Early Markers of Angiogenesis and Ischemia during Bowel Conduit Neovascularization

Abstract

Background Bowel flaps are a good and reliable method to restore the continuity of the aerodigestive tract. Radiated fields, contaminated recipient sites, or depleted recipient vessels may increase the risk for ischemic injury after transfer. During ischemic events, we believe that bowel conduits with serosa have a delayed neovascularization process at its new recipient site.We conducted an ischemia/reperfusion murine model to understand the difference among bowel conduits with and without serosa. Materials and Methods Two groups of rats were compared: control group (jejunal conduit with serosa) and a target group (jejunal conduit without serosa). These conduits were harvested from the peritoneal cavity and transferred into a subcutaneous pocket. After 72 hours of transfer and pedicle ligation, histological changes related to ischemia/reperfusion were assessed. In addition, tissue markers of angiogenesis (CD34), ischemia (lactate dehydrogenase [LDH]), and inflammation (interleukin [IL]-1β and IL-6) were analyzed. Results Two groups (n = 20) of male rats were analyzed. Histology showed intact jejunal mucosa in the target group. The control group showed decreased number of mucin, globet cells, decreased height, and fragmentation of villi with the absence of intestinal glands. Markers of angiogenesis (CD34) were higher in the target group. In addition, markers of ischemia (LDH) (p = 0.0045) and inflammation (IL-1b, p = 0.0008, and IL-6, p = 0.0008) were significantly lower in the target group as compared with the control group. Conclusions In circumstances in which the recipient site does not offer an adequate and healthy bed or a vascular insult occurs, bowel flaps with less amount of serosa may be able to neovascularize faster thereby increasing its chances of survival.