[The biocompatibility of suture materials used in colon surgery. An experimental study in the rat]

The aim of this experimental study was to compare the tissue behavior of biofragmentable anastomotic ring (BAR) with other synthetic materials used in colonic surgery.

Thirty-three rats were divided into four groups: group 1, sham-operated control animals without material implanted; group 2, with fragments of polypropylene monofilament implanted extraperitoneally in abdominal wound, between musculature and peritoneum; group 3, with metal clips implanted extraperitoneally in abdominal wound, between musculature and peritoneum and group 4, with fragments of biofragmentable anastomotic ring implanted extraperitoneally in abdominal wound, between musculature and peritoneum. Animals were sacrificed 30 days after the operation. Macroscopic and histological criteria were used to characterize the resistance of the wound and the tolerance of the host to the foreign material.

The inflammatory cell reaction of host tissue was significantly greater in group 4 compared with other groups (p < 0.05). In three cases, in group 4, we observed the adhesion of implanted fragment to epiploa. The enumeration of giant cells and the degree of fibrotic reaction was similar in all groups with material implanted, but no significant difference between the groups was observed. Our findings showed the greater biocompatibility of polypropylene and metallic clips, compared to the biofragmentable ring anastomosis. The strong inflammatory reaction in the host tissue caused by biofragmentable anastomotic ring may explain partially clinical postoperative complications (anastomotic wound infection and/or dehiscence and/or stricture).

In conclusion, the choice of suture materials should be based not only on the mechanical properties, but also on their biological interactions between host and suture materials and on the evaluation of their effective cost/benefit.