Surgery and Post-Operative Care

Preparation for surgery

Ø Clean the stereotaxic table and surrounding area with a chlorine bleach solution

Ø Lay down clean paper towel where instruments will be laid

Ø Place required instruments onto paper towel

Materials

• Scalpel and blades
• 4 hemostats
• surgical record
• surgical stapler
• surgical staples
• stopwatch
• gap-toothed forceps
• electric hair clippers
• Hamilton micorsyringes
• Sharp pencil
• Cotton balls
• Cotton swabs
• Bone wax
• Dental probe
• Mineral oil
• Staple remover
• 100 ml beaker
• 50 ml beaker
• 100 ml saline
• triple antibiotic ointment
• 50 ml isopropyl alcohol
• Nebutal
• Atropine

Administration of Anesthetic

1. Complete the surgical record

2. Weigh the animal to determine dosage of anesthetic

3. Calculate anesthetic dosage

1. Take animal weight and convert from g to kg
2. Calculate 1 cc / kg of Nebutal + 0.05 cc
3. Draw this amount into the syringe, plus some additional to deal with air bubbles
4. Carefully re-cap the syringe and set aside
5. Record the amount of anesthetic used into the narcotic log book

4. Atropine will now be administered via injection to prevent respiratory complications

a. Draw 0.1ml of Atropine into a 1ml syringe

b. Disorient the animal by spinning slowly – this will relax their muscles

c. Grasp the animal firmly with one hand and with the other locate the xyphoid process and rub gently several times

d. Insert the Atropine needle, pull back slightly to be sure no organ was punctured

e. Depress the needle swiftly and completely and remove the needle quickly – Take care not to move the needle around inside the animal

4. Immediately inject with Nebutal in parallel fashion to the Atropine. Record

Atropine and Nebutal use in surgical record. Return animal to its cage.

5. Prepare Microsyringe with neurotoxin or PBS according to study protocol

6. Check animal for surgical depth

1. Clap hands sharply above animals cage
2. Pinch the animal’s tail about half way its length and observe for response – if no response pinch the tail close to the body
3. If no response the animal is ready to be shaved
4. If there is still responding after 5 min. consult with instructor regarding administration of further anesthetic – typically 0.05ml

Preparation of Animal for Surgery

1. Place the animal ventral side down on a table surface

a. Using electric hair clippers, shave the head from behind the ears to just in front of the eyes

b. Move aside the ear pinnae to get around the ears

2. Generously apply mineral oil to the animals eyes using a cotton swab

3. Use a cotton ball to apply alcohol to the shaved head, avoiding contact with the eyes

Animal Placement in the Stereotaxic Apparatus

v Ear-bars will be placed one at a time. They are inserted slightly in, up, and back. If the ear-bars are too far forward, you will strike bone; if too far back, there will be a spongy feel

v If blood appears stop the procedure and request help

1. Place the animal on the stereotaxic table, with the head centered between the ear-bars, and the snout centered to the incisor bar

2. Gently grasp the pinnae with one hand, while mounting the one ear into the ear-bar. Tighten that ear-bar and continue on with the other ear.

3. If seated properly the animal’s head should be unable to move from side to side or back and forth. You should be able to move the head up and down, rotating on the ear-bars

4. Center the animal’s head by having the ear-bars read equal values.

5. Hook the incisors and adjust the holder for a solid fit

6. Level the animal’s head, and secure the nose bar firmly over its snout

Incision and Lesion Placement

	Intrastriatal (CPu)	Medial Septal	3^rd Ventricle
AP	+ 0.2 Bregma	+ 0.2 Bregma	- 1.8 Bregma
ML	+/- 3.0 Bregma	+/- 0.0 Bregma	+/- 0.0 Bregma
DV	- 5.3 Dura	- 6.0 Dura	- 4.5 Skull

1. Grasp the animals head gently but firmly just below and in front of the eyes, pulling your fingers apart to draw the scalp taut

2. With your other hand press the scalpel blade to the scalp just behind the eyes, and draw a firm incision line back to the ears. Try to only make a single cut

3. Using the scalpel blade, scrape away the fascia to expose Bregma

4. Use hemostats to retract the fascia opening the surgical field. Wipe clean the scalp with a cotton swab soaked in physiological saline

5. Place the Kopf instrument carrier, with mounted Hamilton Microsyringe, on the bar, and position it so the needle tip is directly above Bregma

6. Lower the needle just above Bregma and record AP and ML on the surgical record. Record DV at this time if the surgery requires this measurement to be taken from the skull. Make necessary calculations to obtain the adjusted values.

7. Correct the position of the needle tip to agree with the adjusted values

8. Lower the needle to the skull and use a pencil to mark the spot on the skull to be drilled

9. Ascend the needle and secure the Kopf instrument aside. Using a swab and saline, moisten the skull slightly

Brain Surgery

1. Carefully begin drilling into the skull stopping periodically to swab the area. Descend slowly, mindful not to break through and puncture the cortex. Once through, widen the hole slightly and evenly, without funneling. Swab the area clean

2. Remount the Kopf and position according to adjusted coordinates. Descend the needle tip until it touches the dura mater. Record DV value and calculate adjustments on the surgical record

3. Have an assistant begin timing as you deliver the drug over a specified period of time

4. Once the drug is completely delivered, soak 2 cotton balls in saline and pack them around the needle gently. Leave the needle in place for the specified amount of time

5. Remove cotton balls and slowly ascend the needle out of the brain. Carefully secure the Kopf aside. Swab the surgical area.

6. If using bone wax, use the blunt end of a dental probe to cut a small amount of bone wax and apply this to the drill hole until it is sealed and smoothed – take care not to allow the bone wax to penetrate the skull and touch the cortex.

7. Apply saline using a swab

v For Bilateral lesions repeat steps 7-15

Closing

1. Apply saline to fascia held by each hemostat, removing each in turn

2. Beginning at the back of the incision, use the gap-toothed forceps to gently move the incision flaps until they are near enough to each other to be grasped together by the forceps. Once you have both flaps in the forceps, twist slightly, lift and apply a surgical staple. Repeat until incision is closed.

3. Generously apply antibiotic ointment to the staple and incision area

4. Remove:

1. Nose bar
2. Incisor bar
3. Ear-bars one at a time, while supporting the ehad

Post Surgery Care

1. Return the animal to its cage on a clean paper towel and place on the warmer (~40^◦ C) until the animal shows signs of spontaneous movement

1. 2-3 hrs for septal lesions
2. 3-5 hrs for bilateral caudate lesions

2. Observe the animal for signs of abnormal bleeding, seizure activity, or trouble breathing

3. Once the animal has recovered from anesthesia, it can be replaced on its home rack with food and water available ad lib.

v Monitor feeding behavior closely over the next 24 hrs.

It is extremely important for the welfare of the animal and the study that the students notify an instructor immediately of any uncertainty in procedure or abnormal behavior exhibited by the animal