How to suture

Introduction

  • Suturing entails the closure of a wound or defect using a thread attached to a needle with knots tied to maintain the apposition of wound edges
  • As with all simple procedures, suturing can be done well or poorly
  • Essential skill for many specialities, not just surgery (A&E, GP, Dermatology, Anaesthetics)
  • Appropriate suture material and size should be used

 

Indications for suturing

  • Clean wounds with minimal skin loss allowing for closure under minimal tension
  • Securing drains/lines to prevent loss (e.g. central lines, intercostal drains)
  • Operative closure

 

Equipment required for suturing

  • Sterile Gloves
  • Suture Kit
    • Standard kits include needle holders, forceps (ideally toothed) & scissors
  • Skin preparation
    • Povidone-iodine or chlorhexidine
  • Appropriate suture (size/material/needle)
  • Saline – remember all wounds should be washed before closure
  • Sterile drapes/sheets
  • Sharps Bin
  • Gauze
  • Dressing Materials (many simple wounds closed with sutures may not require a dressing)
  • Local anaesthetic
    • With or without adrenaline (eg 1% Lidocaine with 1:200000 adrenaline)
  • Good lighting

 

Contraindications to suturing

  • Do not close actively infected or grossly contaminated wounds
  • Animal bites
    • These are likely to require operative washout +/- debridement – always discuss with plastics/maxillo-facial surgeons
  • Novices should avoid facial suturing if little experience
  • Do not close wounds if you suspect significant underlying vital structure damage e.g. nerve/tendon/vessel
  • Avoid closing wounds with significant skin loss as this may place undue tension on the wound.
    • In these cases it is best to ask a senior for help/advice or discuss with the appropriate speciality e.g. plastic surgery

 

Pre-Procedure

  • Verbal consent should be obtained from the patient
  • Alternative options to suturing should be discussed including healing by secondary intention, steri-strips (‘butterfly stitches’) and skin glue
  • Administer local anaesthetic
    • Avoid using adrenaline in locations with end-arteries such as digits, penis etc.
  • Ensure wound has been adequately irrigated/washed (e.g. with 1L of normal saline)
    • A basic irrigation can be accomplished with 1L of saline attached to a giving set. Squeeze the bag of saline and irrigating the entire wound (as deep and thoroughly as possible) with the pressurised fluid.
  • Prepare equipment

 

General Principles & Technique of Suturing

  • The needle should be inserted perpendicular to the skin
  • ‘Bites’ should be equal in both distance and depth on both sides of the wound i.e. enter and exit at the same level in the tissues
  • Use the curve of the needle to pass the suture through the skin
    • Rotation of the wrist allows the needle to pass in an atraumatic fashion
    • Avoid pushing or pulling the suture through the skin in a straight line
  • Minimise handling of the wound edges
    • Use toothed forceps to hook the skin and avoid pinching/crushing the tissues
  • Wounds should be closed with minimal tension, use a buried dermal suture (see below) to reduce the tension of the skin closure in deep wounds
    • NOTE: Avoid dermal sutures in the face/hands
  • Wound edges should be slightly everted to ensure dermal apposition and a more cosmetically appealing scar
  • As a general rule, braided sutures should have three throws on the knots, monofilament sutures should have five throws

 

Post-Procedure:

    • Keep wounds clean and dry for a minimum of 48hrs (at this point they should be waterproof
    • Advice on signs of infection and to seek medical attention if they develop
  • Give the patient advice on care of the wound
  • Following removal of sutures, if further support of the wound is required, Micropore™ tape can be used directly on the wound for 1 further week
    • Rough guide based on location on the body:
      • Face- 5 to 7 days (unless using Vicryl Rapide™) to avoid leaving unsightly cross hatching/suture marks
      • Hand/Foot-10-14 days
      • Trunk/Breast- 7-14 days
    • Important to remember that each patient and wound is unique and these are guides only
  • Document information for removal of sutures:
    • Simple ointments can be used around the lips, eyes and other awkward areas e.g. chloramphenicol ointment functions as both a moisturiser, protective layer and antimicrobial agent
    • Brown Micropore™ tape can be placed on facial wounds as a simple dressing which hides the scar/sutures
  • Apply a dressing if required
  • Dispose of sharps- always count your sutures and dispose of them safely in a sharps bin
  • Consider prophylactic antibiotics to reduce the risk of wound infection e.g. Co-Amoxiclav 375mg three times a day for 5 days (consult local guidelines)
  • Consider tetanus prophylaxis treatment
    • High risk wounds include: wounds requiring surgical managements with >6hour delay; puncture injuries or wounds with significant devitalised tissue; wounds in contact with soil or manure; wounds with retained foreign bodies; open fractures; wounds in patients with sepsis
    • Immunoglobulin prophylaxis dose: 250IU IM or 500IU IM if >24hrs since injury, heavy contamination or burns

