One of the most interesting surgical myths - and a long-revered surgical "dogma" - is that the square knot should always be used to tie two ends of a suture together. For ligatures and interrupted closures the square knot is indeed appropriate - but for anchoring a running closure the square knot will tumble as the running (needle end) is pulled and cause a weakening of the suture material at that point from mechanical distortion of its structure (whether mono- or multifilament). A self-tightening knot such as simple half hitches will not undergo this knot conversion and will be much stronger. Using a loop suture will also avoid this problem. But, in the end, the persistence of this square knot myth is simply stunning!!

See "Running sutures anchored with square knots are unreliable" in Am J Surg 2012;204:384-388.

Thank you for the question! However, the theme you suggest to touch is one of the most difficult. Huge work should be done to envistigate surgical myths bases, going back to literature on Surgery for decades and decades. Do you suppose the play is worth candles this very day of Crisis?

As for knots, there is whole science about knots and vast literature on this field. Knots is not business for surgeons only, you know, but for far many prefessionals: from mariners to websters...

For further reading (just an example):

Clifford W. Ashley. The Ashley Book of Knots. Doubleday, New York. ISBN 0-385-04025-3

Geoffrey Budworth (1999). The Ultimate Encyclopedia of Knots & Ropework. Annes Publishing Limited. ISBN 1-55267-986-1

John Cassidy (1985). The Klutz Book of Knots. Klutz Press, Palo Alto, California. ISBN 0-932592-10-4

Cyrus L. Day. Knots & Splices. International Marine/McGraw-Hill Companies. ISBN 0-87742-252-4

Raoul Graumont. Handbook of Knots. Cornell Maritime Press/Tidewater Publishers. ISBN 0-87033-030-6

R.S. Lee. All The Knots You Need. Algrove Publishing. ISBN 0-921335-47-4

Allen Padgett and Bruce Smith. On Rope. National Speleological Society. ISBN 0-9615093-2-5

Des Pawson (2001). Pocket Guide to Knots & Splices. Produced for Propsero Books by RPC Publishing Ltd., London. ISBN 1-55267-218-2

Brion Toss. The Complete Rigger's Apprentice. International Marine/McGraw-Hill Companies. ISBN 0-07-064840-9

J.C. Turner and P. van de Griend (ed.) (1996). History and Science of Knots. World Scientific. ISBN 981-02-2469-9

etc, etc...

By the way, the surgical knot is believed to be one of the most simple and reliable one. Hippocrates might use it already. Perhaps, it might much older than Surgery itself.

Dr. Borodach: Your comment indicates that 1) I was unsuccessful in getting my point across, and 2) This myth will persist!

Myth: "That just because we have always something one way implies that it is the right way" Solution: Only with multifactorial data collection assessing the heterogeneity of disease and treatment and individuality of surgeon, would we only ever to answer the question........so we continue to do things the way we always have, because they seem to work and we only change things because we think they are better, but rarely prove so conclusively and gain universal acceptance!

For example the knot used is a variable of the material, the knotter, the material-tissue interaction, the mechanical factors of the material and the patient.....the only conclusion we can draw is that a knot is better than no knot!

Dr Lars Aanning: I want to thank you for a very interesting answer. The myth that you showed is very interesting and very unexpected. Probably knitting of surgical knots belong to the most frequent "automatic" (almost subliminal) surgical procedures. With this in mind, I admire as a your extraordinary ability to "see" it, as well as the thoroughness of its scientific "preparation" in your brilliant article (Am J Surg. 2012 Sep; 204 (3) :384-8. Running sutures anchored with square knots are unreliable. Aanning HL, Van Osdol A, Allamargot C, Becker BE, Howard TC, Likness ML, Merkwan CE, Tarver DD.). As each "destroyer of myths," you must have the patience and understanding of the primary traditional reaction of surgical community. As aptly noted Moshe Schein: “Traditionally, the surgical profession is known to represent a group that tends to adhere, with its nails, to myths” (Surgical Rounds 2012 Jan; 34-8. Common myths in surgery. Moshe Schein). I believe that identifying of myths and attempt to their destruction (justification) is an activity that is beneficial to the progress of surgery.

I ought to confess that I used to be fond of knots knitting ten years ago or some. I have read about that matter what I could to find and had been checking many knots in my practice. However, I am sure that there is no such a field in Science which is not worth to try and check again and again from time to time (the latest example for this is the Dr.Barry Marshall discovery of the H.p.).

