Sutures and Stitches Flashcards
What is a suture?
Any strand of material used to ligate
blood vessels or to approximate tissues
How are sutures sized?
By diameter; stated as a number of O’s:
the higher the number of O’s, the smaller
the diameter (e.g., 2-O suture has a
larger diameter than 5-O suture)
Which is thicker, 1-O suture
or 3-O suture?
1-O suture (pronounced “one oh”)
What are the two most basic
suture types?
Absorbable and nonabsorbable
What is an absorbable
suture?
Suture that is completely broken down
by the body (dissolving suture)
What is a nonabsorbable
suture
Suture is not broken down (permanent
suture)
What are “catgut” sutures
made of?
Purified collagen fibers from the intestines
of healthy cows or sheep (sorry, no cats)
What are the two types of
gut sutures?
Plain and chromic
What is the difference
between plain and chromic
gut?
Chromic gut is treated with chromium salts
(chromium trioxide), which results in more
collagen crosslinks, making the suture more
resistant to breakdown by the body
What is it? Vicryl
Absorbable, braided, multifilamentous
copolymer of lactide and glycoside
How long does it retain its
strength? vicryl
60% at 2 weeks, 8% at 4 weeks
Should you ever use
PURPLE-colored Vicryl®
for skin closure?
NO—it may cause purple tattooing
pds What is it?
Absorbable, monofilament polymer of
polydioxanone (absorbable fishing line)
How long does it maintain
its tensile strength?
70% to 74% at 2 weeks, 50% to 58% at
4 weeks, 25% to 41% at 6 weeks
How long does it take to
complete absorption?
180 days (6 months)
What is silk?
Braided protein filaments spun by the
silkworm larva; known as a nonabsorbable
suture
What is Prolene?
Nonabsorbable suture (used for vascular anastomoses, hernias, abdominal fascial closure)
What is nylon?
Nonabsorbable “fishing line”
What is monocryl?
Absorbable monofilament
What kind of suture should
be used for the biliary tract
or the urinary tract?
ABSORBABLE—otherwise the suture
will end up as a nidus for stone formation!
What is the purpose of a
suture closure?
To approximate divided tissues to
enhance wound healing
What are the three types of
wound healing?
- Primary closure (intention)
- Secondary intention
- Tertiary intention (Delayed Primary
Closure DPC)
What is primary intention?
When the edges of a clean wound are
closed in some manner immediately
(e.g., suture, Steri-Strips®, staples)
What is secondary intention?
When a wound is allowed to remain open
and heal by granulation, epithelization,
and contraction—used for dirty wounds,
otherwise an abscess can form
What is tertiary intention?
When a wound is allowed to remain open for a time and then closed, allowing for débridement and other wound care to reduce bacterial counts prior to closure (i.e., delayed primary closure)
What is another term for
tertiary intention?
DPC Delayed Primary Closure
Classic time to wait before
closing an open abdominal
wound by DPC?
5 days
What rule is constantly told
to medical students about
wound closure?
“Approximate, don’t strangulate!” Translation: If sutures are pulled too tight, then the tissue becomes ischemic because the blood supply is decreased, possibly resulting in necrosis, infection, and/or scar
What is a taper-point
needle
Round body, leaves a round hole in tissue
spreads without cutting tissue
taper What is it used for?
Suturing of soft tissues other than skin
(e.g., GI tract, muscle, nerve, peritoneum,
fascia)
What is a conventional
cutting needle?
Triangular body with the sharp edge
toward the inner circumference; leaves a
triangular hole in tissue
What is a vertical mattress
stitch?
Simple stitch is made, the needle is
reversed, and a small bite is taken from
each wound edge; the knot ends up on
one side of the wound
What is the vertical mattress
stitch also known as?
Far-far, near-near stitch—oriented
perpendicular to wound
vert mattress What is it used for?
Difficult-to-approximate skin edges;
everts tissue well
What is a horizontal
mattress stitch?
Simple stitch is made, the needle is
reversed, and the same size bite is taken
again—oriented parallel to wound
What is a subcuticular
stitch?
Stitch (usually running) placed just
underneath the epidermis, can be either
absorbable or nonabsorbable (pull-out
stitch if nonabsorbable)
What are the guidelines for
the number of minimal
throws needed?
Depends on the suture material Silk—3 Gut—4 Vicryl®, Dexon®, other braided synthetics—4 Nylon, polyester, polypropylene, PDS, Maxon—6
How long should the ears of
the knot be cut?
Some guidelines are: Silk vessel ties—1 to 2 mm Abdominal fascia closure—5 mm Skin sutures, drain sutures—5 to 10 mm (makes them easier to find and remove
When should skin sutures be
removed?
As soon as the wound has healed enough to withstand expected mechanical trauma Any stitch left in more than 10 days will leave a scar Guidelines are: Face—3 to 5 days Extremities—10 days Joints—10–14 days Back—14 days Abdomen—7 days
In general, in which group
of patients should skin
sutures be left in longer
than normal?
Patients on steroids
How should the sutures
be cut?
Use the tips of the scissors to avoid cutting other tissues Try to remove the cut ends (less foreign material decreases risk of infection) Rest the scissor-hand on the non–scissorhand to steady
