An in vitro evaluation of the stability of mechanical properties of surgical suture materials in various pH conditions.

The effects of pH on the tensile properties of eight commonly used 2-0 suture materials--plain catgut, Dexon, Vicryl, silk, Nurolon, Ethilon, Mersilene, and Prolene--were examined. The pH level ranged from 3.0 to 10.0. In general, absorbable suture materials were more sensitive to pH than non-absorbable suture materials; within the same suture materials, a strong alkaline condition would have a more adverse effect on the strength of suture materials than physiologic and acidic pHs. Plain catgut sutures lost relatively significant amounts of strength at both acidic and alkaline conditions when compared with Dexon and Vicryl sutures; hence, precaution should be taken when they are used in closing tissues in contact with acidic environment like the stomach. Among the non-absorbable suture materials, silk and Nurolon exhibited the largest loss of strength in both alkaline and acidic environments after one month, while other sutures retained almost all of their original strength. Physical configuration of the suture materials seemed also to contribute to the sensitivity of suture materials toward pH. A comparison of Nurolon and Ethilon sutures demonstrated this point of view.