So, I vote up for the question Dr.Aanning raised up. Unfortunately, I cannot read this article completely (for I have no subscription on 'the American Journal of Surgery'), so I am limited by the abstract.

My preliminary impression is as follows:

The hitches as a class of knots have their positive and negative qualities. Dr.Aanning wrote about the positives: the hitch are less distortive as the square knots, and, therefore, they are stronger by themselves. From the other hand, any so-called 'self-tightening knot' will demand twice-fold loading on the tissue upon which it been tightening as comparing with a simple square knot. I saw how easily a tightening cow hitch could tear the cystic artery, for example. A surgeon useful to knit square knots just did not calculate his (her) power down.

A half-stitch is shown here

One can also start a running anchor knot with a square knot as long as the successive throws are half hitches - since it is the final square knot(s) that tumble and weaken the suture when tension is placed on the needle-bearing end.

Try this: fasten a suture to each of the two loops of a needle driver - using square knots to one loop and half hitches to the other loop. Now pull on the middle of the suture (using a pen works well) until it breaks. The suture will ALWAYS break at the square knots!

All your comments are very helpful and really allow me to more fully understand conceptual barriers to myth changing.

Thank you for the fastest reply, dear colleague!

All right, what you are writing about knots is brilliant and enthusiastic, but.. does it remain just a physical experiment, or not? How long do you perform halves-hitches in practice and what kind of tissues for would you recommend them?

I recommend that all running suture closures be anchored with a final series of half hitches to avoid tumbling of the final knot(s). Alternately, use a loop suture or another type of self-tightening knot. The initial knot can be a square knot if you like that - but I have probably always used half hitches - on fascia, bowel, vascular, and other tissues.

Eric Rawdon, a mathematician, studied knot tying by experienced surgeons and concluded that "Knot mechanics are poorly understood and that most surgeons neither tie nor recognize the knots they intend to tie." More at: http://george.math.stthomas.edu/rawdon/Preprints/monofilamentknots.pdf

William Halsted said [JAMA 1913;601:1119-1126], "A granny knot [half hitches] is adequate when fine silk is used. In some instances the granny is better than the reef knot [square knot], for in the tying of the former in the presence of tension the traction on the first turn of the knot can easily be maintained, and should the first turn loosen, in the taking of the second the slack can usually be taken up in the drawing home of the latter." So Halstead was OK with half hitches for ligatures!!

I will be glad to email copies of our two papers on the unreliability of square knots in anchoring running sutures - send inquiry to [email protected].

Again, I am only really illuminating what others have already made known.

The question raised by Igor is extraordinary interesting and stimulating, even if to give an answer in a few lines is impossible, and dealing only with knots is quite reductive. For too many years, let's say for many generations, surgeons have been reluctant and resistant to "accept and apply" one of the major achievement of Cinical Practice: Evidence Based Medicine (EBM). We all know that EBM in surgery, due to major complexity in carrying out randomized studies, is too often disdained by most of the surgeons, even if in the last 25 years major improvements have been recorded. These improvements are mainly due to the remodelling of Residency Programs and the Guide Lines proposed by the most accredited Surgical Scientific Societies, whose major role should be to support the progress of science and technology, but also to educate and persuade surgeons to "accept and apply" the EBM surgical studies. It's a problem of surgical education, in which another crucial role is played by the mentors, the tutors, the instructors, who should be the first to daily question if a traditional surgical mith should be ignored and forgot because most recent studies show that it's obsolete. But, it's not so easy! In fact, there are many "surgical myths" which have been already declared obsolete or modified by the EBM studies and by guide lines proposed by Surgical Societies (how to perform surgical hand scrub - use of drainages - irrigation solutions - incision lines - chemoprophilaxis - aseptic technique and the sterile field - etc...etc...), nevertheless they continue to be adopted. Surgical education should not be restricted to the technical aspects of our practice, but should convince young surgeons to keep always informed to what they are doing, to pose questions, to read the literature, to attend the fundamental meetings of the major societies, to use Internet in the right way. And, the duties of the mentors are not secondary: even the expert surgeons should consider the fact that they are not genius or custodians of the truth: they have to teach what is the best for the patient in that specific situation and educate the young surgeons not only to operate but also to think!

