Pumpless extracorporeal interventional lung assist for bronchiolitis obliterans after allogenic peripheral blood stem cell transplantation for acute lymphocytic leukemia

Bronchiolitis obliterans (BO), which is associated with graft-versus-host disease after allogenic hematopoietic stem cell transplantation, is a major obstacle to survival after bone marrow transplantation due to its gradual progress, eventually leading to respiratory failure. Pumpless extracorporeal interventional lung assist (iLA) is effective in treatment of reversible hypercapnic respiratory failure. In this paper, we present a 23-year-old female patient who underwent allogeneic peripheral blood stem cell transplantation (PBSCT) for acute lymphocytic leukemia. After 6 months, she complained of shortness of breath and was diagnosed with BO. Five months later, she developed an upper respiratory tract infection that worsened her BO and caused life-threatening hypercapnia. Since mechanical ventilation failed to eliminate $CO_2$ effectively, iLA was applied as rescue therapy. Her hypercapnia and respiratory acidosis showed significant improvement within a few hours, and she was successfully weaned off iLA after 12 days. This is the first case report of iLA application for temporarily aggravated hypercapnia of PBSCT-associated BO followed by successful weaning. This rescue therapy should be considered in ventilator-refractory reversible hypercapnia in BO patients.