A knot-tyingprimer

© E

THIC

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ü 01

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No.

62

Impressum

EditorETHICON Products GermanyRobert-Koch-Straße 122851 NorderstedtConsultantPriv.-Doz. Dr. med. Friedrich-Christian RiessCardiac SurgeryAlbertinen-Krankenhaus HamburgConcept & DesignRIESSmedien, NorderstedtCommunication for medicine, science and technologyPhotographs and art designAndreas Riess

A knot-tyingprimer

Foreword

With this new revised edition of our “Knot-tying primer”,Ethicon would like to give those studying and commencingtheir career in medicine instructions to assist them inlearning the most important knots and suturing techniquesof modern surgical practice.

We have limited ourselves quite deliberately to thosetechniques which are helpful for those at the start of theircareer to master. Further techniques, which the surgeonlearns in the course of his professional practice, are not thesubject of this publication.

We hope that our information brochure is of use to you andwish you every success in your professional practice.

Norderstedt, April 2003

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Contents

1 Knots 7

1.1 Square knots, one-hand technique 8–151.2 Square knots, two-hand technique 16–231.3 Instrument knots 24–27

2 Suture techniques 29

2.1 Subcutaneous sutures 302.1.1 Subcutaneous suture using interrupted sutures 312.1.2 Subcutaneous suture using a continuous suture 31

2.2 Suture of asymmetrical wounds 322.2.1 Joining wound edges of different length 322.2.2 Closure of larger wound areas 33

2.3. Skin sutures 342.3.1 Vertical mattress suture according to Donati 34

and McMillen2.3.2 Modified vertical mattress suture according 35

to Allgöwer2.3.3 Intracutaneous suture according to Chassaignac 36

and Halsted using nonabsorbable suture material2.3.4 Intracutaneous suture according to Chassaignac 37

and Halsted using absorbable suture material2.3.5 Skin closure with DERMABOND 39

2.4 Ligature of blood vessels 40–41

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76

1. KNOTS

The knots shown on the following pages are those mostcommonly used in modern surgery, and the pictures showthem from the surgeon’s angle.

The best way to practise tying initially is with a two-coloured string, at first always holding the coloured end inthe right hand. Later practice blind and then with surgicalgloves and surgical suture materials in different sizes. Thatway you can get a feeling of how many throws in opposingdirections are needed with each suture material in order toobtain a secure knot

The right index finger grips thewhite end and pulls it throughunder the purple end.

By turning the right handinwards and extending theright index finger, the purpleend is pushed through thewhite loop ...

98

1.1 Square knotsOne-hand technique

Experience has shown that the square knot is one of the best and is there-fore generally recommended. Whenever possible, it is tied with both handsin order to achieve with a few throws in “genuinely” opposite directions aknot that does not slip. In certain situations, however, use of only one handis unavoidable, either only the left or only the right hand.

The purple end of the thread is held between the thumb and middle fingerof the right hand, while the raised and extended index finger of the righthand acts as a bridge. The white end of the thread is held between thethumb and index finger of the left hand.

1.1 Square knots One-hand technique

11

1.1 Square knots One-hand technique

10

... and then pulled completelythrough the white loop.

The first stage of this knot iscompleted by pulling bothends of the thread vertically.The right hand points towardsthe surgeon and the left handaway from the surgeon.

1.1 Square knots One-hand technique

The right hand moves its graspas shown. The purple end ofthe thread is held between theright thumb and index finger.

The right hand grasping thepurple end of the thread isturned so that the palm of thehand is showing towards thesurgeon.

13

1.1 Square knots One-hand technique

12

The white end of the thread isplaced over the purple end bythe left hand.

The white end is passed bythe right middle finger underthe purple end.

The purple end is graspedbetween the right middle andring finger …

... and passed under the whiteend of the thread …

1.1 Square knots One-hand technique

15

1.1 Square knots One-hand technique

14

... and pulled through fully.

The knot is completed bypulling both ends of the threadvertically. The left hand pointstowards the surgeon and theright hand away from thesurgeon.

Square knot, overview of one-hand technique

1.1 Square knots One-hand technique

1716

1.2 Square knotsTwo-hand technique

Simplest and best knot, if circumstances permit.

