Catgut ligatures

Re: Catgut ligatures

sophia guymer — Tue, 24 Aug 2010 13:32:30 GMT

[quote user="Michael Woodhouse"]A surgeons knot the end is passed through twice (two 'throws')[/quote]

Thanks Michael, thats exactly what I do, just really started to doubt myself after all the above, and the you tube flims, looked on them on the ones saying they were surgeons knots but none of them did the first one like that. Thanks for clearing that up.

Re: Catgut ligatures

Colin Cameron — Mon, 23 Aug 2010 23:54:18 GMT

so do I , come to think of it, so it must be ok ha ha !

Re: Catgut ligatures

Michael Woodhouse — Mon, 23 Aug 2010 23:05:32 GMT

[quote user="Colin Cameron"]Have fun with your string and lets ban half hitches in the theatre!!! [/quote]

I use them for tying limbs to the table - is that ok?

Re: Catgut ligatures

Colin Cameron — Mon, 23 Aug 2010 22:39:27 GMT

Part of the problem is that there are sometimes two names for the same knot and the non scout/guide etc vets seem to be taught the American terminology rather than the uk names eg reef knot or square knot. I presume this is because most of the best text books on surgery come from across the pond.It can actually be quite difficult to describe a knot without pictures or video. I was taught the reef knot and many others in the scouts (quite a few years ago it must be said) but I have come across a number of vets who find even this simplest of knots difficult to tie, especially using instruments. Seeing some referral surgeons and other so called experts using vast numbers of half hitches instead of proper knots will not help at all. I would agree with you that they should all go home with a ball of string and, as you said, " learn your knots".You actually do not need to learn many but please learn to tie them correctly. I did find a very useful tube from University of Virginia on tying sutures which was narrated by a New Zealander I think. It should be shown to all students, unless it already is of course. Here's to proper knots! Have fun with your string and lets ban half hitches in the theatre!!!

Re: Catgut ligatures

Robert Whiteford — Mon, 23 Aug 2010 21:13:31 GMT

Right, everyone, with resonances with some other posts about young people just doing computer games, would you all just join the scouts and guides or take up sailing and learn your knots!

This is a basic for everyone over 12!

If not (knot) then there are books ( yes whole books) on knot tying.There are pamphlets too and, I dare say, articles on the interworldwidecomputerthingy.

Again, with resonances in other posts, there are intelligent veterinary surgeons out there that cannot tie (nor describe) knots?(allowances being made for any language difficulty).??

There is a whole vocabulary surrounding knot tying and suture use and the properties of suture materials that just needs to be learnt. I thought this would be taught at college but apparently not (knot)!

Re: Catgut ligatures

Michael Woodhouse — Mon, 23 Aug 2010 20:46:50 GMT

[quote user="sophia guymer"]I was taught to suture in Belgium, am Dutch so all these English terms don't mean a thing to me and I now don't know anymore if what I do is a surgeons knot or not?[/quote]

A surgeons knot the end is passed through twice (two 'throws') and then once to lock it down. A square knot there is a single throw on each.

Surgeon's knot

Re: Catgut ligatures

sophia guymer — Mon, 23 Aug 2010 19:52:24 GMT

[quote user="Evelyn Barbour-Hill"] have also noticed that a lot of vets ( referral vets as well) are seemingly being taught to use six or seven or more half-hitches round the standing end in skin sutures rather than a proper surgeons knot.[/quote] Ok now I am totally confused by everybody talking about throws, half hitches, standing ends, running ends, 'proper' surgeons knots etc.

I was taught to suture in Belgium, am Dutch so all these English terms don't mean a thing to me and I now don't know anymore if what I do is a surgeons knot or not? When you talk about a half hitch, do you mean making one end go round the other once? When I do a surgeons knot, I make the first 'throw'(? Ithink) by putting one end around the other twice, before making a knot by putting another 'throw' (?) on top, this one will only be wrapped around as it were, once. with then several others on top

Does that make any sense at all? I have looked on surgeons knot on the you tube films and they all seem to be single all the way from the start?

I hope I have made myself sort of clear?

Re: Catgut ligatures

Evelyn Barbour-Hill — Mon, 23 Aug 2010 14:33:46 GMT

[quote user="Mark Holmes"][quote user="Colin Cameron"]

I have also noticed that a lot of vets ( referral vets as well) are seemingly being taught to use six or seven or more half-hitches round the standing end in skin sutures rather than a proper surgeons knot. Does anyone know why?

