Different impact of normo- and hypotensive brain death on renal macro- and microperfusion--an experimental evaluation in a porcine model

Initial experience with hypothermic machine perfusion of kidneys from deceased donors in the Uppsala region in Sweden

BACKGROUND

Simple cold storage (CS) is the gold standard for organ preservation. Recently, evidence has been presented suggesting compared with CS hypothermic machine perfusion (HMP) improves the quality and outcome of kidneys for transplantation. Uppsala has used the LifePort Kidney Transporter to preserve deceased donor kidneys. We evaluated our first single-center 52 cases retrospectively.

METHODS

Deceased donor kidneys preserved with HMP between July 2010 and July 2012 (n = 52) were compared with a matched historical cohort of organs preserved by CS between January 2009 and July 2012 (n = 87). We evaluated delayed graft function (DGF), creatinine level at hospital discharge, length of hospital stay, incidence of acute rejection episodes during the first year after transplantation, and graft survival.

RESULTS

Both groups included approximately 69% expanded criteria donors (ECD). Median cold ischemia time (CIT) was 12.8 hours in the HMP group and 11.7 hours in the CS group. The incidence of DGF was 11.5% with HMP and 20.7% with CS. Compared with CS, HMP significantly reduced the occurrence of DGF from 21.4% to 0% using standard criteria kidneys (P = .046), whereas the use of HMP did not impact the occurrence of DGF with ECD kidneys. The creatinine level at hospital discharge was lower after HMP than after CS (P = .047). No difference in graft survival was observed between the groups.

CONCLUSIONS

Machine perfusion resulted in a lower occurrence of DGF using kidneys from standard criteria donors with a lower creatinine at hospital discharge among the cohort with reasonably low CIT. Using machine perfusion seems to be safe; no adverse surgical events occurred during the study period.

Distinct effects of surgical denervation on hepatic perfusion, bowel ischemia, and oxidative stress in brain dead and living donor porcine models

The liver function and perfusion following brain death is mainly influenced by the sympathetic nerves and hormones. We examined the specific influence of surgical liver denervation on systemic and hepatic perfusion parameters, bowel ischemia and oxidative stress in hemodynamically stable BD and control (living donor [LD]) pigs. Brain death was induced in 8 pigs via saline infusion into the balloon of an epidural Tieman-catheter (1 mL/15 minutes) and compared to the control group (n = 6) over 4 hours. At 2 hours postoperatively, complete liver denervation was initiated. We analyzed systemic cardiocirculatory parameters (mean arterial pressure, aortic flow, bowel ischemia (endotoxin, and endotoxin-neutralizing capacity) and oxidative stress (total glutathione in erythrocytes [tGSH(E)]) and compared them to local/hepatic perfusion parameters (hepatic artery and portal venous flow, liver blood flow index, and microperfusion), local bowel ischemia (intramucosal pH [pHi] of stomach [pHi(S)]/colon[pHi(C)]), and liver oxidative stress (glutathione [rGSH(L), GSSG(L)]). Following brain death, the parameters including mean arterial pressure, aortic flow, pHi, endotoxin, and tGSH(E) showed no significant changes at 2 hours. Portal venous flow and microperfusion were decreased significantly and hepatic arterial buffer response was ineffective. Hepatic oxidative stress was increased in BD animals (decrease rGSH(L), increase GSSG(L)). Surgical denervation/manipulation increased portal venous flow significantly, hepatic arterial buffer response became effective, and stomach pHi decreased (BD and LD groups). Hepatic oxidative stress was reduced in the BD group (increase rGSH(L)/GSSG(L); P < 0.001) while it was increased in the LD group (decrease rGSH(L)/GSSG(L); P < 0.001). In conclusion, denervation reduces hepatic oxidative stress in BD only in contrast to the LD. The reciprocal effect of denervation depends on the state of neural activation and postulates a potential benefit of surgical denervation before organ harvesting in brain death.