Lecture 8 - Advanced Suture and Knots Flashcards
What are the properties of the skin?
tension, shear, and viscoelasticity
What is tension determined by?
the pull of collagen and elastin in dermal and hypodermal tissues
What is the shear skin property?
mobile areas of skin with forces on either wound edge opposing the other
How does viscoelasticity occur?
adaptation to prolonged stress
What are the tension relieving techniques?
undermining tissues, tension-relieving sutures, skin stretching, relaxing incisions
How do you undermine tissue?
You use metzenbaums to dissect superficial to the muscle
What does undermining take advantage of?
the skin’s elastic potential
What type of dissection does undermining use?
blunt and sharp dissection
When should you not use undermining?
when the patient has cancer
What are some tension-relieving sutures?
interrupted vertical mattress, interrupted or continuous horizontal mattress, quilled/stented/bolster, far-near-near-far, far-far-near-near, cruciate, and walking sutures
What tissues is the vertical mattress used for?
skin, gingiva, fascia, and tissues under tension
What bites are used for the vertical mattress suture?
far-far, near-near
Which bites in the vertical mattress suture should be deep?
the far bites
How far from the incision should the near bites in the vertical mattress suture be?
2 mm
If the vertical mattress is tight, what type of suture pattern is it?
everting
When does the vertical mattress appose best?
when the near bites are close
Is the vertical mattress or horizontal mattress stronger?
vertical
In what type of tissue should you use the quilled/stented pattern?
skin under tension
What is the quilled/stented suture a modified suture of?
the interrupted vertical mattress that loops over a stent
What type of pattern is the quilled/stended suture coupled with?
an appositional pattern at the skin edge
What is a potential complication associated with the quilled/stented suture pattern?
ischemia between sutures or under stents
When should the quilled/stented suture pattern be removed?
earlier than the remaining sutures
In what type of tissue should you use a far-near-near-far pattern?
skin and fascia under tension
What is the far-near-near-far pattern a modification of?
a vertical mattress pattern
The far-near-near-far suture pattern avoids excess ______ at the wound edge.
tension
What is the thickness of the bites in the far-near-near-far suture?
full thickness
In what type of tissue should you use a far-far-near-near pattern?
skin and fascia under tension
What is the far-far-near-near pattern a modification of?
modified vertical mattress
The far-far-near-near suture avoids excess ____ at the wound edge?
tension
What is the thickness of the bites in the far-far-near-near pattern?
full thickness
What is the purpose of the walking suture?
move skin across a defect, eliminate dead space, and distribute tension
In the walking suture, the suture bite in ____ is closer to the center of the _____.
fascia; wound
What effect does the walking suture cause?
cosmesis
What is cosmesis?
dimpling
When don’t you use the walking suture?
with flaps or grafts
What are some ways to facilitate skin stretching?
pretensioning sutures, posttensioning sutures, presuturing, acute intraoperative skin stretching, and chronic skin expansion
When do you do pretensioning sutures?
48-72 hours preop
Pretensioning sutures are continuous through ______ or _____ with lead _____ _____.
skin; intradermal; split shots
Pretensioning sutures are considered ____ ____ _____.
external skin stretchers
What is pretensioning suture for and what mechanism does it use?
stress relaxation, mechanical creep
How often are pretensioning sutures tightened?
every 8-24 hours based on your judgement
When are posttensioning sutures applied?
postop to minimize skin tension
Posttensioning sutures are considered ____ ______ _____.
external skin sutures
What can be used to aid in posttensioning sutures?
bolster bandages
What is presuturing?
when sutures are placed around an area of planned excisioinn
What type of suture pattern is used in presuturing?
lembert sutures through intact skin to plicate skin
How many days before surgery is presuturing done?
3 days
What is acute intraoperative skin stretching used for and what mechanism does it use?
stress relaxation and limited mechanical creep
What tools can be used for acute intraoperative skin stretching?
skin hooks, towel clamps, and stay sutures
Acute intraoperative skin stretching provides constant ______.
tension
How long preop do you want to do acute intraoperative skin stretching?
