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 immunosuppression.


METHODS
We performed 15 small-bowel transplantations in pigs. Group 1 (n = 5) had SVD and no immunosuppression; group 2 (n = 6), PVD and no immunosuppression; and group 3 (n = 4), PVD and immunosuppression with tacrolimus and methylprednisolone sodium succinate. Portal and systemic blood, portal and mesenteric lymph nodes, and liver were cultured in donors and recipients on postoperative day 0 (POD 0) and in recipients on postoperative day 3 (POD 3). Jejunal and ileal contents were also sampled at these times.


METHODS
Outbred male Yorkshire-Landrace pigs.


METHODS
(1) Blood and tissue bacterial cultures, (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 samples on POD 0 and 97% (29/30) on POD 3 in group 2, and in 8% (3/40) of samples on POD 0 and 95% (19/20) on POD 3 in group 3. Systemic blood cultures were positive for bacteria on POD 3 in 60% (3/5) of pigs in group 1, 83% (5/6) in group 2, and 100% (4/4) in group 3. Significantly more 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. Bacterial numbers were identical in the ileum and jejunum by POD 3 in all groups. Circulating endotoxin levels were significantly elevated on POD 3 vs POD 0 only in group 1. Endotoxin levels were not significantly different between the SVD group (group 1) and either PVD group (groups 2 and 3).


CONCLUSIONS
Bacterial translocation is prevalent after small-bowel transplantation in pigs whether PVD or SVD is used. Immunosuppression with tacrolimus does not prevent bacterial translocation but may reduce systemic endotoxemia.
Fryer
J P
JP
Department of Surgery, University of Minnesota, Minneapolis, USA.
Kim
S
S
Wells
C L
CL
Fasola
C
C
Jechorek
R P
RP
Dunn
D L
DL
Pirenne
J
J
Arazola
L
L
Gruessner
R W
RW
D000818:Animals; D018988:Bacterial Translocation / Q000187:drug effects; D004322:Drainage; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007421:Intestine, Small / Q000382:microbiology* / Q000473:pathology / Q000637:transplantation*; D008297:Male; D013552:Swine; D016559:Tacrolimus / Q000494:pharmacology
D007166:Immunosuppressive Agents; D016559:Tacrolimus