Recent studies show improved outcomes in ambulated lung failure patients. Ambulation still remains a challenge in these patients. This necessitates development of more compact and less cumbersome respiratory support specifically designed to be wearable. The Paracorporeal Ambulatory Assist Lung (PAAL) is being designed for providing ambulatory support in lung failure patients during bridge to transplant or recovery. We previously published in vitro and acute in vivo results of the PAAL. This study further evaluates the PAAL for 5 days. Five-day in vivo studies with the PAAL were conducted in 50–60 kg sheep after heparinization (activated clotting time range: 190–250 s) and cannulation with a 27 Fr. Avalon Elite dual-lumen cannula. The animals were able to move freely in a stanchion while device flow, resistance, and hemodynamics were recorded hourly. Oxygenation and hemolysis were measured daily. Platelet activation, blood chemistry, and comprehensive blood counts are reported for preoperatively, on POD 0, and POD 5. Three animals survived for 5 days. No study termination resulted from device failure. One animal was terminated on POD 0 and one animal was terminated at POD 3. The device was operated between 1.93 and 2.15 L/min. Blood left the device 100% oxygenated. Plasma-free hemoglobin ranged 10.8–14.5 mg/dl. CD62-P expression was under 10%. Minimal thrombus was seen in devices at explant. Chronic use of the PAAL in awake sheep is promising based on our study. There were no device-related complications over the study course. This study represents the next step in our pathway to eventual clinical translation.
From the *McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
†Department of Bioengineering, University of Pittsburgh, Pittsburgh, Pennsylvania
‡Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
§Computational Fluid Dynamics Group, Center for Advanced Vehicular Systems, Mississippi State University, Starkville, Mississippi
¶Division of Lung Transplantation/Lung Failure, Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
‖Department of Cardiothoracic Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
#Department of Chemical and Petroleum Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania
**Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
Submitted for consideration May 2017; accepted for publication in revised form November 2017.
Disclosure: William J. Federspiel chairs the Scientific Advisory Board and is a Founder of ALung Technologies, in which he has an equity interest. The PAAL technology has not been licensed or optioned to ALung Technologies. Other authors do not have any financial disclosures related to the work presented in this manuscript.
This study was supported by NIH (grant number RO1 HL117637), the Commonwealth of PA, and the McGowan Institute for Regenerative Medicine.
Correspondence: William J. Federspiel, PhD, McGowan Institute for Regenerative Medicine, University of Pittsburgh, 3025 East Carson Street, Pittsburgh, PA 15203. Email: email@example.com.