It can be all too easy to slip into the habit of always using the same suture material and the same technique for specific surgical procedures, forgetting at times why you ever made those choices in the first place. This habitual behaviour can be a positive factor in improving surgical technique according to RCVS recognised and European Specialist is Small Animal Medicine Alison Moores BVSc (Hons) Cert SAS Dip ECVS MRCVS who led this webinar. The key is to keep decision making simple by using only a limited number of suture materials thereby reaping the benefits of familiarisation with these specific materials. Of course, the choice of suture material and technique used has to be ‘appropriate’ for the specific surgical procedure being performed and Alison’s webinar helps to explain the factors which need be taken into account when making these choices.
The tensile strength of a suture material is a key factor within this decision-making process. A material such as monocryl loses 50% of its tensile strength in one to two weeks compared to PDS which loses 50% of its tensile strength in five to six weeks. This would make PDS a far better option for suturing the linea alba for example, where maintaining tensile strength is essential. Alison also uses PDS in her gastrointestinal surgeries as she has more confidence in a material with prolonged tensile strength properties in the face of any delayed wound healing within the gastrointestinal tract. Given the ability of the bladder to heal relatively quickly, it would be easy to assume that a suture material such as monocryl would be an appropriate choice but Alison warned this is not always the case. There has been some evidence to show that monocryl loses its tensile strength when exposed to infected urine, so for patients suffering a urinary tract infection, monocryl would not be appropriate. Placing sutures through the mucosa of the bladder should also be avoided in order to prevent contact between the suture material and potentially infected urine. However, monocryl is appropriate for placement within the intradermal layer where the requirement for tensile strength is significantly less.
Making the right choice of suture material is the first step in achieving surgical success, but if your knotting techniques are not up to scratch, then the choice of material becomes irrelevant. A poorly tied knot is likely to loosen and unravel making the purpose of a suture or ligature redundant. In order to maximise knot security, Alison explained choosing a smaller diameter suture material which will not snap when tightened is ideal as knot security is inversely proportional to the suture diameter. Familiarisation with tying square and surgical knots is also essential in tying secure knots and Alison advised ensuring each throw is tightened one at a time and to avoid placing too many throws. One-handed ties, two-handed ties and instrument ties were also demonstrated within a set of videos offering an excellent reminder of the pros and cons of each technique. Alison also demonstrated the ‘Aberdeen knot’ which is a very clever yet simple way to tie knots and are particularly easy to bury at the end of a line of simple continuous intradermal sutures.
Suture patterns and techniques are also integral to surgical success and play a particularly important role in performing successful gastrointestinal surgery. Alison warns when performing these types of surgeries, an inverting suture pattern should only ever be used within the stomach because using this pattern within the small intestine could lead to narrowing of the intestinal lumen. Sutures placed within the intestinal wall should be full thickness appositional simple or continuous sutures and should be placed at least 3mm from the wound edge and placed 2-3mm apart to prevent dehiscence of the wound.
Some may look at the title of this webinar and perhaps prefer to learn more about what could be conceived as the ‘sexier’ side of surgery. Thoracotomies, lifesaving abdominal surgeries and challenging fracture repairs are all up there when it comes to excitement but without executing the basics (such as knot tying) correctly, these rewarding surgeries are highly unlikely to be successful. This webinar helped to remind us why we make the choices we make when it comes to the vast array of suture materials available and how we can hone our surgical knot tying and suturing skills so that we can maximise our chances of success. Alison delivered an engaging, practical and must-see webinar for any vet performing any form of surgery and personally, I’ve been so inspired that I am now surrounded by a long line of shoe laces preparing to practise my one-handed ties and Aberdeen knots – wish me luck!
The Stethoscope (MRCVS)