The University of New The University of New MexicoMexico

& & The Office of Animal The Office of Animal Care and ComplianceCare and Compliance

presentpresent

Training in Survival Rodent Training in Survival Rodent SurgerySurgery

A learning module developed by the NIHA learning module developed by the NIH

IntroductionIntroduction

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

General Training in Survival Rodent General Training in Survival Rodent SurgerySurgery

• We all have an ethical responsibility We all have an ethical responsibility to animals in terms of minimizing to animals in terms of minimizing pain and distresspain and distress

• This can be accomplished, in part, by This can be accomplished, in part, by using proper surgical techniqueusing proper surgical technique

• The PHS requires that animal care The PHS requires that animal care and use is based on the “Guide for and use is based on the “Guide for the Care and Use of Laboratory the Care and Use of Laboratory Animals”Animals”

The following Principles described in The following Principles described in the “Guide” apply to rodent surgerythe “Guide” apply to rodent surgeryThe following Principles described in The following Principles described in the “Guide” apply to rodent surgerythe “Guide” apply to rodent surgery

• Appropriate pre-operative and post-operative care Appropriate pre-operative and post-operative care of animals in accordance with established of animals in accordance with established veterinary medical and nursing practices is veterinary medical and nursing practices is requiredrequired

• All survival surgery will be performed by using All survival surgery will be performed by using aseptic procedures, including sterile gloves, aseptic procedures, including sterile gloves, masks, sterile instruments, and aseptic techniquesmasks, sterile instruments, and aseptic techniques

• A dedicated surgical facility is not required for A dedicated surgical facility is not required for rodents but surgery must be performed using rodents but surgery must be performed using aseptic techniquesaseptic techniques

• Research personnel will be appropriately qualified Research personnel will be appropriately qualified and trained in all proceduresand trained in all procedures

The “Guide” states that it is important for The “Guide” states that it is important for personnel to have appropriate training to personnel to have appropriate training to

ensure that good surgical technique is ensure that good surgical technique is practicedpracticed

Good technique includes:Good technique includes:• AsepsisAsepsis

• Gentle tissue handlingGentle tissue handling

• Minimal dissection of tissueMinimal dissection of tissue

• Appropriate use of instrumentsAppropriate use of instruments

• Effective hemostasisEffective hemostasis

• Correct use of suture materials and Correct use of suture materials and patternspatterns

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

conductedconducted

This includes:This includes:• Preparation of the Preparation of the

patientpatient

• Preparation of the Preparation of the surgeonsurgeon

• Sterilization of Sterilization of instruments, supplies, instruments, supplies, and implanted materialsand implanted materials

• Use of operative Use of operative techniques to reduce techniques to reduce the likelihood of the likelihood of infectioninfection

Pre-Surgical Planning begins during the Pre-Surgical Planning begins during the protocol development phase in consultation protocol development phase in consultation

with the veterinarianwith the veterinarian

This includes:This includes:

• Identification of personnel, their roles Identification of personnel, their roles and training needsand training needs

• Equipment and supplies required for Equipment and supplies required for the procedures plannedthe procedures planned

• The location and nature of the The location and nature of the facilities in which the procedures will facilities in which the procedures will be conductedbe conducted

• Pre- and Post-operative carePre- and Post-operative care

Location, Location, LocationLocation, Location, Location

• You must select the You must select the best possible locationbest possible location

• Uncluttered and easily Uncluttered and easily organized and organized and disinfecteddisinfected

• Dedicated during the Dedicated during the duration of the duration of the procedureprocedure

• Free of debris and Free of debris and equipment not related equipment not related to surgeryto surgery

AvoidAvoid

• Locations that are Locations that are beneath supply ducts to beneath supply ducts to minimize contamination minimize contamination from dustfrom dust

• High traffic areas such High traffic areas such as those near doorways as those near doorways to prevent unnecessary to prevent unnecessary interruptions and interruptions and creation of air creation of air turbulenceturbulence

AnesthesiaAnesthesia

• Select anesthetics depending upon the type of Select anesthetics depending upon the type of surgical proceduresurgical procedure

• Anesthetic must be approved in your protocolAnesthetic must be approved in your protocol• Most inhalants are administered using a vaporizerMost inhalants are administered using a vaporizer• Gas anesthetics require the use of a scavenging Gas anesthetics require the use of a scavenging

system to remove waste gasessystem to remove waste gases• Injectable anesthetics are widely used in rodent Injectable anesthetics are widely used in rodent

surgeriessurgeries• If using injectables, weigh each animal and dose If using injectables, weigh each animal and dose

according to body weightaccording to body weight

AnesthesiaAnesthesia

• Some anesthetics Some anesthetics abolish blink reflexabolish blink reflex

• Anesthetized Anesthetized animals should animals should have corneas have corneas protected with an protected with an ophthalmic ophthalmic ointmentointment

