Suture materials Flashcards
Define tensile strength
‘breaking strength per unit area’
Define the memory of suture material
‘tendency to retain original configuration’
What is ‘Chatter’ and tissue drag
‘lack of smoothness or friction whilst passing through tissue’
Look at the types of needle
1/2 1/4 3/8th
What type of needle do you need for deep wounds?
The deeper the wound, the more curved the needle
How do you hold curved and straight needles?
Straight needles are handled manually, whereas curved needles are manipulated with needle-holders
What are the problems with using eyed needles?
- double strand of suture material
- multiple use => blunt
- increased tissue trauma
Why do we like a degree of ductility in a needle?
Must be sufficiently rigid to resist forces applied to them during handling, but must be sufficiently flexible to bend before breaking
This bending property is called “ductility” – warns the surgeon that the forces placed on the needle are too great
What are the Pros/cons of Monofilament?
Has smooth surface that allows for easy passage through tissues
Does not support bacterial growth
Has no capillary action
High memory (?)
Stiff ends can cause irritation if the knot is not buried
What are the pros/cons of multifilament?
Has a rough surface that causes tissue drag
Potential spaces between the filaments can act as a nidus for infection
Capillary action/wicking
Easy to handle
Soft and pliable, well tolerated by patients
How do the USP grade their suture material?
United States Pharmacopia
• Based on tensile strength rather than diameter
• 11-0 to 7
Increasing size/strength (11-0, 10-0, 9-0 … 0 … 1, 2, 3, etc)
How does the metric system grade their suture material?
1/10mm of diameter of suture (‘2’ = 0.2 mm)
Runs from 0.1-10
What should you always do before using suture material?
Check its in date
How long does a non-absorbable suture have to remain unchanged for?
60d
What causes suture dehiscence?
The principal causes of suture dehiscence are:
• Knot slippage
• Knot breakage
• Tissue laceration
• Weakening of the suture during its handling; crushing, shearing, etc.
