Suture materials and patterns

Question 1

What is the difference between absorbable and non absorbable suture?

Answer 1

ABSORBABLE = rapid + undergo degradation and rapid loss tensile strength <60 days

NONABSORBABLE = retains tensile strength >60 days

Question 2

What is the difference in capillarity between monofilament and multifilament material?

Answer 2

Monofilament (noncapillary – does not carry disease or bacteria) versus multifilament (more capillary)

Question 3

For surgical cat state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 3

Absorbable and natural

1. Composition - Formaldehyde treated sub-mucosa (collagen) from cow or sheep
2. Capillarity - Multifilament with smooth monofilament appearance
3. Absorption - by phagocytosis, chromatisation decreases the speed of absorption, increased with acidic pepsin from the stomach + other acidic environments + highly vascular tissue, often occurs past 90 days
4. Tensile strength - plain gut has > 67% of its tensile strength by 7 days, chromic gut looses 50% by 7 days then 83% by 14 days then 100% by 21 days - it has a poor strength to size ration
5. Knot security - good when dry (can swell when wet)
6. Suture reactivity - reactive foreign body
7. Handling - easy handling
8. Sterilisation - cannot autoclave as denatures, radiation = good, ethylene oxide may prolong absorption times

Question 4

For polyglactin 910 (PG910) state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 4

Absorbable synthetic

1. Composition -Polymer of glycolic and lactic acid (ratio of 9:1)
2. Capillarity - Multifilament
3. Absorption - hydrolysis greater in hot and alkaline environments think infected urine. More hydrophobic than PGA (looses tensile strength slower). Complete absorption between 40-90 days (70)
4. Tensile strength - Good ratio– loss of strength 50% @ 14 days then 80% at 21 days
5. Knot security - poor knot security
6. Suture reactivity - Well tolerated in most tissues – good for vascular as no reaction is incited
7. Handling - Good handling but ++++ tissue drag
8. Sterilisation

Question 5

For Polydioxanone (PDSII) and Polyglyconate (PGT, Maxon) state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 5

Absorbable synthetic

1. Composition - PDS – polymer of polydioxanone, Maxon – polymer of polytrimethylene carbonate + glycolic acid
2. Capillarity - Monofilament
3. Absorption - Degraded by hydrolysis, PDS, Maxon – some absorption by 91 days, complete by 182 days, significantly slower than PG910 above
4. Tensile strength - Excellent tensile strength to size ratio – initial strength > monofilament nylon and polypropylene
5. Knot security - Good
6. Suture reactivity - Very little tissue reactivity
7. Handling - Minimal tissue drag, does have some memory, greater flexibility than above (PG910)
8. Sterilisation

Question 6

For Poliglecaprone 25 (Monocryl) – Monocryl plus has triclosan  state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 6

Absorbable synthetic

1. Composition - Synthetic polymer
2. Capillarity - Monofilament
3. Absorption - By hydrolysis – complete within 90-120 (119 days)
4. Tensile strength - 50% strength by 10 days then 100% by 21 days
5. Knot security - Good
6. Suture reactivity - Minimal to none
7. Handling - Good – no tissue drag- soft and flexible
8. Sterilisation

Question 7

For Polyglytone 6211  state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 7

Absorbable synthetic

1. Composition
2. Capillarity - monofilament
3. Absorption
4. Tensile strength - 40-50% @ 5d, 70-80% @ 10d, 100% @ 21d – complete absorption in 56 days
5. Knot security - Excellent
6. Suture reactivity
7. Handling - soft + flexible
8. Sterilisation

Question 8

For silk state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 8

Non-absorbable natural

1. Composition - processed sil
2. Capillarity - Multifilament
3. Absorption - Some but limited
4. Tensile strength - 30% @ 14 then 50% @1y then 100% @ 2y
5. Knot security - Good – wetting decreases strength by 10-15%
6. Suture reactivity - can cause GIT ulceration in the lumen
7. Handling - Excellent (gold standard)
8. Sterilisation