MonitoringMonitoring

• Anesthetized animals must be monitored Anesthetized animals must be monitored during the procedure to assure they stay during the procedure to assure they stay in the proper anesthetic planein the proper anesthetic plane

• The anesthetic plane can be assessed by The anesthetic plane can be assessed by pinching the toes, tail or ears of the pinching the toes, tail or ears of the animal, or testing the blink reflexanimal, or testing the blink reflex

• Any reaction of the animal indicates the Any reaction of the animal indicates the animal is too light and should be given animal is too light and should be given more anestheticmore anesthetic

MonitoringMonitoring

• It is important to inspect It is important to inspect the animal and not rely the animal and not rely solely on monitoring solely on monitoring equipmentequipment

• The color of the mucous The color of the mucous membranes and exposed membranes and exposed tissues is easy to monitortissues is easy to monitor

• Bright pink and red as Bright pink and red as apposed to dusky grey or apposed to dusky grey or blue indicates tissue blue indicates tissue perfusion and perfusion and oxygenationoxygenation

MonitoringMonitoring

• Respiratory pattern and frequency will Respiratory pattern and frequency will also give an indication of anesthetic depthalso give an indication of anesthetic depth

• Core body temperature can also be Core body temperature can also be monitored in rats and micemonitored in rats and mice

• Pulse oximetry an be used in larger Pulse oximetry an be used in larger rodents to monitor pulse and oxygenationrodents to monitor pulse and oxygenation

• Electrocardiograms can also be used in Electrocardiograms can also be used in larger rodentslarger rodents

ComplicationsComplications

• The most frequent complication of small The most frequent complication of small animal anesthesia is hypothermiaanimal anesthesia is hypothermia

• Animals should be provided with a heat Animals should be provided with a heat source during the pre-, intra- and post-source during the pre-, intra- and post-operative periodsoperative periods

• Improper heating devices can also be very Improper heating devices can also be very dangerousdangerous

• Use a thermometer to measure the Use a thermometer to measure the temperature adjacent to the animaltemperature adjacent to the animal

Electric Heating PadsElectric Heating Pads

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

Whew! Is it me, or is it hot?

Slide WarmersSlide Warmers

• Slide warmers can be used as a heat Slide warmers can be used as a heat source during recoverysource during recovery

• Animals must be watched closely and Animals must be watched closely and placed in recovery cage as soon as they placed in recovery cage as soon as they begin to stirbegin to stir

• The safest device is a circulating hot water The safest device is a circulating hot water blanketblanket

• All heating devices should be covered with All heating devices should be covered with a towel so the animal doesn’t come in a towel so the animal doesn’t come in contact with the heated surfacecontact with the heated surface

InstrumentsInstruments

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

InstrumentsInstruments

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

Multiple Rodent SurgeriesMultiple Rodent Surgeries

• When performing multiple rodent When performing multiple rodent surgeries have staging areas for the surgeries have staging areas for the different steps in the proceduredifferent steps in the procedure

• Animals waiting for surgery should be Animals waiting for surgery should be kept at a visual and olfactory distance kept at a visual and olfactory distance from those undergoing surgeryfrom those undergoing surgery

Yuck! What’s

that smell?

Space ConstraintsSpace Constraints

• If space necessitates a single location If space necessitates a single location for prep and surgery, the bench towel for prep and surgery, the bench towel used during prep should be replaced for used during prep should be replaced for the surgerythe surgery

• Any open surgery pack must be covered Any open surgery pack must be covered to prevent contamination with hairto prevent contamination with hair

Hey! I don’t shed.

Prepare The AreaPrepare The Area

• Sanitize the area you have selected Sanitize the area you have selected for performing the surgery with an for performing the surgery with an appropriate disinfectantappropriate disinfectant

• Disinfectants include: Clidox, Alcide, Disinfectants include: Clidox, Alcide, or Nolvasanor Nolvasan

• A dedicated surgical site is not A dedicated surgical site is not required for rodent surgeryrequired for rodent surgery

Step 1Step 1

• Once everything is pre-selected and Once everything is pre-selected and organized, it is time to beginorganized, it is time to begin

• Start by anesthetizing the animal and Start by anesthetizing the animal and doing the surgical prepdoing the surgical prep

• Hair must be removed from the Hair must be removed from the surgical sitesurgical site

