SAN DIEGO – Extracorporeal membrane oxygenation with spontaneous breathing is the optimal bridging strategy for patients who have rapidly advancing pulmonary disease and are awaiting lung transplantation, based on data from over 18,000 patients who received lung transplants.
In the study, patients on extracorporeal membrane oxygenation (ECMO) alone had outcomes that were comparable to those of patients requiring no invasive support prior to transplantation, Dr. Matthew Schechter of Duke University in Durham, N.C., reported at the annual meeting of the Society of Thoracic Surgeons.
Dr. Schechter and his colleagues analyzed the United Network for Organ Sharing database for all adult patients who underwent lung transplantations between January 2000 and September 2013.
The 18,392 patients selected for study inclusion were divided into cohorts based on the type of preoperative support they received: ECMO with mechanical ventilation; ECMO only; ventilation only; and no support of any kind. Nearly 95% of the patients received no invasive preoperative support. Over 4% received mechanical ventilation alone, less than 1% received ECMO with mechanical ventilation, and about 0.5%) received ECMO only.
By using Kaplan-Meier survival analyses with log-rank testing, Dr. Schechter and his associates were able to compare survival rates for each type of preoperative support. Cox regression models were used to ascertain whether any particular type of preoperative support could definitively be associated with mortality.
At 3 years post transplantation, the survival rates of patients on ECMO alone and of those who received no preoperative support of any kind were comparable at 66% and 65%, respectively. Survival rates at 3 years after transplant were 38% in patients who received ECMO and mechanical ventilation and 52% in patients who received mechanical ventilation alone. The survival advantage in the ECMO only and no support groups was significantly better when compared to the ECMO and mechanical ventilation and the mechanical ventilation alone cohorts (P < .0001).
The findings held up after a multivariate analysis; the hazard ratio was 1.96 (95% confidence interval, 1.36-2.84) for ECMO with mechanical ventilation and 1.52 (95% CI, 1.31-1.78) for mechanical ventilation only (P < .0001 for both).
ECMO alone was not associated with any significant change in survival rate (HR = 1.07; 95% CI, 0.57-2.01; P = .843).
Patients who received just ECMO had the shortest lengths of stay after lung transplant. They also had the lowest rate of acute rejection prior to discharge, although not to an extent that was statistically significant. The incidence of new-onset dialysis was highest in patients who received ECMO with mechanical ventilation.
“ECMO alone may provide a survival advantage over other bridging strategies,” Dr. Schechter concluded. “One advantage of using ECMO only is an avoidance of the risks that come with mechanical ventilation, [which] include generalized muscle atrophy, maladapted muscle fiber remodeling in the diaphragm – which leads to a decrease in the overall durability of this muscle – as well as the induction of the pulmonary and systemic inflammatory risk responses, [all of which] have been shown to affect outcomes following lung transplantation.”
Dr. Schechter explained that patients receiving ECMO without mechanical ventilation can actively rehabilitate themselves post transplantation since nonintubated ECMO patients can participate in physical therapy.
Further study is needed to find an optimal way of assessing patients and determining exactly which ones would be best suited for ECMO with spontaneous breathing support, he said.
Dr, Schechter had no relevant financial disclosures.