Suturing materials and epidermal closure techniques Flashcards
Buried sutures can be used to close dead space, redistribute tension, decrease dehiscence and increase wound eversion.
T
When undermining wound edges, skin hooks are the least traumatic means of stabilising and mobilising wound edges.
T
The configuration of a suture denotes its composition.
T
Advantages of suture braiding include lower propensity for infection.
F Increased propensity to retain microorganisms.
Advantages of suture braiding include increased tensile strength.
T
Advantages of suture braiding include decreased fraying of cut ends.
T
Newer innovations include suture coating with either antibacterial or antitumor qualities
T
Disadvantages of braided sutures include poorer handling and knot-tying properties.
F Improved
Disadvantages of braided sutures include more resistance when pulled through tissue.
T
Sutures coated with silicone, Teflon and wax decreases friction.
T
Capillarity denotes a suture’s ability to wick fluid from an immersed end to its dry end.
T
Braided sutures have decreased capillarity.
F Increased
Sutures with increased capillarity are more likely to harbor bacteria
T
Tensile strength refers to the weight necessary to break a suture divided by the cross-sectional area.
T
Larger sutures have decreased tensile strength.
F Increased
Synthetic sutures tend to have decreased tensile strength compared to sutures of natural materials.
F Increased
Tensile strength can be decreased by physical factors, such as wetness or increased age of sutures
T
Due to shearing forces between the strands, braided sutures have decrease tensile strength
T
The number/size ranks of sutures refer to their tensile strength – the greater the tensile strength, the fewer the zeros.
T Ie 2-0 suture has more strength than 6-0.
All sutures with the same tensile strength will have the same calibre.
F Eg. The calibre of a 5-0 nylon will be smaller than a 5-0 gut because nylon is stronger.
Knot strength refers to the security of a tied knot and is defined by the degree of slippage that occurs in a knot.
T
Sutures with a decreased coefficient of friction slide more easily and have a lower knot strength.
T
Memory is the ability of a suture to return to its original size and shape after being stretched.
F This is true for elasticity.
Elasticity denotes the ability of a suture to regain its former shape after bending.
F This is true for memory
Knots in sutures with increased memory (eg. polypropylene and nylon) have a greater tendency to untie themselves.
T Should throw extra ties with these sutures.
Sutures with increased memory are less difficult to handle.
F More difficult
Elasticity is a desirable quality for a surface suture as it means the suture will stretch with the tissue and also recoil when the swelling subsides.
T
Plasticity refers to a suture’s ability to retain their deformed shape rather than return to their original shape when stretched.
T
Plasticity is advantageous in knot tying because deformation of the suture may lead to a more secure knot.
T
Sutures made of natural materials are less immunogenic than synthetic materials.
F More immunogenic.
Sutures with a multifilament configuration are more immunogenic than those with a monofilament configuration.
T
Non-absorbable sutures are more immunogenic than absorbable sutures.
F Less immunogenic. The immune response elicited by absorbables cause their dissolution.
Large diameter sutures are more immunogenic than small diameter sutures.
T
All sutures exhibit at least some inflammatory response when placed in tissue.
T
Sutures made of natural material are degraded by proteolysis in contrast to synthetic sutures which are degraded by hydrolysis
T
Non-absorbable sutures cause less tissue reaction because they induce a fibrous shell which coats the suture and decreases the host response.
T
True suture allergy does not occur.
F Rarely.
Absorbable sutures are defined as those that lose the majority of their tensile strength within 60 days after placement in living tissue.
T non-absorbable sutures maintain their tensile strength for periods >60 days.
The presence of wound infection does not affect suture absorption.
F Increases suture absorption.
Suture placement location does not affect the rate of suture absorption.
F Mucosa absorbed faster.
Surgical gut is the only absorbable suture made of natural materials.
T
Surgical gut is a twisted multifilament suture composed mostly of collagen.
T
Fast absorbing gut is recommended for internal use
F
There are two varieties of gut sutures: plain and chromic.
F Three varieties. Also fast-absorbing.
Plain surgical gut loses much of its tensile strength in 3 weeks.
F 7-10 days.
Plain surgical gut is completely absorbed by 70 days.
T
Fast-absorbing gut is heat treated for more rapid deterioration.
T
Fast absorbing gut is used in facial wound closure, or the placement of skin grafts where rapid absorption of the suture is desirable
T
Nearly all of the tensile strength of a fast-absorbing gut suture is lost within 7 days, and complete absorption takes 21-42 days.
T
PDS II has lower tensile strength than fast-absorbing gut initially does
F Fast-absorbing gut –low initial tensile strength, PDSII high initial tensile strength, 50% at 4 weeks, 25% at 6 weeks
The initial tensile strength of Glycomer 631 (Biosyn) has not been studied
T Known at have 49% retained tensile strength at 3 weeks
Chromic gut has been treated with chromate salts which increases the rate of absorption in tissue.
