EXPERIMENTAL AND CLINICAL TRANSPLANTATION

Extracorporeal membrane oxygenation therapy is being used increasingly in different areas. It has become an indispensable assistant to clinicians for hypoxic pulmonary disorders, cardiogenic shock, resuscitation, and during cardiac surgery. In this case report, we describe a patient who is bridged to successful cardiac retransplant under extracorporeal membrane oxygenation therapy support after extracorporeal membrane oxygenation therapy-assisted cardiopulmonary resuscitation.

Key words : Cardiac allograft vasculopathy, Heart transplant, Left ventricle assist device

Cardiac retransplant is sometimes needed for treatment of cardiac allograft vasculopathy (CAV), rejection, and graft failure. Most cardiac retransplant candidates die while waiting for a suitable donor organ. Mechanical circulatory support systems, especially long-term devices, are good options for patients to stay alive during wait for suitable donor organs. Left ventricle assist devices (HeartWare [Heartware Inc., Framingham, MA, USA] and HeartMate [Thoratec Corp., Pleasanton, CA, USA]) are prevalently used worldwide for bridging cardiac transplant candidates.

Short-term devices, usually used for bridging the patient to decision, can also be helpful for some patients. However, only 3% of cardiac retransplants occur in patients who are on mechanical circulatory support,¹ and short-term devices are used in few of these 3%.

A 60-year-old male patient was brought to our clinic under cardiopulmonary resuscitation (CPR) by ambulance. The patient was treated with cardiac transplant in our clinic in 2005 due to restrictive cardiomyopathy. Echocardiography, which was performed 2 months prior, had detected the presence of left and right heart failure with an ejection fraction of 40%. At that time, the patient was admitted to our clinic with severe acid and lower extremity edema. He had been treated with diuretics and positive inotropic treatment. It was determined that the patient required retransplant, and he was placed on the elective wait list. During this time, he received follow-up every 3 months.

While on the wait list, the patient experienced ventricular fibrillation. On the development of asystole, CPR was initiated and continued for approximately 45 minutes.

The patient underwent emergency operation under CPR. To avoid cerebral hypoperfusion, extracorporeal membrane oxygenation (ECMO) therapy support was provided using the subclavian artery by side graft technique, and the patient was taken to the intensive care unit (ICU). The patient received ECMO therapy with the Deltastream Medos model and Novalung iLA Activve Xlung kit (Inspiration Healthcare Group, West Sussex, UK). A 20F arterial cannula (via 8 mm graft) and a 24F venous cannula (65 cm) were used.

Postoperative neurologic examination revealed isochoric pupillary and positive light reflex. Neurologic evaluation with transcranial Doppler in the ICU showed that the patient did not exhibit a neurologic deficit. Transthoracic echocardiography revealed an ejection fraction of 15%, enlargement of both atriums, restriction in the right ventricle, and an increase in wall thickness. Sedative medication was initiated, and the patient was referred to the organ transplant coordination center for national emergency cardiac transplant.

In the ICU, the patient continued on ECMO support. However, on the first day of support, a right hemothorax developed in the patient, requiring surgery. The axillary artery graft was revised, and tube thoracostomy was applied to the right hemithorax. Because cardiac contractions did not provide effective blood pressure, weaning was not planned. On postoperative day 4, an appropriate donor for retransplant was found.

Before retransplant, ECMO was switched to cardiopulmonary bypass. A biatrial orthotopic heart transplant was performed, and the patient returned to the ICU. On posttransplant day 2, the patient was extubated. There was no neurologic sequela in the patient, but the patient did show transient agitation and confusion. He was discharged from the ICU on posttransplant day 9. He remained 1 week more in the hospital with no further events and then was discharged. A combination of sirolimus/everolimus and corticosteroids was given to the patient as immunosuppressive therapy. The patient used mycophenolate mofetil instead of everolimus before retransplant.

A pathologic examination of the recipient’s heart confirmed a definitive diagnosis of CAV.

Six months after retransplant, the functional capacity of the patient was class I. A transthoracic echocardiography showed ejection fraction of 60%, with no pathologic findings.

The rate of adult heart transplants has remained stable at between 2% and 4% since 1982. The period from first heart transplant to heart retransplant is 10 or more years for most patients. Survival after retransplant is 70% in the first year and 38% at 10 years, which is distinctly worse than survival after a first heart transplant.1 In the United States, CAV is the leading cause of retransplant, whereas myopathies are the primary cause in Europe. In our patient, until pathologic examination of the heart was made, we thought that the diagnosis was re-restrictive cardiomyopathy of the donor heart. However, the pathologic examination confirmed a diagnosis of CAV in the patient.

Extracorporeal membrane oxygenation is a form of extracorporeal life support that serves as an alternative to ventricular assist devices to provide prolonged but temporary support of heart or lung function.² The use of ECMO has been well described in patients with primary graft failure after cardiac transplant in the early postoperative period.^3,4 Patients who receive bridge therapy to retransplant have overall lower survival than patients not bridged to retransplant. Therefore, bridging patients to cardiac retransplant with ECMO is not recommended.5 However, there are also other facts that should not be ignored: Patients on short-term circulatory support may be more critical, requiring immediate life-saving therapy before retransplant. Our reason to use ECMO support in our patient was both for ECMO-assisted resuscitation and to provide a “bridge to decision.” The decision for our patient was retransplant. A left ventricular assist device was not feasible because the right ventricle was also affected. A biventricular assist device was also not considered because it could result in high perioperative and postoperative mortality.

Historically, patients who are bridged to transplant under ventricular assist devices or any support devices are considered to have worse prognosis. However, as continuous-flow ventricular assist devices are modernized, this view has become not as valid.¹ In our patient, who required cardiac retransplant after a first transplant, survival would have been also worse with ECMO or combined left and right ventricular support devices. A bridge to cardiac retransplant was necessary to keep the patient alive.

In our clinic, 94 heart transplants were performed between August 1998 and November 2017, with cardiac retransplant performed in 4 patients (4.25%). In 3 of our patients, the indication was CAV and in 1 patient the indication was primary graft failure in the early postoperative period. The patient with primary graft failure died 2 weeks after undergoing retransplant, which was conducted during the first postoperative month after first transplant due to multiorgan dysfunction. One of our patients who underwent retransplant due to CAV died from noncardiac causes at 8 years after retransplant. The other 2 patients are doing well 3 and 6 years after retransplant.

In our country and all over the world, donor limitations are the main problem for patients waiting for heart transplant. An important point to note when deciding whether cardiac retransplant is an option is the patient’s neurologic status. In our center, we consult with the neurology clinic before decision. Patients with ECMO support due to low cardiac output are given a national emergency status on the wait list, which resulted in retransplant in our described patient. Limiting clinical and emotional mistakes in evaluations of neurologic functions can avoid catastrophic outcomes.

In a limited number of patients, even after resuscitation, ECMO support can be used as a bridge to cardiac retransplant.

Volume: 17 Issue: 6 December 2019

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