• Electric clippers are commonly usedElectric clippers are commonly used

Hair RemovalHair Removal

• An easy alternative to clipping is hair An easy alternative to clipping is hair pluckingplucking

• Hair follicles in mice are usually in Hair follicles in mice are usually in telogen or resting phase and hair can telogen or resting phase and hair can be removed without injurybe removed without injury

Surgical PrepSurgical Prep

• Standard surgical prep consists of Standard surgical prep consists of alternating scrubs of an iodophor and alternating scrubs of an iodophor and 70% alcohol70% alcohol

Scrub ProcedureScrub Procedure• Using a gauze sponge or cotton tipped applicator, Using a gauze sponge or cotton tipped applicator,

cleansing should be done in a circular motioncleansing should be done in a circular motion• Begin at the center of the shaved area and work Begin at the center of the shaved area and work

toward the peripherytoward the periphery• Never go back to the center with the same spongeNever go back to the center with the same sponge• Scrubs should be alternated between an iodophor Scrubs should be alternated between an iodophor

scrub and alcohol, ending with the iodophorscrub and alcohol, ending with the iodophor

Surgical PackSurgical Pack

• Once the animal is prepped you must Once the animal is prepped you must open the surgical packopen the surgical pack

• This is to be done BEFORE donning This is to be done BEFORE donning surgical glovessurgical gloves

• Make sure the sterilization indicator Make sure the sterilization indicator has turned the appropriate color has turned the appropriate color (usually autoclave tape – brown (usually autoclave tape – brown stripes)stripes)

Peel PacksPeel Packs

• Peel packs are opened in a manner that Peel packs are opened in a manner that preserves the sterility of the inside surfacepreserves the sterility of the inside surface

• Do not touch the inside surface as it can Do not touch the inside surface as it can be used as a sterile surgical field on which be used as a sterile surgical field on which to keep the instrumentsto keep the instruments

Complex PacksComplex Packs• Complex packs are opened in such a way Complex packs are opened in such a way

as to keep the inside surface of the as to keep the inside surface of the wrapping sterile so that it can be used as wrapping sterile so that it can be used as a sterile fielda sterile field

Liquid SterilantsLiquid Sterilants

• If using cold sterilant solutions make If using cold sterilant solutions make sure instruments are exposed for the sure instruments are exposed for the proper length of time and expiration proper length of time and expiration dates of solutions is observeddates of solutions is observed

• Instruments must be removed from Instruments must be removed from solution and rinsed with sterile water, solution and rinsed with sterile water, saline, or alcoholsaline, or alcohol

• Rinsed instruments must be placed Rinsed instruments must be placed on a sterile fieldon a sterile field

Hot Bead SterilizersHot Bead Sterilizers

• This method sterilizes only the tips of This method sterilizes only the tips of the instrumentsthe instruments

• Beads must be pre-heated to the Beads must be pre-heated to the recommended temperature and the recommended temperature and the instruments exposed for the instruments exposed for the recommended timerecommended time

• Gross debris must be removed from the Gross debris must be removed from the instrument prior to sterilizationinstrument prior to sterilization

• Instrument must be allowed to cool Instrument must be allowed to cool before touching tissuesbefore touching tissues

• Best used for sterilizing instruments Best used for sterilizing instruments between surgeriesbetween surgeries

Delicate InstrumentsDelicate Instruments

• Delicate instruments, materials for Delicate instruments, materials for implantation or items that otherwise implantation or items that otherwise may melt or become damaged when may melt or become damaged when heated can be sterilized using heated can be sterilized using ethylene oxideethylene oxide

• The packs must be sufficiently The packs must be sufficiently aerated to prevent toxic side effects aerated to prevent toxic side effects from residual gasfrom residual gas

• This may require 24 to 72 hoursThis may require 24 to 72 hours

Notes:Notes:

• ““Flash” dry heat sterilizers are Flash” dry heat sterilizers are another alternative for sterilizing another alternative for sterilizing instruments – remember to let them instruments – remember to let them cool before touching tissuescool before touching tissues

• Remember – alcohol provides Remember – alcohol provides disinfection not sterilizationdisinfection not sterilization

Instrument PacksInstrument Packs

• Once packs are opened all other sterile Once packs are opened all other sterile equipment must be placed on the sterile equipment must be placed on the sterile fieldfield

• These items must be opened in a way as to These items must be opened in a way as to prevent contamination of the item or the prevent contamination of the item or the surgical packsurgical pack

Surgical AttireSurgical Attire

• CapCap

• MaskMask

• Clean lab coatClean lab coat

• Wash hands with Wash hands with antibacterial antibacterial soap and don soap and don sterile glovessterile gloves

