Operations on Mammals Xuelian Ma Physiological Department

outline Apparatus Preparations before operation Operations in neck Precautions

Ⅰ Apparatus Scissor Tweezer Forceps Scalpel Tracheal cannula Arterial cannula Bulldog clamp Glass dissecting needle Operation table Bladder funnel for collecting urine

Ⅱ Preparations before operation 1 Anesthesia: 20% urethane (5ml/kg) is administered through the marginal vein in the ear. The position where we begin to inject anesthetic should be near to distal of marginal ear as possible as we can. The velocity of injection should be slow and we should monitor the respiration of the animal.

Ⅱ Preparations before operation 2 Fixing: After anesthesia, the rabbit is fixed. We should lay the rabbit on its back on the operation table, then fix the limbs with the help of the ropes.

Ⅱ Preparations before operation 3 Shearing: Before the operation, the hair of the operation site should be sheared. This step we should avoid injuring the animal’s skin.

Ⅲ Operation in neck 1 Slice the skin: With the scissors make a mid incision 3-4 centimeters in length through the skin over the region from the lower jaw to the breastbone. The anterior chest is now exposed.

Ⅲ Operations in neck 2 Separate the subcutaneous tissue and muscle to expose the trachea In this step, we should avoid injuring the blood and nerve.

Ⅲ Operation in neck 3 Endotracheal intubation Separate the trachea from other tissues, pass a thread under it, make a “⊥”shape incision on the trachea 2-3 cm under the throat, then insert the tracheal cannula toward the lung and tie the cannula and the trachea together.

Ⅲ Operation in neck 4 Separate the nerves and the left common carotid artery Separate the nerves Identify carefully the three nerves located in carotid sheath: vagus nerve is the thickest, buffer nerve is the thinnest, the sympathetic nerve is moderate. Isolate them by glass dissecting needle and pass various color threads separately under them for preparation.

Ⅲ Operation in neck 5 Intubation in the common carotid artery Expose the left common carotid artery and separate it from other tissues for 2-3 cm. Then the arterial cannula was filled with 500u/ml heparin-normal sodium solution.

Ⅲ Operation in neck Tie the artery at the side of the head, clip the artery at the side of the heart, then make a little incision on the artery, insert the arterial cannula into the artery toward the heart, tie the cannula and artery together. Connect the arterial cannula with power lab system via a blood pressure transducer.

Ⅲ Operation in neck The operating action of isolating blood vessels and nerves should be gentle by using glass dissecting needle. The isolating sequence is from thin to thick.

ⅣSeparate the xiphoid process 1 Make a skin incision located in xiphisternum 2-3cm in length. 2 Open the abdominal cavity along the linea alba abdominis 2-3cm in length. 3 Separate the muscles in the middle of the belly to expose and isolate the xiphoid process .

ⅣSeparate the xiphoid process 4 The peritoneum around the xiphoid process was sheared carefully. Lift the xiphoid process, you can see two slips of diaphragm adhering to the xiphoid process. 5 Cut between the body of sternum and the xiphoid process.

ⅣSeparate the xiphoid process 6 Connect the xiphoid process with the computer through a pressure transducer. Do not injury the diaphragm and avoid pneumothorax.

Ⅴ Operations in belly 1 Slice the skin about 4cm in the middle of the belly above the pubic symphysis. 2 Open the abdominal cavity along the linea alba abdominis 3-4cm in length above the pubic symphysis. Do not hurt the organs in the abdominal cavity 3 Find ureters of both sides on the bottom of the bladder. Confirm the positions where both ureters open to the bladder.

Ⅴ Operations in belly 4 Intubation in the urinary bladder A: Make a little incision on the top of the bladder where there are few vessels

Ⅴ Operations in belly 4 Intubation in the urinary bladder B: The bladder funnel is filled with water before the intubation. C: Put the bladder funnel into the bladder , fix the funnel and the bladder together. D: The outlet of bladder funnel should be placed directly at the exit of ureters and should be close to the wall of bladder. the other end of bladder funnel should be connected with the drop recorder.