Suture retention strength

In order to achieve the desired fiber properties, the two monomers were copolymerized so the final product was a block copolymer of the ABA type, where A was pure polyglycoHde and B, a random copolymer of mostly poly (trimethylene carbonate). The selected composition was about 30—40% poly (trimethylene carbonate). This suture reportedly has exceUent flexibiHty and superior in vivo tensile strength retention compared to polyglycoHde. It has been absorbed without adverse reaction ia about seven months (43). MetaboHsm studies show that the route of excretion for the trimethylene carbonate moiety is somewhat different from the glycolate moiety. Most of the glycolate is excreted by urine whereas most of the carbonate is excreted by expired CO2 and uriae. 

Figure 2. In vivo breaking strength retention of Poly(i lactide) compared with commercial absorbable surgical sutures.

S entails the use of about 5 to 7.5 kGy of gamma radiation and a polyformaldehyde package insert capable of a radiolytic, controlled release of formaldehyde in a hermetically sealed package imder dry nitrogen. The process has been applied successfully to absorbable sutures without compromising their clinically relevant properhes, such as their in vivo breaking strength retention. Typical BSR data of radiochemically sterilized suture braids and controls are reported by Anneaux and co-workers. ... 

Anneaux, B. L., Atkins, G. G., Linden, D. E., Corbett, J. T., Fulton, L. K. and Shalaby, S. W, In vivo breaking strength retention of radiochemically sterilized absorbable braided sutures, Trans. Soc. Biomater., 24, 157, 2001. 

In vivo breaking strength retention using a rat model where the sutures are implanted subcutaneously for 1 to 4 weeks and individual lengths are explanted periodically to determine percent of retained breaking strength... 

Prior to in vivo evaluation of the suture breaking strength retention, some of the sutures were subjected to radiochemical sterilization using a 5-kGy dose.i° This sterilization process has been described briefly in Chapter 1 and can be used to achieve suture sterility without compromising its breaking strength. This is contrary to what is known to occur when absorbable sutures are radiation-sterilized using the traditional dose of about 25 kCy. 

Effect of Composition on the Breaking Strength Retention (BSR) of Radiochemically Sterilized Sutures... 

Tensile and in vitro and breaking strength retention data of typical monofilament sutures made of the polymers described in Section 8.3.2 are summarized in Table 8.6. The data in Table 8.6 indicate that the polymers described in Table 8.5 can be converted to monofilament sutures with competitive strength retention and breaking strength profiles as the commercially available braided sutures made of polyglycolide or 90/10 poly(glycolide-co-/-lactide). 

Table 6.4 In vivo breaking strength retention of sterilized, dyed, RCS, safil PG braided sutures...

The strength retention of MonoFlex suture in intramuscular tissue of male Sprague Dawley rats was better than the in vitro data, for example, 70% retention in vivo vs 55% retention in vitro at the end of 4 weeks (Im et al., 2007). Complete absorption was achieved after 180-210 days postimplantation. The sea component was completely absorbed at the end of 180 days, while the island portion was not completely absorbed until 210 days. This in vivo absorption period is similar to but slightly faster than found with the PDSII sutures which were not completely absorbed until 180-240 days. In addition, MonoFlex accelerated its mass decrease only after 120 days, while this did... 

Makela, P, T, P, Tormala, P, Waris,T. and Ashammakhi, N. (2002). Strength retention properties of self-reinforced poly-L-lactide sutures compared with polyg-lyconate (Maxon) and polydiaxanone sutures. An in vitro study. Biomaterials, 23,2587-2592. 

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... 

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

---