Lecture 10 - Suture Materials & Paterns - LA (Exam 1) Flashcards
What needs to be considered when choosing suture material
- Size & chemical make up (Natural v. synthetic) - How long does it need to last?
- Absorbable v. nonabsorbable - in or out of the body? inflammatory response/
- Monofilament v. multifilament - wound contamination
T/F: The suture used in LA is the same as SA but just bigger
True
What sized suture is used for SQ in LA
2-0
What suture size is typically used for the linea alba
2 or 3
The suture should be as strong as what
The suture should be as strong as the norm tissue through which it is placed
Tensile strength reduction over time should correspond to what
Tensile strength reduction over time should correspond to the healing of the affected tissue
When is suture not needed
Suture is not needed after the wound is healed
What is the strength of the wound mostly dependent on
The strength of the wound is more dep on the tissue’s ability to hold the suture than the suture material itself
What suture is ideal for skin closure
Suture w/ elasticity is ideal for skin closure (adapts to wound edema)
What suture is chosen for abdominal closure
Suture w/ high stiffness is chosen for abdominal closure, herniorraphy, prosthesis, etc
What happens if the suture is oversized & why
Oversized suture will weaken your closure due to excessive tissue rxn
What should be done if a wound is under tension
Wounds under tension = increasing the # of sutures or using a tension relieving pattern is better than increasing suture size
What does suture strength mean
How long the suture needs to last
How quick do internal organs & subQ recover
- Few days
- Full strength in a couple of weeks
How quick does fascia heal
- Slowly
- Couple weeks
- Full strength in a couple of months
- EX linea alba
How quick does skin heal
- Based on the quality of the apposition
- Seals w/in 1 day
- Primary incision heals in 10-14 days
- Full strength < 30 days
Better apposition = what
Decreasing healing time
What suture do you use for if what you are working on can not be removed from the body (organs or Sub Q)
Absorbable suture
What suture should you use if you can remove it (skin)
- Non-absorbable
- Should be inert to reduce inflammation
Inflammatory response is needed for what
Absorbable suture absorption
Increasing suture size increases what
The volume of knot
Increasing the volume of knot increases what
Inflammation
Increasing inflammation causes what
Weakened closure
Use the (largest/smallest) suture possible
Smallest
What needle is more commonly used in LA surgery & why
3/8 or 1/2 circle b/c it is more ergonomic to use
What needle size is used for opthalmologic surgery
1/4 circle
What needle size is used for confined or deep locations
5/8 circle
What should be the frame of mind when choosing needle size
Want to be able to reach across both sides of the wound w/ the needle
Describe a taper point needle & what tissue it is used for
- Round shaft doesn’t enlarge hole as it passes through
- Delicate tissue
Describe a reverse cutting needle & what tissue it is used for
- Cutting edge on convex (outer) side
- Makes needle stronger than conventional cutting
- Less risk of tissue cut out
- Skin &/or fibrous tissue
T/F: A conventional cutting needles are commonly used
False
What is this & what is it used for
- Buhner needle
- Used to purse string prolapse
What is this & what is it used for
- S needle
- Used to close cow skin
- Negates need for needle drivers
- Easier to punch through thick skin
- Use suture on a reel
Knot = what
The weakest point in the suture pattern
Why are doing correct knots important
Prevent dehiscence of incision
What is a simple throw
Half a knot
What is a square knot
Two simple throws that are reversed
What is different about a surgeons throw
- More friction
- More suture material left in the wound
- Placed when a square throw is slipping
What is a granny knot
- Two throws not reversed
- Not secure
- Don’t use
What is a half hitch
- Pulling up on the suture end instead of across
- Not secure
What comes in contact with the suture & can change the frictional behavior of suture
Body fluids
How many throws make a secure ligature
4 throws
How many throws should be used for larger suture ( #2 and #3)
5 throws
How long should the suture tag be
@ least 3 mm in length
Decrease in knot security = increase what
Suture size
Describe the suture & components for suturing skin
