31P NMR assessment of orthotopic rat liver transplant viability. The effect of warm ischemia.

The relationship between NMR visible high energy phosphates and transplant outcome for the case of liver damage by warm ischemia was investigated. In vivo 31P nuclear magnetic resonance (NMR) spectroscopy of rat liver was performed before the induction of warm ischemia in the donor and 20 min after reestablishment of portal blood flow in the recipient. Pretransplant damage was varied by subjecting the livers to 0, 15, 30, or 60 min of warm ischemia prior to harvesting. In the controls (0 min warm ischemia), 4 of 4 rats survived transplantation (one week survival end-point) and the mean NTP recovery was 94 +/- 8%; 3 of 6 rats survived in the 15 min warm ischemia group. Mean NTP recovery was 77 +/- 20% in the 15 min survival subgroup and 32 +/- 20% in the nonsurvival subgroup. Of 6 rats, 1 survived in the 30 min group. NTP recovery was 44% for the 30 min survivor and 37 +/- 5% in the nonsurvival subgroup. Of 4 rats, 1 survived in the 60 min warm ischemia group. NTP recovery was 56% for the 60 min survivor and 28 +/- 7% in the nonsurvival subgroup. Overall, there was a significant difference between the mean NTP recovery of the survival and nonsurvival subgroups (78 +/- 21% versus 31 +/- 18%, P < 0.001). The dividing line between the survival and nonsurvival groups was approximately 50% NTP recovery. Of 9 rats with liver NTP recovery greater than 50%, 8 survived while 10 of 11 rats with less than 50% recovery died. NMR visible NTP recovery 20 min after the reestablishment of portal blood flow was a good indicator of transplant outcome in the case of rat liver damage by warm ischemia.