How can I insert a catheter into a rat's tail? - briefly
Clean the tail with antiseptic, make a small longitudinal incision near the base, and gently advance a sterile polyethylene «catheter» into the tail vein using a micromanipulator, securing it with tissue adhesive. Confirm placement by observing blood return and monitor the animal throughout the procedure.
How can I insert a catheter into a rat's tail? - in detail
Insertion of a catheter into the tail of a laboratory rat requires precise preparation, appropriate equipment, and strict aseptic technique.
Materials
- Sterile polyethylene or polyurethane catheter (0.5–0.7 mm outer diameter)
- 26–27 G hypodermic needle (optional for guide)
- Heating pad or infrared lamp
- Isoflurane vaporizer or injectable anesthetic (e.g., ketamine/xylazine)
- Antiseptic solution (70 % ethanol)
- Sterile gauze, adhesive tape, and suturing material
- Saline flush (0.9 % NaCl) and heparinized lock solution
Procedure
-
Anesthesia
• Induce and maintain a surgical plane of anesthesia; confirm lack of pedal reflex. -
Tail preparation
• Place the animal on a warming surface to dilate peripheral vessels.
• Clean the distal third of the tail with ethanol; allow to dry. -
Catheter selection and preparation
• Trim the catheter tip to create a beveled edge if necessary.
• Flush the lumen with saline to remove air bubbles. -
Vessel identification
• Visualize the lateral tail vein using a magnifying lens; the vein runs longitudinally near the skin surface. -
Insertion technique
• Stabilize the tail with one hand; gently lift the skin over the vein.
• Advance the catheter at a 30–45° angle, bevel up, into the lumen.
• Once blood return is observed, advance an additional 2–3 mm, then reduce the angle to parallel the vessel. -
Securing the catheter
• Apply a small drop of tissue adhesive or a single suture to the skin entry point.
• Cover with sterile gauze and secure with adhesive tape. -
Verification
• Flush with 0.2 ml saline; observe free flow without resistance.
• Confirm catheter position by gentle aspiration of venous blood. -
Post‑procedure care
• Maintain body temperature; monitor respiratory rate and limb perfusion.
• Administer analgesic as required.
• Record catheter length, insertion site, and any complications.
Troubleshooting
- No blood return: reassess vein visibility, adjust angle, or select a larger catheter.
- Leakage at entry site: reinforce with additional adhesive or sutures.
- Catheter occlusion: flush with heparinized saline (10 U/ml).
Adherence to these steps ensures reliable vascular access, minimizes tissue trauma, and supports reproducible experimental outcomes.