Microdialysis for detection of renal ischemia after experimental renal transplantation.
OBJECTIVE
We designed an experimental renal transplantation model and evaluated microdialysis as a detector of induced postoperative ischemia, a feared complication that when caused by vascular thrombosis most often causes renal graft loss.


METHODS
Two microdialysis catheters were placed in the left kidney in 16 pigs, including 1 superficially in the renal cortex and 1 fixed on the renal capsule. Two-hour baseline measurements were made at steady state, after which the kidney was removed and subjected to warm and cold ischemia. It was subsequently re-anastomosed end to end in situ and reperfused for 5 hours. Pigs were then randomized into a total renal artery occlusion and a control group.


RESULTS
At baseline there were no changes in local metabolites (glucose, glutamate, glycerol and lactate) and no significant difference between the groups. Glycerol increased 4-fold in each group during cold ischemia but there were no pivotal alterations in other metabolites. After kidney reperfusion glycerol decreased and all metabolites were in steady state after 1 hour. At 30 minutes after postoperative ischemia was introduced there were significant increases in all kidneys in ischemia vs steady state reperfusion levels of cortical lactate, glutamate, glycerol and the lactate-to-glucose ratio (each rank sum test p <0.001). No metabolic changes were seen in controls.


CONCLUSIONS
Microdialysis detected significant metabolic changes after postoperative ischemia in pigs with experimental renal transplantation, while no metabolic changes were observed in controls. In the future microdialysis may become a valuable tool for postoperative observation of transplanted kidneys, most probably with major impact on early graft survival.
Keller
Anna Krarup
AK
Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark.
Jorgensen
Troels Munch
TM
Ravlo
Kristian
K
Nielsen
Torben Kaer
TK
Olsen
L Henning
LH
Stolle
Lars B
LB
D000818:Animals; D005260:Female; D007511:Ischemia / Q000175:diagnosis* / Q000209:etiology* / Q000378:metabolism; D007668:Kidney / Q000098:blood supply* / Q000378:metabolism; D016030:Kidney Transplantation / Q000009:adverse effects*; D017551:Microdialysis; D012077:Renal Artery; D013552:Swine