ASCEPTIC TECHNIQUE

1
ASCEPTIC TECHNIQUE
2
Define sterilization

• Killing of all microbial forms (cells, spores)

3
What is the commonly used method of sterilization
for surgical instruments?

• Steam latent heat of vaporization, press
  increases the temp of steam formation and
  increases In efficacy, avoid overloading
  autoclave and add additional penetration item for
  larger packs

4
List 4 alternative methods.

• Gas (ethylene oxide)
• Plasma sterilization
• Cold chemical
• Ionizing radiation

5
Which of these methods is most often used for
surgical supplies?

• Steam most common have gracity displacement
  sterilizers high prevacuum sterilizer and flash
  sterilization (only in emergency)
• Plasma sterilazation most common alternative
  uses hydrogen peroxide at low temp, some items
  cant be sterilized

6
Why is steam under pressure more lethal than
steam that is not under pressure?

• b/c pressure increases the temp of steam formation

7
Explain how a gravity displacement sterilizer
works

• Steam is lighter than air and the 2 dont mix
  readily steam is admitted into the chamber and
  baffled upward and air flows out the drain on the
  bottom of the chamber

8
. How does a prevacuum sterilizer differ from a
gravity displacement sterilizer?

• Requires energy applied to the pump to make
  vacuum and does fewer number of packs at one time

9
What is flash sterilization?

• When an unwrapped item is placed on perforated
  metal tray in gravity displacement sterilizer,
  only used in emergency

10
When is ethylene oxide sterilization used?

• When you need to penetrate rubber and plastic and
  have several hours to do it

11
What are the environmental and safety hazards of
ethylene oxide?

• Category 1 carcinogens , EPA has discontinued the
  use of cholorofluorocarbon

12
What is plasma sterilization?

• Is a vapor pressure hydrogen peroxide
  sterilization

13
What are its advantages over ethylene oxide
sterilization?

• Uses low pressure sterilization with no aeration
  requires

14
When is glutaraldehyde sterilization used in
veterinary surgery?

• To disinfect lenses and delicate instruments,
  sterilizes by protein and nucleic acid alkylation

15
Describe practices that help to ensure the
efficiency of autoclaving

• Need correct relationship b/w temp, press, and
  exposure time
• Make sure packs arent wrapped too tightly or are
  not improperly loaded into autoclave
• Should be positioned longitudinally and
  vertically
• Heavy packs should be at the periphery
• Small amount of airspace should be b/t the packs
• Linen packs are oriented so that the fabric
  layers are oriented vertically
• Should use sterilization indicators- undergoes
  some chemical or biological change in response to
  correct pressure and temp

16
What organisms do disinfectants destroy?

• microorganisms

17
Name 5 effective disinfectants.

• Phenol
• Betadine
• Chlorohexidine
• Quarternary compounds
• Alcohols

18
Which of these can be used for scrubbing the
patient and surgeons skin?

• Iodine can be used to scrub and betadine and
  chorhexadine

19
What are advantages and disadvantages of
polyvinylpyrrolidone, chlorhexidine glyconate,
and hexachlorophene as skin disinfectants?

• Betadine inhibits chemotaxis and kills spores
• Disadvantages iodine part can be absorbed,
  inactivated by organic material
• Chlorohexidine ad most effective, works against
  gram -/ and pseudomonas, has no systemic
  absorption, may be less irritating to skin
• Dis does not kill spores, residual activity, bc
  it binds to keratin
• Hexacholorphene less caustic and easier to
  handle bc halogenated
• Dis minimal activity against gram -, may be
  neurotoxic

20
WOUND INFECTION AND THE USE OF ANTIBIOTICS
21
List the classification of surgical
procedures/wounds, and give an example of each.

• -clean non traumatic wounds without pre-existing
  inflammation or infection
• -clean/contaminated non-sterile luminal organs
  entered without spillage (GI, resp, oropharynx,
  vagina, urinary, biliary tract) minor break in
  aseptic technique (break gloves)
• -contaminated traumatic wound without purulent
  discharge major break in surgical technique like
  gross spillage or fresh traumatic wound
  requires drbridement, lavage and Ab (ex. Spill
  urine)
• -dirty gross infection present at time of
  surgery, has purulent discharge, devitalized
  tissue, or foreign body (ex. Perforated viscus
  and have fecal contamination)

22
List the 4 sources of infection commonly
encountered in surgical patients.

• -primary surgical disease
• -as complication of surgical procedure nor
  commonly associated with infection
• -complication of support procedures
• -infection associated with prosthesis

23
What is a nosocomial infection? What measures,
other than antibiotic use, can help in the
control of nosocomial infections?

• -nosocomial infection acquired during
  hospitalization
• -control via controlling endogenous flora via
  patient prep, decreasing transmission via sterile
  gloves, sterilization, disinfection, rational Ab
  use

24
Describe 6 host factors that may predispose
patients to infection of surgical wounds.

• -physical condition, nutrition, immune status,
  nature of the wound, diagnostic procedures,
  concurrent metabolic disorders, operating room
  practice (use positive pressure ventilation),
  characteristics of bacterial contaminants (can
  use over nite UV light)

25
How can operating room practice decrease the
incidence of surgical infection?

• -the more sterility, the less contamination in
  OR should use aseptic technique, sterilization
  and disinfection, prepare surgical environment,
  gowning and gloving, prep of surgical patient,
  operative site, surgical team

26
Discuss how patient preparation and tissue
handling are important.

• -proper atraumatic tissue handling and instrument
  use are important in preventing infection
  traumatized tissue promotes bacteria growth

27
Describe prophylactic antibiotic use, including
the specific antibiotics used, the route and
timing of administration, and the length of use.

