EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Right (systemic) ventricular failure is well described after a Mustard procedure for transposition of the great arteries. Sixty-one percent of patients have been reported to show moderate-to-severe dysfunction of the systemic ventricle, 25 years after repair of transposition of the great arteries by a Mustard procedure. In such cases, heart transplant often seems to be the only option. When severe heart failure with hemodynamic instability develops, the only way to bridge these patients to a transplant is implantation of a mechanical circulatory support system. Because of the special anatomic features of the right ventricle, the implantation procedure can be challenging. Here, we report the case of a patient who underwent a left ventricular assist device implant owing to severe heart failure, 36 years after undergoing a Mustard procedure.

Key words : Congenital heart disease, Great vessel anomalies, Transposition, Left ventricular assist device, Mustard procedure

Cardiac transplant is the only treatment option for end-stage right systemic ventricular failure occurring in about 61% of patients late after a Mustard procedure.¹ In some circumstances, patients may deteriorate clinically before a donor heart becomes available, and these patients may require urgent mechanical circulatory support to bridge them to a transplant. This report details the implantation of a Heart Mate II as a morphologic right ventricular assist device to bridge the patient to a transplant.

A 41-year-old woman with D-transposition of the great arteries, combined with subpulmonal stenosis and ventricular septal defect, underwent a Rashkind maneuver at 1 year of age. Three years later, surgical treatment with a Blalock–Taussig shunt was done. A Mustard procedure was done at 5 years of age. After 31 years, the woman developed a global cardiac decompensation, with New York Heart Association (Class III), leading by right heart failure and elevated pressures in the pulmonary circulation. A right heart catheter showed a mean pulmonary artery pressure of 68 mm Hg, and a pulmonary vascular resistance of 248 dyn × sec × cm-5. Subsequently, the woman was waitlisted for a heart transplant. After waiting for 5 years, the woman developed a progressive right (systemic) ventricle failure leading to multiorgan dysfunction. She required intubation owing to onset of a rapid organ deterioration, with acute dyspnea, and peripheral and central cyanosis. Despite intensive inotropic support, her condition worsened, and a left ventricular assist device (HeartMate II, Thoratec Corp, Pleasanton, CA, USA) was inserted.

The inflow cannula was inserted into the right ventricle we resected some trabeculae (Figure 1) with orientation toward the tricuspid valve, while the outflow was inserted into the ascending aorta. Positioning of the inflow cannula was confirmed intraoperatively after placing the device by transesophageal echocardiography (Figure 2). On the 58th day after surgery, the woman recovered fully and was discharged home. A transplant was performed successfully 1 year later.

Late right ventricular failure in patients with transposition of the great arteries after a Senning or Mustard procedure can be problematic. The incidence of systemic ventricular failure ranges from 8% to 44%.^2,3 Reports of a heart transplant in adult patients with congenital heart disease demonstrate that long-term survival is equivalent to the other transplant candidates, but that perioperative risk varies between 27% and 60%.⁴ However, as the time on the donor waitlist lengthens, the clinical condition of patients can abruptly deteriorate, sometimes requiring systemic ventricular assistance.

George and associates⁵ reported a 17-year-old patient, who underwent implantation of a left ventricular assist device 15 years after undergoing Mustard surgery. In this case, a transplant was successfully performed 11 months later. Also, Stewart and associates⁶ describe 2 successful cases of implantation of a left ventricular assist device in patients with transposition of the great arteries.

Considering the anatomic characteristics of these patients, implanting a left ventricular assist device represents a surgical challenge. The moderator band and the trabeculation of the morphologic right ventricle represent a demanding surgical aspect when inserting the left ventricular assist device-inflow cannula. The apex of the right ventricle contains many trabeculae that could disturb the flow in the inflow cannula, leading to inadequate drainage. Attention is required when placing the inflow cannula in the right ventricle to guarantee unobstructed flow in and out of the device. Wiklund and associates⁷ reported a case of implanting a left ventricular assist device into a 15-year-old male patient after undergoing a Mustard operation. Because of the anatomical and topographic factors, the HeartMate I left ventricular assist device had to be implanted back-to-front, with the inflow directed toward the diaphragmatic wall of the right ventricle and the outflow directed toward the apex region. In our case, this was unnecessary.

The need for assist devices in patients after atrial correction, or transposition of the great arteries, represents a technical challenge, surgically. Our report shows that implanting a left ventricular assist device into the systemic right ventricle of a patient with surgically corrected D-transposition of the great arteries is feasible. The device mechanically unloads the systemic ventricle, thus reducing pulmonary hypertension, while acting as a bridge to transplant.

Volume: 13 Issue: 5 October 2015

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