Jugular Vein Catheterization of the Rat:

The following is a description of the basic surgical procedure for the jugular vein catheterization of the rat utilizing Aster Industries catheter products and how to indirectly determine that the catheter tip is properly placed. Aster Industries is committed to its catheter products and offers this service to familiarize its customers with the use of these products. It is assumed that the reader or perspective user of this procedure is knowledgeable in aseptic rodent survival surgical technique and that veterinary approval is obtained.

The correct positioning of the catheter tip is a critical step in proper vascular catheterization surgical technique. As one develops the proper confidence and ?feel? for this step, the entire surgical procedure becomes much more time efficient. The correct position of the jugular catheter tip is the right atrium of the heart.

Recommended Materials List and Function

Aster Industries Catalog No. R-JVC and accessories

Catheter fill solution

General surgical scissors: skin incisions

Adson forceps: handling of skin

Cotton applicator sticks or surgical spears: hemostasis

Curved dressing forceps: isolation of jugular vein and tying of ligatures

Straight dressing forceps: handling of catheter and tying of ligatures

4/0 or 5/0 silk ligatures: securing catheter in the lumen of jugular vein

Micro scissors or 25 ga. needle: performing venotomy

Hemostats or locking forceps (2): adjusting tension to jugular vein

45° angle Dumont forceps: distending venotomy

Autoclipâ wound closure system: wound closure and stabilization of catheter port

Fill the Catheter

Fill the jugular vein catheter with lock solution and insert the port plug into the catheter port a few mm to close the port end of the catheter. It is important that no air spaces are left in the filled catheter

The Approach

The easiest approach is by way of the right jugular vein immediately above the clavicle. A 1 to 1.5 cm skin incision is made over the ventral thorax slightly to the right of center. You should clearly visualize the jugular vein as it passes under the right clavicle into the chest cavity. A portion of the vein should be freed from all underlying tissue. This is accomplished by placing the closed tips of surgical forceps between the vein and underlying musculature and allowing the tips to open; and may have to be repeated several times. It is imperative that the vein is not damaged by this procedure and should be filled with circulating blood. After isolating an approximately 5mm section of the vein; two fine silk ligatures are placed at either end of the isolated portion of the vein. The ligature closest to the head can be tied to occlude blood flow going to the heart. When making this tie take care not to twist the blood vessel and do not trim the ends of the silk ligatures as they will be needed to secure the catheter. With a pair of small hemostats or locking forceps, grasp the ends of the tied ligature and position the hemostats to exert slight tension towards the head. Grasp the ends of the untied ligature closest to the clavicle with a similar instrument and exert slight tension towards the tail. Again, avoid twisting the blood vessel. The isolated portion of the vein should remain filled with blood. Tension can be released on the untied ligature and reapplied allowing blood to backflow into the isolated portion of the vein.

The Venotomy and Catheter Placement

Perform the venotomy in the isolated portion of the vein close to the tied cranial ligature with micro scissors or the point of a 25 ga. needle. A small drop of blood at the site should determine entry into the lumen of the vein. If blood is flowing from the site increase the tension on the untied ligature closest to the clavicle. Take care not to cut the vein excessively or puncture through the vein, as only a small hole in the wall of the vein is needed. Insert the closed tips of fine pointed, 45° angled Dumont forceps into the venotomy and allow the tips to open slightly to distend the opening. Insert the catheter tip into the lumen of the vein using the opening of the Dumont forceps as a guide. Advance the catheter tip to the untied ligature; remove the force on the untied ligature to allow the catheter tip to advance. Insert the catheter until the retention bubble of the catheter is over the venotomy site. Now release the catheter and observe for any movement. If the catheter tries to ?back out? the tip is incorrectly placed and is probably in a subclavial branch of the jugular vein. If left in this position patency to blood sample withdrawal will be compromised or completely impaired. To correct this problem, partially remove the catheter by approximately 25 mm. Lift the chest and reinsert the catheter or shift the patient slightly on to its left side and reinsert the catheter. With the catheter retention bead over the venotomy site, again observe for movement. When the catheter remains stationary you can be virtually certain the catheter tip is positioned properly, at the level of the right atrium of the heart.

Securing the Catheter

With the catheter retention bead over the venotomy site, tie the ligature closest to the clavicle around the jugular vein and catheter. Tie the ligature closest to the head around the catheter. Take on end of each ligature and tie together. Trim the excess ligature close to the ties. Turn the patient over and make a small skin incision between the scapulae. Use the tips of small hemostats to make a subcutaneous tunnel from this incision to the incision over the right thorax. Grasp the catheter port with the hemostats so that the port and port plug are within the hemostat tips and pull the catheter port through the incision between the scapulae. Close the scapular incision and secure the catheter port with a wound clip. Make certain that the catheter port is centered in the wound clip and the right angle interface of the catheter port remains under the closed wound clip, not within the closed wound clip. Turn the patient over on its back and close the ventral skin incision with wound clips making certain that wound clips do not damage the catheter.

The Last Step

When all incisions have been closed, depress the port plug a few more mm into the port. This will ensure that any blood aspirated into the catheter tip due to handling is expelled.