• -give at least 30 minutes before initial incision
  b/c must be present at surgical site during time
  of potential contamination Ab selected must be
  effective against at least 80 of probably
  pathogens (Staph, E.coli, Pasteurella,
  Bacteroides)

28
Give 3 general indications and 3 indications in
specific procedures for prophylaxis.

• -cefazolin for most surgeries, 20mg/kg IV at
  induction of anesthesia (slowly over 5 minutes),
  may repeat in 2-3 hours discontinue immediately
  a/f closure or within 24 hours
• -cefoxitin for colon surgery
• -indication for prophylaxis surgery longer than
  90 minutes, prosthesis implantation, severely
  affected or traumatized wounds, GI strangulation
  or obstruction, esophageal surgery, etc

29
. How is the drug of choice for prophylactic use
determined?

• -specific indications Staph likely with thoracic
  and orthopedic procedures, G cocci, enteric G-
  bact likely with gastric and upper intestinal Sx
  E.coli, Strep and anaerobes common in urogenital
  system
• -Ab selection determine system involved and
  moost likely pathogen, ensure Ab reached taget
  tissue, if amny are effective select the one that
  is least expensive, least toxic, and most
  convenient to administer

30
Describe therapeutic antibiotic use and
differentiate it from prophylactic use.

• -therapy use based on clinical judgement,
  knowledge of Abs mechanism of action and
  micobiologic factors indicated in surgical
  patients with overwhelming systemic infection,
  when infection is present at the surgical site or
  in a body cavity, or with any contaminated or
  dirty surgical procedure usually given b/f
  surgery and then 2-3 after
• -prophy use is to prevent contamination and you
  are not sure of that actual pathogen, but base
  selection on potential pathogen

31
HALSTEDS PRINCIPLES OF SURGERY
32
What are Halsteds Principles of Surgery? What
is their importance to you?

• Gentle tissue handling
• Accurate hemostasis
• Preservation of blood supply
• Strict aseptic technique
• Sutures tied w/o tension
• Accurate tissue apposition
• Obliteration of dead space
• Postoperative wound protection
• They are the keys to a successful surgery.

33
How does knowledge of anatomy improve surgical
technique?

• Knowing where the fascial planes are will allow
  you to avoid cutting muscles and allow for
  avoidence of unnecessary dissection.

34
What is sharp dissection? Blunt dissection?
Which is more traumatic? Why?

• Sharp dissection is accomplished by incising
  tissues with a sharp edge.
• Blunt dissection is accomplished by separating
  tissues along natural cleavage lines, without
  cutting.
• Sharp dissection is less traumatic than blunt
  dissection because blunt dissection requires
  pulling and tearing of tissues.

35
What are two correct ways to hold a scalpel?
What are the indications for each?

• The pencil grip of he scalpel is used for short
  incisions.
• The slide grip of the scalpel is used for long
  incisions.

36
What is the tripod grip? When is it used? What
are alternative methods of holding needle
holders, and what are their advantages and
disadvantages?

• The tripod grip is used with any ring instrument,
  especially scissors, to steady the tip of the
  instrument. The thumb and finger next to the
  pinky finger go into the rings (not through) and
  the index and middle finger brace the instrument
  for steadiness. Needle holders may be held in
  tripod grip or palmed. The palm grid is used for
  rapid suturing. Fine control is decreased. The
  thenar grip is a compromise between the tripod
  and the palm grip.

37
How are curved scissors passed by the assistant
to the surgeon? How is a scalpel passed?

• Instruments are passed to the surgeon in an
  appropriate position for use. Scalpels are
  passed in a manner that avoids injury to either
  party.

38
What are three main reasons that hemostasis
during surgery is important? Describe three
effective means of hemostasis. What are two
complications of excessive application of these
techniques.

• Hemostasis is important because we want to
  preserve the patients blood volume, maintain a
  clean surgical field for surgery and to decrease
  postoperative hematoma formation. Ligation with
  small absorbable suture material for most
  vessels. Electrocoagulation after clamping
  bleeding vessel with hemostat or direct
  application of electrocautery. Clamping with a
  hemostat. Excessive ligating or cautery delays
  wound healing and predisposes to infection.

39
Why is tension at a suture line avoided if
possible? What techniques can be used to reduce
or counteract tension? What are complications of
the use of these techniques? Describe correct
undermining of skin on the trunk and on the
distal limb.

• Tension at suture line may occlude blood supply
  to tissue, resulting in necrosis and tension
  across suture line of anastamosis will predispose
  to stenosis. When tension is present use tension
  patterns and knots or undermine tissue margins to
  reduce tension but avoid excessive undermining.
  Undermining creates dead space, leading to seroma
  formation. Undermining may damage vascular
  supply to tissue margins.
• Undermine skin deep to panniculus muscle to
  preserve direct cutaneous arteries. Skin without
  underlying panniculus muscle is determined in
  loose areolar fascia beneath dermis to preserve
  subdermal plexus.

40
What is the purpose of using moist laparotomy
sponges on the wound margin? Why are exclusion
drapes used when opening hollow viscera?

• They serve to keep the tissues moist and they
  protect the tissues when using self-retaining
  retractors. To pack off the hollow viscus before
  opening it in case of a spill that would cause
  contamination.

41
What is dead space? Why is dead space a problem
in the postoperative period? Describe four
techniques that will prevent formation or reduce
dead space.

• Dead space is space remaining after closure of
  surgical or other wounds, permitting the
  accumulation of blood or serum and resultant
  delay in healing. Seromas may be secondarily
  infected and become abscessed. Accurate tissue
  apposition, use of drains and pressure bandages,
  tracking tissue to deeper layer when closing and
  delayed wound closure when dealing with loss of
  tissue all cause obliteration of dead space.

42
What are the two types of drains? Give an
example, an advantage, and a disadvantage of
each.

• Passive drains and Active suction drains.
  Passive drains are covered with a sterile
  dressing and removed as soon as drainage has
  ceased. Pros include inexpensive, more
  comfortable for patient. Cons include less
  effective, greater risk of ascending infection.
  Active suction drains are attached to the patient
  externally with bandage material. Pros include
  more effective, less risk of retrograde
  infection. Cons more expensive, less
  comfortable for the patient.

