Wound Closure Biomaterials Flashcards
Bladder, fascia, and skin - which one heals the fastest?
The bladder heals very fast, and the fascia and skin take a lot longer. Can use quick absorbing material for sutures in the bladder.
Which 2 tissues are the only tissues that reach 100% tissue strength after healing?
Bladder and bone
Ideal Suture Material
- High initial tensile strength but totally biodegradable at a predictable rate
- Bioinert
- Good handling characterisitcs, strong, supple, lack of memory
- Absolute knot security without loss of strength at knot
- Inexpensive and easily sterilized
Tensile Strength vs Absorption
- Tensile strength: Refers to the strength of the suture and it’s ability to hold wound edges in apposition. As absorption occurs, tensile strength will diminish over time.
- Absorption: refers to the time needed for the body to absorb or dissolve the suture material
Nonabsorbale suture vs Absorbale suture
- Nonabsorbale suture: retaines tensile strength for longer than 60 days
- Absorbale suture: undergoes degredation and rapid loss of tensil strength within 60 days
What are the three suture structures?
- Monofilament
- Woven-braided
- Twisted (catgut)
List two natural absorbale sutures:
- Catgut
- Collagen
Catgut
- Derived from sheep small intestinal submucosa or cattle serosa
- Twisted multifilament
- Capillary action - can swell and become untied
- Absorption by phagocytosis
- Rate of absorption unpredictable from one package to the next
Two sutures that are degraded by phagocytosis
- Silk
- Catgut
Catgut can come in plain and chromic - when would you use one or the other?
- Chromic lasts longer
Synthetic Absorbales
Multifilament - braided
- Polyglactin 910 - Vicryl
- Polyglycolic acid - Dexon II
- Glycolide/lactide copolymer - Polysorb
Synthetic Absorbables
Monofilament
- Polydioxanone - PDS II
- Polyglyconate - Maxon
- Poliglecaprone 25 - Monocryl
- Glycomer 631 - Biosyn
- Polyglytone 6211 - Caprosyn
Polyglactin 910 - Vicryl
- Braided multifilament
- Absorbed by hydrolysis - compete absorption ~ 70 days
- Maintains adquate tensile strength for 14 to 21 days
- High coefficient of friction increases tissue drag - coating attmepts to minimize drag
- Not the best suture if you need a long lasting one!!
Polyglactin 910 - Vicryl Rapide
- Same as vicryl, but maintians adequate tensile strength for wound support for less than 14 days
- Used when fast absorption is advantageous
Polyglycolic acid - Dexon II
- Braided multifilament
- Absorbed by hydrolysis - enhanced in alkaline environment
- Maintains adequate tensile strength for 14-21 days
- Complete absorption 90-120 days
- High coefficient of friction increases tissue drag
- Similar to Vicryl, but handles less desirably than vicryl
Glycolide/lactide - Polysorb
- Braided multifilament
- Absorbed by hydrolysis - complete absorption ~ 70 days (similar to polyglactin 910 - Vicryl)
- Maintains ~ 80% tensile strength at 14 days
- Similar to vicryl
Polydioxanone - PDS II
- Monofilament
- Absorbed by hydrolysis - complete absorption by about 6 months
- Maintains 69% tensile strenght at 42 day
- Takes the longest to be absorbed (180-240)
- Tends to kink when used for continuous patterns
- Used for long-term support (fascia healing)
Polyglyconate - Maxon
- Monofilament
- Absorbed by hydrolysis - complete absorption ~ 180 days
- Maintains 55% of tensile strength at 21 days
- at 21 days is when fascia stops its rapid regaining of strength
- Handling characteristics similar to PDS
Poliglecaprone 25 - Monocryl
- Monofilament
- Absorbed by hydrolysis
- Rapid loss of tensile strenght - 80% lost by 14 days
- But - complete absorption takes up to 120 days
- Used in subcuticular closures, sometimes mucocutaneous junctions - where we want suture absorbed quickly
Glycomer 631 - Biosyn
- Monofilament
- Absorbed by hydrolysis - complete absorption takes 90-180 days
- Maintains 75% tensile strength at 14 days
- Used for subcuticular closures, rather than fascia
Polyglytone 6211 - Caprosyn
- Monofilament
- Absorbed by hydrolysis - complete absorption at 56 days
- Tensile strength
- 50-60% at 5 days
- 20-30% at 10 days
- 0 tensile strength at 21 days
- Rapid absorbing product - even more than catgut
- Used for oral cavity
Antibacterial sutures - what do these sutures have incorporated in them to make them antibacterial? Do they work?
