Pulsatile ventricular assist device as a bridge to transplant for the early high-risk single-ventricle physiology

Abstract

Background: The use of ventricular assist devices (VADs) as a bridge-to-transplant in patients with single-ventricle physiology post-stage one palliation has been associated with poor outcomes. We describe our center's successful experience in the use of paracorporeal pulsatile VADs in the palliation of high-risk single ventricle physiology before or after the first stage of palliation with an impetus on pre-palliation implant.

Methods: This is a single-center retrospective review of univentricular patients implanted with the Berlin Heart EXCOR VAD. Our center's approach includes early implantation of the Berlin Heart EXCOR with common atrial cannulation, a cardiac index between 3.5 and 5 L/min/m², and a bivalirudin-based anticoagulation regimen. Patient-related data were collected postimplant at week 1 and months 1, 2, and 3. Post-transplant data, including neurological outcomes, were collected.

Results: Nine patients were supported. Survival to discharge post-transplant was 83% (5/6) in patients bridged-to-transplant and 33% (1/3) in patients bridged-to-decision. Six patients had no previous palliation. Median hospital stay before implantation was 111 days for nonsurvivors versus 20 days for survivors. The need for extracorporeal membrane oxygenation and cardiopulmonary resuscitation in nonsurvivors versus survivors was 1 in 3 versus 1 in 6 and 2 in 3 versus 1 in 6, respectively. There were no major central nervous system complications except for 1 significant hemorrhagic event. The pediatric overall performance category score on follow-up was normal to mild disability in 83% of survivors. Limitations include hemolysis and intermittent periods of infection and/or inflammation.

Conclusions: The use of pulsatile paracorporeal VADs is a feasible option as a bridge-to-transplant in the peri-stage one high-risk single ventricle.

Keywords: failing high-risk peri–stage-one single ventricle physiology; heart transplantation; mechanical circulatory support; pulsatile paracorporeal VAD.

FIGURE 1.

Depictions of ventricular assist device support in the single ventricle. A, Ventricular assist device with Hybrid palliation. PDA stent and bilateral PA bands. Inflow cannula to the right atrium and outflow cannula to the PA. B, Ventricular assist device with PDA stent. Inflow cannula to the right atrium and outflow cannula to the ascending aorta. C, Ventricular assist device with a PTFE graft connecting the outflow cannula to the pulmonary artery. Inflow cannula to the right atrium and outflow cannula to the ascending aorta. PA, Pulmonary artery; PDA, patent ductus arteriosus; PTFE, polytetrafluoroethylene.

FIGURE 2.

The cohort consisted of 9 patients with single-ventricle physiology. These patients were pre– or post–stage one palliation and were all supported by the Berlin Heart EXCOR. The results including hematologic values, end-organ function, and inflammation are summarized as well as the implications of the results. The 3 surgical procedures performed are depicted. VAD, Ventricular assist device; PDA, patent ductus arteriosus; PA, pulmonary artery; PTFE, polytetrafluoroethylene; BT, Blalock–Thomas–Taussig; WBC, white blood count; Hs-CRP, high sensitivity c-reactive protein; AST, aspartate transaminase; ALT, alanine transaminase.

FIGURE 3.

Comparison of inflammatory markers during VAD support. Inflammatory markers include hs-CRP, WBC, neutrophils, and lymphocytes and are compared among survivors and nonsurvivors. Survival is defined as survival to transplant postdischarge. The laboratory values were collected at week 1 and months 1, 2, and 3 status-postimplant. The hs-CRP, WBC, and neutrophils trended greater in nonsurvivors than survivors. Hs-CRP, High-sensitivity C-reactive protein; WBC, white blood cells.

FIGURE 4.

Comparison of hematologic values during VAD support. Hematologic values include hematocrit, platelet count, PRBC transfusions, platelet transfusions, and FFP transfusions. The laboratory values and transfusions are compared among survivors and nonsurvivors. Survival is defined as survival to transplant postdischarge. The laboratory values were collected at week 1 and months 1, 2, and 3 status-postimplant. On average, the transfusions, hematocrit, and platelets trended greater in nonsurvivors than survivors. PRBC, Packed red blood cells; FFP, fresh frozen plasma.

FIGURE 5.

Comparison of end-organ function during VAD support. End-organ function values include blood urea nitrogen, AST, ALT, and creatinine. AST and ALT are used as markers of liver function whereas blood urea nitrogen and creatinine are used as markers of kidney function. These laboratory values are compared among survivors and nonsurvivors. Survival is defined as survival to transplant postdischarge. The laboratory values were collected at week 1 and months 1, 2, and 3 status-postimplant. End-organ dysfunction is more apparent in nonsurvivors than survivors. AST, Aspartate aminotransferase; ALT, alanine transaminase.