43
List 2 reasons for protecting a surgical incision
in the postoperative period. For each reason,
describe appropriate methods of protection.

• Protection from environmental contamination which
  decreases risk of superficial wound infection.
  When possible, wound dressing is used. If
  incision cannot be covered, frequent cleansing is
  indicated.
• Protection from self-mutilation. Use an
  e-collar, plastic bucket, hobbles prevent chewing
  or scratching or try a foul tasting liquid wound
  dressing. Wounds itch most between 3rd and 7th
  postoperative day.

44
SUTURE MATERIALS
45
List 5 characteristics of the ideal suture
material

• Easy to handle
• Minimally reactive in tissue
• Inhibits bacterial growth
• Does not support sepsis
• High knot security
• High tensile strength
• Is absorbed at a reliable rate
• Inexpensive and easily sterilized

46
How is suture material sized

• Suture graded from fine to coarse
• Scale from 10-0 (smallest) to 7 (largest)

47
Compare USP sizing to metric sizing

• USP of 10-0 0.2 metric gauge
• USP of 7 9 metric
• Metric sizing gauge is 10 times metric diameter
  of suture

48
What is flexibility in regard to suture material

• Determined by the torsional stiffness and diameter

49
When is it important to choose a flexible suture
material

• Ligating vessels and for continuous suture
  patterns

50
Give 2 examples of flexible suture materials

• Silk, polyglactin 910 (Vicryl), poliglecaprone 25
  (Monocryl)

51
What are the advantages of rough and smooth
surfaces in suture material

• Rough
• Increase knot security
• Smooth
• Decrease tissue trauma

52
What are the disadvantages of rough and smooth
surfaces in suture material

• Rough
• Increased tissue trauma
• Smooth
• Decreased knot security

53
What is capillarity

• Process by which fluid and bacteria are carried
  into the interstices, so infection may persist

54
What type of suture material has capillarity

• Multifilament sutures
• Ex silk

55
When is it important to avoid capillary suture
material

• In already infected sites

56
Define knot tensile strength

• The force that the suture strand can withstand
  before breaking when knotted

57
Define knot security

• Holding capacity of a suture as a percentage of
  tensile strength

58
What determines the overall strength of the suture
59
What determines the number of throws needed on
the knot
60
What are the was in which suture material is
classified

• Absorbable/nonabsorbableMonofilament/multifilamen
  tNatural/synthetic

61
Classify polyglyconate

• Maxon
• Monofilament, synthetic, absorbable

62
Classify polydioxanone

• PDS
• Monofilament, synthetic, absorbable

63
Classify poliglecaprone

• Monocryl
• Monofilament, synthetic, absorbable

64
Classify polyglactin 910

• Vicryl
• Multifilament, synthetic, absorbable

65
Classify chromic gut

• Natural, absorbable

66
Classify silk

• Monofilament, natural, nonabsorbable

67
Classify stainless steel

• Monofilament, nonabsorbable, synthetic

68
Classify nylon

• Monofilament, nonabsorbable, synthetic

69
Classify polypropylene

• Prolene
• Monofilament, nonabsorbable, synthetic

70
Classify polyester

• Mersilene, ethibond, dacron, ticron
• Multifilament, nonabsorbable, synthetic

71
Classify caprolactam

• Supramid, braunamid etc
• Monofilament, nonabsorbable, synthetic

72
What is the definition of absorbable

• Looses most of its tensile strength within 60
  days of implantation in tissue

73
When would absorbable suture be indicated

• Use for inner tissues that holding capacity is
  needed for less than 60 days

74
When would nonabsorbable suture be indicated

• Outer tissue layers or in inner tissues where
  strength is needed for greater than 60 days

75
What are the advantages and disadvantages of
monofilament

• Advantages
• No capillarity
• Minimal tissue drag
• Disadvantages
• Reduced knot security
• Easily damaged with forceps or needle holders

76
What are the advantages and disadvantages of
multifilament

• Advantages
• More pliable and flexible than most monofilament
• Disadvantages
• Increased capilarity and potential to promote
  infection
• Increased wicking
• Increased tissue drag

77
Name 2 natural sutures still used in surgery

• Silk, chromic gut

78
What are the disadvantages of natural sutures

• Associated with marked inflammatory reaction
• Looses strength rapidly in infected sites or when
  exposed to digestive enzymes

79
What type of suture material is coated and why is
this done

• Multifilament sutures are often coated to
  decrease tissue drag
• Coating reduces knot security

80
What suture material is preferred for ligating
very large vessels

• Silk
• Causes inflammatory reaction which helps to close
  very large vessels

81
What suture material is preferred for ligating
most vessels and vascular pedicles
82
What suture material is preferred for anastamosis
of blood vessels
83
What suture material is preferred for closing skin

• Nylon

84
What suture material has the greatest tensile
strength
85
SUTURE PATTERNS
86
Describe 4 ways in which suture patterns are
classified

• Continuous/interrupted
• Inverting/everting or apposition
• Partial or full thickness
• Tension patterns

87
Define inversion

• When the edges of the incision turn inward

88
Define eversion

• When the edges of the incision turn outward

89
Define apposition

• When the edges of the incision come together

90
What are the advantages and disadvantages of
continuous suture patterns

• Advantages
• Faster
• Less suture left in wound
• Better seal at tissue margin
• Disadvantages
• Less precise control of tension and apposition
• Disastrous result if suture breaks

91
What are the advantages and disadvantages of
interrupted suture patterns

• Advantages
• Precise placement of each suture
• Stronger
• More secure
• Disadvantages
• More time required
• More suture left in wound
• More expensive

