Luminal contact with University of Wisconsin solution improves human small bowel preservation

Under clinical conditions small bowel mucosa is stored without any contact between the mucosa and the preservation solution. We evaluated the impact of luminal contact with University of Wisconsin solution (UW) on the structural quality of small bowel preservation.

Segments of ileum harvested from stable multi-organ donors were flushed with UW. For each donor, ileal segments were placed in UW without any contact between the mucosa and the preservation solution (group A), as is practiced in clinical conditions. Adjacent segments were cut on their antimesenteric side and placed in UW so that their mucosa was widely in contact with the solution (group B). The grafts preserved in ice were removed from the preservation fluid at different times (0, 3, 6, or 12 hours). Tissues were studied by optical microscopy after H&E staining of formalin-fixed, paraffin-embedded specimens. A median histologic score was calculated after examination of three random slides for each ileal segment per time point. Comparisons were performed between tissues of groups A and B from the same donor.

Control (0h) specimens showed normal histology. As early as 3 hours of preservation, group A tissues showed detachment of the villar epithelium. At 6 and 12 hours of preservation in this group further tissue alteration were obvious with complete epithelial detachment from the basal membrane of the villi. The histologic score of the segments preserved by luminal contact with UW was always significantly higher than the controls from the same donor.

Luminal contact between the mucosa of intestinal grafts and UW improves the quality of human small bowel preservation.