# Outcomes of Heart Transplantation in Single-Ventricle Physiology: A Retrospective Single-Center Experience with Emphasis on Surgical Complexity

## TL;DR

This study examines heart transplant outcomes in patients with single-ventricle physiology, highlighting surgical challenges and survival rates.

## Contribution

The study provides a detailed retrospective analysis of heart transplantation in single-ventricle patients, emphasizing surgical complexity and outcomes.

## Key findings

- Perioperative mortality was 33%, with three deaths due to bleeding and hemodynamic instability.
- Heart transplantation improved outcomes in patients with persistent protein-losing enteropathy.
- Individualized surgical planning and donor pulmonary artery harvesting are critical for success.

## Abstract

Background: Patients with single-ventricle physiology represent a high-risk group for heart transplantation. Due to complex anatomical and physiological challenges, including multiple prior sternotomies, pulmonary artery abnormalities, and systemic consequences of altered circulation, they represent both a surgical and a clinical challenge. We aimed to analyze perioperative challenges, as well as early and long-term complications, in this specific group of patients. Methods: We performed a retrospective data analysis of a high-volume heart transplant center, focusing on patients with single-ventricle physiology who were scheduled for heart transplantation due to end-stage heart failure. We retrospectively analyzed the period from the beginning of the transplant program in November 1985 to the end of November 2024. Results: Among 1553 transplanted patients (adults and children), 29 were transplanted due to congenital heart disease (congenital valvular disease not included). In this group, nine patients were transplanted due to end-stage heart failure in the course of single-ventricle physiology. Age at transplantation ranged from 7 to 31 years (median, 17 years), and body weight ranged from 15 to 69 kg (median, 47.9 kg). All nine patients referred for heart transplantation presented with single-ventricle physiology. Their underlying congenital heart defects were heterogeneous and included hypoplastic left heart syndrome (HLHS), double-outlet left ventricle (DOLV), transposition of the great arteries (TGA) with associated ventricular septal defects (VSDs), atrial septal defects (ASDs), valvular abnormalities such as tricuspid and or pulmonary valve atresia or stenosis, systemic or atrioventricular valve regurgitation, and vascular abnormalities, including right-sided aortic arch, aortic coarctation, and pulmonary artery hypoplasia, stenosis, or occlusion, as well as associated pulmonary vascular abnormalities such as left pulmonary artery stenosis and MAPCAs. All patients had previously undergone staged palliative procedures, including Norwood, Hemi-Fontan, Fontan, bidirectional Glenn, modified Blalock–Taussig shunts, Bjork–Fontan, or pulmonary artery banding, often with repeated interventions such as balloon angioplasty, stent placement, or MAPCA closure. Extracardiac comorbidities were common and included coagulopathies, protein-losing enteropathy, hepatic dysfunction, and chronic venous insufficiency. Preoperative functional status was markedly impaired in all patients (NYHA III-IV, INTERMACS 3-4), with severely reduced exercise capacity and thrombotic events in several individuals. Perioperative transplant surgical strategies included femoral cannulation in four cases and standard aortic and caval cannulation in five cases. Pulmonary artery reconstruction was required in all patients. Extended donor pulmonary arteries were applied in eight cases, while a bifurcated Dacron prosthesis was utilized in one patient. Perioperative mortality was 33%, with three deaths attributed to bleeding and hemodynamic instability, while overall mortality was 44% including one late death unrelated to transplantation. Protein-losing enteropathy, although persistent in the immediate postoperative period, resolved in all surviving patients, underscoring the transformative impact of transplantation. Conclusions: These findings emphasize the importance of individualized surgical planning, extended donor pulmonary artery harvesting, and careful preoperative coordination. Heart transplantation remains a viable and life-extending option for selected single-ventricle patients, despite the significant technical and clinical challenges involved.