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A new era: Use of an intracorporeal systemic ventricular assist device to support a patient with a failing Fontan circulation

2011; Elsevier BV; Volume: 142; Issue: 3 Linguagem: Inglês

10.1016/j.jtcvs.2011.05.018

1097-685X

David L.S. Morales, Iki Adachi, Jeffrey S. Heinle, Charles D. Fraser,

Cardiac Structural Anomalies and Repair

Worldwide experience with ventricular assist device (VAD) support in patients with univentricular physiology has been very limited. In particular, the use of a long-term continuous-flow implantable VAD has never been described. We report the successful application of an intracorporeal systemic ventricular assist device (SVAD), the HeartMate II (Thoratec Corporation, Pleasanton, Calif), in an adolescent with a failing Fontan circulation and protein-losing enteropathy (PLE). The patient is a 15-year-old boy (body surface area, 1.5 m2) with double-outlet right ventricle, mitral atresia, and a systemic right ventricle. He underwent staged palliation culminating in a fenestrated lateral Fontan operation at 3 years old. Although he did well for many years, his condition began to deteriorate with increasing dyspnea on exertion, peripheral pitting edema, and hepatomegaly with ascites. PLE was diagnosed (serum albumin, 2.6 g/dL; prealbumin, 9.7 mg/dL). Echocardiogram revealed severely depressed systolic ventricular function with significant tricuspid regurgitation. In preparation for cardiac transplantation, a cardiac catheterization was performed. After induction of positive-pressure ventilation, he had several periods of cardiac arrest necessitating resuscitation. The abbreviated catheterization demonstrated a severely elevated Fontan pressure of 30 mm Hg, a pulmonary vascular resistance of 1.9 Wood units, normal caliber pulmonary arteries, and a wedge pressure of 22 mm Hg. Because his circulatory failure was primarily the result of systemic ventricular dysfunction and his condition was hemodynamically unstable, he underwent urgent VAD placement. Because the patient had levocardia with normally related great arteries, a HeartMate II SVAD was implanted in the usual manner (Figure 1) on cardiopulmonary bypass without cardiac arrest. The only atypical aspect was the necessity of closing the Fontan fenestration to prevent postoperative cyanosis and aggressively resecting coarse apical right ventricular trabeculations when placing the inflow cannula. After bypass, transesophageal echocardiography demonstrated adequate positioning of the cannulas and good right ventricular decompression with the patient receiving inhaled nitric oxide and nicardipene only. The patient was in hemodynamically stable condition throughout the postoperative period with a central venous pressure that was 10 mm Hg after extubation on postoperative day 7. The HeartMate II SVAD was programmed at higher than normal revolutions per minute to ensure complete decompression of the systemic ventricle because pulmonary blood flow was passive (Table 1). Using aspirin and warfarin sodium (target international normalized ratio of 2.0), there were no thrombotic complications. His exercise tolerance improved significantly, and at 2 months postoperatively he had no heart failure symptoms and the PLE clinically and chemically resolved (albumin, 4.0 g/dL; prealbumin, 12.0 mg/dL). The patient was discharged home and underwent successful transplant at 72 days of support.Table 1Hemodynamic and device parametersOne day before operationOne day after operationOne day before extubationOne day after extubationOne day before dischargeDevice parameters Flow (L/min)—5.25.96.36.0 Speed (rpm)—9200940094009400 Pump power (W)—5.45.86.47.1 Pulsatile index—3.63.74.24.1Hemodynamic parameters Inotropes/vasodilatorsEpinephrine 0.1 μg · kg−1 · min−1, CaCl 10 mg · kg−1 · h, vasopressin 0.2 units · kg−1 · hNicardipine 1.5 mg/hNicardipine 1.0 mg/h—— Respiratory supportIntubated, Fio2 1.0Intubated, Fio2 0.4Intubated, Fio2 0.4Nasal cannula, Fio2 1.0Room air Arterial blood pressure (mm Hg)98/58 (72)(75)(72)(84)(79) Central venous pressure (mm Hg)30151511— Atrial pressure (mm Hg)(22)∗Estimated with a left pulmonary wedge pressure.(8)∗Estimated with a left pulmonary wedge pressure.