The larger the monofilament suture, the ________ the knot security.
Process by which fluid and bacteria are carried into the interstices of a multifilament suture.
The force required to untie or break a knot as compared to the force required to break an untied strand of suture.
relative knot security
The force that a knotted suture strand can withstand before it breaks.
knot tensile strength
Tensile strength of the suture should not need to exceed the ________________.
tensile strength of the tissue (ie. tougher tissue/ more tension on tissue---> bigger, tougher suture)
The ability of a suture material to return to a previous shape after deformation and its proclivity for knot slippage is known.
suture memory (more knot slippage...less desirable) [usually a property of synthetic sutures]
What are the two methods of suture breakdown in absorbable sutures? What method applied to which type of suture?
- phagocytosis- natural suture [CATGUT]- enzymes from bodily tissues, resulting in proteolysis of the suture material.
- hydrolysis- synthetic suture- water penetrates suture filaments, resulting in breakdown of polymer chain (non-enzymatic, typically slower).
How is chromic gut different from plain gut?
treated with chromic acid salts, increasing tensile strength and increased inflammation
What do we use gut for? (2)
- close SQ space- not holding layer, suture doesn't need to be there very long
- ligate vessels- clot forms quickly after ligation, suture doesn't need to be there very long
What are common synthetic sutures? (4)
- Polyglycolic acid- Dexon
- Polyglactin 910- Vicryl
- Poliglecaprone 25- Monocryl
- Polydioxinone- PDS
Synthetic absorbable sutures break down __________ than natural absorbable sutures.
What are properties of non-absorbable suture? (4)
- effective tensile strength remains high over time
- monofilament low tissue reactivity
- braided suture can result in nidus for infection or create fistulous tract
- avoid implanting non-absorbable suture below the skin
What are common natural non-absorbable sutures? (2)
silk, cotton (umbilical tape)
What are common synthetic non-absorbable sutures? (5)
What are veterinary uses of synthetic non-absorbale sutures? (3)
- skin closure
- vascular suturing
What are properties of multifilament sutures? (5)
- high capillarity (wicking- may lead to infection)
- increased inflammation
- good handling
- tissue drag "chatter"
- softer suture ends
What are properties of monofilament suture? (6)
- less wicking (lower capillarity)
- less inflammation, infection
- poorer handling
- less tissue drag
- stiffer ends
- poor knot security
What is the main goal for choosing a suture?
heal before suture break down
Considerations for suture selection. (7)
- specific surgical procedure
- operative site
- handling characteristics
- physical and biological properties
- patient's condition
- presence or risk of infected tissue
- postoperative course
What are approximate wound healing times for highly collangenous tissues and parenchymal tissues?
- Highly collagenous- 50 days
- Parenchymal- 14-21 days
What are the breakdown times of rapidly absorbable suture materials? (4)
- 80% loss of strength in...
- Vicryl Rapide- 5 days
- Vicryl- 14 days
- Monocrl- 7 days
- Chromic gut- 7 days
What are the breakdown times of the prolonged absorbable sutures? (2)
- PDS- 30% strength in 14 days; 50% loss in 28 days
- Maxon- 25% lossin 14 days; 50% loss in 28 days
Why are swaged needles preferred over eyed needles?
swages needles are less traumatic
What type of needles do you use in the different tissue types?
taper needles EXCEPT use cutting needles in skin and tough collagenous tissues
Describe taper, cutting, and reverse cutting needles. Include the use of each.
- Taper: round shaft; parenchymal tissues
- Cutting: triangular shaft w/ cutting edge on concave side; use on collagenated tissues and skin
- Reverse cutting: triangular shaft w/ sutting edge on convex side, stronger than cutting; use on intradermal