Successful 20-hour storage of the canine liver by continuous hypothermic perfusion*

Summary Fifteen canine livers were stored by means of continuous hypothermic (10°C) perfusion using homologous serum as the perfusate. The organs were transplanted as allografts. Succinate and glucose were added as substrates and other additives included hydrocortisone, heparin, insulin, and Keflin. Flow rate was adjusted to give a portal vein pressure of 6 to 8 cm of H 2 O and hepatic artery pressure of 80 mm Hg. Of the initial seven attempts to store the liver for 20 hrs only one organ sustained life for 1 week and it exhibited severe damage. The remaining six died within 12 to 48 hrs from a hemorrhagic diathesis. Two of two organs were held successfully for 7 brs using an identical storage procedure; one of these animals survived 8.5 months. Storage conditions were then altered. The perfusate pH was adjusted to 7.0 (37°C) instead of 7.25 (37°C) which was used in the initial nine attempts. Also, substrate level was supplemented after 6 to 10 hrs of perfusion. The six animals receiving these latter organs after 20-hr storage were walking 2 to 4 hrs after surgery and they exhibited no bleeding. Four of the six organs were considered successfully stored for the 20-hr period. A reusable all-Silastic perfusion system was developed for the above studies. The perfusion circuit consists of a series of Silastic tubings and incorporates a simple reusable membrane oxygenator.