30-45 minutes
What is chronic skin expansion used for?
to produce a new epidermis
In what patients is chronic skin expansion used for?
used in patients that have excessive skin loss
What type of effect does chronic skin expansion have?
delayed effect, biological creep
What tools are used for chronic skin expansion?
inflatable or expandable silicone elastomer devices
How do you do chronic skin expansion?
implant surgically, expand 10-15% every 2-3 days
What are some types of relaxing incisions?
mesh expansion, simple relaxing incision, plasties
How is mesh expansion facilitated?
multiple relaxing incisions adjacent to the incision
How big are the incisions in mesh expansion?
1 cm in length
How far from the incision are mesh expansion incisions made?
1 cm from the edge
How far apart of are incisions for mesh expansion made?
staggered rows 1 cm apart
What is a potential risk associated with mesh expansion?
skin necrosis
What part of the body is mesh expansion useful for?
extremities
What is a single relaxing incision?
a bipedicle flap - an incision parallel to the long axis wound
How does a single relaxing incision heal?
it heals by second intention
What is V-Y plasty?
a chevron incision with point away from the wound that closes in a y
What is V-Y plasty useful for?
to advance skin to a defect or near orifice
What is a Z plasty used for?
cicatrix or closure nearby a wound
How is a Z-plasty performed?
the transposition of 2 triangular flaps from a central limb
For a wound, the central arm of the Z plasty perpendicular to the long axis wound should be ____ cm away.
>3cm
What is an M plasty?
one or both ends of fusiform incision is under tension
When is an M plasty used?
orifice, pat, or bilateral mastectomy
How is an M plasty closed?
as a Y
What is a fingertrap suture pattern used for?
to secure -ostomy tubes and anchor them to the skin
How is the fingertrap suture structured?
repeated loops crossed around tubes
What is the fingertrap suture used to prevent?
accidental distraction or slippage
When does friction increase in the fingertrap suture?
if distract/pull tube
What type of pattern is the kessler locking loop suture?
superior apposition
What is the Kessler locking loop suture used for?
smaller tendons and flat tendons
What does the kessler locking loop suture maintain in tendons?
gliding function
How is the three-loop pulley suture oriented?
3 loops oriented 120 degrees to each other
What is the three-loop pulley suture resistant to?
gap formation
What is the three-loop pulley suture good for?
circular tendons and larger tendons
What is the Bunnell-meyer suture used for?
circular tendons
What is a potential risk of the Burnell-Mayer suture?
it may damage the tendons microcirculation
What type of pattern is the Krackow pattern?
a locking-loop pattern
What type of tendons is the krackow suture good for?
larger tendons and circular or flat tendons
What is a potential risk of the Krackow suture?
may damage tendon circulation
Where is the knot located in the Krackow suture?
it is within the tendon center
What is the weakest point of a suture?
the knot
What are the most reliable knots?
superimposing square knots
How many throws should be done with an interrupted pattern?
4
How many throws should be done with a continuous pattern?
6-8
What are some types of knots?
square, granny, slipped, surgeons, and simple
What is knot strength?
force required to cause a knot to slip
What is knot security?
related to the coefficient of friction of suture and knot strength
What factors affect knot security?
- material coefficient and memory 2. length of the cut suture ends and # of throws 3. structural configuration of the knot 4. body fluids/wound
What affects the net tensile strength of the suture line?
initial tensile strength of the suture and knot security
What are the principles of knot tying?
- use the simplest secure knot for the suture material and the situation 2. avoid friction between the strands as it may weaken the suture 3. use appropriate tension 4. approximate tissues don’t strangulate tissues 5. pull the 2 strands in opposite directions with uniform rate and parallel tension 6.avoid damage to the suture material that remains with the patient 7. knots should be secure and flat
How are knots buried?
take bites deep to superficial and then superficial to deep; in SQ or intradermal sutures
How do you bury a continuous pattern end knot?
superficial to deep, deep to superficial, then superficial to deep
What is the aberdeen method?
a method to end a continuous suture pattern
What are the benefits of the aberdeen method?
increased strength, increased security, decreased number of throws, and decreased size
What are self-locking sutures?
sutures that contain a loop at the end
What are self-locking sutures designed for?
laparoscopic procedures and can be used for intradermal
What is hemostasis used for?
visability of the surgical field, decrease potential for infection, minimize blood loss, reduce hematoma and seroma formation, and decrease surgical times
What are some methods of hemostasis?
