Case Study: Total Artificial Heart in the Failing Fontan Circulation

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Cardiac Connection

The failing Fontan circulation, especially in the setting of protein-losing enteropathy or plastic bronchitis, can be very difficult to support with traditional VADs. This case study represents the first successful use of the Total Artificial Heart in this circulation and has the potential of helping many patients in the future.

A 13-year-old with pulmonary atresia and an intact ventricular septum developed severe, refractory circulatory failure 10 years after an extracardiac nonfenestrated Fontan operation. He was hospitalized at an outside institution for a heart failure exacerbation complicated by severely depressed left ventricular systolic function, respiratory failure, hepatic insufficiency with coagulopathy, and plastic bronchitis.

Cardiac catheterization demonstrated elevated pressures in the Fontan conduit (38 mmHg) and pulmonary arteries (25 mmHg). An Impella 2.5 percutaneous temporary VAD was also inserted; however, he continued to deteriorate with new onset heart block and escalating need for inotropic support. He was transferred to The Children’s Hospital of Philadelphia for consideration of mechanical circulatory support.

Clinical course

The patient arrived in extremis with worsening liver failure with coagulopathy, deteriorating renal function with oliguria, plastic bronchitis, and respiratory failure, despite escalating inotropic support (epinephrine 0.07 mcg/kg/min, milrinone 0.75 mcg/kg/min). He was intubated and sedated, and his physical examination was notable for poor perfusion and severe hepatomegaly.

Echocardiography demonstrated a severely dilated left ventricle with severely depressed ventricular function. It was our opinion that the patient would not survive with a VAD placed in the left (systemic) ventricle given the degree of cardiogenic shock, plastic bronchitis, and failure of his Fontan circulation. Supportive evidence to this was his clinical worsening with the Impella VAD. Thus, with informed consent from the family, a 70cc SynCardia Total Artificial Heart was implanted.

The postoperative course was complicated by significant bleeding requiring re-exploration, external compression of the neo-RA, and reconstructed inferior vena cava, which required stent placement, rhabdomyolysis, and renal failure requiring renal replacement therapy. Rigid bronchoscopy was necessary to clear the airway of the casts resulting from plastic bronchitis. The patient also received inhaled tissue thromboplastin activator (tPA) to reduce the casts.

Throughout the postoperative period, the cardiac output was well preserved. The patient had recovery of all end-organ function, including resolution of the plastic bronchitis, and was transferred to the ward on postoperative day 56. On postoperative day 61, a suitable donor heart became available and the patient underwent orthotopic heart transplantation.

The patient was sensitized with multiple donor-specific antibodies and had a positive B and T cell cross match. In spite of the aggressive immunosuppression, the patient suffered a cardiac arrest on post-transplant day 5 secondary to graft dysfunction from combined acute antibody mediated and cellular rejection. The patient was resuscitated with extracorporeal membrane oxygenation but did suffer some neurologic injury. He underwent rehabilitation and is now at home with his family.

Significance

The failing Fontan circulation, especially in the setting of protein-losing enteropathy or plastic bronchitis, can be very difficult to support with traditional VADs. This represents the first successful use of the Total Artificial Heart in this circulation and has the potential of helping many patients in the future.