The University of New Mexico

1
The University of New Mexico The Office of
Animal Care and Compliance

• present
• Training in Survival Rodent Surgery
• A learning module developed by the NIH

2
Introduction

• This module was developed to assist you in
  becoming more proficient in performing aseptic
  rodent surgery

3
General Training in Survival Rodent Surgery

• We all have an ethical responsibility to animals
  in terms of minimizing pain and distress
• This can be accomplished, in part, by using
  proper surgical technique
• The PHS requires that animal care and use is
  based on the Guide for the Care and Use of
  Laboratory Animals

4
The following Principles described in the Guide
apply to rodent surgery

• Appropriate pre-operative and post-operative care
  of animals in accordance with established
  veterinary medical and nursing practices is
  required
• All survival surgery will be performed by using
  aseptic procedures, including sterile gloves,
  masks, sterile instruments, and aseptic
  techniques
• A dedicated surgical facility is not required for
  rodents but surgery must be performed using
  aseptic techniques
• Research personnel will be appropriately
  qualified and trained in all procedures

5
The Guide states that it is important for
personnel to have appropriate training to ensure
that good surgical technique is practicedGood
technique includes

• Asepsis
• Gentle tissue handling
• Minimal dissection of tissue
• Appropriate use of instruments
• Effective hemostasis
• Correct use of suture materials and patterns

6
The NIH has established specific recommendations
for how survival rodent surgery should be
conductedThis includes

• Preparation of the patient
• Preparation of the surgeon
• Sterilization of instruments, supplies, and
  implanted materials
• Use of operative techniques to reduce the
  likelihood of infection

7
Pre-Surgical Planning begins during the protocol
development phase in consultation with the
veterinarianThis includes

• Identification of personnel, their roles and
  training needs
• Equipment and supplies required for the
  procedures planned
• The location and nature of the facilities in
  which the procedures will be conducted
• Pre- and Post-operative care

8
Location, Location, Location

• You must select the best possible location
• Uncluttered and easily organized and disinfected
• Dedicated during the duration of the procedure
• Free of debris and equipment not related to
  surgery

9
Avoid

• Locations that are beneath supply ducts to
  minimize contamination from dust
• High traffic areas such as those near doorways to
  prevent unnecessary interruptions and creation of
  air turbulence

10
Anesthesia

• Select anesthetics depending upon the type of
  surgical procedure
• Anesthetic must be approved in your protocol
• Most inhalants are administered using a vaporizer
• Gas anesthetics require the use of a scavenging
  system to remove waste gases
• Injectable anesthetics are widely used in rodent
  surgeries
• If using injectables, weigh each animal and dose
  according to body weight

11
Anesthesia

• Some anesthetics abolish blink reflex
• Anesthetized animals should have corneas
  protected with an ophthalmic ointment

12
Monitoring

• Anesthetized animals must be monitored during the
  procedure to assure they stay in the proper
  anesthetic plane
• The anesthetic plane can be assessed by pinching
  the toes, tail or ears of the animal, or testing
  the blink reflex
• Any reaction of the animal indicates the animal
  is too light and should be given more anesthetic

13
Monitoring

• It is important to inspect the animal and not
  rely solely on monitoring equipment
• The color of the mucous membranes and exposed
  tissues is easy to monitor
• Bright pink and red as apposed to dusky grey or
  blue indicates tissue perfusion and oxygenation

14
Monitoring

• Respiratory pattern and frequency will also give
  an indication of anesthetic depth
• Core body temperature can also be monitored in
  rats and mice
• Pulse oximetry an be used in larger rodents to
  monitor pulse and oxygenation
• Electrocardiograms can also be used in larger
  rodents

15
Complications

• The most frequent complication of small animal
  anesthesia is hypothermia
• Animals should be provided with a heat source
  during the pre-, intra- and post-operative
  periods
• Improper heating devices can also be very
  dangerous
• Use a thermometer to measure the temperature
  adjacent to the animal

16
Electric Heating Pads

• These are NOT recommended for use with rodents as
  they have varying temperatures across the surface

Whew! Is it me, or is it hot?
17
Slide Warmers

• Slide warmers can be used as a heat source during
  recovery
• Animals must be watched closely and placed in
  recovery cage as soon as they begin to stir
• The safest device is a circulating hot water
  blanket
• All heating devices should be covered with a
  towel so the animal doesnt come in contact with
  the heated surface

