Long-Term Outcomes of Cadaveric Lobar Lung Transplantation: An Important Surgical Option

Deciphering the interplay: circulating cell-free DNA, signaling pathways, and disease progression in idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a lung disease with an unknown etiology and a short survival rate. There is no accurate method of early diagnosis, and it involves computed tomography (CT) or lung biopsy. Since diagnostic methods are not accurate due to their similarity to other lung pathologies, discovering new biomarkers is a key issue for diagnosticians. Currently, the use of ccf-DNA (circulating cell-free deoxyribonucleic acid) is an important focus due to its association with IPF-induced alterations in metabolic pathways, such as amino acid metabolism, energy metabolism, and lipid metabolism pathways. Other biomarkers associated with metabolic changes have been found, and they are related to changes in type II/type I alveolar epithelial cells (AECs I/II), changes in extracellular matrix (ECM), and inflammatory processes. Currently, IPF pathogenetic treatment remains unknown, and the mortality rates are increasing, and the patients are diagnosed at a late stage. Signaling pathways and metabolic dysfunction have a significant role in the disease occurrence, particularly the transforming growth factor-β (TGF-β) signaling pathway, which plays an essential role. TGF-β, Wnt, Hedgehog (Hh), and integrin signaling are the main drivers of fibrosis. These pathways activate the transformation of fibroblasts into myofibroblasts, extracellular matrix (ECM) deposition, and tissue remodeling fibrosis. Therapy targeting diverse signaling pathways to slow disease progression is crucial in the treatment of IPF. Two antifibrotic medications, including pirfenidone and nintedanib, are Food and Drug Administration (FDA)-approved for treatment. ccf-DNA could become a new biomarker for IPF diagnosis to detect the disease at the early stage, while FDA-approved therapies could help to prevent late conditions from forming and decrease mortality rates.

Lobar Lung Transplantation: A Single-Center 10-Year Experience

BACKGROUND

The shortage of donors for lung transplants is the main limitation of the preceding. Lobar transplantation is an alternative especially useful in patients with short stature and small thoracic cavities. The aim of this study was to perform a descriptive analysis of Portuguese patients who underwent lobar lung transplantation.

METHODS

A retrospective study was conducted, and patients submitted to lobar lung transplantation from January 2012 to December 2023 were evaluated. A descriptive analysis was made, including demographic data, lung diseases, waiting list dynamics, pre-transplant evaluations, and post-transplant outcomes.

RESULTS

Sixteen lobar transplants were performed with a predominance of female patients and a median age of 47 years. Most patients had interstitial lung disease or bronchiectasis either due to cystic fibrosis or non-cystic fibrosis. The median predicted total lung capacity (pTLC) ratio was 0.73. The median waiting list time was 6 months with 9 urgent transplants and 1 emergent lobar retransplant. Extracorporeal membrane oxygenation (ECMO) was used in pre-, intra-, and postoperative periods. Most transplanted lobes were the median lobe (ML) + right upper lobe (RUL) and left upper lobe (LUL). The median length of stay was 58 days, with complications such as PDG grade 3, bronchial tree ischemia, and concentrical stenosis of bronchial anastomosis. Six patients died in this period, 1 in the immediate postoperative period and 5 during the post-transplant hospitalization, with a median survival of 20.7 months and a 1-year and 5-year survival rate of 60%.

CONCLUSION

Our results show a population with an increased waiting list converging in many urgent cases, with an early mortality and high primary graft dysfunction rate. Nevertheless, mid- and long-term survival are promising.

Lung transplantation in children

Lung transplantation is a well-established treatment for children facing advanced lung disease and pulmonary vascular disorders. However, organ shortage remains highest in children. For fitting the small chest of children, transplantation of downsized adult lungs, lobes, or even segments were successfully established. The worldwide median survival after pediatric lung transplantation is currently 5.7 years, while under consideration of age, underlying disease, and peri- and posttransplant center experience, median survival of more than 10 years is reported. Timing of referral for transplantation, ischemia-reperfusion injury, primary graft dysfunction, and acute and chronic rejection after transplantation remain the main challenges.