In summary - sorry if I have been lengthy - how to eradicate "obsolete traditional surgical miths"? For all the surgeons of any age: Continuing Education, Lifelong Learning, Study, Reading, Internet, and...HUMILITY!

Agree entirely with Dr.Dionigi as to 'Surgical education should not be restricted to the technical aspects'! However, there is schedule for surgery classes (in Russia, at any rate), and the rules become more and more strict, not least by this very EBM grace! What would you suggest for classes on this matter, colleagues?

I can see that EBM appeared as methodology counterforcing the Information Explosion. From another hand, the EBM methods seem to be Procrustean bed sometimes. They are evidently too plain, 'far more stupid' than living reflexions of a physician and scientist in many cases and contradict both everyday and formal logic sometimes. Actually, they make a physician thinking unnecessary and obsolete. Who and what will be result of such an education?

What baffles me is that many of the medical myths has been refuted in the literature, yet the practice of these myths continue. I guess medicine is a hard tradition to break.

Should we also add to the list bowel preparation and more generally enhanced recovery protocols for elective colorectal surgery?

To be able to deal with these myths means we need to be able to recognize them in our daily routines. Dr. Dionigi aptly focuses on surgical education, role of mentors, and EBM as playing crucial roles - and Dr. Borodach rightly challenges their inflexibility and thus propagating such myths. This is a never ending struggle.

But knowing our own personal results also helps. Keeping track of our own operations and their results should be a life-long endeavor to improve the quality of our surgical performance. When we ask a patient for consent to operate we should also be able to give an up-to-date summary of complications - recurrences, reoperations, wound infections, etc. - as part of the consent process. Unusual or unexpected outcomes or trends become flags for further investigation - and possibly myth debunking.

So we do, or try to do so at any rate! 'Never ending struggle' is good expression to memorize.

I don't know how much awareness, or the lack of it, perpetuates these myths. Most doctors learn from their seniors without questioning the rationale of the traditions. Perhaps a book or publication on this topic may put things in the right perspective.

Would anyone like to rise to this challenge?

I am ready with the help of many of you!

What achievement of the evidence-based medicine is the highest from your personal point of view?

And one more question:

As commonly known, Sir Isaac Newton wrote: "If I seen further it is by standing on ye [the] shoulders of Giants" (from a letter to R.Hook, 1676). Which shoulders the EBM supporters think be standing on?

To Dr.Aanning:

You are (and were) absolutely right about the running knots securing. The data are convincing, the pictures are gorgeous. If one performs a running knot, he (or she) should do it in the way recommended by Dr.Aanning et al, 2012.

However, I do not like to use running knots on aponeurosis, ducts, large vessels, and stuff like this. A tear of a knot is not the only reason for suture to fail. There is a tear of a tissue itself occured that is of importance; moreover, the tighter a knot made up, the worse circulation inside the knot, and the higher danger for the tissue strangled to snap due to necrosis.

Actually, I hope you and co-workers will continue this interesting work on better knots in surgery.

Adding surgical dogmata: oral nutrition not before bowel movements; nil per mouth for 7 days after gastrectomy, gastroscopy contraindicated for several weeks after upper GI resection...

Many surgical myths, some may be not proven scientifically, are in practice because of the personal beliefs and tradition. If someone who practice it, deviate at one time and not comfortable with the outcome in the same case, always follow the same. On the other hand many practices are obsolete only because of newer techniques and tools we believe are better. But I personally think these are relative to place, time, economy, resources, situation and many more. Nothing is obsolete/ myth in surgery, it is always useful at one time or another.

'I will not cut for stone' is probably the all-time classic.

...but will withdraw in favor of such men as are engaged in this work'.

Amen! But who is to judge about 'such' he is enough, or not yet? Quod modus est?

Big surgeons give big incisions.

Incisions heal from the side and not from the ends.

Hm... Better late, than never!

Before start any discussion participants should achieve agreement about difinitions. So, what are 'the modern trends in General Surgery' and what are 'traditions' (to speak in more harder way, 'myths'), and what namely is thought to be a reasonable evidence for and against? Save the investigation of running knotes (Dr.Anning and Dr.Bonanno), I could not find here any reference on reliable data.

Prophylactic Drainage in Gastrointestinal Surgery

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1356522/pdf/20041200s00016p1074.pdf

and talking about phylosophy: Ἓν οἶδα ὅτι ουδὲν οἶδα (Ένα ξέρω, ότι δεν ξέρω τίποτα), I know one thing: that I know nothing!

