Sutures Flashcards
1
Q
Suture
A
- a strand of material that is used to ligate blood vessels or approximate tissue
2
Q
History of sutures/needles
A
- traced back centuries
- Egyptians documented using silk, cotton, horsehair, and animal tendons/intestines
- needles have similar long history that has led to evolved designs
- absorbable sutures introduced in the early 1970’s
3
Q
What is the suture device composed of?
A
1) the suture strand
2) the surgical needle
3) the packaging material used to protect both of these
4
Q
Suture packaging
A
- non-absorbable sutures are placed in Tyvek packaging
- absorbable sutures are packed in sealed foil (Hermetic seal) to maintain a sterile, gas/moisture resistant barrier
5
Q
Suture Needle
A
- supplied attached to the suture material, either through crimping to the end of the strand or using adhesive
- different needle points: tapered (for tissues easy to penetrate like blood vessels), conventional cutting (penetrating tough tissue like skin), reverse cutting (reduced risk of cutting through tissue, eye surgery)
- inert (stainless steel), slim and strong, sharp, balance of rigidness and ductility, and corrosion resistant
6
Q
Suture materials
A
- natural, synthetic, and metallic
- suture size from 7 (largest) to 11-0 (smallest)
- most are between 6 and 2
- size 0 and smaller, the number of 0s in description increases as the diameter decreases (00 = 2-0)
- use lowest size possible that still supports the wound, minimizing trauma and mass of foreign material left in the body
7
Q
Synthetic suture fabrication
A
- melt extruded or gel spun for fiber formation, then oriented (extrudate is heated and drawn to reduce fiber size and align chains)
- mono- or braided multifilament
- heat treated to anneal the material, then surface coated to increase lubricity, reduce capillarity (??), and maybe add antimicrobial agents
8
Q
Monofilament vs. Braided multifilament
A
- monofilament strands exhibit lower tissue drag
- multifilament have more compliance and physical resilience to damage (but can also have void spaces that harbor bacteria)
9
Q
Absorbable Natural Suture Material
A
- surgical gut sutures derived from bovine intestines, based on collagen (formaldehyde treated, ground/polished, if treated with chromium salts increases functionality from 1-2 weeks to 2-3 weeks)
- tend to fray at tie points, can be inconsistent in performance
- long history of use and less costly
10
Q
Non-adsorbable natural suture materials
A
- silk: protein fiber derived from silkworm cocoon, braided to make thread and coated, not absorbable but does degrade
- cotton: composed of cellulose, twisted multifilament with wax coating, not as strong and not absorbable
11
Q
Non-adsorbable synthetic suture materials
A
- polyester: PET (most common) and PBT, extruded multifilament fiber that is braided and coated
- nylon: nylon 6 and 6,6 (slightly softer) are used with similar mechanical properties, either braided or monofilament, lose strength due to hydrolysis
- polypropylene: isotactic for crystallization, low immune response, good for monofilament but hard to tie
- UHMWP: very strong, crystalline, can use smaller diameters, gel spinning, inherent lubricity can cause creep/slippage
- stainless steel: surgical procedures, very strong but prone to kinks
12
Q
Absorbable synthetic suture materials
A
- polymerized from hard/soft segment monomers
- hard: PG, PL, p-dioxane are major constituents
- soft: TMC, CI, PEG are minor constituents alter material properties
- degrade by hydrolysis via ester groups
- rate of degrading: glycolide > dioxane > lactide-based
- PEG imparts degree of swellability
13
Q
Coatings
A
- primary purpose is to reduce tissue drag/prevent fraying
- fill void spaces and can carry antimicrobial agents
- silicone/PTFE based for non-adsorbable sutures
- polyurethanes, PEG, caprolactone, lactide/glycolide copolymers for absorbable sutures
- alternatives to sutures include staples, tapes, clips, sealants/adhesives
