Suture Materials & Patterns (6) Flashcards
Dr. Thompson
What are sutures’ roles in wound repair?
- provides hemostasis
- supports healing tissue by apposing and supporting tissue layers
What is the ideal suture?
What is the most commonly used standard for suture size?
United States Pharmacopeia
What are the largest and smallest suture sizes?
largest: 7
smallest: 12-0
T/F: 3-0 is smaller than 0
TRUE
What suture should be used to minimize trauma and reduce the amount of foreign material left in the wound?
the smallest diameter suture
When are flexible sutures indicated?
indicated for ligating vessels or performing continuous suture patterns
List the suture types from stiff to flexible
stiff: nylon and surgical gut
intermediate: braided polyester
flexible: silk
T/F: Smooth sutures cause more injury than rough sutures
FALSE - rough sutures do
What are the caveats to sutures with smooth surfaces?
requires greater tension to ensure good apposition of tissues
have less knot security
Which suture material has more drag than monofilament sutures?
braided materials
What is capillarity?
the process by which fluid and bacteria are carried into the interstices of multifilament fibers
Which suture material is more likely to harbor infection?
non-absorbable sutures
braided materials (PGA, silk) - some degrees
Which suture material is considered noncapillary?
monofilament
How is knot tensile strength measured?
by the force in pounds that the suture strand can withstand before it breaks when knotted
Tensile strength of the suture should not greatly exceed _______
the tensile strength of the tissue
What is relative knot security?
the holding capacity (how much force a knot can resist before slipping or failing) of a suture expressed as a percentage of its tensile strength
It shows how much of the suture’s full strength is retained after tying a knot.
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 is tensile strength?
the strength required to break an untied fiber with a force applied to the direction of its length
How are suture materials classified?
- structure: monofilament, multifilament
- behavior in tissue: absorbable, nonabsorbable
- origin: synthetic, organic, metallic
What are the features of monofilament?
- less tissue drag
- do not have interstices
What should you be cautious of with monofilament suture?
nicking or damaging the material with forceps or needle holders may weaken the suture and predispose it to breakage
What are the characteristics of multifilament suture?
- may be coated to reduce tissue drag and enhance handling characteristics
- more pliable and flexible
How are sutures from organic origin broken down?
gradually digested by tissue enzymes and phagocytized
How are sutures manufactured from synthetic polymers broken down?
hydrolysis
How are nonabsorbable sutures broken down?
ultimately encapsulated or walled off by fibrous tissue
What are the absorbable suture materials?
- surgical gut
- chromic gut
- multifilament
- monofilament
PGA is a [mono/multi]filament
multifilament
Vicryl is a [mono/multi]filament
multifilament
PDSII is a [mono/multi]filament
monofilament
When do most absorbable suture materials lose their tensile strength?
60 days
What are the characteristics of catgut?
- most common nonsynthetic absorbable suture material
- elicits a notable inflammatory reaction
- rapidly removed when exposed to digestive enzymes
- knots may loosen when wet
What are the characteristics of synthetic absorbable suture?
- broken down by hydrolysis
- minimal tissue reaction
- not affected by digestion
- hydrolyzed in alkaline environments
- rapidly degraded in infected urine
When are synthetic absorbable suture rapidly degraded?
infected urine
Review flowchart
List the types of nonabsorbable suture materials
- organic
- synthetic
- metallic
What is the most common organic nonabsorbable suture?
silk
When should you not use organic nonabsorbable suture (silk)?
loses tensile strength after 6 months - do not use for vascular grafts
should be avoided in contaminated sites
What are the synthetic nonabsorbable suture marketed as?
- braided multifilament threads
- monofilament threads
What are the benefits of synthetic nonabsorbable suture?
typically strong
induce minimal tissue reaction
T/F: You can use cable ties in the body
FALSE
What are the characteristics of metallic sutures?
- stainless steel
- minimal tissue reaction, though knot ends evoke inflammatory reaction
- tendency to cut tissue
- may fragment and migrate
What are the caveats of using absorbable sutures in the skin?
may be used, but should ultimately be removed because absorption requires contact with body fluids
What do you use for subcutaneous sutures?
multi- or monofilament absorbable suture
Which suture do you select for an abdominal closure?
nonabsorbable or standard absorbable monofilament suture with good knot security - usually standard absorbable
normally simple continuous pattern (one size larger suture)
How many knots in an abdominal closure?
