7 – Suture Materials

Question 1

What is suture material’s role in wound repair?

Answer 1

• Hemostasis
• Support for healing tissue
  o Few days: muscle, SQ, skin
  o Weeks: fascia
  o Months: tendons

Question 2

What makes an ideal suture material?

Answer 2

• Suture will lose strength at same rate that tissues gain strength
• Absorbed by tissue: minimal tissue reaction
• Easy to handle
• Reacts minimally in tissue
• Inhibits bacterial growth
• Holds securely when knotted
• Resists shrinking in tissues
• Noncapillary
• Nonallergenic
• Noncarcinogenic
• Nonferromagnetic
• *does NOT exist

Question 3

Size

Answer 3

• Smallest diameter that will secure wounded tissue
  o Minimize trauma
  o Reduce amount of foreign material
• No advantage to using suture that is stronger than tissue sutured
• *United States Pharmacopeia (USP): 12-0 smallest to 7 largest

Question 4

Suture size and tensile strength

Answer 4

• Smaller it is then the less tensile strength it has

Question 5

Flexibility

Answer 5

• Determined by torsional stiffness and diameter
  o Influences handling and use
• Ligating vessels and continuous suture patterns

Question 6

Flexibility examples:

Answer 6

• Silk: flexible
• Nylon and surgical gut=less flexible
• Braided polyester=intermediate flexibility
• Wire=least flexible

Question 7

Capillarity

Answer 7

• Multifilament fibers
  o Fluid and bacteria get into interstices
  o Coating can reduce (don’t use in infected tissues)
• Braided materials: examples: polyglycolic acid and silk
• Monofilament: noncapillary

Question 8

Knot tensile strength

Answer 8

• *sutures should be as strong as the normal tissue

Question 9

Relative know security

Answer 9

• Holding capacity of suture expressed as percentage of its tensile strength
• *if low knot security then maybe need to go up in size

Question 10

Mechanisms of absorption

Answer 10

• Digestion by tissue enzymes and phagocytosis
  o Sutures of organic origin (ex. surgical gut)
• Hydrolysis
  o Synthetic polymers
• *encapsulated/walled off by fibrous tissues=NON absorbable

Question 11

Monofilament

Answer 11

• single strand of material
• less tissue drag
• lack interstices or bacteria and fluid

Question 12

Multifilament

Answer 12

• more pliable and flexible
• can be coated: reduce drag and increases handling

Question 13

Absorbable suture material: facts

Answer 13

• tensile strength: 60 days
• loss of strength and complete absorption=varies with type of suture material

Question 14

Organic absorbable suture materials

Answer 14

• short term
• phagocytosis
  o inflammatory reaction
• absorption rate increased by infection or digestive enzymes

Question 15

Catgut (surgical gut)

Answer 15

• submucosa of sheep or serosa of bovine intestine
• 90% collagen
• Phagocytosis
  o Rapidly in infected sites or within digestive enzymes
• **Inflammatory reaction occurs
• *loses strength rapidly
• *poor knot security
• *high capillary

Question 16

Synthetic absorbable suture materials

Answer 16

• Hydrolysis
  o Minimal tissue reaction
• Absorption not as influenced by infection or digestive enzymes

Question 17

Monofilament: long term?

Answer 17

• PDS II, Maxon, Biosyn
• *rentain tensile strength longer than multifilament sutures
  o Complete absorption at 6 months (PDS and Maxon)
  o Complete absorption 120 days (Biosyn)

Question 18

PDS II

Answer 18

• Maintain tensile strength
• Noncapillary
• Good handling
• Secure knots; 4 throws

Question 19

Polyglyconate (Maxon)

Answer 19

• Maintain tensile strength
• Noncapillary
• Good handling
• Secure knots

Question 20

Glycomer 631 (Biosyn)

Answer 20

• Maintain tensile strength
• Non capillary
• Good handling
• Secure knots
• *aborbs slightly faster than Maxon and PDS

Question 21

Monofilament: short to medium term

Answer 21

• Monocryl and Caprosyn
  o Tensile strength: 2-3 weeks (30% at 14 days)
  o Absorbed rapidly
• Pliable, lack stiffness, good handling