F
Decreases rate of absorption
Chromic gut maintains its tensile strength for 10-21 days and is completely absorbed after approximately 90 days.
T
Chromic gut is best used to suture skin edges.
F Ligate vessels or suture mucosal wounds.
A history of chromate sensitivity does not preclude use of the chromic gut suture.
F
dont use if chromate sensitivity/allergy
Disadvantages to gut sutures include unpredictable absorption rates, low tensile strength, and increased tissue sensitivity.
T
Polyglycolic acid (Dexon) is a synthetic absorbable suture.
T
Polyglycolic acid is a non-braided suture.
F Braided multifilament suture.
Polyglycolic acid sutures can be coated with polycaprolate coating to reduce drag when pulled through tissues.
T
The polyglycolic acid suture retains 65% of tensile strength for 2 weeks after placement and 35% 3 weeks after implantation.
T
The polygycolic acid suture is completely resorbed between 30-60 days after placement.
F 60-90 days.
Advantages to using the polyglycolic acid suture include good handling and knot security and low tissue reactivity.
T
Polyglactin 910 (Vicryl) is a coated braided multifilament suture.
T
Polyglactin 910 consists of a copolymer made from 90% glycolide and 10% l-lactide.
T
Polyglactin 910 has similar handling properties to polyglycolic acid but has less tense strength.
F More tensile strength.
Polyglactin retains 75% of its tensile strength at 2 weeks and 50% at 3 weeks, and it is completely resorbed after 56-70 days.
T
Vicryl-rapide is a more rapidly dissolving form of polyglactin 910.
T
Vicryl-rapide loses 50% of its tensile strength at 5 days and essentially all tensile strength within 10-14 days.
T
Lactomer (Polysorb) is a coated braided multifilament suture made of copolymers of lactic and glycolic acids
T
Lactomer retains 80% of its tensile strength at 5 weeks and over 30% at 10 weeks. respectively.
F 2 and 3 weeks
Polydioxanone (PDS) if a multifilament synthetic absorbable suture.
F Monofilament.
Polydioxanone has increased tensile strength when compared to polyglactin 910 or polyglycolic acid.
F Decreased tensile strength.
Polydioxanone is more slowly resorbed and retains its strength for longer than polyglactin 910 or polyglycolic acid.
T
Polydioxanone retains 70% of its original tensile strength at 2 weeks, 50% at 4 weeks, and 25% at 6 weeks.
T
Complete absorption of polydiaxanone takes approximately 3 months.
F 6 months. Absorption is negligible until 3 months.
Polydiaxanone may be useful in wounds under high tension or wounds that require prolonged dermal support.
T
Polytrimethylene carbonate (Maxon) is a multifilament synthetic absorbable suture.
F Monofilament.
Polytrimethylene carbonate has lower initial tensile strength than polydiaxanone.
F Higher initial tensile strength.
Polytrimethylene carbonate retains 81% of initial tensile strength at 2 weeks, 59% at 4 weeks, and 30% at 6 weeks.
T
Polytrimethylene carbonate is absorbed more slowly than polydiaxanone.
F More quickly. Its absorption starts 60 days after implantation.
Polytrimethylene carbonate has worse knot strength and handling properties compared to polydiaxanone, polyglycolic acid and polyglactin 910.
F Better.
Poliglecaprone 25 (Monocryl) is a monofilament absorbable synthetic sutre with superior handling and tying properties due to its increased pliability.
T
The knot strength of poliglecaprone is superior to polydiaxanone, polyglycolic acid, polyglactin 910 and polytrimethylene carbonate sutures.
T
Poliglecaprone has lower initial tensile strength than PDS II or Maxon.
F Higher.
Poliglecaprone’s strength diminishes more quickly than the other monofilament synthetic sutures.
T
Poliglecaprone 25 retains 60% of its initial tensile strength at 7 days, 30% at 2 weeks, and loses all of its tensile strength by 3-4 weeks.
T
Dyes Maxon sutures retain their tensile strength and remain in tissue slightly longer than the clear sutures.
T
Absorption of both clear and dyed poliglecaprone sutures is essentially completed by 2-3 months.
F 3-4 months.
Fast absorbing gut is a multifilament, with poor knot strength, high tissue reactivity and loses its tensile strength in 3-7days
T
Surgical silk is a multifilament suture composed of braided fibres of protein harvested from the cocoon of the silkworm larva.
T
Surgical silk is not absorbed.
F Completely absorbed within 2 years.
