Transplantation after Mustard operation for transposition of the great arteries

Abstract As long‐term outcomes of congenital heart diseases improve, the probability of adult patients presenting for heart transplantation for late failure of congenitally corrected heart disease also increases. In patients with dextro‐transposition of the great arteries (d‐TGA) who were initially treated in the era of Mustard or Senning procedures and before Jatene procedure was introduced, progressive systemic right ventricular failure represents a problem in the very long‐term follow‐up. We report a rare case of heart transplantation as a third operation 36 years after Mustard procedure in a patient with d‐TGA experiencing late failure of the systemic right ventricle.


Funding information
Open Access funding enabled and organized by Projekt DEAL. WOA Institution: N/A Blended DEAL: Projekt DEAL

Abstract
As long-term outcomes of congenital heart diseases improve, the probability of adult patients presenting for heart transplantation for late failure of congenitally corrected heart disease also increases. In patients with dextro-transposition of the great arteries (d-TGA) who were initially treated in the era of Mustard or Senning procedures and before Jatene procedure was introduced, progressive systemic right ventricular failure represents a problem in the very long-term follow-up.
We report a rare case of heart transplantation as a third operation 36 years after Mustard procedure in a patient with d-TGA experiencing late failure of the systemic right ventricle.

K E Y W O R D S
d-TGA, heart transplantation, heart failure, mustard augmentation plasty for SVC stenosis at the age of 6 years was admitted to the emergency department for heart failure (HF) symptoms. On echocardiography, sRV was dilated (end-diastolic dimension 56mm) with a severely impaired ejection fraction (EF) of 15% and moderate regurgitation at systemic atrioventricular valve. Preoperative computed tomography showed anterior location of the aorta, regular anatomic relation of the Mustard baffle in the systemic atrium in close anatomic relation to the pulmonary valve, moreover the anterior wall of the systemic ventricle grossly adhering to the dorsal aspect of the sternum ( Figure 1A, B). Pulmonary artery catheterization showed low cardiac index (1.65 l/min*m 2 ) and pulmonary hypertension (mean 40 mmHg). Initial lactate was 1.6 mmol/l. Furthermore, NT-proBNP was significantly elevated to 6792 pg/ml, as also serum creatine (1.4 mg/dl), and total bilirubin (1.4 mg/dl). The patient was admitted to intensive care and high urgency (HU) status was granted. Fiftytwo days after HU status, HTX was performed 35 years after Mustard procedure.
The operative strategy included femoral cannulation and cardiopulmonary bypass (CPB) initiation prior to resternotomy due to expected adhesions to sRV. After partial dissection of the adhesions, the systemic atrium was vented to avoid pulmonary congestion during further preparation and manipulation. Aortic clamping was performed early to avoid air embolism, and both caval veins were incised for later bicaval implantation of donor heart. Next, systemic (ie, anatomic right) atrium was opened and Mustard baffle and pulmonary vein (PV) ostia were identified from the endocardial side as well as PV location from outside of the atrium (Figure 2). Aorta and pulmonary trunk were transected more distally than in regular HTX to achieve a more regular anatomic relation. The resulting recipient dimension of the aorta was remarkably small. Due to the specific technique of Mustard correction, the inter-PV distance revealed to be relatively small and the anatomic left atrial cuff limited in size when compared to the common anatomy in HF patients. Therefore, when excising recipient heart, the incision line was performed as much as possible distant from the PV ostia. Additional perpendicular incision of the remaining left atrial cuff was performed in between the two left PV ostia as well as caudally and cranially in between the left and right atrial PV ostia to enlarge the anastomotic line on the recipient side. As a further modification on the donor side, cardiac graft was harvested with a long segment of the aorta, including most part of the aortic arch. HTX was performed by bicaval method, and the anastomosis was performed in the order of left atrium, IVC, SVC, pulmonary artery, and ascending aorta. Despite the more liberal excision of recipient great arteries, the distal ascending aorta was yet located anteriorly and slightly left to the normal anatomy. Utilizing longer segments of the donor graft and more distal anastomotic lines, it was possible to perform both anastomoses of great arteries without the use of prosthetic materials. The aortic anastomosis was further complicated by a remarkable size mismatch but proved to be feasible without prosthetic material. Total donor heart ischemia time was 214 minutes. After 131 min of reperfusion, weaning from CPB was performed with moderate doses of catecholamines, inhalative nitric oxide, and intermittent inhalative prostacyclin therapy. The patient was extubated on the 1 st postoperative day, and further postoperative course was unremarkable. There was no particular problem with postoperative echocardiography, and he was discharged on the 33 rd postoperative day without any other complications.

| DISCUSSION
Mustard procedure was the preferred type of surgery that was performed on d-TGA before the Jatene procedure was introduced and widely adopted. 2 The problem of Mustard procedure is that by preserving the anatomic right ventricle for systemic circulation late postoperative dysfunction and failure of the sRV is a common complication. Implantable ventricular assist device (VAD) therapy has been reported in the latter scenario, however, with mixed results of VAD in sRV, which may suggest to favor HTX as the first choice in this particular patient cohort 5 .
Beyond pre-operative stabilization and postoperative management, intraoperative technical issues represent important components for successful treatment of d-TGA patients with failing systemic ventricle. Anatomic abnormalities represent a considerable challenge, particularly after previous operations. A thorough diagnostic workup utilizing modern imaging modalities for precise localization of native structures (eg, course and ostia of PVs) and reconstructive implant material (eg, atrial baffle) should be obtained to improve the quality of preoperative decision finding regarding operative strategy. Although not experienced in this case, further reconstruction steps may be necessary for complex anatomic scenarios to enable HTX, for example, using a baffle or vascular grafts 3 .
The point devised in the surgery of this case was the creation of the left atrial anastomosis. Since the adhesion between the right atrium and PV was severe, ascending aorta was clamped, the right atrium was incised to confirm the left atrium and PV from the atrium and pericardium, and the heart can be removed safely without injury. In this case, IVC and SVC were located on the right side, no special reconstruction was required, and reconstruction with the normal bicaval method was possible.

ACKNOWLEDGMENTS
We gratefully acknowledge the work of the members of the heart failure team at the University Hospital Duesseldorf.

CONFLICTS OF INTEREST
The authors declare no conflicts of interest associated with this manuscript.

ETHICAL APPROVAL
This manuscript followed the principles of the Declaration of Helsinki and the Declaration of Istanbul.

CONSENT
The appropriate informed consent was obtained for the publication of this manuscript.

DATA AVAILABILITY STATEMENT
Data sharing is not applicable to this article as no new data were created or analyzed in this study.