Impact of portal and systemic venous drainage on early inflammatory responses in a swine model of living donor intestinal transplantation.

BACKGROUND

Venous outflow is a key determinant of immune and metabolic homeostasis following intestinal transplantation. In living-donor settings, maintaining physiologic portal drainage may attenuate systemic inflammation and support local defense mechanisms during early reperfusion. This study investigated the molecular and histological effects of portal versus systemic venous drainage in a swine model of living-donor intestinal transplantation.

METHODS

Twenty-two swine intestinal transplants were assigned to portal (n = 12) or caval (n = 10) drainage. Grafts were preserved in Custodiol® (HTK), implanted orthotopically, and sampled two hours after reperfusion. Intestinal and hepatic tissues underwent qRT-PCR analysis of inflammatory, apoptotic, endothelial, and oxidative-stress pathways. Histological injury was scored (0-3). Groups were compared using the Mann-Whitney U test with Bonferroni and FDR adjustment.

RESULTS

Histopathological alterations were mild and comparable between groups in both intestinal and hepatic tissues, with no significant differences across epithelial, vascular, inflammatory, or necrotic parameters. In intestinal samples, IL-1α (fold-change = 6.76; p = 0.013) and IFN-γ (fold-change = 2.10; p = 0.023) exhibited higher early expression in portal-drainage grafts, although neither signal remained statistically significant after multiple-testing correction. The remaining markers showed broadly overlapping distributions. In the liver, CD8 demonstrated the largest numerical difference (fold-change = 0.48; p = 0.044), but no hepatic target reached significance after adjustment.

CONCLUSIONS

Portal and caval drainage produced comparable early histological injury and only subtle molecular variation. Although not significant after adjustment, these early transcriptional shifts suggest potential immunometabolic effects of venous outflow configuration and represent exploratory, hypothesis-generating findings that warrant further study.