BACKGROUND: Results in small bowel transplantation are inferior compared to other solid organ transplantations, among other reasons, due to a specific vulnerability to ischemia/reperfusion injury. New strategies are needed to improve organ storage. Here we compare static cold storage in University of Wisconsin solution to storage supplemented with molecular oxygen gas insufflation.

MATERIAL AND METHODS: Rat small bowel was retrieved and either stored unoxygenated (UW) or oxygenated (UW+O2) for 18 h at 4°C. Biochemical parameters, mucosal function, Toll-like receptor upregulation, and parameters of structural integrity were evaluated following isolated reperfusion in vitro for 30 min at 37°C.

RESULTS: Oxygenation showed: ATP concentration was 82 times higher; lactate dehydrogenase release was continuously lower over 30 min; malondialdehyde, a final product of lipid peroxidation (UW+O2 vs. UW; 2.7±0.92 nmol/mL vs. 17.22±10.1 nmol/mL; P<0.05) and nitric oxide concentration (0.87±0.27 µmol/L vs. 2.17±0.29 µmol/L; P<0.001) were significantly lower; whereas mucosal functional integrity (galactose uptake) was better preserved (0.47±0.18 mg/dL vs. 0.35±0.05 mg/dL). Amelioration of tissue damage could be demonstrated by reduced apoptosis (3.3±1.2 AU vs. 28.4±10 AU; P>0.05), and preserved subcellular integrity. Toll-like receptors were significantly less upregulated (TLR2 0.32±0.1 vs. 2.1±1.5-fold and TLR4 1.53±1.14 vs. 11.79±5.4-fold; P<0.05).

CONCLUSIONS: Oxygenated storage is superior to standard storage in University of Wisconsin solution in terms of energetics, tissue damage, and mucosal integrity.

Keywords: Intestine, Small, Organ Preservation Solutions, Organ Transplantation