Anastomotic suture materials and implantation metastasis: an experimental study.

Suture implantation of viable exfoliated malignant cells may be responsible for local recurrence (implantation metastasis) of colorectal cancer. In this study, four anastomotic materials (braided polyamide, braided polyglycolic acid, monofilament polypropylene and monofilament stainless steel) were compared with respect to their ability to entrap and transfer free Mtln3 carcinoma cells from the colonic lumen of a rat. The braided materials transferred greater numbers of cells than did the monofilament sutures (P less than 0.001), but significant differences were also observed between polyglycolic acid and polyamide (P less than 0.001) and between polypropylene and stainless steel (P less than 0.05). Secondly, the firm adherence of tumour cells to the suture materials was assessed by an in vitro technique. The Mtln3 cells were found to adhere in significantly greater quantities to the braided sutures than to the monofilaments (P less than 0.001) and this was supported by in vivo tumour growth studies. These findings may have implications for colorectal cancer surgery in man.