Donning Surgical GlovesDonning Surgical Gloves

• Open the package of gloves Open the package of gloves observing sterile techniqueobserving sterile technique

• Remember, the inside of the package Remember, the inside of the package is STERILE – exam gloves are not the is STERILE – exam gloves are not the same as sterile glovessame as sterile gloves

Donning Surgical GlovesDonning Surgical Gloves

Donning Surgical Gloves - Donning Surgical Gloves - ProcedureProcedure

• It is important to don the gloves in such a way that It is important to don the gloves in such a way that prevents contamination of the outer surface of the prevents contamination of the outer surface of the glovesgloves

• One glove is lifted from the opened glove package by One glove is lifted from the opened glove package by its turned down cuffits turned down cuff

• The glove is pulled on the hand with a rotating motionThe glove is pulled on the hand with a rotating motion• Place the gloved fingers beneath the cuff of the other Place the gloved fingers beneath the cuff of the other

gloveglove• With the gloved fingers under the cuff, the glove is With the gloved fingers under the cuff, the glove is

placed on the ungloved handplaced on the ungloved hand• The folded cuff protects the gloved hand from The folded cuff protects the gloved hand from

contaminationcontamination• It is pulled over the cuff of the lab coat following It is pulled over the cuff of the lab coat following

insertion of the handinsertion of the hand• The fingers are then slipped under the cuff of the first The fingers are then slipped under the cuff of the first

glove to pull it over the lab coat cuffglove to pull it over the lab coat cuff

The Surgical Site - DrapingThe Surgical Site - Draping

• The most common drape is the paper drapeThe most common drape is the paper drape

• It may be precut or one in which you must It may be precut or one in which you must cut a holecut a hole

• A disadvantage to paper drapes is that they A disadvantage to paper drapes is that they usually cover the animal making monitoring usually cover the animal making monitoring difficultdifficult

• Plastic drapes offer the advantage of more Plastic drapes offer the advantage of more visibilityvisibility

• Sterile gauze sponges can also be used for Sterile gauze sponges can also be used for drapesdrapes

OrganizeOrganize

• Organize the instruments in your surgical Organize the instruments in your surgical packpack

• Point all tips in one directionPoint all tips in one direction• It is helpful to place them in the order It is helpful to place them in the order

usedused• Between surgeries cover the tips of the Between surgeries cover the tips of the

instruments with sterile gauzeinstruments with sterile gauze• Note that the space between the pack Note that the space between the pack

and the draped animal is not sterile, do and the draped animal is not sterile, do not lay instruments in this spacenot lay instruments in this space

During Surgery - DrapesDuring Surgery - Drapes

• Be careful not to get paper or cloth Be careful not to get paper or cloth drapes wetdrapes wet

• Wet material acts as a wick to pull Wet material acts as a wick to pull bacteria through from the non-sterile bacteria through from the non-sterile surface belowsurface below

• When this happens instruments When this happens instruments should be considered contaminatedshould be considered contaminated

SutureSuture

• Selection and type should be based upon Selection and type should be based upon the type of surgery and species of animalthe type of surgery and species of animal

• This should be done before hand after This should be done before hand after consultation with the veterinarianconsultation with the veterinarian

I don’t want to talk to

the vet.

Suture self

Sutures and More SuturesSutures and More Sutures

• For small animals a 3-0 suture thickness For small animals a 3-0 suture thickness or smaller is bestor smaller is best

• Cutting and reverse cutting needles Cutting and reverse cutting needles have sharp edges are best for skin have sharp edges are best for skin suturingsuturing

• Non-cutting, taper or round needles are Non-cutting, taper or round needles are used for suturing easily torn tissues used for suturing easily torn tissues such as peritoneum, muscle or intestinesuch as peritoneum, muscle or intestine

… … and More Suturesand More Sutures

• Ligation of vessels or suturing tissues other than Ligation of vessels or suturing tissues other than skin requires an absorbable material such as skin requires an absorbable material such as Vicryl, Dexon, PDS, Maxon, or chromic gutVicryl, Dexon, PDS, Maxon, or chromic gut

• Skin closures require a non-absorbable suture Skin closures require a non-absorbable suture such as Prolene or nylonsuch as Prolene or nylon

• Stainless steel wound clips or staples can also be Stainless steel wound clips or staples can also be usedused

• Most rodents gnaw at externalized sutures so a Most rodents gnaw at externalized sutures so a buried suture line or wound clips are buried suture line or wound clips are recommendedrecommended

