Suture Technique - Knot tying, suture patterns, and hemostasis Flashcards
(52 cards)
1
Q
Knot security is determined by:
A
- Size and structure of the suture material
- Coefficient of friction - the higher the coefficient of friction, the stronger the knot (silk - strong knots)
- Length of cut ends
- Quality of the knot - surgeon dependent
2
Q
Knot Tying Technique and what to avoid
A
- Pull the suture ends in opposite directions at uniform rate and with equal tension
- Avoid:
- Creating friction between the strands while tightening the throw
- Crimping suture with instruments
3
Q
4 throws = how many knots?
A
2 knots
4
Q
3 throws are as secure as 6 for most sutures tested, but tensile failure load is greater with __
A
6
5
Q
Recommendations:
Interrupted pattern’
Continuous Pattern, beginning and end
A
- Interrupted patter - 4 throws (2 square knots)
- Continuous pattern - 6 throws (3 square knots)
6
Q
Where do sutures almost always fail? Why?
A
at the knot, unless the suture has been damaged; knotting reduces strength by 10-40%
7
Q
A
- Simple knot
- Aka - throw
- One throw = simple knot
8
Q
A
Square knot - it takes two throws to make a square knot
9
Q
A
Surgeon’s knot - two wraps around first throw; second throw of a square knot goes ontop
10
Q
A
Half-hitch knot - jerk up on one strand, usually done with a square knot ontop
11
Q
A
Granny knot - BAD
12
Q
Burying the knot - indications
A
- Inverted knot reduces likelihood that suture ends will become exposed
- Indications:
- Subcutaneous sutures
- Intradermal pattern
13
Q
Principles of wound closure
A
- Closure should be as anatomic as possible (like tissues are apposed)
- Use the least amount of suture material that will accurately and reliably appose the tissues
- Dead space should be minimized
- Use absorbable material for buried sutures whenever possible - some excetions
14
Q
“Routine” Wound Closure - what layers are usually included (ex - abdominal incision)
A
- Fascia - want to use longer acting suture material becuase it takes a long time to heal (PDS)
- Subcutaneous tissue
- Skin
15
Q
What is the most common pattern with suturing subcutaneous tissue? And what can be done to decrease “dead space”?
A
- Simple continuous pattern
- Periodic bites into the underlying fascia can be sued to decrease “dead space”
16
Q
Subcutaneous pattern
A
- Can be used for animals with a lot of subcutaneous fat
- Bites taken perpendicular to skin edge, but no dermis engaged
17
Q
Intradermal pattern (aka ____)
A
- Subcuticular pattern
- More accurate apposition of skin edges - engages dermis
- bites taken perpendicular or parallel to skin edge
- Skin sutures may not be needed
- Continuous pattern
- Slightly overlapping bites (<25%) results in tighter closure
18
Q
Perpendicular bites vs Parallel bites
A
- Thick skin - perpendicular to the incision
- Thin skin - parallel to the incision
19
Q
- Skin suture guidelines
- distance between sutures should be:
- Distance between skin suture and wound edge should be:
A
- 2 times the skin thickness
- 5mm rule - you don’t want any skin suture less than 5mm from the wound endge becuase any less will compromise blood supply
20
Q
Interrupted suture patterns: pros and cons
A
- Advantages
- Precise placement and control of tension
- Failure of one suture or knot inconsequential
- Disadvantages:
- Increased surgical time
- Increased volume of suture left in the wound
- Poor suture economy
21
Q
Continuous Suture Patterns
A
- Advantages:
- Speed of placement
- Less suture left in wound
- More air- or water-tight
- Good for urinary bladder and stomach
- Suture economy
- Disadvantages
- Less precise control of tension and approximation
- Failure may result in loss of entire suture line
22
Q
A
Simple interrupted suture
23
Q
A
simple cutnaneous suture
24
Q
A
Ford Interlocking suture
25
Cruciate or Cross Mattress Suture
26
Figure-of-eight suture - like an upside down cruciate
27
Name six appositional suture patterns
* Simple interrupted
* Simple continuous
* Ford interlocking
* Cruciate or cross mattress
* Figure-of-eight
* Intradermal suture pattern (w/ perpendicular or parallel bites)
28
5 Tension relieving sutures
1. Vertical Mattress
2. Far-far-near-near
3. Far-near-near-far
4. Horizontal mattress
5. Quilled and Stent
29
Vertical Mattress
Placed far from the wound incision - if you tie it tight enough, skin will evert
30
Far-far-near-near
31
far-near-near-far
32
Horizontal mattress
\*blood supply is cut off with horizontal mattress - if suturing skin, vertical mattress is preferable
33
Quilled suture - not as common when we have ability to do walking sutures
34
When to use inverting suture patterns?
