reactions after implantation of different suture materials to demonstrate variation in inflammatory reactions. Samples were chosen as representative examples of zero (a), mild (b), moderate (c), and severe (d) inflammatory responses. Suture material was lost in (a) and (b) during processing, but surrounding inflammatory reaction is intact.
Images are 20× magnification.
Various companies manufacture generic versions of most of these suture materials. In one study comparing the same material made by two different companies (Ethicon, Inc., and Hyaiyin Medical Instruments Co. Ltd.), the materials had significantly different tensile strength and stiffness (De La Puerta et al. 2011). In some comparisons, the generic outperformed the brand name materials. Most studies of suture materials are conducted using brand name materials. Based on this study, direct comparisons between brand names and generic materials cannot be made.
Biologic Absorbable Suture Material
Chromic Gut
Chromic gut is a monofilament absorbable suture composed of purified connective tissue (mostly collagen) derived from either bovine or ovine intestine and is absorbed by phagocytosis and enzymatic digestion by macrophages (Bellenger 1982; Roush 2003). Chromic salts are used to coat the suture to help delay absorption, increase tensile strength, and decrease tissue reactivity. Chromic gut is rapidly absorbed in mammals, is completely absorbed in approximately 60–90 days, and only maintains tensile strength for 7–10 days (Ratner et al. 1994). Chromic gut has a tendency to cause increased inflammatory response compared to other absorbable sutures which makes it less desirable.
Synthetic Absorbable Suture Materials
Synthetic absorbable sutures are all composed of different monomers or polymers. Each monomer affects the resultant strength, flexibility, and speed at which the suture is absorbed. Monomers used in most currently available sutures include glycolide, lactide, p‐dioxanone, ε‐caprolactone, and trimethylene carbonate. Glycolide and lactide contribute to the resulting strength of the suture, while ε‐caprolactone and trimethylene carbonate contribute to increased flexibility. p‐Dioxanone contributes moderate strength and moderate flexibility. Combinations of these monomers in different proportions are used to obtain desired properties for different applications.
Polydioxanone
Polydioxanone is a monofilament absorbable suture that elicits minimal reaction, is slowly absorbed, and maintains tensile strength for extended periods. It maintains 70% of its tensile strength at 2 weeks, 50% at 4 weeks, and 25% at 6 weeks with complete absorption in approximately 180 days (Bellenger 1982; Ratner et al. 1994; Roush 2003). Initial tensile strength for polydioxanone is greater than surgical gut, polyglycolic acid, or polyglactin 910, but it has the poorest knot security of the synthetic absorbable sutures (Boothe 1998). It is useful when prolonged support of healing tissue is desired (Tan et al. 2003).
Poliglecaprone 25
Poliglecaprone 25 is a monofilament absorbable suture composed of segmented block copolymers of ε‐caprolactone and glycolide (Bezwada et al. 1995). Soft segments of ε‐caprolactone and glycolide contribute to favorable handling characteristics and hard segments of polyglycolide contribute to tensile strength. Poliglecaprone 25 is one of the strongest absorbable sutures, although it rapidly weakens after implantation (Tan et al. 2003). Tensile strength of 20–30% is maintained at 2 weeks and complete absorption occurs between 90 and 100 days (Bezwada et al. 1995; Roush 2003).
Polyglactin 910
Polyglactin 910 is a multifilament suture composed of a copolymer of lactic and glycolic acids that are coated with calcium stearate and a second copolymer of glycolide and lactide. The braided nature of this suture not only results in good handling properties but also increases tissue drag (Ratner et al. 1994). Tensile strength is approximately 60% at 2 weeks and only 30% at 3 weeks with complete absorption in approximately 60 days (Bellenger 1982; Ratner et al. 1994; Fossum 2002; Roush 2003). Vicryl Rapide™ (polyglactin 910) has 66% of the initial tensile strength and loses tensile strength faster compared to regular polyglactin 910 (Tan et al. 2003). It is designed for rapidly healing tissues where long‐term support is not required.
Polyglyconate
Polyglyconate is a monofilament suture composed of copolymers of glycolide and trimethylene carbonate. Tensile strength is approximately 80% at 1 week, 75% at 2 weeks, 50% at 4 weeks, and 25% at 6 weeks with complete absorption at 180 days (Tan et al. 2003).
Glycomer™ 631
Glycomer 631 is a monofilament suture composed of synthetic polyesters and alternating segments of glycolide and dioxanone with segments of trimethylene carbonate and dioxanone. It retains 75% of its tensile strength at 2 weeks and 40% at 3 weeks. Complete absorption occurs between 90 and 110 days.
Polyglycolic Acid
Polyglycolic acid is a braided suture composed of the homopolymer of glycolic acid and coated with polycaprolate (Tan et al. 2003). Polycaprolate is a copolymer of glycolide and ε‐caprolactone. Polyglycolic acid is rapidly absorbed and quickly loses tensile strength. Fourteen days following implantation, polyglycolic acid only has 20% of its initial tensile strength and is completely absorbed in 60 days.
Polyglytone 6211
Polyglytone 6211 is a newer monofilament absorbable suture composed of synthetic polyester of glycolide, caprolactone, trimethylene carbonate, and lactide (Pineros‐Fernandez et al. 2004). It provides short‐term tensile strength combined with the benefits of rapid absorption losing 70–80% of its tensile strength in 10 days and being completely absorbed in 56 days (van Heerden 2005).
Lactomer™
Lactomer is a braided suture composed of polymers of glycolide and lactide. It is coated with ε‐caprolactone glycolide and calcium stearoyl lactylate to improve handling properties. Lactomer retains 80% of its tensile strength at 2 weeks and 30% at 3 weeks with complete absorption between 56 and 70 days.
Nonabsorbable Suture Materials
Nonabsorbable suture materials do not undergo significant degradation after implantation. These sutures are used where extended wound support is required or in areas where suture removal is expected (skin closure). Nonabsorbable sutures, like absorbable sutures, are composed of natural or synthetic fibers. Natural fibers tend to invoke significant inflammatory reactions; thus, there may be a preference for synthetic nonabsorbable sutures depending on the application. Nonabsorbable suture materials commonly used in veterinary surgery include silk, nylon (Ethilon™, Ethicon Inc., Cincinnati, OH; Monosof™, Covidien, Medtronics, Minneapolis, MN; Nurolon™, Ethicon Inc., Cincinnati, OH; Supramid™, S. Jackson, Inc., Alexandria, VA), polypropylene (Prolene™, Ethicon Inc., Cincinnati, OH; Surgipro™, Covidien, Medtronics, Minneapolis, MN), and stainless steel.
Biologic Nonabsorbable Suture Materials
Silk
Silk is the most commonly used organic nonabsorbable suture material (Fossum
