{{Short description|Methods of tying medical sutures}} {{see also|Surgical suture}} '''Surgical knots''' (ligatures) are the knots used to bind suture materials together while binding tissue in surgery. They are used in medical and veterinary settings. [[File:Diagrams illustrating various surgical stitches and knots. C Wellcome V0016823.jpg|thumb|Historical diagrams illustrating various surgical stitches and knots]]
==History== [[File:Heraklas Plinthios Brokhos Jaw Sling.jpg|thumb|right|Heraklas' sling XIII, the ''plinthios brokhos'' is produced in the same manner as a [[string figure]].]] Surgical knots have been used since the first century when they were described by the [[Ancient Greek medicine|Greek physician]] [[Heraklas]] in a [[monograph]] on surgical [[knot]]s and [[sling (implant)|sling]]s.<ref name="hage">{{citation|last=Hage|first=J. Joris|periodical=World Journal of Surgery|date=April 2008|volume=32|issue=4|pages=648–55|title=Heraklas on Knots: Sixteen Surgical Nooses and Knots from the First Century A.D.|doi=10.1007/s00268-007-9359-x|pmid=18224483|s2cid=21340612}}</ref><ref name="miller1945">{{Citation | last = Miller | first = Lawrence G. | title = The Earliest (?) Description of a String Figure | journal = American Anthropologist |series=New Series | volume = 47 | issue = 3 | pages = 461–462 | year = 1945 | doi = 10.1525/aa.1945.47.3.02a00190}}</ref> In the past, the training of [[astronaut]]s has also included the tying of surgical knots.<ref name="pmid16909881">{{cite journal|vauthors=Rafiq A, Hummel R, Lavrentyev V, Derry W, Williams D, Merrell RC |title=Microgravity effects on fine motor skills: tying surgical knots during parabolic flight|journal=Aviat Space Environ Med|volume=77|issue=8|pages=852–6|date=August 2006|pmid=16909881|url=http://www.ingentaconnect.com/content/asma/asem/2006/00000077/00000008/art00011|access-date=2008-08-27}}</ref>
==Application== The effective tying of surgical knots is a critical skill for surgeons, since if the knot does not stay intact, the consequences may be serious, especially in situations such as following a pulmonary resection, [[laparoscopic]] [[cholecystectomy]], or [[hysterectomy]]. The primary goal of surgical knot tying is to allow the capacity of a knot (or ligature) to be tightened and remain tight. Ligatures are locked in place and finished with multiple overhand knots. Nevertheless, slipping occasionally occurs before the addition of the final knot, particularly during an instrument tie.<ref name="TaylorGrogono2014">{{cite journal|last1=Taylor|first1=H|last2=Grogono|first2=AW|title=The constrictor knot is the best ligature|journal=Annals of the Royal College of Surgeons of England|volume=96|issue=2|year=2014|pages=101–105|issn=0035-8843|doi=10.1308/003588414X13814021677638|pmid=24780665|pmc=4474235}}</ref>
==Knots== The [[constrictor knot]] is the knot most commonly used for binding. The constrictor knot closely resembles the [[clove hitch]], except the two ends form an [[overhand knot]] go under the overriding turn. New knots have also been described.