Question 9

For stainless steel state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 9

Non-absorbable natural

1. Composition - Alloy
2. Capillarity - Available as either
3. Absorption - none
4. Tensile strength - 30% by 14d then 50% by 1y then 100% by 2y
5. Knot security - Good – wetting decreases strength by 10-15%
6. Suture reactivity - tissue reaction - silk may induce ulceration in GIT if present in lumen
7. Handling - gold standard
8. Sterilisation

Question 10

For nylon state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 10

Non-absorbable synthetic

1. Composition - Amine coated thermoplastic
2. Capillarity - Available as monofilament + multifilament
3. Absorption - Little – some extent by chemical degradation
4. Tensile strength - Good strength to size ratio – intermediate in strength (similar to polypropylene). Monofilament will loose tensile strength 30% by 2 years, multifilament – 70-90% by 180 days
5. Knot security - poor to fair
6. Suture reactivity - inert
7. Handling - poor with memory
8. Sterilisation

Question 11

For polymerized caprolactam state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 11

Non-absorbable synthetic
1. Composition - Polyamide suture of the nylon family – enclosed in a sheath of proteinaceous material
2. Capillarity - Multifilament
3. Absorption - Non-absorbable
4. Tensile strength - Good size to strength ratio>than nylon
Caprolactam loses about 15-20% strength when wet
5. Knot security - Fair
6. Suture reactivity - breaking down of coating increases the degree of tissue reaction
7. Handling - good handling characteristics
8. Sterilisation - autoclaving results in decreased tensile strength, chemical sterilisation does not make it safe or sterile for use in other tissues (Ethylene oxide is required)

Question 12

For polyester fibres  state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 12

Non-absorbable synthetic

1. Composition - Plain or coated forms
2. Capillarity - Multifilament
3. Absorption - Non-absorbable
4. Tensile strength - High tensile strength , Excellent tensile strength to size ratio
5. Knot security - Uncoated polyester has high co-efficient of friction
6. Suture reactivity - Causes significant tissue reaction + incidence of sinus tract formation is highest with polyester implantation
7. Handling - coatings improve handling and reduce tissue drag
8. Sterilisation

Question 13

For polypropylene and polybuster state whether it is absorbable or non-absorbable and whether it is natural or synthetic: 
And then its: 
1. Composition
2. Capillarity
3. Absorption 
4. Tensile strength 
5. Knot security 
6. Suture reactivity 
7. Handling
8. Sterilisation

Answer 13

Non-absorbable synthetic
1. Composition - PL – plastic poylmer of propylene , PB – polymer of polybutylene and polytetramethylene
2. Capillarity - Monofilament
3. Absorption - Nonabsorbable
4. Tensile strength - PL – fair to good,
PB – good
5. Knot security - PL- fair to good,
PB – good
6. Suture reactivity - Pl least thrombogenic so good in vascular surgery
7. Handling - PL – quite difficult to handle
PB – excellent handling somewhat elastic meaning its V.good for plastics and tendon + ligament repair
8. Sterilisation

Question 14

Does increase the gauge or increasing the number of throws increase the strength of the suture more?

Answer 14

Increasing the gauge increases the strength more than number of sutures

Question 15

Does increasing gauge or number of throws increase the bulk and suture reaction more?

Answer 15

Increasing the gauge has a greater effect

Question 16

Briefly explain the difference between a closed eye needle and a swaged needle:

Answer 16

Closed eye needle - similar to a household needle and may be round oblong or square
Swaged needle - eyeless needle with the suture permanently attached it is then sterilised and pre-packaged

Question 17

What is a cutting needle and when may it be used?

Answer 17

has the cutting edge on the inside an is used for difficult to penetrate tissue (e.g. skin and fibrous tissue)

Question 18

What is a reverse cutting needle and when might it be used?

Answer 18

Outside of the needle - less likely to tear through tissue

Question 19

When are skin staples used?

Answer 19

Closure of wound skins - quick and inexpensive however they tend to pucker the skin

Question 20

What are some examples of wound adhesives and when are they used?

Answer 20

Cyanoacrylate polymers are catalysed by minute amounts of water on tissue surface. Heat is generated and they are self sterilising