Suture Materials Flashcards
Sutures hold a wound in apposition until…
the natural healing process is established enough to make support from the suture material unnecessary.
What is the adequate duration on average for sutures being left in the body?
14-21 days on avg, except tendon
In the early stages of wound healing, wound strength is due to…
- fibrin from inflammatory reaction
- vascular endothelial ingrowth
- epithelial migration into wound
What factors are likely to influence wound healing?
infection
tension
severe protein depletion
poor vascularisation
What biological properties of suture material have to be considered?
- the likelihood of the material to potentiate infection
- calculogenic?
suture strength should match…
tissue strength
The rate of loss of suture strength must be compatible w/ the…
the rate of gain of wound strength
Define: ‘Straight pull’ tensile strength
Represents the maximum longitudinal force a strand can bear before breaking
Define: ‘Knot-pull’ tensile strength
The force which a suture strand can resist before it breaks when a knot exists
Define: ‘Out of packet’ tensile strength
This is the ‘straight pull’ tensile strength
AKA the original tensile strength
Define: Tensile strength
Time suture will mechanically support the wound, usually measured in days
Define: Mass absorption
Time in days for suture to be totally absorbed by the body
What is the Critical wound healing period (CWHP)?
The time in days a wound requires mechanical support
What is the metric number used in the metric system of suture size?
Metric number = the thread in diameter in tenths of a mm
Explain the USP system of suture size.
System has a standard range in diameter for each size or grade
Denoted in zeros with the finest is (14-0) and a max diameter is at 7.
What are the ideal properties of suture material?
- low cost
- easily sterilised
- pliable
- high tensile strength
- non-capillary
- secure knots
- no tissue rxn
- absorbed/encapsulated
What are the 3 classifications of suture?
- Absorbable or non-absorbable
- Multifilament or monofilament
- Natural or synthetic
What are the different types of absorbable suture that are commonly found?
Catgut, Chromic catgut, Polyglycolic acid (Dexon), Polyglactin 910 (Vicryl/Vicryl RAPIDE), Polydioxanone (PDS), Polyglyconate (Maxon), Poliglecaprone 25 (Monocryl), Glycomer 631 (Biosyn), Polyglytone 6211 (Caprosyn)
Catgut is …
natural, absorbable, monofilament
Catgut is made from the submucosa of…
sheep/cattle
Plain gut (catgut) evokes…
severe sterile pyogenic reaction
Catgut loses tensile strength…
rapidly
How long does it take the body to absorb catgut?
about 7 days
What is important to remember about plain gut (catgut)?
Plain gut should not be used in Surgery
Chromic catgut is…
natural, absorbable, monofilament suture
What differs chromic catgut from plain gut?
Chromic catgut has a chromic oxide treatment to reduce inflammatory reactions in the body. It has a higher tensile strength for longer and a more even absorption pattern
What are some advantages of chromic catgut?
- relatively cheap if purchased in cassettes
- easy to handle
What are some disadvantages of chromic catgut?
- severe inflammatory rxn
- poor knot security
- questionable sterility in cassettes
- variability in strength & loss of strength
- swells & weakens when wet
- weakens when knotted
- capillary action
Polyglycolic acid (aka Dexon)
Synthetic, multifilament, absorbable
How is Polyglycolic acid broken down? What does this do to the body?
It is broken down by hydrolysis thus making it less reactive to the body than catgut.
Polyglycolic acid has better… than catgut.
knot security
The strength of polyglycolic acid is … by knotting than catgut
less affected
polyglycolic acid has some …. due to the ….
tissue drag
multifilament synthetic braided suture
What suture is the main competitor to polyglycolic acid?
Polyglactin 910
Polyglactin 910 (Vicryl) is a
synthetic, multifilament, absorbable suture
Why is polyglactin 910 a competitor for Polyglycolic acid?
it is marginally stronger than the polyglycolic acid
When is it ideal to use Vicryl rapide?
Superficial soft tissue (skin & mucosa) where only short-term wound support is required.
How long does vicryl rapide last?
about 7-10 days
Vicryl rapide should not be used for…
ligation, cardiovascular, GIT, etc
Polydioxanone is also known as
PDS
polydioxanone is a
synthetic, absorbable, monofilament
how is polydioxanone absorbed?
by hydrolysis
Polydioxanone is stronger than…
polypropylene or nylon
At 4 weeks, polydioxanone has what percent of strength remaining?
50-70%
At 6 weeks, polydioxanone has what percent of strength remaining?
25%
What type of filament suture is best for infected tissues? why?
Monofilament because it is made of only 1 strand and isn’t braided like polyfilament. The braiding allows bacterial to get into the suture material and harbor there.
Another name for polyglyconate suture is…
Maxon
Polyglyconate suture is
synthetic, absorbable, monofilament
Polyglyconate differs from PDS how?
