title: Experimental safety and efficacy evaluation of an extracorporeal pumpless artificial lung in providing respiratory support through the axillary vessels.
abstract: OBJECTIVE
  We sought to investigate the safety and feasibility of implanting the pumpless interventional lung assist device (Novalung; Novalung GmbH, Hechingen, Germany) to the axillary vessels either by means of direct cannulation or end-to-side graft interposition and the capability of either type of vascular access to provide respiratory support during apneic ventilation in adult pigs.
  
  
  METHODS
  Ten pigs were ventilated for 4 hours (respiratory rate, 20-25 breaths/min; tidal volume, 10-12 mL/kg; fraction of inspired oxygen, 1.0; positive end-expiratory pressure, 5 cm H2O). Thereafter, the interventional lung assist device was surgically connected to the right axillary artery and vein by using direct cannulation (n = 5) or end-to-side ringed polytetrafluoroethylene graft interposition (n = 5), and ventilatory settings were reduced to achieve near apneic ventilation (respiratory rate, 4 breaths/min; tidal volume, 1-2 mL/kg; fraction of inspired oxygen, 1.0; positive end-expiratory pressure, 20 cm H2O). Hemodynamic and intrathoracic volumes and lung cytokine levels were measured.
  
  
  RESULTS
  Blood flow through the interventional lung assist device was 1.7 +/- 0.4 L/min or 30% +/- 14% of the cardiac output, and the mean pressure gradient across the interventional lung assist device was 10 +/- 2 mm Hg. The interventional lung assist device allowed an O2 transfer of 225.7 +/- 70 mL/min and a CO2 removal of 261.7 +/- 28.5 mL/min. Although the amount of blood flow perfusing the interventional lung assist device was significantly higher (P < .01) with direct cannulation (2.1 +/- 0.3 L/min) compared with that seen in graft interposition (1.3 +/- 0.3 L/min), the latter allowed similar respiratory support with reduced hemodynamic instability.
  
  
  CONCLUSIONS
  The axillary vessels are a safe and attractive cannulation site for pumpless partial respiratory support. Compared with direct cannulation, graft interposition was equally able to support the interventional lung assist device-driven gas exchange requirements during apneic ventilation with better hemodynamic stability.
authors.affiliation: General Thoracic Surgical Experimental Laboratory, Hospital Clinic of Barcelona, University of Barcelona, Barcelona, Spain.
authors.forename: Manuela
authors.initials: M
authors.lastname: Iglesias
authors.forename: Philipp
authors.initials: P
authors.lastname: Jungebluth
authors.forename: Oriol
authors.initials: O
authors.lastname: Sibila
authors.forename: Ivete
authors.initials: I
authors.lastname: Aldabo
authors.forename: María Purificación
authors.initials: MP
authors.lastname: Matute
authors.forename: Carole
authors.initials: C
authors.lastname: Petit
authors.forename: Antoni
authors.initials: A
authors.lastname: Torres
authors.forename: Paolo
authors.initials: P
authors.lastname: Macchiarini
mesh_terms: D000818:Animals; D001187:Artificial Organs; D001367:Axillary Vein; D001784:Blood Gas Analysis; D004195:Disease Models, Animal; D004869:Equipment Safety; D005112:Extracorporeal Circulation / Q000295:instrumentation*; D005240:Feasibility Studies; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D016017:Odds Ratio; D011336:Probability; D011652:Pulmonary Circulation / Q000502:physiology; D011659:Pulmonary Gas Exchange; D012121:Respiration, Artificial / Q000295:instrumentation; D012129:Respiratory Function Tests; D013552:Swine