Sutures and Stitches

Question 1

What is a suture?

Answer 1

Any strand of material used to ligate

blood vessels or to approximate tissues

Question 2

How are sutures sized?

Answer 2

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)

Question 3

Which is thicker, 1-O suture

or 3-O suture?

Answer 3

1-O suture (pronounced “one oh”)

Question 4

What are the two most basic

suture types?

Answer 4

Absorbable and nonabsorbable

Question 5

What is an absorbable

suture?

Answer 5

Suture that is completely broken down

by the body (dissolving suture)

Question 6

What is a nonabsorbable

suture

Answer 6

Suture is not broken down (permanent

suture)

Question 7

What are “catgut” sutures

made of?

Answer 7

Purified collagen fibers from the intestines

of healthy cows or sheep (sorry, no cats)

Question 8

What are the two types of

gut sutures?

Answer 8

Plain and chromic

Question 9

What is the difference
between plain and chromic
gut?

Answer 9

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

Question 10

What is it? Vicryl

Answer 10

Absorbable, braided, multifilamentous

copolymer of lactide and glycoside

Question 11

How long does it retain its

strength? vicryl

Answer 11

60% at 2 weeks, 8% at 4 weeks

Question 12

Should you ever use
PURPLE-colored Vicryl®
for skin closure?

Answer 12

NO—it may cause purple tattooing

Question 13

pds What is it?

Answer 13

Absorbable, monofilament polymer of

polydioxanone (absorbable fishing line)

Question 14

How long does it maintain

its tensile strength?

Answer 14

70% to 74% at 2 weeks, 50% to 58% at

4 weeks, 25% to 41% at 6 weeks

Question 15

How long does it take to

complete absorption?

Answer 15

180 days (6 months)

Question 16

What is silk?

Answer 16

Braided protein filaments spun by the
silkworm larva; known as a nonabsorbable
suture

Question 17

What is Prolene?

Answer 17

Nonabsorbable suture (used for vascular
anastomoses, hernias, abdominal fascial
closure)

Question 18

What is nylon?

Answer 18

Nonabsorbable “fishing line”

Question 19

What is monocryl?

Answer 19

Absorbable monofilament

Question 20

What kind of suture should
be used for the biliary tract
or the urinary tract?

Answer 20

ABSORBABLE—otherwise the suture

will end up as a nidus for stone formation!

Question 21

What is the purpose of a

suture closure?

Answer 21

To approximate divided tissues to

enhance wound healing

Question 22

What are the three types of

wound healing?

Answer 22

1. Primary closure (intention)
2. Secondary intention
3. Tertiary intention (Delayed Primary
   Closure DPC)

Question 23

What is primary intention?

Answer 23

When the edges of a clean wound are
closed in some manner immediately
(e.g., suture, Steri-Strips®, staples)

Question 24

What is secondary intention?

Answer 24

When a wound is allowed to remain open
and heal by granulation, epithelization,
and contraction—used for dirty wounds,
otherwise an abscess can form

Question 25

What is tertiary intention?

Answer 25

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)

Question 26

What is another term for

tertiary intention?

Answer 26

DPC Delayed Primary Closure

Question 27

Classic time to wait before
closing an open abdominal
wound by DPC?

Answer 27

5 days

Question 28

What rule is constantly told
to medical students about
wound closure?

Answer 28

“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

Question 29

What is a taper-point

needle

Answer 29

Round body, leaves a round hole in tissue

spreads without cutting tissue

Question 30

taper What is it used for?

Answer 30

Suturing of soft tissues other than skin
(e.g., GI tract, muscle, nerve, peritoneum,
fascia)

Question 31

What is a conventional

cutting needle?

Answer 31

Triangular body with the sharp edge
toward the inner circumference; leaves a
triangular hole in tissue

Question 32

What is a vertical mattress

stitch?

Answer 32

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

Question 33

What is the vertical mattress

stitch also known as?

Answer 33

Far-far, near-near stitch—oriented

perpendicular to wound

Question 34

vert mattress What is it used for?

Answer 34

Difficult-to-approximate skin edges;

everts tissue well

Question 35

What is a horizontal

mattress stitch?

Answer 35

Simple stitch is made, the needle is
reversed, and the same size bite is taken
again—oriented parallel to wound

Question 36

What is a subcuticular

stitch?

Answer 36

Stitch (usually running) placed just
underneath the epidermis, can be either
absorbable or nonabsorbable (pull-out
stitch if nonabsorbable)

Question 37

What are the guidelines for
the number of minimal
throws needed?

Answer 37

Depends on the suture material
Silk—3
Gut—4
Vicryl®, Dexon®, other braided
synthetics—4
Nylon, polyester, polypropylene,
PDS, Maxon—6

Question 38

How long should the ears of

the knot be cut?

Answer 38

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

Question 39

When should skin sutures be

removed?

Answer 39

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

Question 40

In general, in which group
of patients should skin
sutures be left in longer
than normal?

Answer 40

Patients on steroids

Question 41

How should the sutures

be cut?

Answer 41

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