Double lung transplants are linked to significantly higher survival rates than single lung transplants among pulmonary fibrosis patients younger than 70, a retrospective study shows.
The study, “Single versus Double Lung Transplantation in Pulmonary Fibrosis: Impact of Age and Pulmonary Hypertension,” was published in the journal The Annals of Thoracic Surgery.
In patients with interstitial pulmonary fibrosis (PF), transplantation of both lungs, called a double lung transplant, is linked to a higher five-year survival rate than single lung transplants, according to data gathered by the Registry of the International Society for Heart and Lung Transplantation.
But controversy remains on whether a double lung transplant is suitable for all PF candidates, including those who are older.
Evidence supports more benefits of a double lung transplant than a single transplant in PF patients with a high lung allocation score, or LAS — a calculated score, from zero to 100, assigned to each lung transplant candidate that predicts wait-list survival probability with and without a lung transplant.
The higher the LAS score, the more urgent and the less time candidates need to wait for a transplant, but a double transplant is a much more complex surgery, and the risks are higher for sicker patients.
Another factor that influences the success of a lung transplant surgery is pulmonary hypertension but how it impacts a single versus double lung transplant requires further investigation.
A team of researchers has now performed a retrospective analysis comparing the risks and benefits of double versus single transplants, including the rate of survival among PF patients based on information from the United Network for Organ Sharing database.
They analyzed data according to the LAS score by assigning four cut-offs — below 45, above 45, above 60, and above 75 — and the mean pulmonary artery pressure — 25, above 25, above 30, and above 40. Patients were also classified by age — younger than 60, 60 or older, 65 or older, and older than 70.
The analysis included 9,191 PF patients who underwent lung transplants between 1987 and 2015. Double lung transplants were performed in 4,443 cases, and single lung transplants in 4,724.
In patients who had a double lung transplant, 10-year survival was 55%, compared with 32% of patients who had only a single lung transplant.
Results also showed that patients of all ages — except those older than 70 — had improved survival rates with a double lung transplant, compared with those who had a single transplant. For example, mean survival among patients younger than 60 was 8.1 years in single transplant patients versus 11.5 years in double transplant patients.
Double lung transplants also improved survival rates across all LAS scores and pulmonary artery pressure categories. In fact, the higher the LAS score, the greater the survival advantage associated with a double lung transplant, the researchers wrote.
In contrast, in patients who received a single lung transplant, a pressure above 30 and an LAS score higher than 45 were associated with decreased survival.
“In pulmonary fibrosis, DLT [double lung transplant] has improved survival compared to SLT [single lung transplant], and should be considered the procedure of choice under the age of 70,” the researchers concluded.
The team also emphasized that a single lung transplant in patients with a mean pulmonary artery pressure higher than 30 and an LAS score above 45 should be discouraged.