Triclosan - study found no difference in infection rates using this suture
List three natural nonabsorbable sutures
- Silk
- Cotton
- Stainless steel
Silk
- Braided or twisted multifilament
- Coated to reduce capillarity and friction
- Slowly loses tensile strength - via phagocytosis
- Excellent handling, but can potentiate infection
Stainless Steel
- Monofilament or multifilament
- Highest tensile strength
- Absolute knot security
- Biologically inert
- Poor handling characteristics
- Tends to cycle and break over time
- Usually in the form of skin staples, and vascular clips to ligate vessels
Thoracoabdominal Stapler
- Don’t cut
- Have double row
- Used for lung lobe lobectomies or liver lobe lobectomies becuase stables are very hemostatic
Six Synthetic Nonabsorbale Sutures
- Nylon
- Polypropylene
- Polybutester
- Polymerized caprolactam
- Polyester
- Gore-Tex (polytetrafuorethyelene - PTFE)
- Teflone used in cardiovascular surgies
Nylon - Ethilon, Monosof, Fluorescent Supramide
- Monofilament (multifilament uncommon)
- Loses 30% of tensile strength over 2 years
- Fluorescent suture used to be able to find it easily when time to remove
Polypropylene - Porlene, Surgipro, Propylglo
- Monofilament
- High tensile strength
- Maintains strenght indefinitely - used where longevity is improtant (hernia, cardiovascular surgery)
- Minimally thrombogenic - used in cardiovascular surgires
- *also comes in fluorescent form
Polybutester - Novafil
- Monofilament
- Maintains tensile strength
- Excellent knot security
- Elasticity
- Can elongate 30% and return to original length without altering mechanicmal properites
- Not a first choice for skin sutures
- Eventually degraded, but lasts longer than nylon
Polymerized caprolactam - Supramid, Braunamid
- Twisted multifilament with coating
- Individual packages or bulk reel
- Coating has a tendency to crack - particularly if autoclaved
- Greater tissue reacivity than other nonabsorbales
Polyester - Ethibond, Ti-Cron, Mersilene
- Braided multifilament
- Excellent tensile strength
- Poor handling characteristics
- Poor knot security
- High coefficient of friction unless coated
- High tissue reactivity
- Used to be used for cruciate injury, but now not used in veneral vet practice
Llist one absorbale and one nonabsorbable suture material that has the highest tissue reactivity:
- Catgut - absorbable
- Silk - nonabsorbable
List one absorbable and one nonabsorbable suture material that has the lowest tissue reactivity:
- Polydioxanone - absorbable
- Polypropylene - nonabsorbable
Tips to prevent suture complications
- Open suture material immediately prior to use
- Do not allow buried materials to contact skin
- Handle suture gently to prevent iatrogenic damage
- Do not grasp suture with instruments (except for the part that will be cut off)
Round surgical needle
Square surgical needle
french surgical needle
Two strands of suture material - like sewing - causes tissue damage due to double diameter
Swaged Surgical Needle -
Ideal - suture material in the needle, causing a smooth transition from the suture to the needle
Taper Point needle vs Reverse Cutting Needle vs Tapercut Needle
- Reverse cutting needle - cutting edge on the convex part of the needle
- Tapercut Needle - cutting edge at the point, rest of needle is smooth, very expensive, reserved for cardiovascular sutures
- Taper point needle - no cutting edge, used in tissues that you don’t want any collateral cutting from needles
Most common tissue adhesive - which brand is the best choice?
- Cyanoacrylates
- Tissumend II (better than nexaband and vetbond)
What happens if tissue adhesives are accidentally placed inside the wound?
Foreign body reaction is possible
Tissumend II - Is sterile product available?
Sterile product is no longer available - therefore limited to use on surfaces
Which tissue adhesive is absorbable?
Tessumend II
Which tissue adhesive is manufactured sterile?
dermabond