* closure of hollow viscera
* Imbrication (plication)
* NOT for use in skin b/c skin has natural tendency to already invert - dorsal surface of epithelium won't heal together
35
Three inverting suture patterns:
1. Lembert
1. Halsted variation
2. Cushing
3. Connell
36
Lembert suture
* Different from vertical mattress - you go in and come out and go OVER the skin - needle stays in the same direction
37
Halsted Suture Pattern
38
Cushing
* Needle goes into the skin through the dermis, but does not go all the way to the lumen of that hollow organ
* DOES NOT GO INTO LUMEN!!!
39
Connell
* Same as cushing, but **SUTURE GOES INTO THE LUMEN**
40
Friction sutures are made for:
anchoring tubes
41
How to secure a tube with friction sutures
* Just one square knot
* Then surgeons throw (1/2 of surgeons knot) - tie off tube, and then you finish the surgeon knot.
* Square knot - tube - half of surgeons throw - finish surgeons throw
42
Securing a tube with friction sutures without using needle holders and forceps:
1. Pass the suture through the needle
2. Tie a square knot
3. Insert the tube
4. Place the tube onto the swuare knot and tie a surgeon's knot
5. Repeat the process for multiple friction sutures.
43
Hemostasis - sterile gauze application
Holding pressure with gauze - helps capillary bleeding.
DO NOT DAB!
Press with slight/moderate pressure and hold for a few seconds. Reapply if necessary.
44
Using Hemostatic Forceps
* Pay attention to the grooves inside the forceps
* Should be perpendicular to the suture
* End-on application
* Used for isolated blood vessels (grooves perpendicular to the vessel)
* Perpendicular application
* Used for blood vessels with pedicles (like ovarian pedicle during ovariohysterectomy - NOT for isolated vessels)
45
vet product of gelfoam is:
Vetspon - less expensive, almost identical
46
Electrosurgery:
* Electrodessication
* Electrocoagulation
* Electroincision
* Electrodessication - dessicating tumor surface
* Electrocoagulation - stops vessels from bleeding
* Electroincision - used during surgery, not used on skin because of dermal necrosis
47
Electrosurgery: monopolar vs bipolar
* Monopolar is MC
* foot panel to activate coagulation
* Bipolar
* Looks like a pair of forceps - creates a circuit when you pinch the tissue - neuro surgeons like this one because they feel like they have more control
48
Direct vs Coaptive Electrocoagulation
* Coaptive - apply to forceps
* Direct - apply directly to tissues - control excessive capillary hemorrhage
49
Electrocautery
* Electricity is used to ehat a metal element - no circuit like in electrocoagulation
* Then, that element is applied to the tissue
* No current passes through the tissue!!!!
50
Radiosurgery
* Ultra high-frequency radio waves pass from wire tip (active electrode) into the tissue to be cut or coagulated, depending on the waveform setting chosen, and on to a flat antenna (passive electrode)
* No need for conductive gel
* Patient not part of an electrical circuit
* Wire electrode remains cold
51
When does laser hemostasis not work?
Once you have blood in the field
52
Tissue and Vessel Fusion Benefits
* No dislodged clips
* Reduced lateral thermal spread, sticking, and charring
* No foreign material left behind
* Leaves tissue in its normal anatomical position