The white end of the thread is placed over the extended index finger of theleft hand, which acts as a bridge. The thread is held with the left hand. Thepurple end of the thread which is held in the right hand, is passed betweenthumb and index finger of the left hand.

Left index finger and thumbmove to the left and passunder the white end of thethread.

Left index finger and thumbgrasp the purple end ...

1.2 Square knotsTwo-hand technique

1918

... and pass it under the whiteend.

The purple end of the thread is grasped by the right handand pulled out completelyunder the white end.

The first stage of this knot iscompleted by pulling bothends of the thread vertically.The left hand points towardsthe surgeon and the right handaway from the surgeon.

The white end of the thread isheld by the left hand, with thewhite end passed around theextended thumb.

The left index finger grasps thepurple end ...

1.2 Square knotsTwo-hand technique

1.2 Square knotsTwo-hand technique

2120

... and the left index fingerpushes towards the right underthe white end.

The purple end is placed bythe right hand between leftindex finger and thumb, whichgrasp it.

Left index finger and thumbpass the purple end throughunder the white end of thethread.

With the right hand, the purpleend is pulled out under thewhite end.

The left thumb is pulled outunder the purple and whiteends ...

1.2 Square knotsTwo-hand technique

1.2 Square knotsTwo-hand technique

2322

... and the knot is completed by pulling both ends of the thread vertically.The left hand points away from the surgeon and the right hand towards thesurgeon.

Overview of square knot, two-hand technique

1.2 Square knotsTwo-hand technique

1.2 Square knotsTwo-hand technique

2524

1.3 Instrument knotsA knot tied with the aid of instruments is appropriate in cases where one orboth ends of the thread are short or, for instance, to save on suture materialin the case of interrupted sutures. It is important to ensure that sharp edgesare avoided, especially in the jaws of the instrument employed, as they leadto damage to the surface structure of the thread.

1.3 Instrument knots

The short purple end of the thread is free, while the long white end is heldbetween index finger and thumb of the left hand. The first two loops aremade by placing the thread around the needle holder.

The needle holder grasps theshort purple end and pulls itthrough the two white loopstowards the surgeon.

The first half of the knot iscompleted by pulling theneedle holder towards thesurgeon and the white end ofthe thread away from thesurgeon.

The needle holder nowreleases the purple end of the thread.

2726

1.3 Instrument knots1.3 Instrument knots

A further loop is placed withthe white end of the threadaround the needle holder,which approaches from above,and then the purple end isgrasped with the needle holder.

The knot is completed bypulling the purple end awayfrom the surgeon and the whiteend of the thread towards thesurgeon. The white end canalso be held by an instrumentinstead of the left hand at every stage.

Overview of instrument knots

2928

2. SUTURE TECHNIQUES

The most important suture techniques for closing subcutaneous tissue and skin are described below.

3130

2.1 Subcutaneous sutures 2.1.1 Subcutaneous suture using interruptedsutures

The subcutaneous sutureis placed as shown in-cluding the lowest point ofthe wound, in order toavoid formation of a cavityafter it is tied. Intact fasciashould not be punctured.

The suture is tied loosely.The subcutaneous suturesshould be tightened onlyenough to prevent theformation of cavities in thesubcutaneous fat and onthe other hand to avoiddisorders of perfusion.

Subcutaneous sutures are used to join the subcutaneous tissue. Absorbablesuture materials (e.g. VICRYL, VICRYL RAPID or MONOCRYL) are usuallyemployed for these sutures.

The sutures are placed through the subcutaneous tissue as shown andthen tied.

2.1.2 Subcutaneous suture using a continuous suture

With the continuous subcutaneous suture, the path of the threadthrough the tissue is identical with the subcutaneous suture usinginterrupted sutures. The continuous subcutaneous suture is the fastermethod compared to the interrupted suture technique.

2.1 Subcutaneous sutures

3332

2.2 Suture of asymmetrical wounds

In surgical practice, wounds with margins of different length or wounds withdefects of skin substance require special wound closure techniques.