electrocautery, bipolar vessel sealing device, harmonic scalpel, stapler devices, hemoclips, ligation, pressure/tamponade, torniquet/clamps/bandages, hemostatic agents, hypotension/hypothermia/reduced perfusion
What hemostatic agents are used for topical vasoconstriction?
epinephrine/adrenaline/ephedrine
What hemostatic agents are used for antifibrinolytics?
serine protease inhibitors, lysine analogues
What hemostatic agents are used as sealants?
fibrin (tisseel, evicel, vitagel) and synthetic (coseal, and duraseal)
What are some mechanical hemostatic agents?
gelatin (gelfoam, surgifoam), bovine collagen (avitene, helistat, instat, sanostat), oxidized cellulose (surgicel), bone wax, and ostene
What are some active hemostatic agents?
thrombin (floseal, surgiflo) and alginate (kaltostat, sorbsan)
What is the goal of ligation?
vascular strangulation
Where does transfication occur in ligation?
distal to encircling
What techniques are used for ligation?
simple encircling, transfixation, advanced circumferential friction knots
What is the three clamp technique used for?
ligation of large vessels and vascular pedicles
How do you perform the three clamp technique?
- 3 parallel forceps placed ~ 0.5cm from one another, transect between 2 most distal 2. release most proximal forceps partially while trying ligature in ‘crush’ 3. release completely as ligature is tightened
When is encircling used?
for ligation of vessels, and small vascular pedicles
What can be done with encircling do prevent loosening?
a surgeons knot
How is halsted transfixing performed?
a bite is taken around the vessel but not tied, the ends are passed around the opposite side of the vessel to create the knot
How is modified transfixing performed?
a bite is taken in the vessel with a simple knot performed on one side. The suture ends are passed around the opposite side for a surgeons throw, then completion of the knot
How is figure-of-eight transfixing performed?
the suture needle is passed in figure-of-eight pattern through the vascular pedicle two times, the two loops are tied with a single knot
When is double transfixing used?
for large dog spays
How is double transfixing performed?
it is a modified technique with the use of two simple encircling around either uterine artery
What is the Miller’s knot used for?
large vessels and pedicles; friction
How is the Miller’s knot performed?
place a secure half hitch around the pedicle, one suture end passed around and looped through a space preserved by your finger
What is the modified miller’s used for?
large vessels and pedicles
How does the Modified Miller’s work?
it is a clove-hitch that binds itself when tightened, the 2 loops are parallel
What is the constrictor knot used for?
large vessels and pedicles
How does the constrictor knot work?
it is a clove-hitch that binds itself when tightened, 2 loops cross, and suture end over first loop and under both
What is the strangle knot useful for?
large vessels and pedicles
What is the strangle knot a modification of?
the constrictor with suture end going under and between the cross
What are self-locking loops designed for?
laproscopic surgery
What is a surgitie self-locking loop?
a loop suture in a carrier, loop over vessel/pedicle, and tied with a slip knot
What is a ligatie self-locking loop?
an absorbable device that closes like a zipper
What suture pattern is shown here?
a vertical mattress
What suture pattern is shown here?
quilled/stented
What suture pattern is shown here?
quilled/stented
What suture pattern is shown here?
far-near-near-far
What suture pattern is shown here?
far-far-near-near
What suture patten is shown here?
walking suture
What suture pattern is shown here?
pretensioning sutures
What suture pattern is shown here?
posttensioning sutures
What technique is shown here?
presuturing
What technique is shown here?
acute intraoperative skin stretching
What technique is shown here?
mesh expansion
What technique is shown here?
single relaxing incision
What technique is shown here?
V-Y plasty
What technique is shown here?
Z plasty
What technique is shown here?
M plasty
What technique is shown here?
fingertrap
What suture is shown here?
Kessler locking loop
What suture is shown here?
three-loop pulley
What suture is shown here?
Bunnell-mayer
What suture is shown here?
Krackow
What technique is shown here?
halsted transfixing
What technique is shown here?
modified transfixing
What technique is shown here?
figure-of-eight transfixing
What technique is shown here?
double transfixing
What knot is shown here?
a Miller’s knot
What knot is shown here?
a modified Miller’s knot
What knot is shown here?
a constrictor knot