Plato

Dr.Darmamanis,

Both Plato and the Evidence-based medicine are dear for me, but dearer still is Truth.

By the way, Phylosophy is not a way of 'idly chattering about elusive things', but is a real science. Just for example, let us to look at this very article 'Evidence-based value of prophylactic drainage in Gastrointestinal surgery' (PubMed Central 1356522):

On the 1st page of the article cited we find that

the authors use the definitions slipshodly, namely, from the very beginning they fall into misunderstanding of the most important definition in their article:

"...Prophylactic drains have been employed to remove intraperitoneal collections such as ascites, blood, bile, chyle, and pancreatic or intestinal juice."

If so, they are NOT PROPHYLACTIC, but curative! In other words, what is the question? To remove the collections or not?

Is it worth to read further?

But we shall procede a little later, if it is needed for one only, because the price of wrong strategy in Surgery is too high.

M.Schein / To drain or not to drain? The role of drainage in the contaminated and infected abdomen: an international and personal perspective // World J Surg. 2008 Feb;32(2):312-21.

Unfortunately, I did not read this. Would any colleague kindly provide its summary?

However, works by Dr.M.Schein ought to be read completely. They are difficult things to retell in short. However, they are rather a publicism, a kind of social journalizm, most talanted though.

A physicean has to master the statistical methods of investigation, lest he or she being a blind instrument in other person's hands. He or she was educated at university and must know the bases of Statistics, Phylosophy along with the own specialization. A meta-analysis is only a tool that one can use on this way or that, fruitefully, or vice versa.

Any way, thanks to Dr.Bonanno for this wise, enthusiastic speech! Agree completely, save one thing: I did not understand the abbreviations he used:

LDV

PRCT

NEJM.

What are their meanings?

well I see that you like the topic, so I would like to provoke you even more (more RCTs!)

Irrigation versus suction alone during laparoscopic appendectomy for perforated appendicitis: a prospective randomized trial. Ann Surg. 2012 Oct;256(4):581-5.

http://www.ncbi.nlm.nih.gov/pubmed/22964730

Dr. Bonanno, I did say nor about 'a juvenile reverberation', neither about 'your classical studies', of which I know not. :))

Prefer not to answer

There are many myths in surgery still. Gerych is quite right, and if it's true that the surgeon should be wise and brave, he should have the bravery to try to change them applying, when possible, data and suggestions coming from evidence based medicine. How to do it? That's the problem! The best tool we had in the last 15-20 years is the periodical (monthly) audit of our surgical performance. Besides writing papers, we should challenge ourselves in our departments comparing a likely "local" myth with its exact antithetical alternative. For example, try in your department if there is any difference on wound infection rate if scrubbing your hands for 2 or 3 or 5 or 10 minutes in clean operations performed by different surgeons, I am sure you'll be surprised by the results! The young surgeons should be the ones to provoke the traditional Master, and the Master should be so humble to accept the method and update his teaching...

If the surgeon is really wise, he/she ought to remember that who is under risque due to his\her actions is not he\she, but the patient.

So, to begin with, try not to change your scrub habits in your real practice before the appropriate microbilological studies of your skin after various scrub regimens have done, and so on. If experiments of dermatological drugs on the animals are considered as crude and have lack of humanity, why likewise experiments are thought being safe for human beings?

The old traditions in Surgery, however they might look like, are based on huge experience of centuries, some of them, perhaps, on thousands years. On the other hand, the so-called 'evidence based medicine' remains still just a novel tool of healthcare analysis. Just a tool having limitations of its own. To 're-check' reliably enough all the old traditions in Surgery will take centuries, let us not forget it, please.

This article by Moshe Schein provides a lot of insights on the myths in surgery around the world. A very interesting observation mentioned in the text is as below:

When you tell a surgeon today that his or her practice is based on myth,

he or she would reply instantly: “What is your evidence?”

article retrieved from: http://www.docschein.com/Myths.pdf

I think, The surgical prophylactic drainage is one of the most important myths because the drain itself can increase the seroma formation and it will irritate tissue to make transuda, so I prefer prevent it by proper subcutaneous sutures and dead space reduction during surgery. In veterinary surgery, using drainage is very common for mastectomies but I dont use drainage and the outcome is much better and the patient convenience is more with less recovery period and hospitalization