Dear Sirs,
What are the disadvantages of if we sterilized surgical sutures such as silk, catgut, polyamide and polyester with EtO sterilization method?

Dr. Mahdi

Ethylene oxide is the preferred method for sterilization of sutures. Gamma or Electron Beam irradiation will alter the chemical structure of the sutures. I have processed sutures in Tyvek pouches, thermoformed trays, and foil/foil pouches. In this last method we sealed the sutures in a foil/foil pouch with a Tyvek header. After EO sterilization we sealed the foil pouch below the header and then cut off the header. This leaves sterile sutures in a foil pouch where they do not gain nor lose any moisture. The most important part of the validation is deterining how long the pouches must be aerated before the header can be removed. Follow ISO 10993-7 for EO and ECH limits. I suggest a mild cycle not exceeding 400 mg/l. Also, determine through sublethal developments what the exact half cycle time should be so as to limit the overkill.

Paul J. Sordellini

Dr. Mahdi

In addition to my answer, let me add that my assumption was that you were asking about sterilization of sutures at the point of manufacturing. Sutures are generally distributed sterile by the manufacturer. If instead sutures are opened in a hospital and not used, then the resterilization of the sutures presents many problems from degradation due to double exposure to ethylene oxide, to a weakening of the sutures and high chemical residuals.

I advise against the resterilization of sutures, regardless of the sterilization method. Once the sterile barrier is opened, if the sutures are not used that should be discarded.

Paul J. Sordellini

This is what Ethicon Europe says:
"Q00455 and Q00457. The answers presently there are factually incorrect.
It is up to individual manufacturers to determine the best method of sterilization for their range of suture products. The preferred method, because it is less expensive and technologically easier, is gamma irradiation and is the method used to sterilise products like nylon, polyester, stainless steel, silk and catgut sutures. However a number of products are detrimentally affected through degradation by irradiation and then ethylene oxide becomes the preferred option. Typically degradation occurs with most of the synthetic absorbable sutures. When using ethylene oxide as a sterilization method precautions have to be taken to assure acceptable ethylene sterilisation residues are obtained.
The type of packaging material employed as the sterile barrier can also influence the choice of sterilization method.
Sutures are single use devices and should never be resterilised once the packaging has been breached"