Long-term Survival Similar Between Double, Single Lung Transplants in IPF Patients, Review Study Finds
People with idiopathic pulmonary fibrosis (IPF) who undergo a bilateral lung transplant may have better postoperative lung function than those receiving single lung transplants, but long-term survival appears to be similar between the two procedures, a review study shows.
While these findings may help guide clinicians’ decisions, further large studies considering patient factors and risk profile are needed to confirm them, according to the researchers.
The review study, “Single versus bilateral lung transplantation in idiopathic pulmonary fibrosis: A systematic review and meta-analysis,” was published in the journal PLOS One.
A lung transplant procedure remains the only curative treatment for end-stage lung disease, prolonging patients’ lives and improving their quality of life. With the increasing number of IPF patients waiting for a lung transplant and the short supply of suitable donor lungs, it is important to understand which type of lung transplant — double (bilateral) or single — patients should receive.
Because of a lack of clinical trials comparing the two procedures, conclusions on their benefits must rely on analyses of large registries.
However, which of the two is more beneficial for IPF patients remains controversial, with some studies reporting an association between bilateral lung transplants and better survival and others suggesting similar survival benefits with either procedure.
In an attempt to address these discrepancies, researchers at the West China School of Medicine and West China Hospital of Sichuan University in China set out to evaluate which type of lung transplant procedure was more effective and safe in IPF patients.
They analyzed published studies comparing bilateral and single lung transplants in IPF patients, including data on overall survival and patients’ perioperative parameters up to October 2019. The perioperative period includes the time immediately before, during, and after a surgery.
A total of 16 retrospective studies, published between 2005 and 2019 and covering 17,872 IPF patients across five countries, were included in the meta-analysis. Of these studies, 10 were multicenter, and six included patients from a single center.
The patients’ mean age ranged from 52 to 62.7 years, and the follow-up period from one to 20 years. A total of 10,215 (57.2%) patients underwent a single lung transplant (SLT group), while 7,657 (42.8%) underwent a bilateral transplant (BLT group).
Data showed that patients in the BLT group had higher survival rates at one and three months and at one and three years after surgery, as well as better overall survival than those in the SLT group. However, this survival difference was not statistically significant, highlighting that “the use of SLT versus [BLT] in IPF did not correspond to significantly different survival,” according to the researchers.
Subgroup analyses by age, sample size, and data source (single and multicenter) also indicated that the survival benefits were similar between single and bilateral lung transpalnts. In contrast, pooled data from studies with shorter follow-up periods (published after 2014; less than five years of follow-up) indicated that the SLT group had a lower overall survival, while data from those with longer follow-up periods showed no survival difference between the two groups.
As such, the researchers suggest “that the long-term prognosis is similar for IPF patients treated with these two procedures.”
Despite the absence of a significant survival benefit of bilateral over single lung transplant, patients undergoing a double transplant had better postoperative lung function than those in the SLT group. Nonetheless, patients undergoing either procedure showed similar periods of postoperative mechanical ventilation, heart-lung life support, days hospitalized, and similar hospital mortality.
When looking at the main cause of death in the two groups, the team found that, compared with bilateral lung transplants, single lung transplants were associated with a nearly 70% lower likelihood of death from primary graft dysfunction, but a more than threefold higher risk of cancer-related death. Primary graft dysfunction is a form of acute lung injury that can occur within the first 72 hours after lung transplant.
These findings suggest that bilateral lung transplants are associated with better lung function right after surgery, but this does not result in a significant long-term survival benefit over single lung transplants.
Nonetheless, “further high-quality and large-scale studies are needed to confirm these findings with attention to multiple perioperative factors and the context of the individual patient’s risk profile,” the researchers concluded.