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Flashcards in 17 Deck (62):
1

how are needles define

fraction of a circlecord length (bite width)needle lengthneedle diameterneedle radius

2

channel vs laser drilled swaged needles

channel: suture is crimped in a depression in the body of the needlelaser: suture is crimped in a hole drilled in the body of the needle (less drag, better grip with needle holders)

3

breaking strength of suture

the stress value on a stress-strain curve at which the suture acutely fails

4

capillarity of suture

degree to which absorbed fluid is transferred along the suture linemultifilament > monofilament

5

creep of suture

tendency of suture to slowly and permanently deform under constant stress

6

elasticity of suture

degree to which suture will deform with load applied and return to normal shape when load is removed

7

knot pull out strength of suture

load required to break a suture deformed by a knotknots generally decr suture strength by 10-40%

8

knot strength of suture

force necessary to cause a knot to slip

9

memory of suture

tendency for a suture to return to its original shape after deformation

10

plasticity of suture

degree to which a suture will deform without breaking and will maintain shape after removal of the deforming force

11

pliability of suture

the ease of handling and the ability to change shape of suture

12

stress relaxation of suture

the ability of suture to reduce stress under constant strain

13

suture pull out value

the weight required to full a suture loop from tissuedepends on type of tissue fat < muscle< skin < fascia

14

tensile strength of suture

measure of a sutures ability to resist deformation and breakage and the stress at which it deforms (yield strength) or rupture (breaking/ultimate strength) occurs

15

general characteristics of monofilament vs multifilament suture

monofilament =less pliable, more susceptible to catastrophic damage from crushing/nicking, lower tissue drag and is smoothermultifilament =greater strength & pliability, more tissue drag, greater capillarity and tendency for bacT colonization

16

T/FCatgut is monofilament

FALSECatgut is multifilament suture with TWISTED not braided filaments

17

newer types of sutures

polyblend suture (core polymer and braided exterior): extremely strong and resistant to failureSelf anchoring, barbed suture: surface barbs, decrease bulky knots, monofilament

18

water soluble vs insoluble suture coating in terms of knot security

water soluble coatings improve knot securitywater insoluble coatings reduce knot security

19

antibiotic coating for suture

+PLUStriclosan: inhibitor of bacT fatty acid synthesis

20

study of PDS PLUS with % percent of wound infections

PDS PLUS (polydiaxone w triclosan)11% wound infection PDS5% wound infection PDS PLUS

21

two major mechanisms of suture absorption

1. hydrolytic: synthetics2. enzymatic: Catgut (acid phosphatase, leucine amino peptidase)

22

PDS in sterile urine vs infected urine

PDS polydioxanonesterile urine: lost all strength 3 daysinfected urine: lost all strength 1 day (Proteus)

23

Dexon in sterile urine vs infected urine

Dexon polyglycolic acidsterile urine: lost 64% strength in 10 daysinfected urine: lost all strength 1 day (Proteus)

24

T/F rates of suture absorption are dramatically increased in infected urine

TRUE

25

what sutures degrade more rapidly in alkaline pH

moncryl (polyglecaparone 25)maxon (polyglyconate)biosyn (glycomer 631)

26

what suture loses tensile strength rapidly in acidic pH

PDS polydioxanonenylon (even thought considered non absorbable)

27

T/Fprestraining suture material to reduce suture memory will enhance suture degredation

true

28

catgut characteristics

natural twisted multifilament intestinal submucosa/serosaabsorbable (variable) via enzymaticweak, not uniformhigh tissue reactioncompletely absorbed in 2-3 weeks

29

do NOT use catgut in

harsh environments (GI, urinary surgery)areas requiring prolonged strength (>5days)important structures (body wall closure, fascial repair)

30

list rapidly absorbing suture

Polyglycolic acid (dexon)polyglactin 901 (vicryl)--braided multifilamentpolyglecaparone 25 (monocryl)polyglytone 6211 (caprosyn)

31

list slowly absorbing suture

polydioxanone (PDS)polyglyconate (Maxon)glycomer 631 (Biosyn)

