Three things you need to know

about sutures

By Dr. Courtney Campbell, KeraVet Bio Advisor

There’s a lot to consider when suturing a wound. Suturing wounds and apposing tissue must be done in consideration of suture material, anticipated wound healing times, tissue types, local factors, location of the wound, as well as other specific patient factors like (e.g., age, weight, overall health status, presence of infection), and a host of other factors. Although the process of selecting suture doesn’t have to be another source of anxiety in the operating room.

Here are three factors about suture that, when selected appropriately, can help you sleep better at night.

Infection

The sources and potential causes for surgical site infection are plentiful. From surgical preparation, to patient health status, to surgical technique, and perioperative use of antibiotics, there are a host of variables that can potentially contribute to surgical site infection. Therefore, attention to detail during surgery is a top priority. One detail that warrants serious attention in the prevention of surgical site infections is suture choice. 

Monofilament has an advantage over other sutures in helping to prevent surgical site infection.2  The advantage of multifilament suture is rooted in its ability to decrease bacterial  bio-adhesion and its improvement of the ability of phagocytes to reach bacteria with the suture. To underscore the importance of monofilament suture, one company has made available the opportunity to use a monofilament suture for all types of surgeries

Triclosan coated suture can also be considered when looking to decrease surgical site infection. Although some earlier studies have questioned their use, a recent study indicated that suture type may be an important factor in the efficacy of triclosan. The in vitro study found that of the 3 triclosan-coated sutures used in the present study – triclosan-coated polydioxanone (monofilament), poliglecaprone-25 (monofilament), and polyglactin-910 (multifilament) – polyglactin-910 had the smallest zones of inhibition for all of the bacterial isolates, and durations of inhibition were shorter for this suture type than for the 2 monofilament sutures. On visual assessment, uncoated polyglactin-910 suture was found to have the greatest burden of adherent bacteria (E coli).  Although in vivo prospective investigation is required to confirm that their results would be similar in a  clinical setting, their study provided compelling in vitro evidence to support the use of triclosan-coated materials in contaminated surgical sites or in patients for which the development of surgical site infection would lead to severe morbidity.  

Essentially, due to the morbidity related to surgical site infections, the patient welfare implications and other evidence suggesting that triclosan-coated suture materials are safe, it is wise to consider their use. Additionally, CDC recommendations in the human medical field do support their potential to decrease the incidence of surgical site infections.

Monofilament sutures have multiple advantages over multifilament sutures however multifilament does have the edge when it comes to memory. A suture with a high memory will spring back to its original position.  While suture with high memory tend to be strong, they may be difficult to handle and have decreased knot security. This may cause your suture line to tangle, induce a great deal of frustration, and knot failure during healing. The knot security is lower in sutures with high memory because the suture has a tendency to return to its original straight extruded state. Therefore, more throws in the knot are required to securely hold monofilament than braided nylon sutures.  Furthermore, sutures with a high degree of memory can be more challenging to handle and can increase surgical time.

Although many surgeons stretch the suture to remove suture memory, that technique may cause inadvertent displacement of the swaged-on needle from the suture strand.

Fortuitously, sutures have been made available in racetrack packaging. This innovative storage solution gives sutures fewer turns around the track, which allow for less memory, easier handling and faster more efficient wound closure.

Absorption

It is not natural for the body to contain suture. By definition, suture material is a foreign body implanted into tissues. As a foreign material, it is possible for suture to elicit a foreign-body tissue reaction. Among the various characteristics of an ideal suture material, having a favorable absorption profile, low tissue reactivity and high tensile strength are some of the most important. 

Absorbable sutures are intended to temporarily support the wound during the natural healing process. Absorption occurs by enzymatic degradation in natural materials and by hydrolysis in synthetic materials. Hydrolysis causes less tissue reaction than enzymatic degradation. If the suture degrades too quickly the wound may dehisce with normal movement and stress. Therefore it is paramount to select suture material with the ideal tensile strength and the optimal absorption rate for the surgical wound. It is important to remember that loss of tensile strength and absorption rate are two separate characteristics.

Suture absorption rates can be generally defined as short term, mid-term and long-term.  Long term has also colloquially been referred to as “Max” as in the maximum time suture mass absorption occurs for the suture to still be considered absorbable. 

The differences in the suture absorption rates can be complicated and difficult to remember. To help simplify your choice, consider selecting suture material with the absorption class incorporated into the name of the suture. This may help make the process easier particularly in cases in which it’s difficult to recall the exact mass absorption times. For example, it may be more challenging to the remember the absorption time of suture labeled “Glyconate monofilament suture” versus a suture labeled “Glyconate – Short term” or “Glyconate Mid Term”.

Although the factors that influence final wound and tissue healing can seem overwhelming, allow your suture selection to improve your chance for an excellent surgical outcome.

References:

1. Tan RH, Bell RJ, Dowling BA, Dart AJ. Suture materials: composition and applications in veterinary wound repair. Aust Vet J. 2003;81(3):140–145.
2. Alexander JW, Solomkin JS, Edwards MJ Updated Recommendation for Control of Surgical Site Infections. Annals of Surgerry. 2011;253(6):1082-1093
3. Etter, S. W., Ragetly, G. R., Bennett, R. A., & Schaeffer, D. J. (2013). Effect of using triclosan-impregnated suture for incisional closure on surgical site infection and inflammation following tibial plateau leveling osteotomy in dogs. Journal of the American Veterinary Medical Association, 242(3), 355–358. doi:10.2460/javma.242.3.355
4. McCagherty, J., Yool, D. A., Paterson, G. K., Mitchell, S. R., Woods, S., Marques, A. I., … Nuttall, T. J. (2020). Investigation of the in vitro antimicrobial activity of triclosan-coated suture material on bacteria commonly isolated from wounds in dogs. American Journal of Veterinary Research, 81(1), 84–90. doi:10.2460/ajvr.81.1.8
5. Berríos-Torres SI, Umscheid CA, Bratzler DW, Leas B, Stone EC, Kelz RR, et al. Centers for Disease Control and Prevention guideline for the prevention of surgical site infection, 2017. JAMA Surg 2017;152:784-91.  

This article has been modified to better fit this format. The original article was posted on May 23, 2020  to MyVetCandy.com.

Learn more about KeraVet Bio Advisor, Dr. Courtney Campbell, DVM, DACVS-SA, Board-certified Veterinary Surgeon, Host and Producer of Vet Candy on Watch by visiting his page on LinkedIn.