A Suture, is a Suture, is Not a Suture?
Synthetic absorbable suture materials have traditionally been produced by a small number of well-known manufacturers. Recently comparable products that are labeled as having the same chemical composition as the “name brand” but at a lower cost have become available from suppliers in emerging economies. In this study, 3 absorbable suture materials (polyglactin 910, polydioxanone, poliglecaprone 25) from 2 different manufacturers (Huaiyin Medical Instruments Co Ltd and Ethicon Inc) were compared. Samples from the same lot from the same company were used throughout the experiment. In part 1, 10 samples of each suture were incubated in bovine serum and tested for ultimate load and stiffness at days 0, 1, 7, 14, 21, and 28. In part 2, 10 knotted samples without incubation were similarly tested. For polydioxanone, Huaiyin had significantly greater load on days 0, 1, and 7 than Ethicon and greater stiffness throughout the study. Ethicon polydioxanone maintained 83% of its initial strength at 2 weeks and 76% at 4 weeks, while Huaiyin retained 76% at 2 weeks and 72% at 4 weeks. Ethicon poliglecaprone 25 had significantly greater load and stiffness than Huaiyin on days 0, 1, and 7 but no difference in load on day 14. Huaiyin had significantly greater ultimate load on day 21. Ethicon poliglecaprone retained 28% of its initial strength at 14 days and Huaiyin retained 39%. At 21 days, Ethicon poliglecaprone retained 7% of its initial strength and Huaiyin 16%. For polyglactin 910, Ethicon had significantly greater ultimate load than Huaiyin at all times and significantly greater stiffness at days 0, 1, 7, and 14. On days 21 and 28, Huaiyin polyglactin 910 had significant degradation, so ultimate load and stiffness could not be assessed. Ethicon polyglactin 910 retained 57% of initial strength at 2 weeks and 16% at 4 weeks, whereas Huaiyin retained 48% at 2 weeks and 3% at 4 weeks. When knot breaking was tested, Huaiyin polydioxanone and polyglactin 910 had significantly greater strength than Ethicon products. There was no difference in poliglecaprone 25 between the two manufacturers. The authors conclude that suture materials from different manufacturers do have different mechanical properties, but these discrepancies may not be clinically important.
Commentary: In this study, the authors test important mechanical properties of 3 suture types from 2 different companies. The clinical importance of the differences found is difficult to assess, as this was a purely mechanical study, and factors such as tissue drag, enzymatic degradation, and ability to withstand a septic environment were not evaluated. However, this article brings up a key point: it is not appropriate to assume that 2 sutures of the same chemical composition will behave identically, and thus clinicians should familiarize themselves with the mechanical and behavioral properties of any suture material before choosing it in practice.—Sara A. Colopy, DVM, Diplomate ACVS
In vitro comparison of mechanical and degradation properties of equivalent absorbable suture materials from two different manufacturers. de la Puerta B, Parsons KJ, Draper ERC, et al. VET SURG 40:223-227, 2011.