92
Give an example of the use of the simple
interrupted pattern

• Skin, SQ, fascia, hollow viscera, vessels, nerves

93
Give an example of the use of the simple
continuous pattern

• Skin, SQ, fascia, hollow viscera, vessels, nerves

94
Give an example of the use of the continuous
interlocking

• Diaphragm (skin in large animals)

95
Give an example of the use of the cruciate

• Skin, flat tendons

96
Give an example of the use of the intradermal

• Subdermal fascia

97
When is an inverting pattern indicated

• Hollow viscera

98
When is an inverting pattern contraindicated
99
What is the difference between the cushing and
connel patterns

• Cushing penetrates the submucosa but not the
  mucosa
• Connell penetrates the mucosa

100
What is the difference between a cushing and a
lembert

• Cushing is a continuous horizontal mattress,
  lembert is a variation of a vertical mattress

101
When would a purse string suture be used

• Inverting visceral stumps, closing anus before
  perineal surgery, closing skin tightly around
  drains

102
What are the advantages and disadvantages of a
horizontal mattress pattern

• Advantages
• Potential for apposition, eversion, or inversion
• Disadvantages
• Potential for strangulation of tissue margins

103
What are the advantages and disadvantages of a
vertical mattress pattern

• Advantages
• Stronger than horizontal
• No risk of strangulating tissue margins
• Disadvantages
• More time consuming to place
• More suture left in wound

104
What is the advantage of the near and far
variation of the vertical mattress

• Opposes tension at wound edge without applying
  tension at the wound itself
• Quicker to apply than standard vertical mattress

105
In what tissues would you use a horizontal
mattress

• Skin, SQ, fascia, muscle, flat tendons

106
In what tissues would you use a vertical mattress

• Skin, SQ, fascia

107
What are stents

• Object over or through which suture is placed
  (prevents suture from getting too tight)

108
What are 2 reasons to use a stent with an
incision that is under tension

• Reduces risk of tissue strangulation
• Obliterates dead space deep to the incision

109
Define knot vs throw

• Consists of at least 2 throws laid on top of each
  other

110
What is a transfixing ligature

• The needle is placed through the wall of the
  vessel
• The ends of the suture are wrapped around the
  vessel in opposite directions
• The suture is tied

111
When can a transfixing ligature be used

• Can be used to ligate uterine vessels in OHE

112
How can you close a curved or jagged incision
accurately
113
How can you close an incision in which one side
is longer than the other accurately
114
How do you close a long incision accurately

• Divide very log incisions into thirds
• Start at the center and fill in

115
What types of needles are atraumatic

• Taper
• Reverse cutting
• Spatula point
• Must be swaged to be atraumatic

116
When would you choose a taper point needle

• Soft easily penetrated tissues

117
When would you use a cutting point needle

• Tough tissues such as skin and fascia

118
What suture materials and patterns are used to
close the SQ layer

• Simple continuous with monocryl/ PDS etc

119
What is the purpose of closing this layer

• To oliterate dead space and reduce tension on
  skin edges

120
What suture material and patterns are used to
close the skin

• Nylon using simple interupted

121
What special suturing is indicated in male dogs

• Preputialis muscles must be accurately apposed
  using horizontal mattress or cruciate

122
What suture materials and patterns are used to
close the subcutaneous layer?

• Subcutaneous tissue is closed in simple
  continusous or simple interrupted pattern using
  3-0 or 4-0 synthetic absorbable.

123
What is the purpose of closing this layer?

• The subcutaneous layer is closed to decrease the
  amount of dead space.

124
What suture material and patterns are used to
close the skin?

• The skin is closed with 3-0 or 4-0 nylon.

125
APPROACHES TO THE ABDOMINAL CAVITY
126
List three standard approaches to the abdominal
cavity and two combined approaches.

• Standard approaches include ventral midline,
  paramedian, and flank (also paracostal).
• Combined approaches include ventral midline
  plus paracostal, ventral midline plus median
  sternotomy

127
List the tissues incised in a ventral midline
approach.

• The tissues incised are the skin, subcutaneous
  layer and the linea alba.

128
What are the advantages of this approach?

• The ventral midline approach is the easiest and
  quickest approach and closure, there is minimal
  hemorrhage and you have exposure of all abdominal
  organs.

129
What organs or parts of organs are not ideally
exposed by a ventral midline approach?
130
How does a paramedian approach differ from a
ventral midline approach?

• The paramedian approach is a ventral abdominal
  incision through the rectus abdominus muscle
  parallel to the midline

131
What are the advantages and disadvantages of
this approach?

• With this approach there is increased exposure to
  organs on one side of the abdominal cavity,
  increased hemorrhage and increased closure time.

132
Describe the flank approach and the paracostal
approach.

• The flank approach is a lateral incision caudal
  to the last rib and cranial to ilium. The
  paracostal approach is caudal and parallel to the
  last rib.

133
What are advantages and disadvantages of these
approaches?

• The flank approach allows limited access to the
  entire abdomen and excellent exposure of one
  kidney, one adrenal gland and one ovary but
  should not be done in dogs. The paracostal
  approach allows for very limited exposure and is
  rarely used alone.

134
When would each be used, either alone or in
combination?

• A flank approach can used to spay a dog and a
  paracostal approach is used with a ventral
  midline when access to the gall bladder or liver
  is needed.

135
Why would a surgeon choose to extend a ventral
midline approach into a partial median
sternotomy?

• Doing this procedure would allow for increased
  exposure of the cranial abdomen (liver and
  diaphragm).

136
What body cavity does this open?

• This procedure opens the pleural cavity and
  mechanical ventilation is required.

137
What measures must be taken during and after
surgery as a result of this approach?

• A thoracostomy tube may be required.

138
Describe, in detail, the ventral midline
approach.

• Exact location and length of incision is
  determined by goal of surgery in exploratory
  celiotomy, the abdomen is opened from xiphoid
  process to pubis.

139
What is the best anatomical landmark on the
ventrum of the dog and cat?

• . The umbilicus should be included in the
  surgical field as a landmark.

