Suture choice when securing central lines: an update in the light of NICE surgical guidance

Abstract

Despite substantial advances in care packages to reduce central venous catheter-related blood stream infections, silk sutures are used widely to secure lines. This may be due to the opening on to sets or as part of pre-arranged procurement processes, likely originating from the very easy handling characteristics of a braided silk stitch, and its ability to grip a tube such as a line or drain when tied circumferentially. Surgical practice guidelines, however, suggest that antimicrobial-coated monofilament sutures should be used due to lower surface area and direct antimicrobial effects that lead to lower rates of infection.

Due to the braided construction, the large surface area of silk sutures predisposes to colonisation and biofilm formation, and the antigenic properties of (animal-derived) silk protein lead to local inflammation [1]. This sloughy tissue can be difficult to discern from early infective changes. These are of limited consequence when securing a drain or vascular access device for a period of hours to a couple of days.

In surgical wound closure, monofilament antimicrobial-coated sutures have been available for many years. Whilst they are slightly harder to handle, and do not grip well to a structure like a drain, they work perfectly well for securing lines fitted with a collar and suture holes. They require an increased number of throws to guarantee security and must be locked with an appropriate locking knot. Since 2021, National Institute for Health and Care Excellence surgical guidance has been that antimicrobial-coated sutures should be used for all wound closures due to an overall reduction in wound infection rates [2]. We suggest that an antibiotic-coated monofilament should be used instead of a silk stitch to secure vascular access devices anticipated to remain in situ for > 48 h. There are a wide selection of sizes and needle styles available. When tying the knot, such sutures benefit from additional throws beyond the three needed for silk; typically, six for a monofilament. Whilst monofilament is absorbable, it absorbs over several months which does not preclude its use for securing lines. The only additional requirement is training in correct suture tying technique, as the sutures are broadly equivocal in price.