STEEN Solution™ Leaflet
For reliable objective ex vivo assessment of "marginal" and rejected lungs
STEEN Solution™ is a buffered extracellular solution optimally designed to perfuse the isolated donor lung during ex-vivo lung perfusion. STEEN Solution™ includes human serum albumin to provide an optimal colloid osmotic pressure and dextran 40 to coat and protect the endothelium from excessive leucocyte interaction. STEEN Solution™ is intended for assessment of isolated lungs after removal from the donor body for eventual transplantation into a recipient.
STEEN Solution™ is designed to facilitate prolonged evaluation and promote stability of isolated lungs ex vivo. The STEEN Solution™ perfusate and circuitry can maintain stable lung function, without edema formation, for up to 10 hours at 37 °C 7, 12, 20-24.
About four of every five lungs offered for transplantation are currently rejected by present selection criteria1,2. Rejected lungs from marginal and extended donors have been successfully used for transplantation for almost 2 decades and the concept has now become routine practice 3,4,5,18, 19, 20. The number of transplants of lungs perfused ex vivo is now well above 350 and the number is increasing with the clinical EVLP programs being established world-wide.
Already in 1935, Alexis Carrel and Charles Lindbergh reported the first ex vivo organ perfusion showing that organs could remain viable for several days25. After a lapse of some 60 years, the concept was re-ignited again by Steen et al in the 1990s who developed ex vivo lung perfusion (EVLP) as a modern practical procedure for the assessment of marginal lung function, including gaseous exchange at 37 °C 6,7, 8, 9,10 and has since been adopted and modified by other centres12,13. The method is now an established clinical routine in most major lung transplant centres world-wide 11, 18, 19, 21-24.
With EVLP, the perfusion circuit of the lung mimics in-vivo conditions; the ventilated lung is perfused with deoxygenated STEEN Solution™, with or without red cells, and the critical parameters of gaseous exchange, pulmonary vascular resistance and other key variables under normothermic conditions are monitored. Variables such as pressures, flow rate, dynamic compliance, and small airway resistance are frequently used as markers of organ status.
The lungs are enclosed in the transparent container, XVIVO Organ Chamber, to maintain optimal humidity.
The “venous” afferent side of the closed circuit is connected to a pump and a heat and gas exchanger so that the perfusate – STEEN Solution™ (with or without red blood cells) – assumes physiological temperature and partial gas pressures. A leucocyte filter is connected before the inflow to prevent leucocyte-induced tissue injury. Perfusion pressure is closely monitored and should never exceed 20 mm Hg.
Since the lungs are generally cold before perfusion, initial flow rates must be very low, gradually increasing as the temperature increases. The flow should never exceed 4 l/min. Careful ventilation is begun as the temperature of the perfusate outflow reaches 32 °C and full ventilation is begun as it reaches 37 °C.
Functional assessment can begin when the circuit has reached the steady state described above, monitoring arterial and venous blood gases, end-tidal carbon dioxide and a range of hemodynamic parameters.
To Order: REF 19004; 500 mL bottle
Content: 1 bottle contain 500 ml STEEN Solution™
Packaging: PETG bottle
Storage: Store dark at +2 to + 8oC in an upright position. Use only unopened and undamaged packages.
Shelf life: At least three months from date of shipment.
Intended Use: STEEN Solution™ is intended for assessment of isolated lungs after removal from the donor in preparation for eventual transplantation into a recipient.
Bacterial Endotoxins EU/ml <0.25
Osmolality (mOsm/kg) 275 – 315
pH 7.1 – 7.7
*Humanitarian Device. Authorized by Federal law in the USA for use in flushing and temporary continuous normothermic machine perfusion of initially unacceptable excised donor lungs during which time the ex-vivo function of the lungs can be reassessed for transplantation. The effectiveness of this device for this use has not been demonstrated.