18
Instruments

• A simple peel pack can contain small numbers of
  small to medium sized instruments

19
Instruments

• A complex pack consists of overlapping cloth or
  paper drapes folded together and sealed with
  autoclave tape

20
Multiple Rodent Surgeries

• When performing multiple rodent surgeries have
  staging areas for the different steps in the
  procedure
• Animals waiting for surgery should be kept at a
  visual and olfactory distance from those
  undergoing surgery

Yuck! Whats that smell?
21
Space Constraints

• If space necessitates a single location for prep
  and surgery, the bench towel used during prep
  should be replaced for the surgery
• Any open surgery pack must be covered to prevent
  contamination with hair

Hey! I dont shed.
22
Prepare The Area

• Sanitize the area you have selected for
  performing the surgery with an appropriate
  disinfectant
• Disinfectants include Clidox, Alcide, or
  Nolvasan
• A dedicated surgical site is not required for
  rodent surgery

23
Step 1

• Once everything is pre-selected and organized, it
  is time to begin
• Start by anesthetizing the animal and doing the
  surgical prep
• Hair must be removed from the surgical site
• Electric clippers are commonly used

24
Hair Removal

• An easy alternative to clipping is hair plucking
• Hair follicles in mice are usually in telogen or
  resting phase and hair can be removed without
  injury

25
Surgical Prep

• Standard surgical prep consists of alternating
  scrubs of an iodophor and 70 alcohol

26
Scrub Procedure

• Using a gauze sponge or cotton tipped applicator,
  cleansing should be done in a circular motion
• Begin at the center of the shaved area and work
  toward the periphery
• Never go back to the center with the same sponge
• Scrubs should be alternated between an iodophor
  scrub and alcohol, ending with the iodophor

27
Surgical Pack

• Once the animal is prepped you must open the
  surgical pack
• This is to be done BEFORE donning surgical gloves
• Make sure the sterilization indicator has turned
  the appropriate color (usually autoclave tape
  brown stripes)

28
Peel Packs

• Peel packs are opened in a manner that preserves
  the sterility of the inside surface
• Do not touch the inside surface as it can be used
  as a sterile surgical field on which to keep the
  instruments

29
Complex Packs

• Complex packs are opened in such a way as to keep
  the inside surface of the wrapping sterile so
  that it can be used as a sterile field

30
Liquid Sterilants

• If using cold sterilant solutions make sure
  instruments are exposed for the proper length of
  time and expiration dates of solutions is
  observed
• Instruments must be removed from solution and
  rinsed with sterile water, saline, or alcohol
• Rinsed instruments must be placed on a sterile
  field

31
Hot Bead Sterilizers

• This method sterilizes only the tips of the
  instruments
• Beads must be pre-heated to the recommended
  temperature and the instruments exposed for the
  recommended time
• Gross debris must be removed from the instrument
  prior to sterilization
• Instrument must be allowed to cool before
  touching tissues
• Best used for sterilizing instruments between
  surgeries

32
Delicate Instruments

• Delicate instruments, materials for implantation
  or items that otherwise may melt or become
  damaged when heated can be sterilized using
  ethylene oxide
• The packs must be sufficiently aerated to prevent
  toxic side effects from residual gas
• This may require 24 to 72 hours

33
Notes

• Flash dry heat sterilizers are another
  alternative for sterilizing instruments
  remember to let them cool before touching tissues
• Remember alcohol provides disinfection not
  sterilization

34
Instrument Packs

• Once packs are opened all other sterile equipment
  must be placed on the sterile field
• These items must be opened in a way as to prevent
  contamination of the item or the surgical pack

35
Surgical Attire

• Cap
• Mask
• Clean lab coat
• Wash hands with antibacterial soap and don
  sterile gloves

36
Donning Surgical Gloves

• Open the package of gloves observing sterile
  technique
• Remember, the inside of the package is STERILE
  exam gloves are not the same as sterile gloves

37
Donning Surgical Gloves
38
Donning Surgical Gloves - Procedure

• It is important to don the gloves in such a way
  that prevents contamination of the outer surface
  of the gloves
• One glove is lifted from the opened glove package
  by its turned down cuff
• The glove is pulled on the hand with a rotating
  motion
• Place the gloved fingers beneath the cuff of the
  other glove
• With the gloved fingers under the cuff, the glove
  is placed on the ungloved hand
• The folded cuff protects the gloved hand from
  contamination
• It is pulled over the cuff of the lab coat
  following insertion of the hand
• The fingers are then slipped under the cuff of
  the first glove to pull it over the lab coat cuff

