Effect of cyclosporine on fresh and preserved orthotopic small bowel allografts.

Twenty-three unrelated mongrel dogs underwent successful transplantation of the entire small intestine in the orthotopic location. Four groups of unrelated mongrel dogs were studied. Group I (n = 6) animals served as controls and received no immunosuppression. Survival of 5.3 +/- 3.8 days (M +/- SD) was noted. Poor survival (7.2 +/- 7.9 days; M +/- SD) was also seen in Group II (n = 6) dogs receiving immunosuppression with azathioprine post-operatively. Animals in Group III (n = 6) were treated with cyclosporine, until death or sacrifice at 40 days, and demonstrated a prolonged survival of (17.5 +/- 13.7 days; M +/- SD). All animals in Groups I, II and III were immediately transplanted with fresh bowel from the donor animal. Small bowel allografts in Group IV (n = 5) animals were stored for 24 hours in hypothermic TP-V (a hypersomolar colloid solution containing ATP-MgC1(2)) prior to transplantation. These animals received the same amount of cyclosporine as those in Group III, and similar survival was noted (16.4 +/- 12.9 days; M +/- SD) (p greater than 0.1). These results indicate that transplanted animals who were treated with cyclosporine post-operatively, and for successive days thereafter (Groups III and IV), achieved prolonged but not uniformly indefinite graft survival. Most importantly, similar survival among these two groups was evident, whether or not the allograft was fresh, or preserved for 24 hours in hypothermic storage with TP-V prior to transplantation.