[/quote][/quote]

It's because they have been taught that every additional half hitch makes the knot more secure. Of course it doesn't, to any significant degree.

What works with rope doesn't work on slippery suture material. If a straight suture end will slip through two half hitches it will slip almost as easily through ten. To prevent the two ends slipping apart, you have to both construct the knot, and apply the correct force, so that both elements are deformed.

[quote user="Anthony Todd"]elizabethan collars[/quote]

Oo now there's another thread in the making. I haven't put one of those things on a dog for a quarter of a century. I'll put one on a cat maybe once a year.

Re: Catgut ligatures

Colin Cameron — Mon, 23 Aug 2010 12:05:16 GMT

[quote user="i am ed"]A sliding knot is not quite simply two half hitches. It's thrown the same way as a square knot and pulled tight in a different manner (essentially by pulling on the ends of a loose square knot asymmetrically it 'flips' into a sliding knot. [/quote] This is an old method for untying a reef knot by pulling one end across the actual knot and then sliding it off. The sliding knot is, I believe, still two half hitches but the second one is reversed ( same as you have stated). I would reiterate that a simple reef knot in Vicryl will pull tight and can then be locked with further throws ( 1 or 2 ).

Re: Catgut ligatures

Colin Cameron — Mon, 23 Aug 2010 09:08:08 GMT

I agree. I have just noticed that in my previous post I said the half hitches were round the standing end but I should have said the running end. Still the same non-knot.

Re: Catgut ligatures

Niall Taylor — Sun, 22 Aug 2010 21:53:12 GMT

[quote user="Anthony Todd"]

if an experienced cat spayer did 100 spays with cat gut throughout and 100 spays with gloves and the modern, better, non-negligent, university taught and approved, specialist recommended materials, the complication rate would be the same,probably zero.

The key is the spayer's experience and ability in the simple things like ligature competence suture tension, tissue trauma, time of exposure, gentle tissue handling etc

[/quote]

Niall

Re: Catgut ligatures

Edward Jones — Sun, 22 Aug 2010 21:40:54 GMT

I presume MN is referring to the usual practise of crushing the perivascular tissue with a clamp, removing the clamp, then placing the ligature on the crush. A shortcut is perhaps to place the ligature on fresh tissue and tighten until the tissue turns white - not a sure sign in my book personally (depends on the thickness of the tissue being ligated).

Perhaps why we talk of placing such a tight initial throw is because we think a tight first throw is less likely to loosen whilst the second throw is being placed to lock it. I've always thought this to be the case instinctively (that a tight first throw is less likely to immediately loosen) but in practise I don't think it's true - if the throw will loosen it'll happen immediately regardless of the tension used.

Re: Catgut ligatures

Virginia Campbell — Sun, 22 Aug 2010 13:38:21 GMT

[quote user="Malcolm Ness"]Little concerned about the accounts of pulling - the ligature only needs to be tight enough to overcome peak arterial BP. Sounds like some are using the ligature to crush perivascular tissues and that would be a potentially serious technical error. I[/quote]

(embarrassed cough) Can you explain why this is a bad thing? I try to clear away as much fat as i can from the vessels in the ovarian pedicle, then crank the catgut tight to squish the remaining fat. I know that ischaemic necrosis of tissue can cause a ligature to loosen, but I would have thought that the risk of slipping a day or two later isn't as bad as the risk of a not-tight-enough ligature slipping at the time of surgery. When tying off the cervix I do two transfixing ligatures, setting them off centre so that each vessel is essentially ligated separately, then secured around what will be the cervical stump. Would I be better off just ligating the vessels alone and not ligating the cervix itself at all to avoid crushing the tissue? (I do try to put the two ligatures very close to each other to avoid getting a big chunk of necrosing tissue between them). Please explain... I don't want to keep doing it wrongly if there is a better way!