39
The Surgical Site - Draping

• The most common drape is the paper drape
• It may be precut or one in which you must cut a
  hole
• A disadvantage to paper drapes is that they
  usually cover the animal making monitoring
  difficult
• Plastic drapes offer the advantage of more
  visibility
• Sterile gauze sponges can also be used for drapes

40
Organize

• Organize the instruments in your surgical pack
• Point all tips in one direction
• It is helpful to place them in the order used
• Between surgeries cover the tips of the
  instruments with sterile gauze
• Note that the space between the pack and the
  draped animal is not sterile, do not lay
  instruments in this space

41
During Surgery - Drapes

• Be careful not to get paper or cloth drapes wet
• Wet material acts as a wick to pull bacteria
  through from the non-sterile surface below
• When this happens instruments should be
  considered contaminated

42
Suture

• Selection and type should be based upon the type
  of surgery and species of animal
• This should be done before hand after
  consultation with the veterinarian

I dont want to talk to the vet.
Suture self
43
Sutures and More Sutures

• For small animals a 3-0 suture thickness or
  smaller is best
• Cutting and reverse cutting needles have sharp
  edges are best for skin suturing
• Non-cutting, taper or round needles are used for
  suturing easily torn tissues such as peritoneum,
  muscle or intestine

44
and More Sutures

• Ligation of vessels or suturing tissues other
  than skin requires an absorbable material such as
  Vicryl, Dexon, PDS, Maxon, or chromic gut
• Skin closures require a non-absorbable suture
  such as Prolene or nylon
• Stainless steel wound clips or staples can also
  be used
• Most rodents gnaw at externalized sutures so a
  buried suture line or wound clips are recommended

45
and Finally

• Cyanoacrylate surgical adhesives such as Vetbond
  or Nexaband may be used to close incisions or the
  area between sutures
• Silk is a non-absorbable suture material that can
  cause tissue reactions and may wick
  microorganisms into the wound
• Silk is best used for cardiovascular procedures
  only

46
Antibiotics

• The Guide states that the application of
  prophylactic antibiotics is not a substitute for
  the practice of proper aseptic surgery
• If they must be used, you must choose an
  appropriate antibiotic that is given for the
  correct length of time and dose
• In guinea pigs and hamsters an inappropriate
  antibiotic can cause fatalities

47
Recovery

• Keep the recovering patient warm
• Do not lay recovering animals directly on the
  bedding they may aspirate and asphyxiate

48
Analgesia

• Part of the surgical planning should include
  intra-operative and post-operative analgesia

Oh Yeah! I likes dem drugs!
49
Fluids

• Recovery from anesthesia can be aided by the
  administration of warmed fluids
• Fluids should be given subcutaneously or
  intra-peritoneally
• Consult the veterinarian for appropriate volumes
  and routes of administration

Funny, I gotta pee.
50
Neonates

• Neonates or animals recovering from prolonged
  surgeries can suffer from hypoglycemia
• These animals can benefit from administration of
  oral glucose
• Glucose should never be given SQ or IP

51
Return to the Cage

• Animals can be returned to their holding area
  once they are awake and appear to be making a
  normal recovery
• Be sure to mark the cage card with the surgical
  procedure and the date
• Post-operative care does not end with the return
  of the animal to its home environment

52
After the Surgery

• Animals must be monitored for several days after
  the surgical procedure
• Daily weighing is a sensitive method of
  monitoring the animal
• While subtle changes in activity or appetite may
  not be observed, changes in weight will be
  quickly detected
• Some analgesics depress appetite and must be
  differentiated from that which occurs if an
  animal is not feeling well

53
Continued Monitoring

• Animals must be monitored for the continued need
  for analgesics
• This assessment should be made at least twice
  daily in the first few days post-op
• Supplying a softer, more palatable, easily
  accessible diet may encourage the animal to eat
• Hydration can be checked by tenting the
  animals skin
• In a well hydrated animal the skin will quickly
  fall back in place when released
• In a dehydrated animal the skin will be slow to
  return to its original place

54
Wound Closures

• Wound closures must be removed at 10 to 14 days
  post-op
• Suture scissors or staple removers must be used

55
This Concludes Module 2 Training in Survival
Rodent Surgery

• Please download the exam, complete it, then
  e-mail it to KMirowsky_at_salud.unm.edu