3 or 4 square knots (6 or 8 throws)
How should you suture muscle? Which suture material?
NOT parallel
absorbable or non absorbable
What type of suture material and needle should you use when suturing a tendon?
strong, nonabsorbable, and minimally reactive
taper or taper-cut needle
How should you suture parenchymal organs?
absorbable monofilament suture
What type of suture material for hollow viscus organs?
absorbable monofilament
What suture material should you select for infected or contaminated wounds?
monofilament, absorbable
Which suture material for ligating vessels? Anastomoses?
absorbable
anastomoses: monofilament, nonabsorbable suture
Most surgical needles are made from _____
stainless steel wire
What is surgical yield?
the amount of angular deformation a needle can withstand before becoming permanently deformed
What is ductility?
the needle’s resistance to breaking under a specified amount of bending
What is sharpness?
related to the angle of the point and the taper ratio of the needle
What are the most commonly used surgical needles in veterinary medicine?
- 3/8ths
- 1/2
What needle is easier to use in confined locations?
1/2 or 5/8, as opposed to a 3/8 curved needle
What type of needle?
taperpoint
What type of needle?
tapercut
What type of needle?
reverse cutting
What type of needle?
regular cutting
Suture patterns can be classified as _______
- interrupted or continuous
- by the way they appose tissue
- by which tissues they primarily appose
What does everting mean?
turn the tissue edges outward, away from the patient and toward the surgeon
What does inverting mean?
turn tissue away from the surgeon, or toward the lumen of a hollow viscus organ
What are the purpose of subcutaneous sutures? Which pattern?
- eliminate dead space
- provide some apposition of skin so less tension
simple continuous
Where is suture advanced in subcuticular sutures?
dermal tissue
How are bites placed in subcuticular sutures?
parallel to the long axis of the incision
Suture pattern?
subcuticular
Suture pattern?
subcutaneous
How is the knot placed in a simple interrupted?
knot is offset
In simple interrupted, sutures should be placed approximately _____ away from the skin edge
2-3 mm away from the skin edge
When are horizontal mattress sutures used?
primarily in areas of tension
often cause tissue eversion - appose, not evert
What do cruciate sutures do?
can relieve low to moderate tension
Suture pattern?
simple interrupted
Suture pattern?
horizontal mattress
Suture pattern?
cruciate
[Vertical/Horizontal] mattress sutures are stronger
vertical - also less disruption to blood supply
What do stents do?
relieve more tension
What is a Halsted pattern?
an interrupted mattress pattern that is a modification of a continuous Lembert pattern
What is a Gambee pattern? Used for?
interrupted pattern used in intestinal surgery to reduce mucosal eversion
Suture type?
vertical mattress
Suture type?
halsted
Suture type?
Gambee
What are the characteristics of simple continuous?
- series of simple interrupted sutures with a knot on either end
- provides maximum tissue apposition
- relatively air and fluid tight
- frequently used to close the lines alba and SQ tissue
Suture pattern?
simple continuous
Suture pattern?
running
What is the difference between simple continuous and running?
simple continuous: needle passed perpendicular to the incision and advanced above the incision line as diagonal
running: suture is advanced above and below incision line
Running or simple continuous?
running
What are the characteristics of a ford interlocking pattern?
What is a Lembert pattern?
a variation of a vertical mattress pattern applied in a continuous fashion
often used to close hollow viscera
What is the difference between a Cushing and Connell pattern?
coneLL: enters the Lumen
Cushing: extends only to the submucosal layer
both are inverting patterns
Suture pattern?
lembert
Suture pattern?
Connell
Suture pattern?
cushing
What is the Parker-Kerr oversew?
two-layer closure for inverted closure of a transected, clamped, stump of hollow viscera
How are tendon sutures used?
used to approximate severed ends of a tendon or to secure one end of a tendon to bone or muscle
What is an Aberdeen knot?
alternative to the square knot at the end of a continuous line
larger knot volume, larger holding capacity
What is this?
Aberdeen knot