Other commonly employed knots include the [[surgeon's knot]], [[modified surgeon's knot]], [[single-double other side knot]], [[strangle knot]] and modified [[miller's knot]]. The [[Surgeon's knot]] has been a standard ligature, however in one study, it demonstrated slippage.<ref name="TaylorGrogono2014" />
While the suture is being put in place a knot is used to secure the suture. Tying the knot may be done inside the body or outside the body. Between these two options, knot tying inside the body requires more experience, as the surgeon is required to use laparoscopic instrumentation rather than their fingers to loop the suture. Tying the knot outside the body is far simpler for most surgeons, as the suture is looped with fingers similar to that of traditional tying. Each knot that is formed has to be guided through a laparoscopic [[cannula]] and made tight with a knot-pusher to create the knot.<ref name="Hoffman2012" />
In laparoscopic surgery, a stronger braided suture is often preferred if the [[knot pusher]] is used because suture fraying can be a possible side effect of this technique. A disadvantage of knot tying being done outside the body is that it often causes more tension and can cause tissue tearing while suturing delicate tissue.<ref name="Hoffman2012">{{cite book | last = Hoffman | first = Barbara | title = Williams gynecology | publisher = McGraw-Hill Medical | pages=1119–22|location = New York | year = 2012 | isbn = 9780071716727 }}</ref>
<gallery> File:Roeder Knot.svg|[[Roeder knot]] File:Von Leffern knot.jpg|[[Von Leffern knot]] </gallery>
==Alternatives and risks== An alternative to the surgical knot is a disposable clip that is placed at the end of the suture to keep stitches secure. A [[hemoclip]] is a titanium V-shaped clip with extensions that are squeezed together during application. The clips are available in various sizes and were originally designed to compress vessels for [[hemostasis]].<ref name=Hoffman2012/>
Stronger braided suturing thread is preferred during this type of procedure, as the knot has a tendency to fray as it is slides down the cannula. At the end of the running suture line, clips can be placed across the suture tail. The barbed suture is a knotless [[surgical suture]] that has a pattern of barbs on its surface. These barbs lock the suture into the tissue, eliminating the tying of knots. Barbed sutures are typically used in cosmetic and reconstructive surgery.<ref name=Hoffman2012/><ref>{{cite journal |author=Malcolm D. Paul |title=Using Barbed Sutures in Open/Subperiosteal Midface Lifting |journal=Aesthetic Surgery Journal |date=Nov–Dec 2006 |volume=26 |issue=6 |pages=725–732 |doi=10.1016/j.asj.2006.10.011|pmid=19338966 |doi-access=free }}</ref> There are concerns that knot tying may be related to glove puncture but a current study demonstrated that instead friction from continuous suturing only left ‘marks’ on the little finger with no glove puncture.<ref name="GiordanoKoch2014">{{cite journal|last1=Giordano|first1=Vincenzo|last2=Koch|first2=Hilton|last3=de Sousa Prado|first3=Juliano|last4=de Morais|first4=Leonardo|last5=de Araújo Hara|first5=Rafael|last6=de Souza|first6=Felipe|last7=do Amaral|first7=Ney|title=Is the surgical knot tying technique associated with a risk for unnoticed glove perforation? An experimental study|journal=Patient Safety in Surgery|volume=8|issue=1|year=2014|pages=26|issn=1754-9493|doi=10.1186/1754-9493-8-26|pmid=24991234|pmc=4078929 |doi-access=free }}</ref>
==Training== Much effort goes into the training of medical students regarding the surgical skill of knot tying. One method, called the “[[quiet eye|Quiet Eye Training]]” has shown greater success than more traditional forms of instruction.<ref name="CauserHarvey2014">{{cite journal|last1=Causer|first1=Joe|last2=Harvey|first2=Adrian|last3=Snelgrove|first3=Ryan|last4=Arsenault|first4=Gina|last5=Vickers|first5=Joan N.|title=Quiet eye training improves surgical knot tying more than traditional technical training: a randomized controlled study|journal=The American Journal of Surgery|volume=208|issue=2|year=2014|pages=171–177|issn=0002-9610|doi=10.1016/j.amjsurg.2013.12.042|pmid=24881015|s2cid=43100982 |url=http://researchonline.ljmu.ac.uk/id/eprint/3560/3/R1_JCJ%5B1%5D.pdf}}</ref>
==See also== * [[List of bend knots]] * [[List of binding knots]] * [[List of knots]] * [[List of surgeries by type]]
==References== {{reflist}}
==External links== * [http://www.animatedknots.com/indexsurgical.php Surgical Knots, Animated Surgical Knots] <!--accessdate = 2015-06-09 --> [[Category:Surgical procedures and techniques]] [[Category:Surgical stitches]]