Re: Catgut ligatures

Mark Holmes — Sat, 21 Aug 2010 23:54:36 GMT

[quote user="Colin Cameron"]

[/quote] I noticed this when I ha some sutures placed at the doctors, he placed half a dozen half hitches on a standing end, they all fell out in 48 hours. I do wonder though whether they have the potential to give as the tissue swells under the suture where as a locking suture does not. (or knot)

Re: Catgut ligatures

Michael Woodhouse — Sat, 21 Aug 2010 23:27:06 GMT

[quote user="i am ed"]I'll try to find a nice write-up of the sliding knot. I find it much more effective than a surgeons knot at bringing together tissue under tension.[/quote]

www.youtube.com/watch

Re: Catgut ligatures

Anthony Todd — Sat, 21 Aug 2010 10:58:25 GMT

[quote user="Jillian Hall"]Do any the fans of catgut for ligatures use it elsewhere too?[/quote]

Before Vicryl and its clones and copies were invented or in vogue all the vets I know used catgut throughout, including the skin in cats, and a synthetic like Vetafil in dogs' skin.

Cat spays were never seen post-op and we did have some clients moaning that the gut suture was still present, unnoticed by the cat, months later. gut seemed to cause absolutely no skin or tissue reaction if placed sympathetically.

We had few problems with wound breakdowns and other failures of technique but this was invariably a technique failure as opposed to a technical failure, due to inexperience or, a concurrent hand infected with a cat bite [gloves came later].

Problems were so rare that the more malevolent vets I worked with would ring each other up to report, gleefully, a problem.

My impression is that now, and with fewer routine procedures, we seem to see more wound/post op problems, even with analgesia, elizabethan collars and, I suspect, post-op antibiotics, but each one does take many times longer.

I would bet my house and car that if an experienced cat spayer did 100 spays with cat gut throughout and 100 spays with gloves and the modern, better, non-negligent, university taught and approved, specialist recommended materials, the complication rate would be the same,probably zero.

The key is the spayer's experience and ability in the simple things like ligature competence suture tension, tissue trauma, time of exposure, gentle tissue handling etc. Have you looked at the skin closure after an undoubtedly brilliant human surgeon has done a major op.; looks like it was done with a knife and fork.... then look at the facial sutures placed by a competent plastic surgeon; it's all in the detail.

Why, oh why, are uterine stump granulomas and post-op vaginal bleeding always blamed on the ligature material when the obvious causes are an excessive necrotic mass anterior to the ligature and/or part of the body, and sometimes part of the uterine horns, posterior to the ligature?

Re: Catgut ligatures

Laurence Webb — Sat, 21 Aug 2010 10:28:52 GMT

[quote user="James Allsop"]

. for the last few years though I have been prefering monofilament material for most areas and therefore use a lot of biosyn and caprosyn and tend to use monodox (on a reel) for ligatures and midlines in bitch spays. Since changing to monofilament I rarely if ever get any suture reactions, but I still see quite a few in midlines and subcut where my colleagues have used vicryl. I tend only to use vicryl where I want a softer material such as eyelid surgery.

[/quote]

Yes, I'm quite of fan of Biosyn as a good all rounder. For ligatures the 1st throw sticks beter than vicryl and PDS. If has less memory than PDS and is a bit softer too. Suture tensile strength lasts about as long as Vicryl but it is absorbed faster thereafter. I'll use it for ligatures, abdominal wall, fat and intradermal sutures. If you're stingy then you can do a whole bitch spay with a packet.

I don't get on as well with catgut, but I can't see any problem with using it for ligatures as knot slippage with vicryl is a problem.

Re: Catgut ligatures

Edward Jones — Sat, 21 Aug 2010 01:22:01 GMT

A sliding knot is not quite simply two half hitches. It's thrown the same way as a square knot and pulled tight in a different manner (essentially by pulling on the ends of a loose square knot asymmetrically it 'flips' into a sliding knot. You tighten the loop to bring the tissue together then pull symmetrically to flip it back to a square knot. Hard to put into words but simple in practise!).

Personally I find that simply laying a square knot with vicryl can result in the first throw loosening before the second throw can be tightened, with the result that the knot locks (due to the resistance of the material) and can not be tightened further. A surgeons knot overcomes this problem to some extent but is supposedly weaker than a square knot. Dick White taught against the surgeons knot when I was at college.

I'll try to find a nice write-up of the sliding knot. I find it much more effective than a surgeons knot at bringing together tissue under tension.

