have failed inotropic therapy may be treated with an LVAD and medical therapy for congestive heart failure anticipating native heart recovery. A variety of devices have been tried. All small LVADs yielded comparable results. Larger and older children also have a chance of recovery, but our experience with them is too small except to note that they do well with larger devices and transplantation.

Lack of radiographic loosening signs in a hip resurfacing that failed by stem fracture.

Fracture of the femoral stem is a rare manifestation of femoral component loosening in hip resurfacing. The patient had undergone successful hip resurfacing 3 years prior to presentation, presenting with complaints of groin pain, but without radiographic evidence of loosening. At 6 years post-operatively, the patient again presented with groin pain. Radiographs demonstrated a mid-stem fracture. Analysis of the retrieved implant and resected femoral head following conversion to total hip arthroplasty indicated that component failure and fracture appeared to be secondary to failed fixation and implant loosening not related to osteonecrosis or acute femoral neck fracture. The case report highlights the difficulty in diagnosing femoral component loosening in hip resurfacing in the absence of gross implant subsidence or stem radiolucency.

Total artificial heart bridge to transplantation: a 9-year experience with 62 patients.

BACKGROUND: The SynCardia CardioWest total artificial heart (CardioWest TAH) is a biventricular, orthotopic, pneumatic, pulsatile blood pump driven by an external console. For each ventricle, the length of the blood-flow path is shorter and the inflow and outflow valves are larger than in any other bridge-to-transplant device, resulting in greater blood flow at smaller pre-load. Such a device should be optimal for bridging transplant candidates who have biventricular failure and for whom all other therapies have failed. METHODS: From January 1, 1993, to April 1, 2002, we prospectively studied 62 consecutive CardioWest TAH implant recipients to document safety and efficacy in bridge to transplantation. We used multisystem monitoring and multidrug therapy for anti-coagulation in 58 patients starting September 1, 1994. RESULTS: Before implantation, patients were critically ill with biventricular heart failure. Mortality in this group from the time of implantation until transplantation was 23%. Causes of death during device support included multi-organ failure (6), sepsis (3), and valve entrapment (2). Forty-eight patients underwent transplantation (77%). Forty-two survived to hospital discharge (68% of the total, 88% of those undergoing transplantation). Adverse events included bleeding (20%), device malfunction (5%), fit complications (3%), mediastinal infections (5%), visceral embolus (1.6%), and stroke during support (1.6%). The linearized stroke rate was 0.068 events per patient-year. CONCLUSIONS: Sixty-eight percent of critically ill transplant candidates for whom medical therapy failed were bridged to transplantation with the CardioWest TAH and survived long-term. Most deaths that occurred during device support were related to pre-implant problems. Infection and stroke were rare events. Therefore, we recommend the CardioWest TAH as the biventricular bridge-to-transplant device of choice.

Experience with more than 100 total artificial heart implants.

OBJECTIVE: The SynCardia Total Artificial Heart (SynCardia Systems Inc, Tucson, Ariz) has been used as a bridge to cardiac transplantation in 930 patients worldwide and in 101 patients in our program. Our experience with SynCardia Total Artificial Heart implantation documents its indications, safety, and efficacy. METHODS: Data regarding preoperative condition, mortality, and morbidity have been reviewed and analyzed. RESULTS: From January 1993 to December 2009, 101 patients had bridge to transplant procedures with the SynCardia Total Artificial Heart. Ninety-one percent of cases were Interagency Registry for Mechanically Assisted Circulatory Support profile 1, and the remaining 9% of cases were failing medical therapy on multiple inotropic medications. The mean support time was 87 days (median, 53 days; range, 1-441 days). Pump outputs during support were 7 to 9 L/min. Adverse events included strokes in 7.9% of cases and take-back for hemorrhage in 24.7% of cases. Survival to transplantation was 68.3%. Causes of death of 32 patients on device support included multiple organ failure (13), pulmonary failure (6), and neurologic injury (4). Survival after transplantation at 1, 5, and 10 years was 76.8%, 60.5%, and 41.2%, respectively. The longest-term survivor is currently alive 16.4 years postimplantation. CONCLUSIONS: These patients were not candidates for left ventricular assist device therapy and were expected to die. The SynCardia Total Artificial Heart offers a real alternative for survival with a reasonable complication rate in appropriate candidates who otherwise might have been assigned to hospice care.

Recovery of dilated cardiomyopathies in infants and children using left ventricular assist devices.

Most infants and children implanted with left ventricular assist devices (LVADs) are bridged to cardiac transplantation. Prioritizing recovery may decrease this trend. Patients were treated with LVAD ventricular decompression, medical heart failure therapy, and bolus therapy with a beta-agonist before weaning trials. Devices were removed if adequate function was observed. Eleven patients with a mean age of 1.7 years presented for LVAD implantation. The mean Z score for left ventricular end diastolic diameter (LVEDD) was +5.5 (+1.6 to +7.3), and the mean fractional shortening was 9% (5%-14%). They were on maximal medical therapy and inotropic support. Duration of device support ranged from 6 to 22 days (mean: 13 days). There were three deaths, one from preimplant anoxic brain damage and two from thromboembolism. Eight patients (73%) recovered, were explanted, and are alive 0.6-6 years with hearts that have a mean Z score for LVEDD of 1.0 (0.09-3.7) and fractional shortening of 23%-36%. Left ventricular assist device decompression of dilated left ventricles in infants and children led to long-term survival in 73%. Ventricular size was significantly reduced and contractility significantly increased. None of these patients required transplantation.