Silk Fibroin Sheets Improve the Strength of Colon Anastomoses in Wistar Rats

Colorectal resection and subsequent anastomosis are the standard curative procedures for a variety of colorectal pathologies. However, anastomotic leakage (AL) is an early and frequent complication that can have life-threatening outcomes. The study aimed to evaluate the effect of silkworm fibroin sheets on colon anastomotic strength and wound healing early after intervention in Wistar rats. Male Wistar rats were randomized into two groups, control (N = 11) and fibroin (N = 11), and subjected to end-to-end colo-colic anastomosis. In the fibroin group, a single layer of fibroin membrane was applied externally around the anastomosis. The animals were sacrificed three days after the operation (POD3) and intestinal adhesions, anastomotic bursting pressure and histological parameters based on the eosin, hematoxylin, and Masson's trichrome stains were compared between the groups. Fibroin-treated rats showed a significant increase in anastomotic bursting pressure compared to control animals (69 (18) vs. 41 (28) mmHg), whereas no differences in the intestinal adhesion scores were detected. No significant differences in the numbers of granulocytes, monocytes/macrophages and fibroblasts, nor the amount of collagen fibers, as measured by Masson's trichrome stain, were found between the groups. These results indicate that fibroin sheets could represent a simple and promising tool to provide mechanical support and improve colonic anastomotic strength early after intervention.