Mechanical Comparison of 10 Suture Materials before and after in Vivo Incubation

The material properties of ten 2-0 suture materials were evaluated tensiometrically at time = O and again alter 6 weeks incubation in rats. AII suture material was incubated and tested without knots. Specialized machinery was used with a custom securing apparatus to pull suture material apart at constant speed. Stressstrain curves were derived, and from these strength, toughness, strain at rupture, and elastic modulus were determined. Sutures tested included Vicryl [poly(glycolide-lactide)], Dexon (polyglycolic acid) , Ethibond (polyester), silk, plain gut, chromic gut, Maxon (polyglyconate), PDS (polydioxanone), nylon, and Prolene (polypropylene). Elastic modulus was greatest for braided, least for monofilament, and intermediate for gut sutures, regardless of chemical composition (ANOV A, P = 0.0001). Strength, strain, and toughness decreased in all of the sutures over time in vivo with the exception of braided polyester (Ethibond), which remained stable. Silk demonstrated the least strength and toughness while PDS and Maxon were the strongest and toughest at time = O. Vicryl, Dexon, and gut sutures were absorbed to the point that they could not be tested alter 6 weeks in vivo. Performance tables are provided for all sutures. @ 1994 Academic Press, Inc. Nonabsorbable sutures can be made from n)'lon, polypropylene, stainless steel, silk, cotton, Teflon, polyester, Dacron, and a variety of less commonly used synthetic materials. Each of these can be manufactured in clifferent sizes, and many are available with or \\,ithout coatings. The advantage ofthese sutur~s is that they remain permanently in place and that they elicit little tissue reactivity. Absorbable sutures include plain gut (made from the submucosa of sheep intestine and the serosal layer of cattIe intestine) , chromic gut (plain gut precipitated with chromium salts), synthetic polymers ofpolyglycolic acid (Dexon), poly(glycolide-lactide) (Vicryl), polydioxallane (PDS), and polyglyconate (Maxon). Gut sutures are constructed primarily of interlacing collagen molecules; Maxon and PDS are monofilaments; Dexon and Vicryl are prepared as braids. These absorbable sutures are used when their presence is required temporarily. They incite varying degrees of tissue response and are degraded by hydrolysis (Dexon, Vicr)'l, PDS, Maxon) and enzymatic digestion and phagocy"tosis (gut). Each of these sutures behaves differentIy in the surgeon's hands and in host tissues. There are many ways to evaluate the properties of these materials. Tissue reactivity [2, 3] and wound strength [4,5] analysis provide complimentary information, especially ifviewed in light ofthe mechanical properties of the material used to clase the wounds. The current study was designed to catalog the mechanical properties of 10 commonly used suture materials and to compare their performance over time in an in vivo modelo Sutures behave differentIy if they are stretched, knotted, kinked, nicked, or otherwise damaged. Furthermore, knot types and number of throws can influence whether a knot will slip before it will break under loado To minimize the effects of these variables, all sutures were incubated and tested in unknotted and undamaged formo Thou shouldst draw tagether lar him his gash with stitching. Edwin Smith Surgical Papyrus [1]