BACTERIAL TRANSLOCATION IN A LARGE-ANIMAL MODEL OF SMALL-BOWEL TRANSPLANTATION - PORTAL VS SYSTEMIC VENOUS DRAINAGE AND THE EFFECT OF TACROLIMUS IMMUNOSUPPRESSION

Objective: To study whether bacterial translocation is more prevalent after small-bowel transplantation with systemic venous drainage (SVD) vs portal venous drainage (PVD) and whether it is influenced by immuno suppression. Design: We performed 15 small-bowel transplantations in p igs. Group 1 (n=5) had SVD and no immunosuppression; group 2 (n=6), PV D and no immunosuppression; and group 3 (n=4), PVD and immunosuppressi on with tacrolimus and methylprednisolone sodium succinate. Portal and systemic blood, portal and mesenteric lymph nodes, and liver were cul tured in donors and recipients on postoperative day 0 (POD 0) and in r ecipients on postoperative day 3 (POD 3). Jejunal and ileal contents w ere also sampled at these times. Subjects: Outbred male Yorkshire-Land race pigs. Main Outcome Measures: (1) Blood and tissue bacterial cultu res, (2) blood endotoxin levels, and (3) histopathologic examination. Results: Cultures were positive for bacteria in 32% (16/50) of samples on POD 0 and 88% (22/25) on POD 3 in group 1, in 18% (11/60) of sampl es on POD 0 and 97% (29/30) on POD 3 in group 2, and in 8% (3/40) of s amples on POD 0 and 95% (19/20) on POD 3 in group 3. Systemic blood cu ltures were positive for bacteria on POD 3 in 60% (3/5) of pigs in gro up 1, 83% (5/6) in group 2, and 100% (4/4) in group 3. Significantly m ore bacteria were present in the ileum than in the jejunum on POD 0 in group 2; this difference approached significance in groups 1 and 3. B acterial numbers were identical in the ileum and jejunum by POD 3 in a ll groups. Circulating endotoxin levels were significantly elevated on POD 3 vs POD 0 only in group 1. Endotoxin levels were not significant ly different between the SVD group (group 1) and either PVD group (gro ups 2 and 3). Conclusions: Bacterial translocation is prevalent after small-bowel transplantation in pigs whether PVD or SVD is used. Immuno suppression with tacrolimus does not prevent bacterial translocation b ut may reduce systemic endotoxemia.