32

list nonabsorbable suture

SilkPolypropryleneNylonpolymerized caprolactampolyesterstainless steel

33

dexon

polyglycolic acidbraided multifilrapidly absorbabletensile strength 50% at 2-3 weeksabsorption 60-90 daysgreat knot security

34

vicryl

polyglactin 910braided multifilrapidly absorbabletensile strength 50 % at 2-3 weeks (0% at 2-3 weeks if rapide)absorption 56-70 days (42 days if rapide)

35

monocryl

polyglecaparone 25monofilrapidly absorbabletensile strength 50% at 1 week 70-80% at 2 weeksabsorption 119 days

36

caprosyn

polygytone 6211monofilrapidly absorbabletensile strength 0% at 2-3 weeksabsorption 56 days

37

PDS II

polydioxanonemonofilslowly absorbabletensile strength 50% at 5-6 weeksabsorption 180 days

38

Maxon

polyglyconatemonofilslowly absorbabletensile strength 50% at 4-5 (5-6) weeksabsorption 180 days

39

Biosyn

glycomer 631monofilslowly absorbabletensile strength 50% at 2-3 weeksabsorption 90-110 days

40

silk characteristics

silk-braided multifilament nonabsorbablefibroin and sericinactually slowly degraded by hydration (gone in 2 years)good for knots around large vesselshigh tissue reactivity

41

polypropylene

nonabsorbable monofilamentvery stronghighest energy to break pointgood handling

42

nylon

nonabsorbable monofilamentBUT susceptible to degradaton via hydrationwill elongate

43

steam sterilization and elongation of nylon leader line

steam sterilization resulted in 2-4x increase in elongationit did NOT effect ultimate strength

44

Vetafil

polymerized caprolactamtwisted multifilamentskin only

45

canine sternotomy closurestainless steel vs polybutester

20 g stainless steel wire had less displacement and appeared more stable than #2 polybutester suture

46

fiberwire vs orthocord polyblend suture

#2 suturefiberwire = greatest maximal failure load (263 N)orthocord = greatest elongation (50%)

47

knitted vs woven mesh

woven is stiffer, stronger and less porous than knittedknitted is anisotropic, more porous, flexible and less strong/stiff

48

types of knitted polypropylene mesh

prolene and marlex mesh

49

pore size of polypropylene meshes

macroporous0.6=0.9 mmporosity 28-32%MUCH bigger than expanded polytetrafluoroethylene 20-25 micrometers

50

type of collagen found in mesh with a large pore size

type I collagen ingrowth

51

name a synthetic mesh that prevents adhesions to viscera

expanded polytetrafluoroethylene ePTFE

52

biologic material used to cover defects

pericardiumfascia lataporcine small intestinal submucosa

53

characteristics of porcine small intestinal submucosa

SISmultilaminatebioscaffoldinflammatory (intense WBC infiltration; more than polypropylene mesh)not apparent histologically after 3 months

54

polypropylene Mesh, fascia lata, SIS multi and single in terms of best strength

fascia > Marlex polypropylene > multi SIS > single SIS

55

recommendations for overlapping mesh with or without the presence of tension

with tension 1 cm overlapwithout tension 0.6 cm overlap

56

complications of mesh

failure: migration, extrusion (fails at tissue-mesh interface)fistulainfectionadhesionreduce complications with use of muscle or mental pedicle and use the smallest amount of mesh possible

57

Frey et al 2010 compared stifle surgeries closed with nonmetallic vs metallic sutures and what % were infected

9.1% skin staples infected5.1% non metallic sutures infected

58

basic principles of vascular clip application

1. skeletonize the vessels2. diameter of vessel should be no more then 2/3 and no less than 1/3 the length of the clip3. clip is applied several mm away from the cut edge4. arteries and veins clipped separately

59

green TA

giant double rows4mm w x 4.8mm Hclose 2.0 mm

60

blue TA

middle double rows4 mm w x 3.5 mmm Hclose 1.5 mm

61

white TA

three rows ONLY 30 mm length3 mm w x 2.5 mm Hclose 1.0 mm

62

tissue thickness recommendations when using circular staplers

circular staplers should NOT be used if tissue is < 1 mm or greater than 2.5 mmdouble staggered circular rows