Suture Materials & Staples

Question 1

What are some basic considerations a surgeon should have when choosing suture materials?

Answer 1

• Use the smallest diameter suture that will adequately secure the wounded tissue
• Sutures should be as strong as the normal tissue through which they are being placed
• Suture must maintain strength until the tissue is adequately healed
• Avoid suture use if possible in contaminated or infected wounds

Question 2

The smaller the suture size, the ____ tensile strength it has.

Answer 2

Less

Question 3

What is capillarity?

Answer 3

The process by which fluid and microorganisms are wicked into the interstices of multifilament fibers; immune cells are too large to enter

Question 4

Why should multifilament suture never be used in contaminated or infected sites?

Answer 4

Because all braided materials have some degree of capillarity whereas monofilament sutures are considered noncapillary

Question 5

What is knot tensile strength?

Answer 5

A measure of the tensile force that the suture strand can withstand before it breaks when knotted

Question 6

What is tensile strength?

Answer 6

The strength required to break an untied fiber with a force applied in the direction of its length (i.e. in tension)

Question 7

What is relative knot security?

Answer 7

The holding capacity of the suture expressed as a percentage of its tensile strength.

Question 8

What is knot-holding capacity?

Answer 8

The strength required to untie or break a defined knot by loading the part of the suture that forms the loop

Question 9

What are characteristics of absorbable suture?

Answer 9

• Degraded by one of two major mechanisms:
  
  • organic (ie catgut) - digested by tissue enzymes and phagocytized
  • synthetic - broken down by hydrolysis
• Lose tensile strength within 60 days
• May remain in tissues for greater than 60 days but with none of their tensile strength

Question 10

What is the difference between natural and synthetic sutures?

Answer 10

Natural sutures are treated with biological substances while synthetic sutures are chemically formulated.

Question 11

What are the characteristics of monofilament sutures?

Answer 11

• Made of a single strand of material
• less tissue drag
• do not have any interstices that may harbor bacteria/fluid
• nicking/damaging material with instruments may weaken and predispose to breakage
• less flexible thus harder to handle
• have “memory” and tend to return to their packaged configuration

Question 12

What are the characteristics of multifilament sutures?

Answer 12

Several strands of suture twisted or braided together, more pliable and flexible, may be coated to reduce tissue drag and enhance handling

Question 13

What are the characteristics of barbed sutures?

Answer 13

• Eliminate knots and decrease sx time
• even distribution of tensile forces throughout entire length of a closed incision
• have either unidirectional or bidirectional

Question 14

What are the characteristics of surgical gut (catgut)?

Answer 14

• Capillary, multifilament
• Biodegraded by proteolysis/phagocytosis (by 60 days)
• Collagenous nature elicits moderate to severe foreign body reaction
• Absorption is dependent on degree of chromicization but is still unpredictable and is greatly dependent on wound environment (I.e. presence of infection)

Question 15

What are the advantages and disadvantages of using surgical gut?

Answer 15

A: good handling, minimal capillarity, good knot security when dry

DA: reactive, variability in rate of loss of tensile strength and rate of absorption, poor knot security when wet, not autoclavable, tissue irritation from packaging liquids, availability?

Question 16

What are examples of synthetic absorbable sutures?

Answer 16

Polyglycolic acid (PGA) -Dexon, Polyglactin 910 - Vicryl, Poliglecaprone 25 - Monocryl, Polydioxanone - PDS, Polyglyconate - Maxon

Question 17

What’s are the advantages and disadvantages of Polyglycolic acid (PGA) or Dexon?

Answer 17

A: only slight inflamm rxn, predictable absorption (100-120d), breakdown products are antibacterial in vitro, wide range of suture/needle sizes

DA: poor knot security, high coefficient of friction/tissue drag, premature degradation in the face of urine or alkaline environments, inferior in slow healing tissues due to rapid loss of tensile strength

Question 18

What’s are the advantages and disadvantages of Polyglactin 910 or Vicryl?

Answer 18

A: minimal reactivity, good handling and knot security, strong, stable in contaminated wounds (monofilament still preferred), absorbed predictably (90d), soft, easily buried suture ends

DA: tissue drag (when dry is less than PGA, when wet is greater than PGA)

Question 19

What’s are the advantages and disadvantages of Poliglecaprone 25 or Monocryl?