… … and Finallyand Finally

• Cyanoacrylate surgical adhesives Cyanoacrylate surgical adhesives such as Vetbond or Nexaband may such as Vetbond or Nexaband may be used to close incisions or the area be used to close incisions or the area between suturesbetween sutures

• Silk is a non-absorbable suture Silk is a non-absorbable suture material that can cause tissue material that can cause tissue reactions and may wick reactions and may wick microorganisms into the woundmicroorganisms into the wound

• Silk is best used for cardiovascular Silk is best used for cardiovascular procedures onlyprocedures only

AntibioticsAntibiotics

• The “Guide” states that the application The “Guide” states that the application of prophylactic antibiotics is not a of prophylactic antibiotics is not a substitute for the practice of proper substitute for the practice of proper aseptic surgeryaseptic surgery

• If they must be used, you must choose If they must be used, you must choose an appropriate antibiotic that is given for an appropriate antibiotic that is given for the correct length of time and dosethe correct length of time and dose

• In guinea pigs and hamsters an In guinea pigs and hamsters an inappropriate antibiotic can cause inappropriate antibiotic can cause fatalitiesfatalities

RecoveryRecovery

• Keep the recovering patient warmKeep the recovering patient warm

• Do not lay recovering animals directly Do not lay recovering animals directly on the bedding – they may aspirate on the bedding – they may aspirate and asphyxiateand asphyxiate

AnalgesiaAnalgesia

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

Oh Yeah! I likes dem

drugs!

FluidsFluids• Recovery from anesthesia can be aided Recovery from anesthesia can be aided

by the administration of warmed fluidsby the administration of warmed fluids

• Fluids should be given subcutaneously Fluids should be given subcutaneously or intra-peritoneallyor intra-peritoneally

• Consult the veterinarian for appropriate Consult the veterinarian for appropriate volumes and routes of administrationvolumes and routes of administration

Funny, I gotta pee.

NeonatesNeonates

• Neonates or animals recovering from Neonates or animals recovering from prolonged surgeries can suffer from prolonged surgeries can suffer from hypoglycemiahypoglycemia

• These animals can benefit from These animals can benefit from administration of oral glucoseadministration of oral glucose

• Glucose should never be given SQ or Glucose should never be given SQ or IPIP

Return to the CageReturn to the Cage

• Animals can be returned to their Animals can be returned to their holding area once they are awake and holding area once they are awake and appear to be making a normal appear to be making a normal recoveryrecovery

• Be sure to mark the cage card with Be sure to mark the cage card with the surgical procedure and the datethe surgical procedure and the date

• Post-operative care does not end with Post-operative care does not end with the return of the animal to its home the return of the animal to its home environmentenvironment

After the SurgeryAfter the Surgery

• Animals must be monitored for several Animals must be monitored for several days after the surgical proceduredays after the surgical procedure

• Daily weighing is a sensitive method of Daily weighing is a sensitive method of monitoring the animalmonitoring the animal

• While subtle changes in activity or While subtle changes in activity or appetite may not be observed, changes appetite may not be observed, changes in weight will be quickly detectedin weight will be quickly detected

• Some analgesics depress appetite and Some analgesics depress appetite and must be differentiated from that which must be differentiated from that which occurs if an animal is not feeling welloccurs if an animal is not feeling well

Continued MonitoringContinued Monitoring• Animals must be monitored for the continued Animals must be monitored for the continued

need for analgesicsneed for analgesics• This assessment should be made at least twice This assessment should be made at least twice

daily in the first few days post-opdaily in the first few days post-op• Supplying a softer, more palatable, easily Supplying a softer, more palatable, easily

accessible diet may encourage the animal to accessible diet may encourage the animal to eateat

• Hydration can be checked by “tenting” the Hydration can be checked by “tenting” the animal’s skinanimal’s skin

• In a well hydrated animal the skin will quickly In a well hydrated animal the skin will quickly fall back in place when releasedfall back in place when released

• In a dehydrated animal the skin will be slow to In a dehydrated animal the skin will be slow to return to its original placereturn to its original place

Wound ClosuresWound Closures

• Wound closures must be removed at Wound closures must be removed at 10 to 14 days post-op10 to 14 days post-op

• Suture scissors or staple removers Suture scissors or staple removers must be usedmust be used

This Concludes Module 2 – This Concludes Module 2 – Training in Survival Rodent Training in Survival Rodent

SurgerySurgery• Please download the exam, complete it, then e-Please download the exam, complete it, then e-

mail it to mail it to KMirowsky@salud.unm.eduKMirowsky@salud.unm.edu