Abstract

Background

Acute superior mesenteric venous thrombosis (ASMVT) is an abdominal vascular condition. Early recanalization is essential to successful treatment. The aim of the study was to establish rabbit models of ASMVT and assess the time course of intestinal epithelial barrier disruption.

Methods

After surgical exposure of superior mesenteric vein (Sham group), large-vessel (L-group) and small-vessel (S-group) models were established by endothelium damage, stenosis creation, and thrombin injection. At baseline, 6, 9, and 12 h, hemodynamic and serum parameters were tested. Serum from ASMVT patients diagnosed at 24, 36, 48, and 60 h from symptom onset was collected. Intestinal barrier disruption was assessed by tight junction (TJ) protein expression, morphology changes, and bacterial translocation. Mesenteric arteriospasm was measured by flow velocity and intestinal wet/dry weight ratio. The serum level of intestinal fatty acid–binding protein and endotoxin in patients was also measured as an indicator for intestinal barrier function.

Results

Severe acidosis and lacticemia were observed in both the groups. The L-group experienced greater hemodynamic alteration than the S-group. Intestinal barrier disruption was detected by significantly decreased TJ protein expression, histology and ultrastructure injury of TJ, increased permeability, and bacterial translocation, at 9 h in the S-group and 12 h in the L-group. Secondary mesenteric arteriospasm occurred at the same time of complete intestinal barrier disruption and could be a significant cause of bowel necrosis. Significant increased level of intestinal fatty acid–binding protein and endotoxin was found in patients at 48 h in the S-group type and 60 h in the L-group type.

Conclusions

The ASMVT animal models of both the types were first established. The loss of intestinal barrier function occurred at 6 h in the S-group model and 9 h in the L-group model. For clinical patients, the time window extended to 36 h in the S-group type and 48 h in the L-group type.

Keywords:

Mesenteric venous thrombosis; Intestinal epithelial barrier; Acute ischemic injury; Therapeutic time window