Effects of nonocclusive mesenteric hypertension on intestinal function: implications for gastroschisis-related intestinal dysfunction.

ABSTRACT

INTRODUCTION: Infants with gastroschisis (GS) have significant morbidity from dysmotility, feeding intolerance, and are at increased risk of developing intestinal failure. Although the molecular mechanisms regulating GS-related intestinal dysfunction (GRID) are largely unknown, we hypothesized that mechanical constriction (nonocclusive mesenteric hypertension (NMH)) from the abdominal wall defect acts as a stimulus for GRID. The purpose of this study was to determine the effect of NMH on intestinal function and inflammation. METHODS: Neonatal rats had placement of a silastic disk to the base of the mesentery (NMH) or no disk placement (Sham). At 24 and 72 h, mesenteric venous pressures (MVPs), intestinal transit, electric impedance, permeability, length, and tissue water content were measured. RESULTS: After placement of the silastic disk, there was a significant increase in MVP at both time points. There was also decreased intestinal transit. As compared to Sham animals, NMH animals had significant changes in bowel impedance without an increase in tissue water, suggesting significant intestinal remodeling. NMH rats had significantly increased smooth-muscle thickness and loss of intestinal length as compared with Sham rats. DISCUSSION: NMH may be an initiating factor for GRID. Measurement of MVP and/or bowel impedance may be a way to assess severity and monitor progression and/or resolution of GRID.