Surgical silk loses almost all of its tensile strength 6 months after implantation
F 1 year
Silk suture is very soft. It should not be used on mucosa or intertriginous areas
F
Silk suture has superior handling and knot tying characteristics
T
Silk suture use is limited due to its tendency to cause tissue reactions
T
Silk is a monofilament
F Multifilament
Silk had low tensile strength
T
Silk has poor knot strength
F
Silk has low memory
T
Polypropylene (prolene) has excellent knot strength
F Poor
Polybutester (novafil) has excellent knot strength
F Good
Nylon sutures have high tensile strength and are absorbed at a rate of 15-20% per year if left in tissue.
T
Monofilamentous nylon has a high degree of memory, decreasing its pliability, handling and knot security.
T
Nylon sutures are unaffected by moisture.
F Made more pliable by moisture.
Polypropylene (Prolene) is a multifilament synthetic suture.
F Monofilament.
Polypropylene has a lower tensile strength than other synthetic non-absorbable suture.
T
Polypropylene has low tissue reactivity and an extremely low fiction coefficient.
T therefore decreased knot security.
Polypropylene will eventually be degraded if left in tissue.
F therefore good to reapproximate ear cartilage
Polypropylene has significant plasticity.
T
Polyester is a braided multifilamentous synthetic suture that is soft and pliable.
T
Polyester has a high tensile strength, which is only exceeded by metal sutures.
T
Polyester is generally uncoated.
F Coated with Teflon, silicone or polybutylate.
Polybutester (Novofil) is a monofilament suture composed of polyglycol terephthate and polybutylene terephthate.
T
Polybutester exhibits elasticity.
T
Polyhexafluoropropylene-VDF (Pronova) is a monofilament non-absorbable suture composed of a polymer blend of polyvinylidene fluoride and polyvinylidene fluoridecohexafluropropylene.
T
Pronova has a high coefficient of friction.
F Low.
Most suture needles are composed of stainless steel.
T
An ideal suture needle is malleable, strong and sharp.
T
Malleability refers to a needle’s resistance to breaking under a given degree of bending.
T
Reshaping a bent needle generally does not affect the needle’s strength or lead to breakage.
F
Sharp needles result in less tissue trauma and better cosmetic results.
T
Needles are often coated with silicone or other lubricants to improve the ease of needle penetration.
T
There are two parts to a suture needle – the shank and the point.
F Three parts – also the body.
The shank is the portion of the needle that attaches to the suture.
T
The point is the weakest part of the needle.
F The shank is weakest.
The point is the largest pat of the needle-suture unit, and hence it determines the size of the suture tract.
F This is true for the shank.
The point of the needle extends from the tip of the needle to the largest cross-section of the body.
T
The body is the middle portion of the needle between the shank and the point.
T
The body is the strongest portion of the needle and this part should therefore be grasped with the needle holder.
T
A conventional cutting needle has its primary cutting edge on the outside of the curve.
F Inside.
Reverse cutting needles have their primary cutting edge on the inside of the curve.
F Outside.
Reverse cutting needles result in less tissue tearing by the suture after tying.
T
Rounded needles cause less tissue tearing than conventional or reverse cutting needles.
T Use in delicate areas or in fascia.
Staple placement is 50% faster than suture placement.
F 80% faster.
Staples have an increased risk of tissue strangulation, reactivity and infection than sutures. .
F Decreased risk
Flaps that are stapled have a lower risk of partial necrosis compared to sutured flaps.
F Higher risk.
Tissue adhesives are made of cyanoacrylate compounds.
T
Histoacryl is octyl cyanoacrylate.
F Dermabond is.
Dermabond is N-butyl-2-cyanoacrylate.
F Histoacryl is.
Octyl cyanoacrylate has improved flexibility, less tissue toxicity, and at least three times the bonding strength of n-butyl-2-cyanoacrylate.
T
Octyl cyanoacrylate is used with application of a single layer.
F Triple layer.
Horizontal mattress sutures should not be used when suturing flaps because there is a greater theoretical risk of dermal strangulation.
T Also shouldn’t used in poorly vascularised wounds.
Locking horizontal mattress suture is helpful for wounds that need wound edge compression or haemostasis
T
Horizontal mattress stitches can be placed with half of the suture buried in the dermis
T
The half-buried horizontal mattress stitch is often used as a ‘tip stitch’ to secure the triangular tips of flaps.
T
Half buried horizontal mattress stitch uses non absorbable suture
T
A running epidermal stitch is stronger than an interrupted stitch
F
A running locked suture can facilitate haemostasis.
T
The running subcuticular stitch minimises epidermal puncture points, allowing sutures to be left in place longer.
T
A buried vertical mattress suture results in more wound eversion than a buried butterfly suture.
F
Suture tracks occur when sutures have been left in place too long, needles and suture calibre is too large, or if sutures are tied too tightly.
T
Purse string suture decreases the diameter of a wound
T
The purse string suture involves vertically orientated bites spaces 5-10mm apart placed continuously along the circumference
F Horizontally
Wounds partially closed using a purse string suture may be left to granulate or may be closed with an overlying skin graft
T