140
What are the relative lengths of the incisions in
the layers of the body wall?

• . The skin incision is extended 1cm cranial and
  caudal to the anticipated body wall incision.
  The subcutaneous layer is incised in the same
  line as the skin. The linea alba is identified
  and incised. The linea in dogs is most easily
  recognized at or cranial to the umbilicus. The
  cranial superficial epigastric vessels parallel
  the linea cranial to the umbilicus. The
  falciform ligament may be removed completely
  (ligae cranial vessels) or moved to one side.

141
How does the approach differ in male dogs?

• In male dogs the preputial orifice is draped out
  of the field. The skin incision curves lateral
  to the penis and prepuce.

142
What vessels are encountered in male dogs? In
all dogs and cats?

• . After caudal superficial epigastric vessels
  lateral to the prepuce are ligated, the incision
  returns to midline.

143
What is the holding layer of the ventral body
wall?

• The external rectus fascia is the holding layer
  of the ventral body wall.

144
Why is the internal rectus fascia not routinely
closed in small animals?

• The internal sheath is not usually closed because
  it does not add to the strength of closure and
  increases adhesion formation.

145
Why is the rectus abdominis muscle not included
in the closure?

• The rectus muscle layer is avoided because it
  also does not add to strength of closure and
  increases inflammation.

146
What is the spacing and bite of sutures in the
linea alba? What determines this spacing?

• Full thickness bites must be taken in the linea
  alba and should be placed 5 to 10mm apart and
  incorporate 4 to 10mm of tissue.

147
Describe the standard suture patterns used in
closing the linea alba. What suture materials
are acceptable for each pattern? Which are
unacceptable? What size should the suture
material be in dogs? In cats?

• Simple interrupted closure absorbable or
  monofilament nonabsorbable suture size 2-0 to 1
  in dogs, 2-0 or 3-0 in cat, place one suture in
  center of incision, then close each end toward
  the center.
• Simple continuous closure synthetic absorbable
  or monofilament nonabsorbable suture, size 2-0 to
  1 in dogs, 2-0 or 3-0 in cats with extra throws
  that must be placed on the knots. Start at each
  end and close toward the center of the incision.
  Tie two sutures together at center of incison.
  Do not use chromic gut or stainless steel suture
  in continuous pattern in linea alba.

148
SURGERY OF THE STOMACH
149
Describe, in detail, the abdominal approach used
for gastric procedures in small animals.

• Approach ventral midline incision from xyphoid
  process to umbilicus, go through skin, sub Q,
  linea alba, on stomach incise through mucosa and
  submucosal layers

150
Include the location of the incision, the tissue
layers incised, the vascular structures
encountered and how they are handled, and the
methods that may be used to manipulate the
falciform ligament.

• Vascular structures watch for cranial epigastric
  artery
• Falciform ligament cut it out

151
How is the stomach elevated to the level of the
incision?

• Via placement of 2 stay sutures or babcock forceps

152
Where is the incision made in the stomach?

• In an avascular area on ventral body of stomach,
  between greater curvature and lesser curvatures

153
Describe 2 methods of closing a gastrotomy
incision, with an advantage of each.

• 2 inverting layers cushing advantage
  penetrates submucosa but not mucosa
• Then a connell or lembert
• Connell penetrates mucosa a through and through
  pattern
• Lembert penetrates submucosa not mucosa, no
  wicking effect

154
What suture material (type and size) would you
choose for this application?

• ????

155
Describe, in detail, the care of the
post-gastrotomy patient in the first 24 hours
following surgery.

• NPO for 12-24 hours
• Maintain hydration ie preload fluids
• Offer small amount of fluids at 12-24 hours
• If no vomiting offer small amount of digestible
  food 1-2 hours later
• Gradually return to normal diet 2-3 days later

156
Of the 4 pyloric surgeries discussed, which
is/are a.) indicated only for congential pyloric
stenosis b.) best for biopsy sample c.) likely
to provide the largest increase in size of
pyloric opening d.) best choice for necrosis or
neoplasia of pylorus or pyloric antrum e.) a
clean procedure?

• Congenital pyloric stenosis fredet-ramstedt
  pyloromyotomy
• Biopsy sample Heineke-Mikulicz pyloroplasty
• Largest increase in size of pyloric opening
  pylorectomy and gastroduodenostomy
• Necrosis or neoplasia of pylorus or pyloric
  antrum parital gastrectomy
• Clean procedure ???

157
What is the most common indication for partial
gastrectomy in the dog?

• Ischemic injury ( secondary to GDV) or
  penetrating injury
• Ischemic injury commonly at greature curvature
• Ischemic injury involving greater and lesser
  curvatures

158
Which part of the stomach is most commonly
resected?

• Part of greater curvature

159
Describe 2 types of resection and the closure for
each.

• Resection stapled
• ??????

160
What are the indications for a Billroth II
procedure?

• Neplasia
• Necrosis

161
Why might you choose this procedure rather than a
Billroth I?

• Bc decreases tension on suture line when
  extensive resection is required

162
What complication may occur with a Billroth II
that does not occur with a Billroth I?

• ????

163
Healthy canine gastric tissue almost invariably
heals extremely well. What do you think is the
most important reason for this?

• Bc very vascular

164
SURGERY OF THE INTESTINE
165
Explain why intestinal surgery should be done as
soon as it is determined to be necessary.

• To prevent worsening of the condition and
  decreased gut wall competance

166
Which layer of the intestinal wall is the holding
layer?

• Submucosa

167
Which layer provides the earliest fluid-tight
seal?

• Mucosa

168
Why are inverting patterns not usually used for
anastamosis of the small intestine in dogs and
cats?

• Will decrease the size of the lumen

169
Why is the omentum brought to the site of an
intestinal incision?

• To seal off the area and provide a blood supply

170
When is serosal patching indicated, rather than
wrapping with the omentum?

• If there is significant damage to the serosal
  surface

171
What antibiotic is recommended for prophylaxis in
the small intestine?

• Cefazolin

172
Is the same drug used for prophylaxis in colonic
surgery?

• Cefoxitin

173
Why is an enterotomy incision to remove a foreign
body made distal to the foreign body, rather than
over or proximal to it?

