Cannulation of the Carotid Artery in a Rat Model

Overview

In this video, we demonstrate a surgical procedure to cannulate the left carotid artery in a rat model.

Protocol

All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Cannulation of the Carotid Artery

The carotid artery cannulation may be performed before or after the cannulation of the mesenteric lymph duct. Some operators prefer to cannulate the carotid artery prior to cannulating the lymph duct so as to reduce potentially dislodging the lymph cannula when moving the animal.

1. Place a mark on the carotid artery cannula 2.5 cm from the bevel tip to identify the portion of the tubing to insert into the artery. Connect the other end of the cannula (i.e., without bevel) to a 23 or 25-G needle attached to a syringe filled with anticoagulant solution and fill the cannula with the anti-coagulant solution making sure no air gaps are present.
2. To facilitate cannulation, place the anesthetized rat in dorsal recumbency with the neck stretched and the head pointing toward the operator. Note that some operators prefer to perform this technique with the rat's tail pointing toward the operator.
3. Place a 1 - 1.5 cm longitudinal incision through the skin layer above the left of the trachea in the sagittal plane.
4. Dissect the subcutaneous connective tissue using blunt tip forceps to expose the underlying paired neck muscles.
5. Retract the neck muscles to reveal the left carotid artery (located ~1 cm below the skin surface and pulsing). Clean the overlying connective tissue from the artery by blunt dissection.
6. Isolate a ~1 cm section of the artery carefully using blunt tissue forceps, taking care not to damage the adjacent vagal nerve tract. Perform this by opening and closing the blunt tip forceps vertically along either side of the artery to free it from the surrounding tissue and vagus nerve.
7. Using fine-tip forceps, thread two silk sutures underneath the carotid artery and place them at each end of the isolated artery section. Tie off the suture closest to the operator and furthest from the rat's heart and clavicle (Figure 1A).
8. Occlude blood flow through the artery by placing a pair of straight fine-tip forceps underneath the artery (Figure 1B).
9. Using the fine-tip iris scissors, place a small incision on the top surface of the artery (about 1/3 of the way down from the top of the isolated area). Flush any spilled blood on the surface of the artery with heparinized saline and gently wipe using cotton tips.
10. Insert the tip of the cannula into the artery with a pair of curved tip forceps. Once inserted, remove the straight fine tip forceps occluding the blood flow and advance the cannula 2.5 cm into the artery using two pairs of forceps, one to hold the cannula inside the artery to stop blood from leaking back and the other to insert the cannula.
11. Use a small artery clamp to hold the cannula inside the artery and remove the straight fine tip forceps that were placed below the artery in step 1.8 to occlude the blood flow.
12. Confirm the patency of the cannula by injecting an anti-coagulant solution into the cannula and drawing back a small amount of blood (Figure 1C). Then flush the cannula with an anticoagulant solution and seal the end using the flame of a lighter or a cannula plug.
13. Tie the cannula in place with the two sutures placed under the artery in step 1.8.
14. Remove the artery clamp and secure a third suture around the artery and cannula. Close the neck wound with sutures.

Representative Results

Figure 1. Photographs of (A) the carotid artery isolated with two silk sutures with the one closest to the operator tied off, (B) the carotid artery isolated and blood flow occluded with a pair of straight fine tip forceps placed underneath the artery, and (C) a carotid artery with the cannula in place and the patency being checked by drawing back a small amount of blood.