- possibly a little stronger than PDS II
- slightly better knot security
Poliglecaprone 25 is also known as
monocryl
Poliglecaprone 25 is
synthetic, absorbable, monofilament
poliglecaprone 25 is rapidly…
absorbed
How long does it take poliglecaprone 25 to lose most or all of its significant strength?
14 days
When should you use poliglecaprone 25?
in rapidly healing tissues or when you don’t want suture material present for long
Glycomer 631 is also known as
biosyn
Glycomer 631 is
monofilament, synthetic, absorbable suture
What is glycomer 631 excellent in?
initial strength and in vivo strength over the CWHP
Glycomer 631 has minimal
memory
glycomer 631 is used for
general soft tissue approximation
Polyglytone 6211 is also known as
caprosyn
Polyglytone 6211 is
absorbable monofilament suture
How long does complete absorption take in Polyglytone 6211?
56 days
polyglytone 6211 has what good characteristics?
- excellent handling
- retains up to 30% knot strength, even at 10 days post-implantation
rapid absorption limits application in which absorbable suture?
polyglytone 6211 (caprosyn)
Any suture degraded by hydrolysis may be at risk of…
premature degradation when used in a bladder infected w/ Proteus spp.
What are the types of non-absorbable sutures?
silk, polyamide (nylon), polypropylene (prolene), stainless steel, coated caprolactum (supramid)
Silk is…
natural multifilament non-absorbable suture
what are advantages with silk suture?
- cheap & easy to handle
- tensile strength lost after 6 mos
- good knot security
When is silk used?
cardiovascular surgery
What are the problems with silk suture?
- causes ulceration in the GIT
- unsuited in contaminated sites
- predisposes to calculi in the bladder
polyamide is also known as
nylon
polyamide is
synthetic mono or multifilament non-absorbable suture
The half life of polyamide
exceeds 6 months
what are some key characteristics of polyamide suture?
- minimal tissue reaction
- moderate strength
- moderate security
- little discomfort on removal
- commonly used for skin
Polypropylene is also known as
prolene
polypropylene is
synthetic monofilament non-absorbable suture
What are some key characteristics of polypropylene suture?
- minimal tissue drag
- moderate knot security
- moderate strength
- good for skin
- least thrombogenic, so great for cardiovascular surgery
What is the memory like in polypropylene suture?
slightly difficult to handle
What are some key characteristics for stainless steel suture?
- very strong & retains strength
- non-capillary & inert
- difficult to handle
- can be used for skin suture
What is another name for coated caprolactum?
Supramid
Coated caprolactum is
synthetic, multifilament, non-absorbable suture
What are some key characteristics of coated caprolactum?
- twisted multifilament of the nylon family
- coated in a proteinaceous material
- common for skin closure
- chemical disinfection does not sterilise so cannot be used for anyone other than skin closure
- intermediate tissue reactivity
- superior tensile strength to nylon
What are the main problems w/ multifilaments?
- capillary properties
- tissue drag/friction
- premature locking of knots, especially ligatures
How were multi-filaments fixed?
they were coated to solve tissue drag & premature locking
When are multi-filament sutures unsuitable?
- slow healing tissues like tendon
- delayed healing situations (infections)
What are the two types of needles used in suture?
Swaged needles
Eyed needles
What are some advantages to swaged needles?
- less traumatic
- immediately available
- always sharp
- guaranteed sterile
- slim as possible without compromising strength
- stable in needle holder
- coated w/ silicone to improve sensation of sharpness
What are some advantages to eyed needles?
- less expensive
- reusable
What are some disadvantages to eyed needle suture?
- soft steel, easily bent
- larger than swaged due to the eyelet
- edge is lost with autoclaving/chemical sterilization
Needle bodies can be either…
straight or curved
Needle choice depends on the
depth and size of the wound
What fraction of a circle in needle curvature is available?
1/4 circle
3/8 circle
1/2 circle
5/8 circle
Cutting needles come in what types?
Taper point, reverse cutting, conventional cutting, taper cutting
Round-bodied needles have
no sharp edges
What are some tissues that taper point needles are used on?
biliary tract
nerve
vessels
dura
peritoneum
pleura
GIT
SQ fat
muscles
myocardium
What are some tissues that reverse cutting needles are used on?
fascia
ligaments
skin
tendons
What are some tissues that conventional cutting needles are used on?
skin, ligaments, tendons
When is a taper cutting needle used?
bronchus, tendons, calcified tissue, trachea, fascia, uterus, ligaments, vessels, ovary
When are round-bodied needles used?
parenchyma, fat, muscles
straight needles are used…
in open access areas
skin, GI
1/4 circle needles are used in
ophthalmic or microsurgeries
3/8 circle needles are used…
most of the time
skin, muscle, GIT, cardiovascular, vascular, tendon, etc.
1/2 circle needles are used…
in deeper tissues usually
GI, CV, vascular, muscle, oral cavity, etc
5/8 circle needles are used
- in tight access areas
- urology, pelvic cavity
- prostatectomy, pelvic cavity