• Because you need to make the incision in healthy
  tissue

174
How can closure of an enterotomy increase luminal
diameter?

• Close transversely, placing first suture at ends
  of incision

175
List 3 reasons for using the end-to-end
appositional (approximating) technique for
intestinal resection and anastamosis in small
animals.

• Technically easy
• Maximizes luminal diameter
• Results in rapid mucosal regeneration

176
Describe placement of the sutures when using a
simple interrupted pattern and a modified simple
continuous pattern.

• The first suture is placed at the mesenteric
  border (leave suture long if you are using simple
  continuous)
• The second suture is placed at the antimesenteric
  border (leave suture long if you are using simple
  continuous)
• If you are doing simple interrupted place the
  remaining sutures 2mm from the edge and 2-3 mm
  apart
• If you are doing simple continuous use the long
  ends of the suture to complete each half of the
  incision

177
Why is the first suture placed at the mesenteric
border?

• Because its the hardest to place

178
Why is the mesentery closed?

• To avoid strangulating intestine that may get
  stuck inside the hole

179
What complication must be avoided in suturing the
mesentery?

• Avoid strangulating the mesenteric vessels

180
List 3 methods of correcting disparity in lumen
size during anastamosis.

• Transect small segment at acute angle, large
  segment at more obtuse angle
• Space sutures in large segment farther apart
• Incise antimesenteric border of smaller segment
  to spatulate or fish mouth smaller segment

181
Which one is best for a large disparity?

• Incise antimesenteric border of smaller segment
  to spatulate or fish mouth smaller segment

182
Which is technically easiest to do ?

• Transect small segment at acute angle, large
  segment at more obtuse angle

183
How does closing the colon after colectomy in the
cat differ from closing the small intestine after
resection and anastamosis?

• Inverting closure for colectomy vs end to end
  anastamosis for SI

184
Why is this application a good use of an EEA
stapler?

• Provides a double layer inverting closure

185
Ovariohysterectomy
186
Where is the incision placed on the ventral
abdomen of the dog for ovariohysterectomy?

• The incision for the dog is a ventral midline
  approach. The incision begins in the cranial 1/3
  of distance from umbilicus to pubis.

187
Where is it placed for the cat?

• In the cat, the incision is in the middle 1/3.

188
Why should keyhole incisions be avoided?

• A keyhole is a small incision and these should be
  avoided because if a pedicle starts to hemorrhage
  the hemorrhage will not be detectable through
  such a small incision.

189
Describe the location of the ovaries and uterus
in the abdominal cavity as a whole and in
relation to the kidney, the colon, the urinary
bladder and the uterus.

• The mesovairum and mesometrium contain ovarian
  and uterine vessels with or without fat. The
  ovaries are located at the caudal pole of the
  kidneys. The uterine horns are dorsal-lateral in
  the body cavity. The uterine body is located
  between urinary bladder and colon, adjacent to
  ureters.

190
   What are the attachment sites of the proper
ligament and the suspensory ligament?

• The proper ligament attaches the uterine horn and
  ovary. The suspensory ligament attaches the
  ovary to the body wall (cranial and dorsal to the
  kidney).

191
Which arteries supply the ovaries and the uterus?

• The ovarian arteries supply the cranial uterine
  horns. The ovarian arteries and some branches of
  the uterine arteries supply the ovaries and the
  uterine arteries supply the uterus.

192
How does venous drainage differ between right and
left sides of the animal?

• The right ovarian vein drains into the vena cava
  and the left drains into the left renal vein

193
What is the most important difference to you as a
surgeon between the mesometrium and mesovarium of
the dog compared to the cat?

• . In dogs, fat in the ovarian bursa, mesovarium
  and mesometrium may obscure vessels.

194
Describe the use of a spay hook to elevate the
uterine horn.

• The spay hook is placed into the abdominal cavity
  in a dorsaocranial direction with the hook
  portion facing the abdominal wall. The hook is
  then turned around and brought back towards the
  incision, this action should catch the uterine
  horn.

195
Why is the proper ligament clamped instead of the
uterine horn for retraction?

• The proper ligament is clamped to manipulate the
  ovary and this ligament is used because of its
  relative toughness as a tissue.

196
Why is the suspensory ligament torn?

• The suspensory ligament is torn to permit
  elevation of the ovary.

197
1.      What are two disadvantages to cutting the
suspensory ligament rather then tearing it?

• . The suspensory ligament is torn and not cut
  because the suspensory ligament is located deep
  in the cavity and one can not see what is being
  cut.

198
Describe the placement of Rochester-Carmelt
forceps when using the three clamp method of
ligation of the ovarian pedicle.

• Three Rochester Carmealt forceps are placed
  across the ovarian pedicle through the window in
  the mesovarium. The most distal clamp must be
  proximal to the entire ovary.

199
What suture material (type and size) is used for
ovarian and uterine ligations?

• The ligation of the ovarian pedicle absorbable
  suture material (2-0 for dogs, 2-0 or 3-0 for
  cats) or hemoclips are used.

200
What suture material is contraindicated?

• Do not use non-absorbable material.

201
1.      How do you decide if the mesometrium must
be ligated in the dog?

• If the dog is very fat then ligation may be
  required.

202
What is the reason for removing all of the
uterine body in a dog?

• The entire uterine body in the dog is removed
  because of a few cases of stump pyometria where
  the dogs developed an infection following
  spaying.

203
1.      Is this thinking valid, or would
ovariectomy be a better procedure?

