Postoperative monitoring of colorectal anastomosis - experimental study.

Introduction: Inadequate blood supply is one of the major risk factors for colorectal anastomotic leak. Early postoperative detection of local ischemic changes can predict complicated healing and lead to better outcome. Microdialysis (MD) offers real-time evaluation of adequate bowel perfusion through monitoring of tissue metabolism. The aim of this study was to assess the feasibility of MD for early detection of ischemic changes in colorectal anastomosis.

Method: Five pigs with end-to-end colorectal anastomosis were included. MD catheter was placed intramurally 5mm from anastomotic edge. Occlusive ischemia was induced after 3 measurements and followed by another 3 hours of monitoring. Tissue levels of different metabolites were measured every 60 minutes before and after ischemia induction. Mann-Whitney test was used to compare pre and post ischemic changes.

Results: The monitoring of colorectal anastomosis using MD was technically feasible and associated with no complications. Significant changes caused by local ischemia were observed in decreased levels of glucose or pyruvate and increased levels of lactate and glycerol. All metabolic changes were detectable already in first samples 60 minutes after ischemia induction.

Conclusion: Postoperative ischemic changes in colorectal anastomosis can be detected by means of microdialysis.Key words: colorectal anastomosis anastomotic leak microdialysis.