Materials

Name	Company	Catalog Number	Comments
Sterile saline	Baxter healthcare	AHB 1307	Any brand can be used. Example here is Baxter 100 ml saline bags, box of 50
70 % ethanol in water	Any		Any brand can be used
Heparin (35000I.U. in 35 mL)	Sigma Pharmaceuticals	337220	http://sigmaco.com.au/
Polyethylene (PE) cannula o.d. 0.96 mm x i.d. 0.58 mm	Microtube extensions	PE8050	Any brand can be used. Example here is PE tubing 0.8x0.5 mm, 30 m
Polyethylene (PE) cannula o.d. 0.8 mm x i.d. 0.5 mm	Microtube extensions	PE9658	Any brand can be used. Example here is PE tubing 0.96x0.58 mm, 30 m
Ruler	Any		Any brand can be used
Markers	Any		Any brand can be used
Cigarette lighter	Any		Any brand can be used
23 gauge needles	Livingstone International	DN23GX0.75LV	Any brand can be used. Example here is Livingstone Disposable Needle, Sterile, 23GX0.75inch, 100/BOX. http://www.livingstone.com.au/?PG=search_result&CAT= 6&search=DN23GX0.75LV
25 gauge needles	Livingstone International	DN25GX1.0LV	Any brand can be used. Example here is Livingstone Disposable Needle, Sterile, 25GX1.0inch, 100/BOX. http://www.livingstone.com.au/?PG=search_result&CAT=6&search= DN25GX1.0LV
1 ml syringe	Livingstone International	T3SS01TA	Any brand can be used. Example here is Terumo syringe 1 ml Slip Tuberculin 100/Box. http://www.livingstone.com.au/?PG=search_result&CAT=6&search =T3SS01TA
10 ml syringe	Livingstone International	T3SS10SA	Any brand can be used. Example here is Terumo syringe 10 ml Slip 100/Box. http://www.livingstone.com.au/?PG=search_result&CAT=6&search =T3SS10SA
Gauze swabs	Livingstone International	GSC075	Any brand can be used and cut to required size. Example here is gauze swabs cotton filled 7.5x7.5 cm, 8 ply. http://www.livingstone.com.au/?PG=search_result&CAT=6&search =GSC075
Cotton buds	Livingstone International	CTAST075DP	Any brand can be used. Example here is Livingstone cotton applicator plastic double tipped. 75MM. 100/PK. http://www.livingstone.com.au/?PG=search_result&CAT=6&search =CTAST075DP
Silk suture	Livingstone International	DTSK163019F4
Scalpel blades	Fine Science Tools (FST)	10020-00	Any brand can be used. Example here is FST Scalpel Blade #20. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=191
Scalpel handle	Fine Science Tools (FST)	10004-13	Any brand can be used. Example here is FST Scalpel Handle #4. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=298&CategoryId=51
1 x Small surgical scissors	Fine Science Tools (FST)	14060-09	Any brand can be used. Example here is FST Fine Scissors, 9 cm with 21 mm cutting edge, sharp, straight. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=40&CategoryId=17
2 x Forceps with serrated curved tip	Fine Science Tools (FST)	11001-13	Any brand can be used. Example here is FST 13 cm standard pattern forceps with curved 2.8x1.4 mm tip. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=405&CategoryId=32
1 x Iridectomy scissors	Fine Science Tools (FST)	15000-08	Any brand can be used. Example here is FST Vannas Spring Scissors - 2.5mm Cutting Edge, Straight. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=17&CategoryId=16
1 x Forceps with straight serated tip	Fine Science Tools (FST)	11650-10	Any brand can be used. Example here is FST Graefe 10 cm straight with serrated 1 x 0.99 mm tip. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=390&CategoryId=32
1 x Forceps with smooth sharp straight fine tip	Fine Science Tools (FST)	11251-10	Any brand can be used. Example here is FST Dumont #5 forceps straight 11cm with 0.08 x 0.04mm tip. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=335&CategoryId=29
1 x Forceps with smooth fine curved forceps	Fine Science Tools (FST)	11063-07	Any brand can be used. Example here is FST Delicate Forceps 9 cm with smooth 0.4 x 0.3mm tip. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=360
1 x Suture needle holder	Fine Science Tools (FST)	12001-13	Any brand can be used. Example here is FST 13cm Hasley Needle Holder with 16 mm length x 1.9 mm width tip. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=254&CategoryId=70
1 x Artery clamp	Fine Science Tools (FST)	18050-28	Any brand can be used. Example here is FST Bulldog Serrefines straight, 28 mm long, 9x1.6 mm jaw dimension with medium clamp press. http://www.finescience.ca/Special-Pages/Products.aspx?ProductId=270&CategoryId=82