Suture material

Question 1

Label the parts of a surgical needle.

Answer 1

Question 2

What are the different needle point and body configurations?

Answer 2

Question 3

How much does knot placement typically reduce suture strength?

Answer 3

10 - 40%

Question 4

What are the suture pull out values of the following materials; fat, muscle, skin and fascia?

Answer 4

Fat: 0.2 kg
Muscle: 1.27 kg
Skin: 1.82 kg
Fascia: 3.77 kg

Question 5

What are the main differences between monofilament and multifilament sutures?

Answer 5

Less tissue drag, decreased capillarity and tendency for bacterial colonization and decreased pliability of monofilament sutures

Question 6

Are barbed sutures more or less stiff than their smooth counterparts?

Answer 6

Stiffer and have less elongation

Question 7

What smooth polypropylene suture size was comparable in breaking strength to 2-0 barbed polypropylene suture?

Answer 7

3-0

Question 8

What affect does triclosan suture coating have on bacteria?

Answer 8

Inhibits bacterial fatty acid synthesis

Question 9

Describe the general characteristics of common absorbable sutures.

Answer 9

Question 10

What is the definition of an absorbable suture?

Answer 10

A suture that loses most of its tensile strength in 60-90 days

Question 11

What are the two major mechanisms of suture absorption?

Answer 11

1. Proteolytic/enzymatic: natural sutures are absorbed through the action of cellular proteases and collagenases
2. Hydrolysis: synthetic sutures are absorbed in this fashion

Question 12

What factors can effect the rate of suture absorption?

Answer 12

Environmental, pH, bodily fluids, temperature, application and amount of strain

Question 13

What is catgut made from?

Answer 13

Twisted suture material from small intestinal submucosa of sheep or intestinal serosa of cattle

Question 14

How long does silk take to deteriorate in vivo?

Answer 14

Complete deterioration by 12-months with significant loss of strength in the first 12-weeks. This is caused by hydration.

Question 15

What effect does steam sterilization have on nylon leader line?

Answer 15

Increased elongation (2-4 fold)

Question 16

Is nylon susceptible to degradation in vivo?

Answer 16

Yes, begins as a result of hydration. In an acid environment 50% loss of tensile strength expected in 12 weeks

Question 17

Do sutures with a glycolide component degrade more or less rapidly in an alkaline environment?

Answer 17

More rapidly

Question 18

Do sutures with a dioxanone component degrade more or less rapidly in an acid environment?

Answer 18

More rapidly

Question 19

Describe the general characteristics of common non-absorbable sutures?

Answer 19

Question 20

What is the composition of FiberWire?

Answer 20

Multifilament ultra high molecular weight polyethylene core surrounded by a braided polyester and polyethylene exterior

Question 21

Is FiberWire or stainless steel stronger?

Answer 21

FiberWire - greater strength and maintenance of stiffness under 3-point bending

Question 22

What is the bias direction of a woven material?

Answer 22

45 degrees to the warp and weft

Question 23

What accounts for the strength of a knitted mesh?

Answer 23

The wale. Elongation along the course ifs greater than elongation along the wale (anisotrophy)

Question 24

What is the downside of a small pore size in a mesh?

Answer 24

Ingrowth of capillaries and fibroblasts are prevented resulting in encapsulation rather than incorporation

Question 25

How long does porcine small intestinal submucosa take to be replaced by native connective tissue?

Answer 25

3-months

Question 26

What is the effect of porcine small intestinal submucosa on the local wound environment?

Answer 26

Modulatory effect on local cytokines evoking an intense initial leukocyte infiltration

Question 27

Is porcine small intestinal submucosa suitable for use in high strain environments?

Answer 27

No (particularly single layer)

Question 28

How much overlap of a mesh with the native tissue is recommended?

Answer 28

1cm if under tension, 0.6 cm if not under tension

Question 29

What are the dimensions of regular and wide skin staples?

Answer 29

Question 30

What are the dimensions of ligate-divide-staple (LDS) staples, both regular and wide?

Answer 30

Regular: 5.79mm wide, 5.23mm tall, closure width 5.33mm Wide: 8mm wide, 7.2mm tall, closure width 7.3mm

Question 31

What are the basic principles of vascular clip application?

Answer 31

1. Vessel is skeletonized 2. Diameter of the vessel to be occluded is not more than 2/3 and no less than 1/3 the length of the clip 3. Clip is applied several mm from the vessel edge 4. Arteries and veins are clipped separately

Question 32

What are the staple sizes for use in the TA stapler?

Answer 32

Question 33

What are the staple sizes for use in the GIA stapler?

Answer 33

Question 34

What is the combined tissue thickness limitation for use of a circular stapling device?

Answer 34

Should not be used if combined tissue thickness is less than 1mm or greater than 2.5mm

Question 35

What causes tissue bonding when using cyanoacrylate glue?

Answer 35

Polymerization when the glue encounters anions associated with moisture on the surface of the skin or wound edge

Question 36

What are the byproducts of cyanoacrylate polymerization?

Answer 36

Formaldehyde and cyanoacetate

Question 37

Are short or long alkyl cyanoacrylate derivative glues preferred for medical use?

Answer 37

Long alkyl derivatives as they have slow conversion to toxic byproducts allowing tissue to clear and leading to less toxicity. Bonding is also less brittle and has higher wound bursting strength