In many cases, tissue‐healing times were determined using animal models to assess healing in mammalian tissues. Studies have shown differences in healing times between mammalian species (Cornell 2012), and these will vary significantly from reptile or amphibian tissues. The healing times presented here are to demonstrate the relationship between loss of tensile strength, time to complete absorption, and tissue healing. Veterinarians must consider the specifics of the species and tissues they are operating on to determine the best suture choice.
Table 2.1 Percentage of retained tensile strength following implantation and number of days required for complete absorption for commonly available suture materials.
| Suture material | 7 d | 14 d | 21 d | 28 d | 42 d | Complete absorption (d) |
|---|---|---|---|---|---|---|
| Chromic gut | 0 | 60–90 | ||||
| Polydioxanone (PDS) | 70 | 50 | 25 | 180–210 | ||
| Polyglyconate (Maxon) | 80 | 75 | 65 | 50 | 25 | 180 |
| Glycomer 631 (Biosyn) | 75 | 40 | 90–110 | |||
| Polyglecaprone 25 (Monocryl) | 60–70 | 30–40 | 90–120 | |||
| Polyglycolic acid (Dexon) | 20 | 60 | ||||
| Polyglactin 910 (Vicryl) | 75 | 50 | 25 | 56–70 | ||
| Lactomer (Polysorb) | 80 | 30 | 56–70 | |||
| Polyglytone 6211 (Caprosyn) | 50–60 | 20–30 | 0 | 56 | ||
| Polyglactin 910 (Vicryl Rapide) | 50 | 0 | 42 | |||
| Oral mucosa | X‐‐‐‐X | |||||
| Skin | X‐‐‐‐‐‐‐‐‐‐‐‐‐‐X | |||||
| Subcutaneous tissue | X‐‐‐‐‐‐‐‐‐‐‐‐‐‐X | |||||
| Bladder | X‐‐‐‐‐‐‐‐‐‐‐‐‐X | |||||
| Gastrointestinal tract | X‐‐‐‐‐‐‐‐‐‐‐X (SI) X‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐X (LI) | |||||
| Fascia | X‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐X | |||||
Ranges in healing times are shown for different tissues. SI, small intestine; LI, large intestine.
Sutures in Exotic Animals
Rodents
Due to extensive use of rodents in research, suture reaction in rodents has been studied extensively with studies evaluating many suture types in specific applications. Rats have been used extensively to compare suture materials in the body wall, subcutaneous tissues, skin, urogenital tract, gastrointestinal tract, and oral cavity.
Several studies have compared suture materials in the body wall, subcutaneous tissues, and skin using rodent models. A study evaluating polyglyconate, polyglactin 910, chromic gut, and polydioxanone in the body wall of rats showed that polyglyconate and polydioxanone caused significantly less inflammation 28 days following implantation (Sanz et al. 1988). When polyglytone 6211 was compared to poliglecaprone 25 in the body wall of rats, there was no significant difference in the inflammatory response 2 or 10 days following implantation (van Heerden 2005). Comparison of poliglecaprone 25, polyglactin 910, and polytetrafluoroethylene (Teflon) in subcutaneous tissues showed that poliglecaprone 25 caused significantly less inflammation 48 hours after implantation and polytetrafluoroethylene sutures caused significantly more inflammation and fibrosis 7, 14, and 21 days following implantation (Nary‐Filho et al. 2002). A study comparing polyglactin 910, catgut, silk, and polypropylene in the skin showed that polyglactin 910 caused significantly less inflammation over a period of 7 days (Yaltirik et al. 2003). Comparison of polydioxanone, poliglecaprone 25, and Glycomer 631 in rat skin showed that poliglecaprone 25 and Glycomer 631 were less reactive than polydioxanone, but all three were acceptable due to extremely low reaction scores (Molea et al. 2000). When polyglytone 6211 was compared to chromic gut for skin closure in rats, polyglytone 6211 had significantly less tissue drag and less potentiation for infection when surgical wounds were inoculated with Staphylococcus aureus (Pineros‐Fernandez et al. 2004).
Several studies have been performed comparing suture materials in the urogenital tracts of rats with the aim to evaluate inflammation, fibrosis, and adhesion formation. A comparison of polyglactin 910 and polyglycolic acid in uterine tissue showed that there was significantly less inflammation and fibrosis with polyglactin 910 90 days following implantation (Riddick et al. 1977). Another study evaluating suture material in uterine tissues compared polyglycolic acid, polyglactin 910, polydioxanone, silk, and polypropylene. The results showed that polydioxanone caused the lowest reaction scores and polypropylene lead to the highest rate of granuloma formation (Quesada et al. 1995). Evaluation of inflammatory reactions to polypropylene, polyglactin 910, and catgut and their role in adhesion formation showed that polypropylene