The omentum is a site of stromal cell–derived factor 1α production and reservoir for CXC chemokine receptor 4–positive cell recruitment

Abstract Background The mechanism of the omental response to injury remains poorly defined. This study investigates the omental reaction to a foreign body, examining the role of a chemokine ligand/receptor pair known to play a crucial role in angiogenesis and wound healing. Methods A ventral hernia, surgically created in the abdominal wall of 6 swine, was repaired with silicone sheeting to activate the omentum. Omental thickness was determined by ultrasonography. Serial stromal cell–derived factor 1α (SDF-1α) concentrations were measured in blood, wound, and peritoneal fluids by enzyme-linked immunosorbent assay. Results During the 14-day study period, serial ultrasonography showed a 20-fold increase in omental thickness, and enzyme-linked immunosorbent assay revealed a 4-fold increase in SDF-1α concentration in local wound fluid. Omental vessel count and vascular surface area were 8- to 10-fold higher in reactive omentum. Immunohistochemistry showed nearly complete replacement of control omental fat with CXC chemokine receptor 4 (CXCR4)-positive cells by day 14. Conclusions Activated omentum, important in the SDF-1α/CXCR4 axis, may serve as an intraperitoneal reservoir for recruitment of circulating bone marrow–derived cells vital to healing.