Sutures and needles Flashcards
what is suturing used for?
hemostasis, ligation, and apposition of tissue with suture material, needles, knots, patterns, staples, clips, and tissue adhesives
also tighten/stabilize joints and attach catheters
square knot
most desirable
combines 2 simple or half knots one on top of the other
reverse direction on each successive simple knot
maintain even tension on both strands
pull strands parallel and horizontal to the plane of the knot and skin
which knots are undesirable?
granny: successive simple knots without reversing direction
half-hitch: made when there is failure to keep even tension on each strand or when 1 strand is pulled upward and not kept horizontal
surgeon’s knot
essentially square knot where the 1st simple knot is made using a double throw (or loop)
double throw increases the friction of the knot and yields better holding power under tension
interrupted suture pattern
individually tied and if one breaks the rest will still be intact
good for spay/neuter in puppies/kittens
simple interrupted: precise tension along the incision, easiest pattern to use but takes longer and uses more material
mattress suture pattern
resist tension
horizontal mattress: may be used with stents
vertical mattress: may be used with stents
cruciate or cross mattress: can take the place of 2 simple interrupted sutures, good for closing circular holes (like punch biopses)
simple uninterrupted suture pattern
saves time and material, can seal incisions better and evenly distributes tension along incision, but if breaks all can unravel
subcuticular suture pattern
subcanteous: closes SQ tissues, decreases dead space, and if there is very little skin tension it can be used to hold skin closed without skin sutures
suture needle shapes
can be half curved, straight, half circle, or 3/8 circle
usually described by shape, size, tips, and eyes
sizes determined by numbers: larger number = smaller needle
taper suture needle tip
traumatic and similar to sewing needle tip, hard time penetrating tougher tissue like skin so used on tissue that is easily torn/cut, tip makes best air and liquid tight hole
cutting suture needle tip
has a cutting edge on concave surface
reverse cutting suture needle tip
has a cutting edge on convex surface
suture needle eyes
can be round, square, french or split
needle eyes also include swaged which has suture material permanently attached to the eye end of the needle
what are the properties of good suture material?
available in all sizes, be sterile, be low in cost, hold knots well, be non-irritating and non-carcinogenic, be strong and have increased tensile strength, absorb completely after healing without reactions, inhibit bacterial growth or wicking, have desirable handling characteristics (friction, memory, drag, chatter)
monofilament suture material
1 stranded
smooth surface, less friction than multifilament (less drag and chatter= less tissue trauma, no wicking, more memory than multifilament, less overall strength than multifilament
multifilament suture material
more than 1 strand twisted together (aka braided)
has opposite characteristics of monofilaments
absorbable suture material
requires an immune response to phagocytize material, there must be some inflammation for this to occur
natural absorbable suture material
catgut: retains tensile strength for the shortest time (3-5 days), faster absorption= greater inflammatory response, comes from sheep intestinal submucosa
chronic catgut: “tanned” cat gut, slows inflammatory response and tensile strength is held longer (10-15 days)
synthetic absorbable suture material
PDS II-polydioxanone: slowest absorbed and has the least inflammatory response
nonabsorbable suture material
never goes away, becomes encapsulated by tissue
natural nonabsorbable suture material
silk: strongest material, braided and often coated to decrease wicking, has some of the least memory and handles well so often good choice for cardio and ophthalmic surgery
cotton/linen: sterile strips of fabric used in large animal, can have static electricity, wicks
synthetic nonabsorbable suture material
nylon: slippery
Caprolactams: (Veetifil, Supramed, Braunamid), these are coated multifilament suture materials
stainless steel wire: very strong, difficult to handle, bulky knots, no give
other wound closure methods
staples: used for skin closure and muscle closure
clips: used for ligating, hemoclips is a common brand
tissue adhesive: type of super glue, to be used at or above skin layer, typically glue not absorbed but it is sloughed off or if buried under skin, it is extruded through the skin
suture removal
- swab area to remove debris
- apply tension with fingers to see if incision will separate (even the commonly expected 10-14 days for skin healing can be incorrect if wound healing is delayed by wetness, trauma, poor hygiene, infection, or it is under tension
don’t tear the suture through the skin - cut off extra suture material above the skin so that it isn’t dragged under the surface when the sutures are removed
