How to do a surgery

This page is not complete

Nor will it ever be, as you can't learn a surgery from a Wiki and you shouldn't try to, but it is a pretty helpful guide. You should read our animal protocol (available on eprotocol) to see exactly what we are approved to do. You will also need that information to be certified. certified. And obviously someone should be mentoring you.

A fairly detailed set of instructions for chronic array implantation is on our Google Drive. Some info may be out of date and it is all specific to chronic array implantation.

I started making a presentation that helps orient you to the zebra finch brain. https://docs.google.com/presentation/d/1JnuwqSocO5LAJmgZDnlcflryXxJv5x5t_XUooJ5oy6E/edit?usp=sharing

Contents

1. Preparation
   • Day before
   • 1 hour before surgery
2. Anesthesia
3. Placing the Bird in the Stereotax
4. Making a Craniotomy
5. Injections or Electrode Placement
6. Finished the Surgery
7. Recovery and Post-operative care

1 Preparation

Day before

All surgical tools should be sterilized in the autoclave on the 2nd floor of LKS before each surgery. If you are doing multiple surgeries in a row it is admissable to use alcohol and the glass bead sterilizer between animals. Other tools that may be good to sterilize are cotton tipped pipettes and kimwipe twists.

The surgical room should be clean before starting any surgery. The stereotax and surgical area should be wiped down with alcohol. If you will be using biological hazards (viruses, for instance) you need to flip the sign on the door to indicate so.

1 Hour before Surgery

1. Isolate and fast the bird by separating it in a carrying cage. Cover it with a dark cloth to help keep it calm. Document the time you do this.

2. Give 100uL of meloxicam soluion about 15-30 mins before surgery. Prepare with 10uL of Metacam (Meloxicam, 1.5mg/mL) and 290uL of distilled water.

3. Trim the ear feathers of the bird so that the ear holes are easily visible (to make putting in earbars easier), and trim feathers on the top of head so that it will be easier to inject lidocaine.

4. Prepare a cage for the bird to recover in so you don't need to do this at the end of surgery.

5. Turn on glass bead sterilizer so it starts heating. You don't want to wait for it to heat up when you need it.

6. Make sure you have everything you need for the entire surgery (tracers/viruses etc).

2 Anesthesia

For isoflurane anesthesia, see the isoflurane machine page. It is generally advisable to have two people helping during every surgery, where the second person't job is to basically monitor anesthesia level to make sure that the animal doesn't die from an overdose. For urethane surgeries, TODO make a urethane page. There may be an old google doc somewhere documenting this.

1. Prepare the isoflurane induction chamber. Turn the oxygen to 1.0 L/min and isoflurane to 2%. Make sure the iso is routed to the induction box and not the stereotax. Make sure the passive scavenger is attached to the induction box.

2. Place the bird in the induction box until properly anesthetized, for about 4 minutes. The time here is very approximate and variable between subjects, you must be vigilant and watch the breathing carefully. There is more detail on the isoflurane machine page. (We probably should devote an entire page to Anesthesia - kevin). Either cover the induction box with a dark box with dark fabric or simply move to the far end of the room to keep the bird calm.

3. Breathing will slow to 60-80 respirations per minute. If breathing becomes irregular the bird is too deeply anesthetized.

3 Placing the Bird in the Stereotax

This is likely the most difficult part of the whole surgery to learn.

1. Once the bird is properly anesthetized (It's breathing should be slow and steady, less than 80 resp/min): a. Make sure the stereotax is ready- you should have spare tape already cut and a blanket for wrapping the bird. The microscope and stereotax arms should be out of your way. Make sure the iso scavenger is turned on. b. Switch the isoflurane routing to the stereotax instead of the inductino box. c. Reduce Iso to 0.5%. d. Reduce oxygen to 0.4 L/min. e. Grab a pair of sturdy forceps and remove the bird from the chamber.

2. Moving quickly, attach the bird to the beak bar and ear bars. It is very important to do this step quickly before the bird starts to wake up. Pick the bird up in your left hand and lift open the beak with coarse forceps (#2). Place the birds beak over the beak bar with the isoflourane tube in or at least very near the bird's beak. Press the ear bars into place, starting with the right one. Make sure they are aligned with the ears and you are not crushing the bird's skull. When they are in place, tighten the ear bars and the beak bar so that the head cannot move.

3. Turn on the heating pad, place the thermometer under the wing, and wrap the bird in the cloth blanket. It helps to lightly tape the bird down (wrapped in the blanket, not directly on the feathers). From this point on, keep a record in the lab notebook of the bird's state every 15 minutes including breathing rate of the bird (should be 60-100 breaths per minute), temperature (should be 39-40 deg but is highly dependent on thermistor placement), and reflexes (should have no response when pinched on foot with forceps).

4 Incision and Craniotomy

1. Using fine forceps, slightly lift skin on top of head and inject a small bump of lidocaine (~100-300 microliters?). Press lightly to spread it around a bit, and wait for a bit to kick in.

2. Using coarse forceps, pull feathers off of head so that surgical area is well clear. Make sure to pull the feathers in the direction of the grain to minimize distress. Collect feathers in a glass bin with wet paper towels.

3. Once the area is clear of feathers, do three rounds of cleaning the surface of the head, alternating iodine swaps and alcohol swabs (3x each).

4. Sterilize surgical tools in glass beads. After this point, everything should be done with sterile tip technique.

5. Make an incision in the scalp by pinching a large section of skin together with forceps and cutting in a directly rostral-caudal line with fine scissors. The incision is generally 2-3 cm long and centered on top of the skull.

6. Using sterile cotton swabs, gently spread the skin laterally, exposing the skull. Lightly scrub the skull with cotton swabs.

7. Locate and mark the Y-sinus (pictures??). Do this as soon as you can since it is easiest to see when fresh. Cut outer-layer of skull above Y-sinus superficially to mark it. Work horizontally with #5 forceps of 18G syringe to be careful not to puncture it.

8. Measure where to make your craniotomy using a ruler. Mark rough coordinates on skull with a blade or dental drill.

9. Optional: If you are going to glue anything to the skull it is a good idea to make a base layer of adhesive now.

10. Using the dental drill, remove the upper layer of skull.

11. Remove the lower layer of skull as well, using both the dental drill and a yellow syringe tip and forceps.

12. Spray sterile saline onto Dura and staunch any bleeding if necessary.

13. Measure your exact coordinates using the stereotax.

14. Identify exact penetration point and make a small tear in the dura using the tip of a fresh insulin syringe. For array implantations you much retract a large portion of dura and this is technically demanding. All bleeding must be staunched before lowering anything into the brain.

5 Injections or Electrode Placement

1. Different types of surgeries branch at this point and I haven't finished it. TODO finish this.

6 Closing the Incision

1. Fill the craniotomy with kwiksil or other biocompatible gel.

2. Re-apply lidocaine to the edges of the incision.

3. Pull the skin back together, overlapping slightly.

4. Apply a very small amount of VetBond to close the wound. A second person is helpful at this stage. Be sure not to get any in the bird's eyes

7 Post-Operative Monitoring

1. Fill out a Blue Card and place it on the cage.

2. Place the cage either in the colony room or in a monitored location in 131 or 125.

3. Check regularly that the animal is recovering. See our Animal Use Protocol for specifics.