• . It is very possible that because the incidence
  is so low that this is not really a valid reason
  for performing this procedure and that an
  ovariectomy would be a better procedure.

204
Describe methods of exposing the right and left
ovarian pedicles if hemorrhage occurs

• The right ovarian pedicle is examined for
  bleeding by using the mesoduodenum to retract the
  intestines. The left ovarian pedicle is examined
  by using the mesocolon to retract the intestines.
  Extension of he incision may be necessary to see
  the ovarian pedicles.

205
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206
CYSTOTOMY
207
Describe the location of the urinary bladder in
relation to other abdominal organs.

• The full bladder is located along the ventral
  abdominal wall. It is directly ventral to the
  uterus in the female and directly ventral to the
  rectum in the male

208
Describe the anatomy of the organ ligamental
attachments, location of ureters and trigone,
apex, neck of bladder, urethral sphincter.

• The lateral ligaments contain the ureters and
  must be preserved
• The ventral ligament of the bladder attaches the
  bladder to the ventral body wall and may be
  excised
• The ureters enter the bladder at the trigone
  which is on the dorsal aspect of the bladder
• The apex of the bladder is the most cranial
  portion whereas the neck of the bladder is at the
  caudal aspect
• The urethral sphincter is the most caudal portion
  of the trigone of the bladder and is within the
  neck of the bladder

209
Is the sphincter grossly visible at surgery?

• No

210
Why is a cystotomy incision commonly made on the
ventral aspect rather than the dorsal?

• To avoid the trigone and the nervous attachments

211
What is one procedure in which the incision must
be on the ventrum?

• Cystostomy

212
What is one possible complication of a ventral
incision?

• Risk of inverting the ventral ligament of the
  bladder into the incision
• Urine leakage is more likely

213
Is the incision in the wall of the bladder more
or less likely to leak when the incision is made
on the ventrum?

• More likely due to gravity

214
How can edema of the bladder wall during
cystotomy be minimized?

• Avoid handling of the bladder

215
What part of the bladder is especially prone to
becoming edematous with surgical manipulation?
216
How can the surgeon handle this specific problem?
217
The urinary bladder is well vascularized and
usually heals very rapidly. In what 2 situations
might you expect healing to be delayed?

• Chronic cystitis
• Presence of a large amount of edema

218
What suture pattern(s) would you use if you
expect healing to be delayed?

• An inverting pattern

219
If you are suturing a healthy bladder with a
simple continuous suture pattern, what type of
suture must you use?

• 3-0 or 4-0 absorbable suture

220
The bladder usually bleeds profusely when
incised. How is hemorrhage from the cystotomy
incision controlled?

• Apply pressure

221
Blood clots should be removed from the lumen of
the bladder before the bladder is closed. The
mucosa will continue to bleed during closure, but
large clots are seldom passed out the patients
urethra after surgery. What is happening to
control bleeding and to prevent formation of
large clots in the lumen of the bladder?
222
CRYOSURGERY, ELECTROSURGERY AND LASER SURGERY
223
What are 3 advantages of cryosurgical treatment
of a tumor, compared to treatment by sharp
excision or by chemotherapy?

• Rapid relief of pain
• Hemostasis
• No cumulative effect

224
What is the major disadvantage, again compared to
other treatment modalities?

• Can only be used for superficial tumors

225
List the events of direct and indirect cellular
injury expected with freezing.

• Direct
• Formation of ice crystals
• Intracellular ice crystals (most damaging d/t
  rupture of cell membranes)
• Extracellular ice crystals
• Indirect
• Vascular stasis (increased vessel permeability,
  loss of plasma, causes thrombosis and infarction)

226
 Why does slow thawing cause more reliable cell
death?

• Permits recrystallization, expansion of small
  crystals to larger more damaging size

227
Does the rate of thaw affect direct or indirect
cell injury?

• Direct

228
Why is a second freeze-thaw cycle used why is
one cycle not always sufficient?

• Tissues near periphery of ice ball or near major
  blood vessels may not be destroyed
• Pre-cooled tissue freezes faster

229
List 3 anatomical/physiological characteristics
of tissue that reduce susceptibility to
cryonecrosis.

• Low water content (ie cornea)
• Low cellularity (nerves and bones)
• Highly vascular tissues and large blood vessels

230
Which of these situations is helpful to you as a
surgeon?

• Low cellularity- you wont damage nerves or bone

231
What are 2 reasons that liquid nitrogen is used
routinely as a cryogen, rather than nitrous
oxide?

• More versatile
• Non toxic

232
What are 2 advantages of spray application of
liquid nitrogen, compared to probe application?

• More heat removed from tissue
• More effective

233
What are 2 advantages of probe application?

• Easier to control
• Less lethal to tissues

234
Why is only about 75 of the tissue within the
visible ice ball destroyed?

• Not all of the cells in the periphery of the ice
  ball will die due to higher temperatures

235
When using a pyrometer, where are the temperature
probes placed?

• In the normal tissue adjacent to the deepest
  portion of the target tissue

236
What recorded temperature indicates that the
target tissue is destroyed?

• -20 C

237
Is sterile preparation of the target tissue
required for cryosurgery?

• The area is clipped and cleaned if possible but
  not necessary

238
Describe the preparation used for a lesion on
the eyelid of a dog
239
Describe the preparation used for a lesion in a
cats mouth.
240
How can surrounding tissues be protected when
using spray application?

• Use Styrofoam or petroleum jelly

241
Describe the steps of tissue death, necrosis and
healing immediately after freezing, at 1-3 days,
and at 1-2 weeks.

• Immediately- edema and erythema followed by
  vascular stasis, thrombosis and ischemia
• 1-3 days dark, sharply demarcated zone
  separating necrotic tissue from surrounding
  tissue
• 1-2 weeks tissue sloughs, leaving granulation
  tissue bed

242
What type of healing occurs?

• Second intention

243
In what parts of the animals body might this
process cause secondary problems?

• Any area that is subject to frequent movement (ie
  knee)

244
List 2 specific indications for cryosurgery

• Cutaneous lesions
• Lesions on or near the eye
• Oral lesions, perineal lesions

245
List 2 specific contraindications for
cryosurgery, explain the possible problems that
may result from use of cryosurgery.

