Sutures

Question 1

Generic name - Brand Name - 50 % reduction of tensile strength - complete absorption

Answer 1

Polygractin 910 - Vicryl - 21 days - 70 days
Poliglecaprone 25 - Monocryl - 7 days - 120 days
Polydioxanone - PDS - 30 days - 180 days

Question 2

Recommended suture material type, size and needle for closure of subcutaneous and subcuticular layers

Answer 2

A 3-0 or 4-0 absorbable suture (e.g., polyglyconate, polydioxanone, poliglecaprone 25, glycomer 631, polyglactin 910) with a swaged taper point needle should be used to close subcutaneous and subcuticular tissue.

Question 3

Recommended suture type, size and needle for closure of skin layers

Answer 3

A 3-0 or 4-0 monofilament, nonabsorbable suture (e.g., nylon, polypropylene, polybutester) with a reverse cutting needle is preferred for most skin sutures.

Question 4

Briefly discuss the effect of closing a wound with simple interrupted versus simple continuous suture patterns as well as a tightly versus loosely approximated wound

Answer 4

Wounds closed with interrupted sutures have less edema, improved microcirculation, and higher initial tensile strength, whereas continuous suture patterns allow for faster wound closure, less use of suture material, and create a better seal across the incision line. Suture tension should just appose edges, as loosely approximated wounds are stronger during the first 21 days.

Question 5

Discuss the use of Tissumend II sterile in the closure of wounds and how it compares to traditional cyanoacrylate skin glu (Vetbond, Liquivet, GLUture)

Answer 5

An absorbable, sterile, methoxypropyl cyanoacrylate tissue adhesive is available (Tissumend II Sterile). It may be used externally and internally, with trials having been performed on lung, liver, spleen, kidney, and cornea. It has hemostatic properties, enhances healing, is nonreactive, and absorbs via hydrolysis in 60 to 90 days.

Of the nonabsorbable tissue adhesives, N-butyl or isobutyl-2 cyanoacrylates (e.g., Vetbond, LiquiVet, GLUture) are preferred over propyl or methyl cyanoacrylates as they are less toxic. These adhesives should not be placed within the wound or incision but rather over the apposed surface to prevent foreign body reactions.

Question 6

Under what conditions can passive drains (penrose) be applied to a surgical wound?

Answer 6

Only if the drain and the wound can be covered by a sterile absorbent dressing

Question 7

Which of the following is NOT an absorbable suture material?

Answer 7

D. Polypropylene (Prolene)

Question 8

What is the primary advantage of using a swaged (eyeless) needle over a nonswaged (eyed) needle?

Answer 8

B. Causes less tissue trauma

Question 9

Which suture material is most rapidly absorbed in living tissue?

Answer 9

A. Polyglytone 6211 (Caprosyn)

Question 10

Which of the following needle types is best suited for suturing delicate tissues such as the urinary bladder or intestine?

Answer 10

C. Taper

Question 11

In Figure 16.2 (Needle point and body configurations), which needle is most appropriate for tough, fibrous tissue such as skin?

Answer 11

C. Reverse cutting

Figure 16.2

Question 12

Which suture configuration is most resistant to loosening under tension, based on mechanical testing?

Answer 12

C. Double loop cerclage

Question 13

Which of the following suture materials is contraindicated for use in the urinary bladder due to rapid loss of tensile strength in an alkaline environment?

Answer 13

C. Catgut

Question 14

Which suture material is most likely to induce a marked inflammatory reaction in tissues?

Answer 14

A. Catgut

Question 15

In suture size nomenclature, which of the following is the largest diameter?

Answer 15

C. 1

Question 16

Which figure (Figure 16.4 or 16.6) best demonstrates a unidirectional barbed suture?

Answer 16

B. Figure 16.4B

Figure 16.4B

Question 17

What is the main mechanical property measured by the Young’s modulus of a suture?

Answer 17

A. Elasticity

Question 18

Which needle curvature is most useful for work in deep or confined surgical fields?

Answer 18

C. 1/2 circle

Question 19

Which suture pattern is associated with the greatest risk of tissue strangulation if tied too tightly?

Answer 19

C. Horizontal mattress

Question 20

Multifilament sutures are generally avoided in contaminated wounds because:

Answer 20

B. They act as a wick for bacteria

Question 21

Which of the following would be the best suture material for closing the skin of a healthy dog after an elective procedure?

Answer 21

B. Nylon (Ethilon)

Nylon/Ethilon

Question 22

Which is a confounding factor in choosing suture material for use in the urinary bladder?

Answer 22

C. Urine pH

Question 23

Which suture material is considered to have the highest memory, making it more likely to spring back to its original shape?

Answer 23

A. Polypropylene

Question 24

What is a key difference between a cutting and reverse-cutting needle?

Answer 24

B. Reverse-cutting needle has the edge on the inside curve

Question 25

In Figure 16.3, which needle is least likely to cause suture pull-through in skin closure?

Answer 25

C. Reverse cutting ## Footnote Figure 16.3

Question 26

What is the primary knot security issue with monofilament suture materials?

Answer 26

C. Tendency to untie/slip if not enough throws are used

Question 27

In a dog with a known allergy to nylon, which suture would be most appropriate for skin closure?

Answer 27

A. Polypropylene ## Footnote Polypropylene

Question 28

Which suture property describes the tendency to soak up fluid and allow it to track along the length of the suture?

Answer 28

B. Capillarity

Question 29

Which scenario is most likely to require a swaged-on needle?

Answer 29

B. Fine ophthalmic surgery

Question 30

What is the recommended minimum number of throws for a secure square knot using 3-0 polydioxanone (PDS) in a continuous pattern?

Answer 30

D. 5

Question 31

Which of the following is NOT a potential complication of using multifilament suture in contaminated wounds?

Answer 31

C. Stronger tensile strength

Question 32

Which of the following is an advantage of barbed suture over smooth suture?

Answer 32

B. Eliminates the need for knots

Question 33

A suture needle with a J-curve is particularly useful for:

Answer 33

B. Intracorporeal endoscopic suturing

Question 34

Which of the following statements about suture coating is correct?

Answer 34

C. Water-insoluble coatings may reduce knot security

Question 35

Which suture material is LEAST likely to lose tensile strength rapidly in infected urine?

Answer 35

C. Polyglyconate (Maxon)

Question 36

Which needle point would be most appropriate for use in friable tissue such as liver?

Answer 36

C. Blunt