Surgical Knots & Suture Patterns Flashcards
A knot consists of at least…
2 throws laid on top of each other and ignited
the knot is the _____ point of the suture
weak
incorrectly tied knots may lead to…
dehiscence/opening
Knot security is influenced by:
- configuration of the knot
- coefficient of friction of the material
- Length of the cut ends
What are the 4 types of basic knots that are important to recognize?
- Granny knot
- Square knot
- half-hitch/slip/tumble
- surgeon’s
When is a good time to use a hand tie with suture material?
confined areas
Which knot do you want to avoid doing?
Granny knot
What type of knot is this?
Square knot
Failure to reverse the throws of a square knot results in a …
granny knot
What type of knot is this?
Granny knot
How is a half-hitch knot created?
by pulling one suture end vertically when tightening a knot
What type of knot is this?
Surgeon’s knot
What type of tissue is the surgeon’s knot used for?
elastic tissue or an area under tension
to ligate vascular pedicles where tissue tension precludes adequate tightening of a square knot
A Secure knot requires…
- a correctly thrown knot
- correctly tightened throws
- correct type of first throw (single or double)
- correct number of throws
How do you prevent the loosening of knots?
- use square knots
- ensure enough throws are placed for the material being used
- leave sufficiently long ears (3mm)
What are the principles of suture placement?
- use square or surgeon’s knot
- ensure enough throws are placed
- leave ears sufficiently long
- choose suitable suture material & pattern
- Choose appropriate size/strength
- place a sufficient number of sutures
- place sutures approx. 5 mm from wound edge
Do not over-tighten sutures
What are the general rules & things of note for the number of throws?
- 4 throws for interrupted patterns
- 5 throws at the start of a continuous pattern - single strand to single strand
- 6 throws at end of a continuous pattern (single strand to loop)
- extra throws do not increase security
- extra throws increase the amt of foreign material wound
What type of ligature is this?
When do you use it?
Single ligature
Use on small vessels
What type of ligature is this?
When do you use it?
Double ligature
Use on large vessels/arteries
What type of ligature is this?
Transfixing ligature
When is the 3 forceps technique commonly used?
for ovarian & uterine pedicles during spay (OVE/OVH)
What is the 3 forceps technique used for?
it allows for the placement of a ligature to a crushed line of tissue on a vascular pedicle
What are some important things to remember about knots?
- knot security is inversely proportional to suture diameter
- inadequate tightening of each throw results in bulkier, less secure knots
- suture ears must be adequately long
- Don’t include a frayed portion of material in a suture or ligature
- Extra knots result in extra bulk
How do you classify suture patterns?
Based on:
-anatomical location
- tendency to cause tissue apposition, inversion, eversion
- continuous or interrupted pattern
What classification of suture patterns is this?
interrupted
What classification of suture patterns is this?
continuous
What are some advantages to a interrupted suture pattern?
- each suture is a separate entity
- can more precisely adjust tension along a wound
- easy to place
- failure of one knot often inconsequential
What are some disadvantages to interrupted suture patterns?
- take longer to place
- more foreign material is introduced into the wound/body
- can run out of suture faster
What suture pattern is this?
Simple suture - needle passes through the tissue once on each side of the wound before being tied
What types of suture pattern are these?
Mattress - needle passes thorugh the tissue twice on each side before being tied
A simple interrupted suture is a ______ suture.
appositional
Inversion can occur with a simple interrupted suture pattern if…
the suture is overtightened
When is it most common to use a simple interrupted suture?
skin, SQ tissue, GIT
Why would you place a series of simple interrupted sutures?
- to facilitate proper alignment
- to prevent tissue strangulation
- to use just enough tension to prevent gaping
A cruciate mattress suture is an ______ suture & resists ______.
appositional; tension
A cruciate mattress suture helps to avoid…
ischemia and eversion
Where do you commonly use a cruciate mattress suture?
skin
Horizontal mattress suture is an ______ suture pattern.
appositional
horizontal mattress suture resists _____ but can cause _______ _______ if tied too tightly
tension; marked eversion
A vertical mattress suture resists _______ more than the horizontal mattress suture.
tension
a vertical mattress suture causes _______ eversion than a horizontal mattress.
less
vertical mattress suture is used in
high tension areas
What are some advantages to continuous suture patterns?
- fewer knots
- less foreign material
- quicker
- potentially better for an air-tight/water-tight seal
- better suture economy
What are some disadvantages of continuous sutures?
- less control of wound tension & approximation
- disastrous effect if suture breakage
- suture material needs to be handled more carefully
A simple continuous suture is an ______ pattern used in areas of _____ tension.
appositional; low
A simple continuous suture pattern is most commonly used on….
SQ tissue, linea alba
Excess tension on a simple continuous suture pattern can cause…
tissue strangulation
A ford interlocking suture is also known as a
blanket stitch
A ford interlocking suture is commonly used in
large animal surgery, long wounds (ventral midline/thoracotomy), skin suture
A ford interlocking suture is an ______ pattern
appositional
What suture pattern is this?
Ford interlocking suture pattern (aka Blanket stitch)
intradermal sutures are great because…
there is no need to remove sutures
intradermal sutures are ______ sutures.
appositional
a disadvantage for intradermal suture is…
it has less strength so cannot be used for high tension wounds
What does the image represent?
the process for burying knots
Lembert suture is when you invert a
continuous vertical mattress suture
A Lembert suture is used to close…
hollow viscera
Connell & Cushing sutures are inverting, __________________
continuous horizontal mattress sutures.
Connel & Cushing sutures cause…
greater inversion & stenosis of the viscus than appositional patterns
What is the difference between Connell and Cushing sutures?
Cushing takes bites parallel to incision and the bite goes into the submucosa but not the mucosa.
Connell bites are parallel to the incision but the bite penetrates the lumen and is often the first layer of a 2-layer closure
When is a purse-string suture used?
- Closure of hollow viscera or stumps
- securing tubes/catheters
- around anus during perineal Sx
Tendon sutures resist tension/distraction forces caused by…
weight bearing
What are the three main types of tendon sutures used?
- three-loop pulley
- Bunnell
- Far-Near-Near-Far
Skin staples are an alternative to…
sutures
skin staples are fast and have reasonable…
cosmetic results
To place skin staples, you need
- to evert wound edges
What are some disadvantages to skin staples?
- more expensive than suture
- need special extractor for removal
What are some tissue adhesives that can be used?
- Cyanoacrylates
- non-absorbable synthetic adhesives