——— Oxygen saturation (%)8593959592Fio2, Forced expiratory volume in 1 second.∗ Estimated with a left pulmonary wedge pressure. Open table in a new tab Fio2, Forced expiratory volume in 1 second. Implantation of a VAD to sustain the Fontan circulation has been reported but mostly in the setting of short-term support using extracorporeal devices or long-term support with paracorporeal devices.1Frazier O.H. Gregoric I.D. Messner G.N. Total circulatory support with an LVAD in an adolescent with a previous Fontan procedure.Tex Heart Inst J. 2005; 32: 402-404PubMed Google Scholar, 2Prêtre R. Häussler A. Bettex D. Genoni M. Right-sided univentricular cardiac assistance in a failing Fontan circulation.Ann Thorac Surg. 2008; 86: 1018-1020Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar, 3Nathan M. Baird C. Fynn-Thompson F. Almond C. Thiagarajan R. Laussen P. et al.Successful implantation of a Berlin heart biventricular assist device in a failing single ventricle.J Thorac Cardiovasc Surg. 2006; 131: 1407-1408Abstract Full Text Full Text PDF PubMed Scopus (83) Google Scholar Frazier, Gregoric, and Messner1Frazier O.H. Gregoric I.D. Messner G.N. Total circulatory support with an LVAD in an adolescent with a previous Fontan procedure.Tex Heart Inst J. 2005; 32: 402-404PubMed Google Scholar did report the use of a pneumatic HeartMate IP LVAS (Thoratec Corp) in a Fontan patient who while recovering in the hospital received a transplant at 45 days of support. In particular, the use of an implantable VAD in anticipation of long-term support and discharging the patient home has not been described. The chronic failure of a Fontan circulation is multifactorial and is not always primarily a systemic ventricular problem.4Morales D.L.S. Fraser C.D. Surgical strategy for the failing systemic ventricle.in: Chang A.C. Towbin J.A. Heart failure in children and young adults. Elsevier, Philadelphia2006: 591-606Google Scholar This may explain why successful VAD support of the failing Fontan circulation has been inconsistent. Therefore, careful consideration should be given to assess whether systemic ventricular failure is the main cause of the failing circulation. If it is, then an SVAD should improve the overall circulation. However, if the left ventricular end-diastolic pressure is not high, then an SVAD is unlikely to improve hemodynamics. If the pulmonary circulation is primarily responsible for hemodynamic deterioration, then insertion of a VAD at a subpulmonary position is an option.2Prêtre R. Häussler A. Bettex D. Genoni M. Right-sided univentricular cardiac assistance in a failing Fontan circulation.Ann Thorac Surg. 2008; 86: 1018-1020Abstract Full Text Full Text PDF PubMed Scopus (97) Google Scholar Much animal and computer modeling has been done to study the possibility of mechanically augmenting pulmonary blood flow in the Fontan baffle.5Lacour-Gayet F.G. Lanning C.J. Stoica S. Wang R. Rech B.A. Goldberg S. et al.An artificial right ventricle for failing Fontan: in vitro and computational study.Ann Thorac Surg. 2009; 88: 170-176Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar The lack of a subpulmonary ventricle in the Fontan physiology may result in suboptimal filling of an SVAD. Therefore, we believe that it is important to ensure almost complete systemic ventricular decompression by setting the HeartMate II SVAD at higher revolutions per minute to encourage passive flow into the pulmonary arteries. Also, with a single ventricle, unlike in a biventricular heart, there is little concern, even at high revolutions per minute, of jeopardizing output of the pulmonary ventricle by shifting of the intraventricular septum. With these settings, central venous pressure decreased significantly with adequate systemic blood pressure (Table 1), yielding reasonable end-organ perfusion pressure, which presumably contributed to the improvement in his PLE. This is the first report of successfully discharging home a patient who has a failing Fontan circulation with an implantable VAD. Given the increasing cohort of adults and children with failing Fontan circulations, this case represents a significant evolution in therapy for single ventricle patients who will increasingly be receiving SVADs not only for support to transplant but also perhaps to destination.