 

Top Tips for suturing

  • Practice, Practice, Practice
  • Observe how your seniors and colleagues suture, the materials and sizes they choose and develop a set of sutures and a technique that you are comfortable with
  • Mount the needle approximately 2/3 from the tip in the needle-holder
  • Holding the needle-holders like a pen with the index finger supporting the tip of the needle holders gives better control for fine suturing than holding the handles with finger and thumb
  • Eversion of wound edges is best achieved by taking decent sized bites and ensuring that the needle is inserted perpendicular (or even slightly beyond 90o) to the skin
  • Try to use absorbable sutures in children wherever possible- they heal very well and removal of non-absorbable sutures can be almost as challenging as the suturing itself!
  • Avoid using the forceps to pinch the edges of the wound, rather use them to lift or hook the skin
  • Fine debridement of the wound edges to remove traumatised/inflamed/dirty skin promotes healing and produces a more cosmetically pleasing scar
  • Use a Penrose Drain and an artery clip as a tourniquet for suturing digits (remember to use a local anaesthetic ‘ring block’ (see Local Anaesthetics), document the tourniquet time and don’t forget to take it off!)
  • Consider use of nerve blocks for analgesia e.g. median nerve block, often less painful than local infiltration

 

Complications of suturing

  • Poor apposition of wound edges
  • ‘Dog Ear’- unsightly and bulky ends to a wound due to uneven closure
  • Stitch Marks- scarring at the entry and exit point of the suture
  • Stitch Abscess- localised inflammation/infection around the suture material, more common with absorbable sutures
  • Infection- more common with braided sutures
  • Dehiscence- either due to poor technique, wound infection or excessive strain on the wound post closure
  • Skin necrosis- usually due to overly tight sutures or sutures placed too close together

 

Suture Materials, Sizes & Choice

  • Sutures can be broadly divided into Absorbable and Non-absorbable materials
    • Further subdivision into monofilament and multifilament (polyfilament) or braided
    • Also consider whether the material is synthetic or naturally occurring
  • Absorbable:
    • Do not need to be removed and can be left to breakdown in-situ
    • Nearly all synthetic materials, exception is catgut
      • Catgut: twisted thread of collagen fibres harvested from ruminants or beef tendon; not used in Europe (and other countries) due to risk of Bovine Spongiform Encephalopathy (BSE).
    • Absorbable materials are broken down through hydrolysis, thus inducing little tissue reaction (exception is catgut which is broken down through active inflammation)
      • Granuloma formation still occurs around sutures
      • Risk of ‘stitch abscess’ formation
    • At least 50% of strength is lost by 4 weeks (for majority)
    • Preferred in children as no need for removal
  • Non-absorbable:
    • Non-absorbable sutures (if on the skin) require removal- the duration of this is determined by the location on the body of the suture
    • Majority are synthetic, silk is the exception
      • Silk: gold standard for handling however is rarely used due to associated inflammatory response (response resolves swiftly after suture removal)
    • If used for skin closure, will require removal
  • Braided vs Monofilament:
    • Monofilaments:
      • Have ‘memory’- require straightening before use (pull to length and give one short sharp tug on the suture), otherwise will curl up, catch and irritate
      • Reduced surface area hence less tissue reaction (if absorbable)
      • If surface is damaged (poor handling, crush etc) strength is reduced significantly
      • Knots require tight tying due to tendency to come undone
    • Braided:
      • More difficult to handle
      • Do not easily ‘run’ through tissues
      • Slightly increased risk of infection
      • Increased reaction with surrounding tissues due to increased surface area
  • See table below for summary of common suture materials
  • Suture Sizes:
    • Many different sizes of suture used for different parts of the body/size of defect
    • Not referred to by the their size in metric units e.g. mm but by the USP (United States Pharmacopeia) sizes
    • Begin from the smallest ’11-0’ with the first number decreasing in size as the suture gets larger ie 10-0, 9-0, 8-0, 7-0 etc.
    • 1-0 is simply called 0
    • Sutures larger than 0 are given a single number i.e. 1,2,3,4,5 with increasing size
    • Table 2 below lists suture sizes, their equivalent in mm and suggested uses
  • Needle selection:
    • Many different types of needle
    • Do not need to be too concerned with needle selection for simple procedures
    • As a rule use a curved conventional cutting needle for skin suturing. Reverse cutting needles can be used for fine closures but caution must be taken to avoid the suture ‘cutting out’

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