Anastomotic stability and wound healing of colorectal anastomoses sealed and sutured with a collagen fleece in a rat peritonitis model

Background/Objective: Anastomotic insufficiency is associated with increased morbidity and mortality. A collagen fleece that supports anastomosis is effective for preventing anastomosis insufficiency. The objective of this study was to compare between the stability of sutured anastomoses and that of anastomoses sealed with a thrombin/fibrinogen-coated collagen fleece in a rat peritonitis model. Methods: In 72 male Wistar rats, peritonitis was induced with a specially prepared human fecal solution. Surgery at the rectosigmoid junction was performed 24–36 hours later. The different anastomotic techniques used were circular sutured anastomoses, semicircular sutured anastomosis and closure of the anterior wall with collagen patch, and complete closure with a collagen fleece. Bursting pressure, histology of anastomosis, mRNA expression of collagen types I and III, matrix metalloproteinase-13, and vascular endothelial growth factor (VEGF) were investigated after 24 hours, 72 hours, and 120 hours. Results: All animals developed peritonitis of comparable severity. There were no differences in bursting pressures between the three suture techniques after 24 hours, 72 hours, or 120 hours. Anastomoses sealed with a collagen fleece appeared to be slightly less stable only at 24 hours, whereas they appeared to be more stable than semisutured or fully sutured anastomoses at 72 hours and 120 hours. Sealing with a collagen fleece was associated with an increase in granulation tissue, higher mRNA levels for collagen types I and III, and higher VEGF compared to sutured anastomoses. Conclusion: The use of a thrombin/fibrinogen-coated collagen fleece showed similar efficacy to conventional sutures in colorectal anastomoses in the presence of peritonitis inflammation, and may provide additional benefits due to an increase in mature granulation tissue