1 - Suture Material Flashcards
Purpose of suture material
- Approximate tissue until healing takes place (skin, bone, tendon, ligament, etc.)
- Ligate vessels (tie up/close off)
- Tag fragile or important structures
o Example: tendon paratenon or sheath can roll back during procedure and be difficult to find again when ready to repair it, so you can “tag” it so you don’t lose it
Selection of suture material
- Biological and mechanical properties
- Structured to be sutured (tendon, fascia, skin, vessels and bone)
- Bacterial presence
Suture characteristics
- Strength and thread dimensions
- Suture volume
- Size (diameter)
- Tensile strength (when you pull on suture, does it elongate or snap?)
- Knot strength (ability of the knot to stay tied when you tie it)
- Elongation
- Flexibility
- Configurations (monofilament or braided)
- Capillarity
- Coating
Suture volume
o Use of smaller sutures decrease foreign body volume with the sacrifice of knot pull strength (less material so less reaction to it, but might break)
Elongation of suture
o Elasticity –> the ability to return to original length after applied strain (stainless steel, braided polyester, catgut, silk)
o Plasticity –> elongation persists with the cessation of strain (polypropylene – due to smaller diameter)
o Intermediate –> possesses properties of both elastic and plastic (nylon, polyglactin 910)
Flexibility of suture
Based on material and diameter of suture
- Small diameter is more flexible than large
- Silk and dexton is flexible (superior “handling ability”)
- Nylon and catgut are stiff (inferior “handling ability”)
Configurations (monofilament or braided)
o Monofilament - has low coefficient of friction, easier to pass through tissue, less damage to tissue, better suited for contaminated wounds
o Braided - high coefficient of friction, more tissue damage, greater strength, and capillarity (bacteria can be present in the folds between the braid)
Capillarity of suture
o Fluid and bacteria may penetrate into interstices of braided suture
o PMN’s, macrophages are too large to reach interstices
Coating of suture
o Helps decrease capillarity of braided suture
o Improves handling and reduces drag
Handling characteristics of suture
- Pliability flexibility of the suture
- Tissue drag = ability to pass through tissue
- Knot tying = ease of knot tying, some can be very difficult
- Knot slippage = hold ability of a knot
Tissue reaction characteristics
How tissues respond to the sutures themselves
- Inflammatory or fibrous cell reaction
- Absorption - causes higher tissue reactivity because body has to break it down
- Potentiation of infection - higher risk with absorbable sutures
- Allergic reaction (reactivity)
Absorbable surgical sutures
Natural filament
o Derived from animals (multifilament/braided)
Synthetic (artificial)
o Multifilament (braided)
o Monofilament
Non-absorbable surgical sutures
Natural filament o Multifilament (braided) Metal Synthetic o Multifilament (braided) o Monofilament
Classifications of natural absorbable surgical sutures
Plain gut
- Submucosa sheep intestine
- Serosa of beef intestine
Chromic gut
- Positive buffered chromicizing
Plain collagen
- Bovine deep flexor tendon
Chromic collagen
- Positive chromicizing
NOTE - Natural absorbable surgical sutures will have an increased reactivity when compared to synthetics
Classification of non-absorbable surgical suture
Class I
- Suture composed of silk or synthetic fibers (monofilament or braided)
Class II
- Suture composed of natural or synthetic fibers but consisting of a coating
Class III
- Suture composed of monofilament or multifilament metal wire
Classification of absorbable surgical sutures
- Polyglycolic acid
- Polyglycolic acid (with coating)
- Polyglactin 910
- Polydioxanone
- Polyglyconate
Polyglycolic acid
- Homopolymer of glycolide
- Trade name = Dexon-S
- Multifilament/braided, either undyed (beige) or dyed (green)
Polyglycolic acid (with coating)
- Homopolymer of glycolide (with poloxamer 188 coating)
- Trade name =Dexon-Plus
- Coated multifilament/ braided, either undyed (beige) or dyed (green)
Polyglactin 910
- Copolymer lactide-glycolide (with calcium stearate coating)
- Trade name: Vicryl
- Coated multifilament/ braided, either undyed (white) or dyed (violet)
Polydioxanone
- Polymer of paradioxanone
- Trade name: PDS
- Monofilament, either undyed (clear) or dyed (violet or blue)
Polyglyconate
- Copolymer of glycolide and trimethylene carbonate
- Trade name = Maxon
- Monofilament, either undyed (clear) or dyed (green)
General notes on classifications of synthetic absorbable surgical sutures
o Dexon and Vicryl are commonly utilized for subcutaneous closure because they are absorbable (you can leave it in there)
o PDS may be used more for plastic surgery because it is more of a monofilament (lower coefficient, decreased reactivity, good closure)
Synthetic nonabsorbable surgical sutures
- Nylon = Dermalon, Ethilon, Nurolon, Surgilon - Used for skin closure
- Polypropylene = Surgilene, Prolene
- Polybutester = Novafil
- Polyester = Mersilene, Dacron, Polydeck, Tevdek, Ethibond, Ticron –> Used for anchoring tendons to add strength to injured area
Diagram of different suture materials
Chromic or plain catgut o Not truly monofilament because they are naturally occurring o They are not truly braided, but they are made out of multiple filaments
Trends in resorption of different suture materials
look at graph
Resorption of polyester and polypropylene
o After a couple years, still present
Resorption of nylon
o After a couple years, material has somewhat resorbed
Resorption of silk
o By about 1 year, complete resorption has occurred
