Suture Materials & Staples Flashcards
What are some basic considerations a surgeon should have when choosing suture materials?
- 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
The smaller the suture size, the ____ tensile strength it has.
Less
What is capillarity?
The process by which fluid and microorganisms are wicked into the interstices of multifilament fibers; immune cells are too large to enter
Why should multifilament suture never be used in contaminated or infected sites?
Because all braided materials have some degree of capillarity whereas monofilament sutures are considered noncapillary
What is knot tensile strength?
A measure of the tensile force that the suture strand can withstand before it breaks when knotted
What is tensile strength?
The strength required to break an untied fiber with a force applied in the direction of its length (i.e. in tension)
What is relative knot security?
The holding capacity of the suture expressed as a percentage of its tensile strength.
What is knot-holding capacity?
The strength required to untie or break a defined knot by loading the part of the suture that forms the loop
What are characteristics of absorbable suture?
- 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
What is the difference between natural and synthetic sutures?
Natural sutures are treated with biological substances while synthetic sutures are chemically formulated.
What are the characteristics of monofilament sutures?
- 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
What are the characteristics of multifilament sutures?
Several strands of suture twisted or braided together, more pliable and flexible, may be coated to reduce tissue drag and enhance handling
What are the characteristics of barbed sutures?
- Eliminate knots and decrease sx time
- even distribution of tensile forces throughout entire length of a closed incision
- have either unidirectional or bidirectional
What are the characteristics of surgical gut (catgut)?
- 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)
What are the advantages and disadvantages of using surgical gut?
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?
What are examples of synthetic absorbable sutures?
Polyglycolic acid (PGA) -Dexon, Polyglactin 910 - Vicryl, Poliglecaprone 25 - Monocryl, Polydioxanone - PDS, Polyglyconate - Maxon
What’s are the advantages and disadvantages of Polyglycolic acid (PGA) or Dexon?
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
What’s are the advantages and disadvantages of Polyglactin 910 or Vicryl?
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)
What’s are the advantages and disadvantages of Poliglecaprone 25 or Monocryl?
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?
What’s are the advantages and disadvantages of Polydioxanone or PDS?
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
What’s are the advantages and disadvantages of Polyglyconate or Maxon?
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
What’s are the advantages and disadvantages of silk suture?
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
What are examples of synthetic non-absorbable sutures?
- Polyamides (Nylon and polymerized caprolactam - Vetafil)
- Polyester
- Polyolefin Plastics (Polyproylene - Proline, Polyethylene)
What are the advantages/disadvantages of using nylon?
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
What’s are the advantages and disadvantages of polymerized caprolactam or Vetafil?
A: good handling, inexpensive, good tensile strength
DA: tissue reactivity, not sterile (SHOULD NOT BE BURIED), multifilament composition favors contamination, poor knot security
What’s are the advantages and disadvantages of polyester?
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
What’s are the advantages and disadvantages of polypropylene or Prolene?
A: inert, minimal tissue reaction, fairly strong with good knot strength and security, appropriate for contaminated wounds (non-potentiating)
D: slippery handling, memory
What’s are the advantages and disadvantages of polyethylene?
A: excellent tensile strength, minimal tissue reaction, resists bacterial contamination
DA: poor knot security
What’s are the advantages and disadvantages of stainless steel?
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
What’s are the advantages and disadvantages of cyanoacrylate tissue adhesive (Tissueglue/Vetbond)?
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
What are the advantages/disadvantages of using stapling devices?
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
What are the 5 types of staplers?
- 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)
What are characteristics of non absorbable suture?
- 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
