Bowel ischemia monitoring using rapid sampling microdialysis biosensor system

Abstract

Objective: Intestinal ischemia, during and after surgery, is a major cause of sepsis leading to multiple organ failure. Complications associated with gastrointestinal surgery can be severe enough to present high mortality rate among patients. Anastomosis site, the connection site of the transected bowels, is prone to leak, leading to intestinal ischemia. Monitoring metabolic changes in the bowel intraoperatively and post-surgery is of great interest as an early marker of intestinal ischemia. Methods: Microdialysis has proved its efficacy in monitoring ischemia in bowel. We have developed an on-line rsMD technique for monitoring metabolites in the human bowel during gastrointestinal surgery. This analyses electrochemically the dialysate glucose and lactate at high time resolution (typically 30sec.) The system consists of a flow injection analysis (FIA) system coupled to an enzyme based amperometric detector. This work compares the metabolic changes monitored in healthy human bowel during surgery and in the compromised anastomotic site of swine models. Results: Metabolic response of ischemia in healthy human tissue showed a 20 min therapeutic window, subtend by collateral flow. In contrast, microdialysis monitoring in anastomosis site in animal models showed a rapid response 5 min after artery transection, indicating the severe effect of ischemia when the tissue blood supply was compromised. Conclusion: On-line rapid sampling microdialysis biosensor system can be used to monitor the transit from healthy to ischemic tissue in human bowel and to predict an early ischemic event in the anastomotic segment of porcine animal models. © 2011 Springer-Verlag.