A comparative study of biological reactions to different suture materials in animal model

Sutures play an important role in wound healing. The search for more appropriate suture material has resulted in a variety of natural and synthetic, absorbable and non-absorbable sutures available commercially. These features influence biological reactions to the sutures. Surgical trauma and the presence of foreign body material, both induce inflammatory tissue reaction surrounding sutures causing damages to the tissue defenses, infection, delay in coordinated onset of the proliferative phase and impairs optimum wound healing, also causing excessive scar tissue which is associated with poor wound strength. Study aimed to compare the biological reactions (intensity of inflammation, neo-vascularization, and fibrosis formation) to four different suture materials silk, polypropylene [Prolene], polyamide [nylon], and polyglactin [Vicryl]) implanted in the subcutaneous tissue of guinea pigs and decide on suture material having better effect on wound healing. Assessment was done for histopathological evaluation on light microscope. Study was conducted at central animal house, a tertiary care medical college in western Maharashtra, India. It involved 25 healthy adult guinea pigs, randomly divided into five groups, with 4 groups receiving different suture materials and 1 control group. Age (P=0.97), weight (P=0.96) across the groups showed no significant differences, ensuring uniformity in the physical condition of the subjects. Inflammatory response- silk showed the highest moderate infiltration (60%), followed by nylon (40%). However, differences in inflammation levels among the groups were not statistically significant (P=0.271). Fibrosis- were present in most animals, with no significant differences across the groups (P=0.384). Neovascularization- were observed in all groups, with vicryl showing the highest absence (80%) and the control group showing a balanced distribution. Variations were not statistically significant (P=0.797). Gross findings like visible sutures, erythema, swelling, seroma, suture extrusion, wound dehiscence, stitch abscess were not observed in any study animals, indicating good biocompatibility. There were no statistically significant differences among the suture materials in terms of inflammatory cell infiltration, fibrosis formation, neovascularization. Also, no significant gross findings. This suggests that all the tested suture materials show similar levels of biocompatibility and minimal adverse reactions when used in the subcutaneous tissue of guinea pigs.