Luminal Preservation Protects the Small Intestine in a Brain-dead Rat Model

Intestinal transplantation depends on donation after brain death (DBD). Luminal preservation (LP) has been beneficial against preservation injury in previous studies in animal models, but none include DBD. This study aims to investigate whether these benefits occur also with DBD.

Wistar rats (male, N = 9) underwent brain death for 2 h. Thereafter, vascular perfusion was done with University of Wisconsin solution (UW). The small intestine was then explanted and randomized into 3 groups: control (empty segment), LP+PEG (with polyethylene glycol 3350 solution), or LP+UW (with UW), treated and tied shut. Ice-cold UW was used for cold storage. Samples were taken at procurement and after 4 (t = 4) and 8 h (t = 8) of preservation. Histopathological scorings were performed for intestinal preservation injury, subepithelial space, absence of epithelial lining, and hemeoxygenase-1 expression.

There was low-level mucosal injury (median intestinal preservation injury score 2) at procurement. At t = 4, bowels treated without LP had more damage than LP-treated samples (control score 4, LP+PEG 2 and LP+UW 2, P < 0.001 control versus LP+UW). At t = 8, no benefit of LP was observed (control 2, LP+PEG 3, LP+UW 2). Subepithelial space increased with time and the presence of LP; epithelial lining was better conserved in LP-treated samples. Hemeoxygenase-1 staining showed increased intensity with increased damage, irrespective of treatment.

Luminal perfusion of the small intestine with UW or PEG protects the mucosa in brain-dead rats for up to 4 h. Fewer benefits of LP were found than previously described in non-DBD models. To mimic the clinical situation, DBD should be included in future animal studies on intestinal preservation.