• Mast cell tumors- cell lysis releases histamine
  and heparin
• Tumors with major bony involvement- may result in
  spontaneous fractures
• Lesions near major blood vessels and nerves- can
  be destroyed by necrosis and sloughing of
  surrounding tissues

246
What are the advantages of electroscalpel
technique?

• Decreases total blood loss
• Decrease need for ligatures therefore decrease
  foreign material left in wound
• Decrease operating time

247
What are the disadvantages of electroscalpel
technique?

• Decrease wound healing
• Decrease resistance of wound to infection

248
 In which tissue layer is delayed healing most
pronounced?
249
What are 2 contraindications for electrosurgery?

• Presence of alcohol, methane, bowel gases, ether,
  or cyclopropane
• Tissue with poor blood supply

250
Hemostasis by electrocautery is not effective if
the vessels are too large. What are the limits
in diameter of vessels for this technique?

• Arterieslt 1mm in diameter
• Veins lt 2 mm in diameter

251
Explain the pathway of the current used with
monopolar cautery and with bipolar cautery.

• Monopolar
• From active electrode through patients body to a
  ground plate
• Bipolar
• Current passes from one tip through tissues to
  opposite tip

252
What are advantages associated specifically with
monopolar cautery?

• Same handpiece used for coagulation, cutting and
  fulgration
• Modulated pulsed sine wave permits simultaneous
  cutting and coagulation

253
What are 2 important advantages of bipolar
cautery?

• Less current required because current passes
  through much smaller volume of tissue
• Less risk of injury to surrounding tissues
• No risk of alternate pathway burns
• Effective coagulation in wet field

254
Define electrofulguration.

• Passage of a damped current from an active
  electrode to tissue using a spark gap of gt1mm
• Dehydrates superficial tissue, resulting in cell
  death and coagulation of small vessels

255
Give an example of appropriate use of
electrofulguration in small animals

• Good for rectal polyps
• Very superficial tissues

256
What is photothermal laser-tissue interaction?

• Laser light absorbed and converted to heat within
  tissue

257
What is the primary use of this type of
interaction?

• Precise cutting by vaporizing tissue

258
What is a possible complication?

•  Risk of carbonization of tissues

259
Define photodisruptive and photochemical
laser-tissue interaction.

• Photodisruptive- mechanical disruption of tissue
  or calculi
• Photochemical laser-tissue interaction- directly
  breaks chemical bonds or excites molecules to
  reactive biochemical sates

260
What are potential uses of these modalities?

• Photodisruptive- lithotripsy, ophthalmic
  procedures
• Photochemical- killing neoplastic cells

261
List 2 advantages associated with use of
operative lasers.

• Excellent hemostasis
• Reduced postop swelling and pain

262
List 1 disadvantage associated with use of
operative lasers.

• Slow healing compared to scalpel created
  incisions

263
List 3 dangers associated with use of operative
lasers.

• Corneal and retinal injuries (protect patients
  eyes)
• Smoke
• Fire (laser safe ET tube must be used)

264
Several applications of laser surgery in small
animal practice are mentioned in your notes.
With the information you have been given about
many surgical procedures, can you think of other
possible applications?

• Declaw

265
CASTRATION
266
Describe the clipping and prepping of the skin
before prescrotal castration in the dog. How
would this differ in castration by scrotal
ablation?

• The prescrotal area is clipped and prepped
  routinely but be careful with clipper blade, may
  cause edema. The scrotum is prepped by cutting
  hairs with scissors, it is draped out of the
  field
• The scrotum is shaved and draped within the field
  for scrotal ablation

267
What are the landmarks for the skin incision in a
prescrotal castration in the dog?

• From caudal end of penis to the cranial base of
  the scrotum

268
What precautions must be taken in making this
incision?

• Avoid damaging the penis and urethra

269
What are two ways of making this incision (skin
incision)

• Incise through the tunic (open)
• Dont incise through the tunic (closed)

270
List the tissue layers incised for closed
castration and for open castration?

• Closed
• Skin of scrotum, spermatic fascia
• Open
• Skin of scrotum, spermatic fascia, parietal tunic

271
What are the 2 important advantages of open
castration?

• Less risk of ligature slipping
• Less risk of abdominal hemorrhage

272
What are the 2 important advantages of closed
castration?

• Less risk of scrotal hematoma
• Less postop swelling
• Slightly quicker

273
Describe closure of a prescrotal castration.

• Deep fascia/SQ tissue
• SQ tissue
• Skin or intradermal pattern

274
In what important way does feline castration
differ from canine castration?

• Complications are more rare in cats

275
Is feline castration an aseptic procedure?

• No

276
Is canine castration an aseptic procedure?

• Yes

277
In which species is infection following
castration more common?

• Dog

278
Why do you think would this be true?

• Complications in general are more common in the
  dog
• The incision is closed in dogs which doesnt
  allow for draining

279
SURGERY OF THE EAR
280
What are 2 surgical procedures used for
correction of auricula hematoma?

• Fresh hematoma
• aspirate of hematoma, injection of
  glucocorticoid into space, pressure bandage
• Fresh or chronic hematoma
• incise, evavuate hematoma, suture

281
What are the indications and complications for
each procedure?

• Pressure necrosis
• recurrance

282
Where are the major arteries and veins of the
pinna?

• Arterial branches of great auricular artery
  from external carotid artery
• Medial caudal auricular artery
• Intermediate caudal auricular artery
• Lateral caudal auricalar artery
• venous branches of internal maxillary vein
• Cranial auricular vein
• Caudal auricular vein

Slide 283