o Good material for handling, but high tissue reactivity
Resorption and tensile strength of polyglycolic acid (Dexon) and polyglactin 910 (Vicryl)
(look at graph)
Tensile strength
o Even though the material is retained by the body,
it is no longer benefitting the patient because it
loses its tensile strength 3 weeks post-op
Resorption
o It takes a long time for this material to reabsorb
o Typically reabsorbed by hydrolysis
Relative tensile strength of non-absorbable sutures
KNOW THIS
TOP = greatest tensile strength - Stainless steel wire - Coated braided polyester - Uncoated braided polyester - Monofilament nylon - Polybutester - Braided nylon - Polypropylene - Natural fibers (silk, cotton, linen) BOTTOM - least tensile strength
This compares a standard diameter, so the one monofilament strand is being compared to numerous braided nylon strands. Also, coated polyester has greater strength than uncoated
Relative tissue reaction of nonabsorbable sutures
**KNOW THIS **
TOP = least tissue reaction - Monofilament polypropylene - Monofilament polybutester - Monofilament nylon - Stainless steel wire - Polybutilate-coated polyester - Teflon/silicone-coated polyester - Uncoated braided polyester - Natural fiber materials BOTTOM = greatest tissue reaction
Natural fibers will have the greatest tissue reactivity
Absorbable sutures
- Generally loses tensile strength within 60 days
- Natural sutures (catgut, collagen) degraded by LYSOSOMES
- Synthetic sutures degraded by HYDROLYSIS
Synthetic Polyglycolic acid (Dexon)
Braided Good tensile strength & knot pull Very inert (not chemically active) May be coated Used for skin and subcutaneous
Synthetic Polyglactin 910 (Vicryl)
Braided 65% tensile strength at 14 days Very inert Completely hydrolyzed at 80 days May be coated w/ polyglactin 370 and Ca+ stearate
Synthetic Polydiaxonone (PDS)
Monofilament High flexibility and tensile strength Completely hydrolyzed at 90 days Very inert 70% tensile strength at 14 days
Synthetic Polyglyconate (Maxon)
Monofilament Resists kinking and curling Becomes softer with exposure to tissue fluid (not necessarily good) Loses 30% tensile strength in 2 weeks Completely hydrolyzed at 180 days
Synthetic Poliglecaprone (Monocryl)
Monofilament
Very pliable and inert
Completely hydrolyzed in 90-120 days
20-30% tensile strength lost at 14 days
Nonabsorbable sutures
Generally maintains tensile strength longer than 60 days
Natural nonabsorbable
- Silk
- Cotton, linen
Silk
Known for superior handling properties
impregnated and coated with waxes
Low tensile strength (slowly absorbable)
Highly tissue reactive
Cotton, linen
Similar to silk
Increased tissue reaction
Very low tensile strength, weakest suture
Synthetic nonabsorbable
o Nylon (Ethilon, Surgilon) o Polyester (Ethiond, Dacron) o Polypropylene (Prolene, Surgilene) o Stainless steel (Flexon braided)
Nylon (Ethilon, Surgilon)
Possesses memory Elastic in nature High tensile strength and low tissue reactivity Monofilament and braided May be used in contaminated wounds***
Polyester (Ethiond, Dacron)
Braided
High tissue strength, low tissue reactivity
May be coated with silicone
Used when strong apposition of tissue is needed (tendon repair)
Polypropylene (Prolene, Surgilene)
Very inert
Monofilament
Good for pliability and handling, excellent tensile strength
Minimal tissue drag
Often used in contaminated wounds and plastics
Stainless steel (Flexon braided)
Monofilament and braided
May corrode especially at stress points
Mild to moderate tissue reactivity
May fracture, fatigue or kink
Used for bone fixation, tendon repair and retention sutures (high stress area)
Suture needles
- Made of high quality steel
- Slim as possible without compromising strength
- Sharp enough to penetrate tissue with minimum resistance
- Rigid enough not to bend or break
Suture attachments
- Closed (eyed)
- French (split or spring)
- Swaged (eyeless)
o Most common
o Suture attachment directly into needle
o Decrease tissue damage
Curve and shape
Curve o Straight o ½ curved o ¼ circle o ½ circle (MOST COMMON) o 3/8 circle o 5/8 circle
Geometric shape o Round o Flat o Oval o Triangular
Length, point
Length
o 4mm to 60 mm
Point
o Blunt = Used for friable tissue (easily crumbled)
o Tapered = used for tissue with slight resistance (paratenon, tendon sheath, sub-Q)
Cutting
Conventional
Cutting edge on concave curvature
Cuts through dense tissue, but care must be taken not to cut through tissue
Reverse
Cutting edge on convex curvature
Greater strength, prevents cutting through tissue or causing extra damage
Simple interrupted suture
o Not a running, so you have individual sutures through the cross-section of the skin
o Tie with a surgeon’s knot
o If you need to take one or a few stitches out, you can take them out individually
Running baseball stitch
o Very similar to simple interrupted, but it is running, so it is all one
o The downfall of this is that if there is a post-op infection or hematoma and you need to open up the wound and let some of it heal by secondary intention, you have to take out the entire suture, can’t just take out part of it
Interrupted horizontal mattress
o Suture goes in on one side, out the other, then then make a square
o Need to evert the skin edges
o Typically used when there is tension on the skin edges
Interrupted vertical mattress
o Suture goes in one side, out the other, then in and out superior to the first
o Similar to a horizontal mattress, but in a vertical, not horizontal orientation
Staples
o Can be used if you are running short on time
o Stronger apposition of the soft tissue
o Typically utilized at a trans-met site or ankle fracture
