Suturing has traditionally been regarded as the mainstay of surgical skin closure. However, newer techniques of wound closure utilising modern skin adhesives such as cyanoacrylates offer the surgeon an attractive, non-invasive method of quick and effective skin closure1.Surgeons become adept at skin closure with conventional techniques such as sutures and staples. The use of cyanoacrylates will however for many be a new technique to learn. Rightly or wrongly, despite the expertise we may demonstrate beneath the skin during a procedure, patients often judge us on how neat their superficial skin scar appears! Any new technique for skin closure therefore, not only needs to be effective but needs to be at least cosmetically equivalent or better than conventional closure techniques.
I have used a number of different cyanoacrylates but the advent of improved, fast setting cyanoacrylate glues and purpose designed surgical applicators means that I can now use them in routine practice to achieve good clinical and cosmetic wound closure. I have found that in order to achieve this, it is useful to understand how these skin adhesives work and their limitations. With this in mind I would like to share a few practical tips that I have found helpful.
Cyanoacrylate monomers polymerise in the presence of moisture to form a strong covalent bond to the epidermis and form a strong, semi-occlusive wound dressing. The cyanoacrylate dressing lasts for 5-10 days and naturally falls off as skin desquamation occurs. Early studies used the fast-setting, strong but relatively brittle n-butyl cyanoacrylates i,e, HistoAcryl. (B Braun), Indermil (Vygon), or LiquiBand (Medlogic). These are commonly used in the Emergency Departments for small wound closure. DermaBond (Ethicon) is a slower-setting, but more flexible octyl cyanoacrylate that can be used for surgical wound closure. More recently we have seen the development of blended cyanoacrylates for surgical wound closure such as LiquiBand Laparoscopic (Medlogic). These newer cyanoacrylates either blend Butyl and Octyl monomers together so that they are both strong and fast setting, with a good degree of flexibility or, as with LiquiBand Surgical (Medlogic) use a butyl-cyanoacrylate for closure and a secondary liquid bandage layer (Octyl/butyl) to reinforce and provide a semi-occlusive microbial dressing.
Potential benefits of surgical wound closure with cyanoacrylates;
- Quicker wound closure.
- Comparable / better scar cosmesis than sutures or staples.
- Occlusive microbial dressing.
- Non-invasive – less tissue trauma with reduced inflammatory reaction.
- No requirement for secondary dressings.
- No requirement for subsequent non-absorbable suture / staple removal.
- Easy to use / quick learning curve
- Wound visualisation easy (i.e. no dressings to remove).
- Reduced closure / dressing products.
- Reduced risk of needle-stick injury.
- Cost-effective.
Which wounds? – Surgical wound closure with cyanoacrylates is best suited for wounds that are not subjected to too much stress or flexion. A good “rule of thumb” is that if the skin needs more than simple pulling together with forceps or fingers to achieve apposition, then deeper sutures and/or subcutaneous sutures should be used before the glue is applied. Areas of flexion should be avoided as this may lead to the polymersised cyanoacrylate film cracking and leading to disruption of the microbial barrier and possibly to wound dehiscence.
Clean and dry – optimal results are obtained if the wound incision is clean and dry with absolute haemostasis prior to application of the skin adhesive (otherwise the cyanoacrylate will polymerise with the fluids rather than bonding to the skin). Bleeding needs to be minimal and I have found that time taken in ensuring good haemostasis during surgical incision e.g. using monopolar diathermy to cut and coagulate subcutaneous / fat layer tissues, saves time during wound closure. In laparoscopic port sites the use of a local anaesthetic such as 5ml of 0.5% Bupivicaine with 1:200,000 adrenaline into each skin port site prior to incision also minimises the amount of bleeding when it comes to application of the glue at the end of the procedure. After cleaning wounds with a damp swab a second clean dry swab should dry the wound immediately prior to glue application once the skin edges are in apposition.
Good wound edge apposition – Cyanoacrylate adhesives close the skin by forming a polymerised layer across the top of the skin that binds the skin edges together. Hence it is important that excellent epidermal edge-to-edge apposition is obtained and held whilst the glue sets over the wound. This can be affected on small wounds by the use of the surgeons (or assistants) fingers holding the edges together and/or the use of a pair of Officer Forceps to appose the edges. It is here that a fast setting cyanoacrylate is preferable so that the wound is rapidly closed whilst maintaining optimal apposition. One should remember that these glues set very rapidly and care needs to be taken not to inadvertently glue gloves, forceps or assistants to the patient! If stuck, fingers or forceps should be gently peeled towards the wound so as not to disrupt the glue bond, rather than pulling. It is important that the glue is layered across the apposed wound so that there is none or negligible glue getting between the skin edges. If cyanoacrylate gets between the skin edges it will form a layer that may prevent healing by primary intention potentially leading to a foreign body reaction / delayed wound healing. It should be remembered that the skin edges will be held in the position that the glue sets/polymerises, so the better the apposition the smaller the scar.
Dot or continuous line – When the wound skin edges are held tightly together the skin glue can be applied as series of dots along the wound to effect closure (a small amount of cyanoacrylate may wick along the epidermis helping wound adhesion). The technique I prefer however is to gently run the applicator tip across the top of the closed incision (barely touching the wound) to form a continuous line of skin adhesive. Care should be taken not to push the applicator tip into the wo