Re: Catgut ligatures

Colin Cameron — Sat, 21 Aug 2010 00:19:26 GMT

It seems to me that vet students are being taught that catgut is "old fashioned" and and therefore not recommended whereas little diddy packets of "new"synthetic stuff are the bee knees. I too have no liking for Vicryl having had some really bad reactions to it when used subcut. I now use Monodox midline and chromic catgut subcut with very little trouble. I never use Vicryl anywhere near the eye for the same reason. Regarding the sliding knot ( which appears to be,basically, two half-hitches round the standing end of the suture) I would say that a simple reef knot will pull tight quite nicely with Vicryl and then one or two more throws to lock the knot. I have also noticed that a lot of vets ( referral vets as well) are seemingly being taught to use six or seven or more half-hitches round the standing end in skin sutures rather than a proper surgeons knot. Does anyone know why?

Re: Catgut ligatures

James Allsop — Sat, 07 Aug 2010 12:47:00 GMT

I generally dont like vircyl for anything.... but then the other surgeons at my practice do think im a bit odd

I used to use catgut when seeing practice and got on well with this for ligatures (did get reactions when used in sub cut though). Catgug was generally not available at the practice I subsequently worked for and vicryl was the routine material available. for the last few years though I have been prefering monofilament material for most areas and therefore use a lot of biosyn and caprosyn and tend to use monodox (on a reel) for ligatures and midlines in bitch spays. Since changing to monofilament I rarely if ever get any suture reactions, but I still see quite a few in midlines and subcut where my colleagues have used vicryl. I tend only to use vicryl where I want a softer material such as eyelid surgery.

Re: Catgut ligatures

Edward Jones — Fri, 06 Aug 2010 08:19:26 GMT

For those having problems with the first throw of a vicryl knot loosening before you manage to get the second throw tightened - use a sliding knot. It's only a small variation on the square knot. It tends to waste a bit more material though, until you get practiced.

Re: Catgut ligatures

Michael Woodhouse — Thu, 05 Aug 2010 23:16:32 GMT

[quote user="Jillian Hall"]I'd never come across people using catgut for anything other than spays until recently. A current colleague uses catgut quite a lot for subcutaneous sutures in lump removals and wounds[/quote]

[quote user="Jillian Hall"]Do any the fans of catgut for ligatures use it elsewhere too?[/quote]

I use catgut for almost all subcut sutures. So would use synthetic absorbable to close abdomen then catgut to close the fat/subcut. It is quickly absorbed with least reaction IMO.

When I think about the fact I stich cows flank wounds back together using the stuff I don't worry about using it subcut.

Re: Catgut ligatures

Evelyn Barbour-Hill — Thu, 05 Aug 2010 23:04:41 GMT

[quote user="Jillian Hall"] A current colleague uses catgut quite a lot for subcutaneous sutures in lump removals and wounds. I found this quite shocking but my boss is a little more experienced with catgut[/quote]

Why shocking?

[quote user="Jillian Hall"]Do any the fans of catgut for ligatures use it elsewhere too?[/quote]

Oh yes, although not very much now.

We had a thread about gut sutures a while ago, but I really wanted to stick to ligatures. My original theme was that the authors of an article, both high in a veterinary school surgery department, condemned the use of gut for ligatures. They offered four points to demonstrate why gut should not be used but each of those points was nonsensical. Now that was shocking.

I gather from the discussion that there are lecturers and professors running round telling the students that "catgut is negligence". Heaven help us.

Re: Catgut ligatures

salome2001 — Thu, 05 Aug 2010 21:55:08 GMT

hands up here again for using catgut for ligatures and also for NOT liking vicryl as the knots, especially the first few before the suture material gets a bit of blood in it, come undone almost before you've got the second throw lined up. Catgut wins on the knot security.

Just as an aside: I've seen a couple of spay wound dehiscences recently (none mine, I locum) and they have not been single interrupted catgut like I was taught nearly 20 years ago, but vicryl continuous sutures in the linea alba where one of the knots has come undone. Yet that's the "proper" way to close an abdominal incision, isn't it???

Re: Catgut ligatures

Vikki Halliday LLB — Thu, 05 Aug 2010 21:44:06 GMT

[quote user="Fiona Dale"]I qualified from the RVC 3 years ago. [/quote]

I qualified from Glasgow 13 years ago, and even then there were surgeons who where in the "catgut is negligence" brigade, however using catgut for ligating pedicles in a routine spey, and as Malcolm Ness says, with enough pressure to stop arterial BP, I haven't yet had a bleeder. (LOTS OF TOUCHING WOOD!)

The only one I had was after using Vicryl, because I was strongly advised to by a "university" specialist.