Absorbable vs. nonabsorbable

Nonabsorbable suture materials

Definition: materials that maintain their tensile strength in tissue at least 60 days

  • some lose strength over prolonged periods (eg. silk)
  • others maintain original strength and are walled off by fibrous tissue
  • can be permanently buried in tissues when necessary
    • monofilament form preferred as associated with fewer infections
    • avoid burying multifilament nonabsorbable sutures (associated with infection and draining tracts)
  • should not be placed in
    • lumen of urinary bladder or biliary system as predispose to calculi formation
    • infected or contaminated sites where can form a nidus for infection

Nonabsorbable suture materials

Absorbable suture materials

Definition: Materials that lose significant tensile strength within 60 days of being placed in tissue

    • arbitrary 60-day time frame refers to loss of strength NOT disappearance from the tissue. Some absorbable materials are physically present a long time but have no appreciable strength.
    • suture is broken down by phagocytosis or hydrolysis
  • how rapidly a suture loses strength IS important trivia
    • has to be compared with how long the incision needs to heal and regain its strength
    • dehiscence results if use a suture that loses most of its strength before the tissues regain theirs.

Absorbable suture materials

Monofilament vs. multifilament

Monofilament sutures

  • consists of a single strand of material
  • has minimal tissue drag
  • decreased knot security because of smoothness so additional throws are needed to achieve secure knots
  • significantly weakened by kinking or if crushed by instruments

Monofilament

Multifilament (braided) sutures

  • consists of several fibers twisted or braided into a single strand
  • generally stronger
  • usually better knot security
  • more tissue drag
  • many available with coatings applied by manufacturer to minimize tissue drag but also decreases knot security
  • should NOT be placed in infected or contaminated areas
    • bacteria can reside between individual fibers of the strand
    • isolated from immune system and antibiotics
    • results in persistence of infection as long as suture present
  • can form nidus for calculi formation in bladder and biliary system if persist for significant duration

Multifilament

Natural vs. Synthetic

Natural suture materials

  • made of natural fibers
  • are absorbable or nonabsorbable types
  • tend to induce more tissue reaction than synthetic materials
  • common examples include surgical gut (catgut) and silk

Natural Sutures

Synthetic suture materials

  • made of man-made materials
  • are absorbable or nonabsorbable types
  • tend to be less reactive than natural materials
  • tend to lose tensile strength and be absorbed at more predictable rates
  • common examples include polydioxanone (PDS) and nylon

Synthetic Sutures