Absorbable sutures synthetic materials

The first synthetic absorbable suture was made from a homopolymer of glycolic acid by Davis Geek Co. and manufactured with the tradename Dexon (1970). This suture was followed by a second material produced by Ethicon, Inc., in 1974, a copolymer of lactide and glycolide known as poly-glactine 910 or Vicryl. Both Vicryl and Dexon are made from polymer fibers, which are braided to produce sutures. In addition. Vicryl is Teflon coated for... 

McCarthy, W. H., A new synthetic absorbable suture material a clinical trial of polyglycolic acid suture in general surgery, Aust. NZ J. Surg., 39, 422, 1970. 

Loh IH, Lin HL, Chu CC. Plasma surface modification of synthetic absorbable sutures. In Proceedings, Clemson University Conference on Medical Textiles and Biomedical Polymers and Materials 1996. 

Sutures remain the most common method of tpproximating the divided edges of tissue (1). Sutures are categorised by size, material, design and behaviour. Absorbable and nonabsorbable materials are further divided into synthetic versus natural products, some of vdiich can be fabricated in braided and/or monofilament form. Non-absorbable sutures have played an important role in the development of surgical procedures, generally made of silk, polyamide, polyester, polypropylene, polyethylene and poly(tetrafluoroethylene) (2). 

An absorbable suture was one that lost a significant portion of its mechanical strength over a period of 2 months > hile a non-absorbable suture was one that maintained a significant portion of its strength longer than 2 months [4]. A suture may lose its toisile strength over a relatively short period of time, but require months or evoi years to absorb completely and be eliminated from the body. The prinuiry mode of degradation for natural materials is enzymolysis, vdiereas for synthetic absorbable materials it is hydrolysis [3]. 

The previous chapter provided a general overview of the properties of materials used for surgical sutures and of the desirable characteristics of such materials. This chapter considers absorbable and nonabsorbable materials in greater detail, looking within each category first at natural materials, and second at synthetic materials. In the section on absorbable materials, natural materials reviewed are ... 

Materials for absorbable and nonabsorbable surgical sutures 279 Table 11.1 Building blocks of commercial synthetic absorbable sutures... 

The latest addition to the synthetic absorbable suture materials is TephaFLEX which is thermally melt-spun from poly-4-hydroxybutyrate, a member of the class of absorbable biomaterials known as polydroxyal-kanoates, or PHA (FDA, 2007 Martin and Williams, 2003). Studies have shown that TephaFLEX is both biocompatible and noninflammatory. Their biodegradation occurs through normal processes and the products of the breakdown are metabolites that already exist in the body. 

However, the availability of some new synthetic long-lasting absorbable sutures pushes the tensile strength retention period beyond 2-3 months. Table 10.A.1 in the Appendix at the end of this chapter summarizes all commercial absorbable and nonabsorbable suture materials that are available in the United States, Europe and the Pacific, their generic and trade... 

Sutures are also classified according to size. Currently, two standards are used to describe size USP (United States Pharmacopeia) and EP (European Pharmacopeia) (Chu et al., 1997). Appendix 2 at the end of this chapter provides a summary of these. In the USP standard, which is used most commonly, the size is represented by a series combination of two Arabic numbers a zero and any number other than zero, for example, 2-0 (or 2/0). The higher the first number, the finer is the suture material. Sizes larger than 0 (1/0) are denoted by 1,2,3 etc. This standard also varies with the type of suture material. In the EP standard, the code ranges from 0.1 to 10. The corresponding minimum diameter (mm) can be easily calculated by taking the code number and dividing it by 10. The EP standard does not separate natural from synthetic absorbable sutures as does USP. Table 10.A.2 in the Appendix at the end of this chapter outlines USP and EP suture size classification... 

The percentage of retention of tensile breaking force of five 2/0 synthetic absorbable sutures upon 0.005 M superoxide ion-induced hydrolytic degradation at 25°C. (Sourcff. From Keun-Ho Lee and C. C. Chu, The effect of superoxide ions in the degradation of five synthetic absorbable suture materials, J. Biomed. Mater. Res., 49(1) 25-35, 2000.)... 

Walton M (1989), Strength retention of chromic gut and monofilament synthetic absorbable suture materials in joint tissues , Clin Orthop Related Res, 242,... 

During the healing period, absorbable sutures are replaced by healthy tissue. In general, the tissue response to synthetic absorbable sutures is foreign body in nature. Further, the inflammatory response has been reported by Blomstedt (Blomstedt and Osterberg, 1978) to be less pronounced around suture materials wath low capillarity. 

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