Question 22

Multifilament: medium term

Answer 22

• Dexon
  o 100-120 days: absorption
• Vicryl
  o CLOSE ABDOMEN IN COLIC SURGERY
  o 40-90 days: absorption
• *braided
  o Harbor bacteria
  o Increased capillary
• *good handling: saws tissues
• *secure knots: want long tails

Question 23

Silk

Answer 23

• Maintain tensile strength
  o 50% at 1 year
• Good handling
• Secure knots

Question 24

Polymerized caprolactam (Supramid)

Answer 24

• Maintain tensile strength (greater than nylon)
• Good handling
• Cheap
• Secure knots: 4 throws
• **don’t bury: infectious and fistulation
  o Inner core and outer sheath: breaks and allows bacteria

Question 25

Polyester (Ethibond)

Answer 25

• Maintain tensile strength (greater than nylon)
• Good handling: saw tissue
• Secure knot: 6 throws

Question 26

Polybutester (Novafil) and Polypropylene (prolene)

Answer 26

• *common for skin
• Maintain tensile strength
• Noncapillary
• Good handling: slippery
• Secure knot: 4 throws

Question 27

Dermalon

Answer 27

• Maintain tensile strength
• Good hangling: more memory
• Secure knots: 4 throws
• Antibacterial

Question 28

Stainless steel

Answer 28

• Maintain tensile strength (greater than nylon)
• Non capillary
• Secure knots
• Difficult to handle

Question 29

What will you use for skin?

Answer 29

• Monofilament nonabsorbable

Question 30

What will you use for subcutaneous tissue?

Answer 30

• Synthetic absorbable

Question 31

What will you use for fascia?

Answer 31

• Monofilament absorbable or nonabsorbable

Question 32

What will you use for a tendon?

Answer 32

• Monofilament absorbable or Nylon

Question 33

Suture needles (2)

Answer 33

• Swaged on
  o Less traumatic
  o Technically easier
• Eye needle
  o More traumatic
  o Technically difficult

Question 34

Suture needle shapes

Answer 34

• Straight
• **3/8 circle: what we use most of the time
• ½ curved
• Half circle
• *depth of wound might determine your type of circle

Question 35

Suture needle points

Answer 35

• Taper: point and then circular
  o Fascia, SQ, intestine or bladder (NOT skin)
• Cutting: point is within the curve of needle=could cut through tissue
• Reverse cutting: doesn’t cut when you are pulling up (flat on inside of circle)
  o Most of the swaged on needles
• Trocar cut

Question 36

Needle choice for different tissues

Answer 36

• Skin: cutting
• Bowel, SQ: taper
• Fascia, tendon: taper or modified cutting

Question 37

Linea alba: suture choice

Answer 37

• Absorbable
• Either: monofilament or multifilament
• Cutting needle
• Long lasting
• *PDS or vicryl

Question 38

Subcutaneous tissue: suture choice

Answer 38

• Absorbable
• Monofilament or coated multifilament
• Taper
• Quick to absorb
• *monocryl

Question 39

Skin: suture choice

Answer 39

• Non-absorbable (except if not going to see the patient again)
• Monofilament
• Cutting
• Non-absorbable
• *prolene, novalfil, PDS (non-absorbable)

Question 40

Parenchymal organs (liver, spleen, kidney): suture choice

Answer 40

• Absorbable
• Monofilament
• Taper
• Quick to absorb
• *Monocryl

Question 41

Hollow viscous organs (trachea, GI, bladder): suture choice

Answer 41

• Absorbable
• Monofilament
• Taper
• In between
• *monocryl, dexon (not in urine)

Question 42

Vessel ligation: suture choice

Answer 42

• Absorbable
• Multifilament=will allow for better knot security
• Either: not using a needle most of the time
• Long lasting
• *PDS, vicryl, maxon, biosyn

Question 43

Vessel anastomosis: suture choice

Answer 43

• Nonabsorbable
• Monofilament
• Taper
• Long lasting
• *prolene