The purpose of a suture

• to hold a wound together in good apposition until such time as the natural healing process is sufficiently well established to make the support from the suture material unnecessary and redundant.

Choice of a suture

• Choice of suture depends on:
  • Properties of suture material
  • Absorption rate
  • Handling characteristics and knotting properties
  • Size of suture
  • Type of needle

Natural suture materials

• Absorbable
  • Catgut - Plain or chromic
• Non-Absorbable
  • Silk
  • Linen
  • Stainless Steel Wire

Synthetic suture materials

• Absorbable
  • Polyglycolic Acid (Dexon)
  • Polyglactin (Vicryl)
  • Polydioxone (PDS)
  • Polyglyconate (Maxon)
• Non-Absorbable
  • Polyamide (Nylon)
  • Polyester (Dacron)
  • Polypropylene (Prolene)

Absorbable suture are broken down by either:

• Proteolysis (e.g. Catgut)
• Hydrolysis (e.g. Vicryl, Dexon)

Catgut

• Made from the submucosa of sheep gastrointestinal tract
• Broken down within about a week
• Chromic acid delays hydrolysis
• Even so it is destroyed before many wounds have healed

Silk

• Strong and handles well but induces strong tissue reaction
• Capillarity encourages infection causing suture sinuses and abscesses

Vicryl

• Tensile strength
  • 65% @ 14 days
  • 40% @ 21 days
  • 10% @ 35 days
• Absorption complete by 70 days

Polydioxone

• Tensile strength
  • 70% @ 14 days
  • 50% @ 28 days
  • 14% @ 56 days
• Absorption complete by 180 days

Common errors of suture use

• Too many throws. Increases foreign body size. Causes stitch abscesses
• Intra-cuticular rather than subcuticular sutures causing hypertrophic scars
• Holding monofilament sutures with instruments reduces tensile strength by over 50%
• Holding butt of needle causes needle and suture breakage

Bibliography

Hsiao W C, Young K C, Wang S T, Lin P W. Incisional hernia after laparotomy: randomised comparison between early-absorbable and late-absorbable suture materials. World J Surg 2000; 24: 747-751.

suture needles producers.