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How to suture



  • 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 (see Bites)
  • 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



  • 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 (see Local anaesthetics)
    • 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


Click here for full details and videos of the different suturing techniques



    • 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
    • Click here for full UK government advice on tetanus
    • 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


Click here for full table of when to give tetanus cover in wound care 


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

Click here for full table of suture materials and here for suture sizes

  • 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’


Useful links


Click here for medical student OSCE and PACES questions about suturing

Common How to suture exam questions for medical students, finals, OSCEs and MRCP PACES