Answer 19

A: monofilament, most pliable and flexible monofilament absorbable suture (good handling), good strength and predictable absorption (90-120d), minimally reactive, use appropriate in contaminated absorption

DA: expense?

Question 20

What’s are the advantages and disadvantages of Polydioxanone or PDS?

Answer 20

A: minimally reactive, monofilament, no capillarity, minimal drag, good handling and knot security, excellent tensile strength and predictable absorption (182d), good in contaminated sites

DA: expense, tendency to kink, clear product is difficult to see

Question 21

What’s are the advantages and disadvantages of Polyglyconate or Maxon?

Answer 21

A: monofilament, good handling and knot security, excellent strength, predictable absorption (180d), use appropriate in contaminated areas, minimally reactive, less expensive

DA: clear product difficult to see, buried suture ends are stiff and may irritate skin if used SQ and left too long

Question 22

What’s are the advantages and disadvantages of silk suture?

Answer 22

A: excellent handling properties but has a tendency to “stick” to gloves when wet, inexpensive

DA: moderate tissue reactivity, capillarity, and multifilament composition may potentiate infection, loses tensile strength when wet

*avoid in contaminated wounds and in situations in which it’s protruding into the lumen of a hollow viscus

Question 23

What are examples of synthetic non-absorbable sutures?

Answer 23

• Polyamides (Nylon and polymerized caprolactam - Vetafil)
• Polyester
• Polyolefin Plastics (Polyproylene - Proline, Polyethylene)

Question 24

What are the advantages/disadvantages of using nylon?

Answer 24

A: minimal reactivity, biologically inert, non-capillarity and antibacterial by-products useful for contaminated wounds, inexpensive, good tensile properties

DA: “memory” - poor tissue handling and low tissue drag, poor knot security, suture ends cause frictional irritation if used within a serous or synovial cavity

Question 25

What’s are the advantages and disadvantages of polymerized caprolactam or Vetafil?

Answer 25

A: good handling, inexpensive, good tensile strength

DA: tissue reactivity, not sterile (SHOULD NOT BE BURIED), multifilament composition favors contamination, poor knot security

Question 26

What’s are the advantages and disadvantages of polyester?

Answer 26

A: good handling, prolonged support for slow healing tissues with little loss of initial strength, strong

DA: coating reduces knot security (5 throws), high degree of tissue reaction, acts as a nidus for infection - do NOT use in a contaminated wound

Question 27

What’s are the advantages and disadvantages of polypropylene or Prolene?

Answer 27

A: inert, minimal tissue reaction, fairly strong with good knot strength and security, appropriate for contaminated wounds (non-potentiating)

D: slippery handling, memory

Question 28

What’s are the advantages and disadvantages of polyethylene?

Answer 28

A: excellent tensile strength, minimal tissue reaction, resists bacterial contamination

DA: poor knot security

Question 29

What’s are the advantages and disadvantages of stainless steel?

Answer 29

A: highest strength and knot security, incites little tissue reaction, monofilament does not support infection, autoclavable, inexpensive

DA: poor handling characteristics, breakage secondary to repeated bending, buried suture ends cause inflammation and tissue necrosis

Question 30

What’s are the advantages and disadvantages of cyanoacrylate tissue adhesive (Tissueglue/Vetbond)?

Answer 30

A: ease of use, rapid polymerization, early strong flexible bond, non-toxic, non-antigenic, good tissue apposition

DA: slow biodegration, patient FB, nidus for infection/fistulation formation, poor adhesive action of wet tissues, not rx in compromised, contaminated or infected tissue

Question 31

What are the advantages/disadvantages of using stapling devices?

Answer 31

A: speed and precision, accurate tissue apposition, reduced hemorrhage, decr likelihood of contamination during resection/anastomoses, economical if sx and anesthesia time are considered

DA: expensive, training required for proper use

Question 32

What are the 5 types of staplers?

Answer 32

• Thoracoabdominal stapler
• GI anastomoses stapler
• end to end anastomosis stapler
• lighting - dividing stapler, skin and fascia stapler
• hemoclips (not dependable for any vessel in which slippage might have grave consequences)

Question 33

What are characteristics of non absorbable suture?

Answer 33

• Walled off and encapsulated in fibrous tissue
• hold tensile strength longer than 60 days but need to be removed
• Although still in recognizable form, may but can become fragmented and lose strength