- Monofilament to decrease bacterial transport into deeper tissues
- Non absorbable suture (nylon & polypropylene)
- Simple interrupted w/ no tension
- Apposition of tissue edges or slight eversion
- Bites about 5mm from skin edge
Describe the suture & components for suturing fascia
- Most common in large animal linea alba
- bites are 15mm away from cut edge (extra suture needed)
- Can close using polygalctin 910 or polydioxanone (PDS)
- Size = #2 - 7 (#2 or #3 most common)
- Cattle: catgut is common but to much inflammation to use in horses
Describe the suture & components for suturing delicate tissue
- SubQ or GI organs
- PDS, Vicryl, or moncryl
- USP 2-0 typically
- Inverting suture patterns (lembert or simple cont. oversewn w/ a cushings)
Describe the suture & components for suturing contaminated wounds
- Monofilament only
- nonabsorbable suture - inert
- Elastic allows for tissue swelling
T/F: All wounds are contaminated in horses
True
What is some reduce cost suture for farm animals
- Chromic cat gut
- Suture on a reel like supramid (braided nylon) & Braunamid (Braided polyamide)
When should suture be removed
10 to 14 days
What should be done to remove suture from wounds under tension
staged removal (take out every other suture or every 1/3 initially)
How should skin staplers be used
- Stainless steel - inert
- Fast to put it
- Use staple remover or hemostat to remove
- For wounds with no tension (appose wound edges)
Describe the inverting suture patterns
- Invert the tissue edges to help make a seal
- used in the uterus, GI tract, & urinary bladder
- Suture doesn’t come out the tissue edge (adjacent to the edge to fold in some tissue)
Describe the utrect suture pattern
- Inverting suture pattern
- Commonly used on the uterus
Describe the cushings suture patter
- Invert
- Commonly used on GI & Urinary bladder
- Often combined w/ a simple continuous first
Describe the Lembert suture pattern
- Invert
- For GI or urinary bladder
- Can be interrupted or continuous
- Be careful not to make a “cuff” of tissue deep to your suture line
How does tension impede healing
- Impairs blood supply
- Prevents perfect apposition
- Shear stress on wound
What is this and describe it
- Langer’s lines
- Relaxed skin tension lines
- Incision parallel = least tension
- Incision perpendicular = most tension
What is preferable for suturing wounds under tension
- Use limb immobilization
- Add more suture
- Use tension-relieving techniques
What is not preferable for suturing wounds under tension
Using bigger suture
List some tension relieving techs
- Release incisions
- Walking sutures
- Tension relieving suture patterns like +/- stents, combo patterns, & using skin tension lines
What is relief incisions
Close the primary wound and leave the relief incisions to heal by second intention
What is walking sutures
- Using you suture to pull the skin over the top of the defect
- Evens out tension
- Obliterate dead space
- No closer than 2 - 3 cm apart ( can increase inflammatory response w/ suture
What are stents
- Distribute tension more evenly along suture to prevent pull through
- staged removal if needed
- Avoid using a stented closure on its own (always a combo of stents & other suture patterns)
Describe the vertical mattress as a tension relieving suture pattern
- Less impingement of blood supply compared to horizontal mattress
- Good apposition but some eversion
- Interrupted only
- Bites are perpendicular to cut
Describe the horizontal mattress as a tension relieving suture pattern
- Strong tension relieving (will not tear through tissue) but tends to impede blood supply & rarely use w/out
- Most eversion possible
- Can apply in continuous pattern
- Visible bites are parallel to cut egdge
Describe the near far far near as a tension relieving suture pattern
- Excellent apposition & tension relief
- Interrupted only
- Most suture in wound
Describe the ford interlocking suture pattern
- Mild tension relieving cont pattern
- Reduces suture disruption if on part breaks
- Good apposition
- Commonly used to close skin on cow flank incisions
What are some differences from SA
- Punching through skin (much thicker)
- Tightness on skin sutures should be snug
- More freq use surgeon’s throws
- PDS 2 is not preferred for closing the linea alba
- Rarely use intradermal patterns
- Bigger incisions = longer suture (management is critical)
- Sometimes standing on your head