2.2.1 Joining wound edges of different length

With wound edges ofdifferent length, it is helpfulto divide the overall lengthinto several smallersections by one or moretemporary sutures. This can be done withinterrupted mattresssutures, for instance.

2.2.2 Closure of larger wound areas

After tying the temporarysuture, tension-freeclosure by means of sub-cutaneous and skinsutures is possible.

Temporary sutures areremoved after closure ofthe wound.

When there is a skindefect, a mattress suturethat picks up only thesubcutaneous parts ofthe lappets can shift the wound edges so thattension-free woundclosure can take place.

After tying the mattresssuture, the subcutaneousand skin closure takesplace. The mattress sutureused for adaptation can be left, as it is of advantagefor the perfusion of theskin lappets that only thesubcutaneous tissue ispunctured.

2.2 Suture of asymmetrical wounds

3534

2.3 Skin sutures

The importance attached by the patient to the cosmetic result after anoperative procedure must not be underestimated. Besides a step-freeapproximation of the wound edges through appropriate subcutaneoussutures, the technique for skin closure has a crucial influence on thecosmetic result. The needle should pass vertically through the skin, asresistance is least so that the needle characteristics can be exploitedoptimally.

2.3.1 Vertical mattress suture according toDonati and McMillen

When the subcu-taneous fat layer isthin, both skin andsubcutaneous tissueare closed as shown.The suture should be placed in such away that a cavity isavoided. With goodadaptation, a verygood cosmetic resultis obtained.

2.3.2 Modified vertical mattress suture according to Allgöwer

The Allgöwer mattress suture differs from the Donati and McMillen mattresssuture only in the fact that the thread does not penetrate the surface of theskin on the contralateral side.

2.3 Skin sutures

3736

2.3 Skin sutures

2.3.3 Intracutaneous suture according to Chassaignac and Halsted usingnonabsorbable suture material

With good adaptation due to subcutaneous sutures, the intracutaneoussuture gives an outstanding cosmetic result. With non-absorbable sutures,both ends of the thread are secured with a suture fixation clip. The fixationclip at the same time acts as an aid when removing the nonabsorbablesuture.

2.3.4 Intracutaneous suture according to Chassaignac and Halsted using absorbable suture material

Intracutaneous suturing givesoutstanding adaptation.

The suture is tied in the sub-cutaneous area. The stitch isthen taken back as far as thepole of the wound, so that theknot is buried.

By tautening the end of thethread, the knot is buried in thewound pole. Finally, the suture is cut at skin level.

The suture is tied with the lastloop and this is cut short. Thelast stitch leads from the pole ofthe wound through the sub-cutaneous tissue back to thesurface of the skin.

2.3 Skin sutures

3938

2.3.5 Skin closure with DERMABOND

Exact adaptation of the skin surface by manual approximation of bothwound edges between the thumb and index finger is important for a goodresult. The adhesive is applied in several layers and forms a stable water-proof wound closure.

For skin closure there are now modern adhesives available (2-OctylCyanoacrylate). With good adaptation an outstanding cosmetic result canbe obtained. The stress of surgical wound care can be greatly reduced bythis method, especially in children.

2.3 Skin sutures

DERMABOND

Correct placement of aligature of a vessel branch.

Ligature too close to thevessel leads to gathering ofthe adventitial tissue and thus to circular narrowing ofthe vessel which can lead to turbulence and vesselocclusion.

Ligature distant from thevessel leads to turbulence and thrombus formation in theresidual stump.

Wrong!

Wrong!

2.4 Ligature of blood vessels

40 41

2.4 Ligature of blood vessels

When ligating side branches, correct placement of the ligature is of greatimportance in order to prevent turbulence and thrombus formation along withvessel stenosis and occlusion.

To ligate a side branch of a blood vessel securely, the ligature is secured bytaking the surface of the adventitia on both sides of the origin of the vessel,so that the ligature is prevented from slipping off. For example, whenligating the branches of the great saphenous vein, which is used as bypassmaterial in coronary and vascular surgery, the correct ligature of thebranches has a direct influence on the patency rate and thus on the long-term operative result of coronary and vascular surgery.

Notes:Notes: