Mar 27, 2025
Mouse VAB Catheter Maintenance
- Adrien Stanley1
- 1Allen Institute for Neural Dynamics
- Allen Institute for Neural Dynamics
Protocol Citation: Adrien Stanley 2025. Mouse VAB Catheter Maintenance. protocols.io https://dx.doi.org/10.17504/protocols.io.8epv52o5dv1b/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: January 27, 2025
Last Modified: March 27, 2025
Protocol Integer ID: 119653
Keywords: Prepare syringes, Catheter maintenance, Anesthetize mouse, Recovery and takedown
Abstract
This protocol describes how to perform catheter maintenance to preserve mouse catheter patency after Vascular Access Button (VAB) implant.
Guidelines
- Maintenance should be performed upon arrival of animal or 4-7 days post VAB implantation and then every 2-7 days thereafter.
- Maintenance can be performed on awake or anesthetized mice.
Materials
| Material | Manufacturer/Supplier | Catalog Number | |
| Animal with VAB implant | Instech | C20PU-MJV2013 | |
| VAB cap | Instech | VABM1C-5 | |
| Weight scale | Fisher Scientfic | 01-922-341 | |
| Container for weighing mouse | |||
| Isoflurane | |||
| Large paper towel | |||
| Forceps | Fine Science Tools | 11253-25 | |
| Ethanol swabs | Uline | 13-680-63 | |
| Sterile saline (0.9%) | Fisher Scientfic | NC9054335 | |
| 500 units/mL heparinized 50% glycerol | Instech | USP-HGS-500-10-VB-5 | |
| 1 20 µL Hamilton syringe | Sigma-Aldrich | 24531 | |
| 23 Gauge needle attachments | BD | BD305143 | |
| 2 1 mL syringes per mouse | Fisher Scientific | 309659 | |
| 3 pinport injectors per mouse | Instech | PNP3M |
Jugular Vein Catheters for MiceInstech SolomonCatalog #C20PU-MJV2013
One Channel Vascular Access Button™ for MiceInstech SolomonCatalog #VABM1C-5
Dumont Forceps - Micro-Blunted TipsFine Science ToolsCatalog #11253-25
0.9% SODIUM CHLOR. INJ.10MLThermo Fisher ScientificCatalog #NC9054335
500 units/mL heparinized 50% glycerol Instech SolomonCatalog #USP-HGS-500-10-VB-5
Hamilton® syringe, luer tipMerck MilliporeSigma (Sigma-Aldrich)Catalog #24531
BD® Needle 3/4 in. single use, sterile, 23 GBecton Dickinson (BD)Catalog #305143
BD Slip Tip Sterile SyringesThermo Fisher ScientificCatalog #BD 309659/14-823-434
PinPort™ InjectorsInstech SolomonCatalog #PNP3M
Equipment
Compass CR Series
NAME
Scale
TYPE
OHAUS™
BRAND
01-922-341
SKU
Safety warnings
- Wear required PPE for animal facility. Proper PPE includes lab coat, eye protection, and disposable gloves.
- If maintenance is being performed under isoflurane anesthesia, ensure proper ventilation and airflow in a fume hood or air extraction system to reduce exposure.
- When handling syringes with needles, always ensure needles are pointed away from you to avoid any accidental sticks.
- Report any accidental sticks to EHS.
- Used needles and syringes should be disposed of in biohazard sharps container.
Ethics statement
This protocol has been approved by the Allen Institute Animal Care and Use Committee (IACUC).
PHS Assurance: D16-00781
AAALAC: Unit 1854
Before start
- Implant or acquire mice with VAB Instech implanted catheters from animal vendor.
Prepare syringes
Prepare syringes
1m
1m
Prefill a flush syringe(s) (slip tip syringes Fisher Scientific catalog # 309656) with 50 µL of sterile saline (1 per mouse).
Wipe septum of vial with 70% ethanol swab and let air dry for 00:00:30 prior to puncturing septum.
30s
Use a 1 mL syringe with 23 Gauge needle attachment to withdraw ~100 µL saline solution to account for any dead volume when pinport injector is added.
Note
After withdrawal, point the syringe upward and away from you and gently flick the syringe to knock any bubbles up towards the needle.
Remove the 23-gauge needle and attach pinport injector.
Note
- Ensure the needle is pointed away from you and grip the base of the needle while pulling the syringe out.
- Dispose of needle in sharps waste container.
Push saline through pinport until a small drop is seen and no bubbles are noticeable in syringe or pinport connection.
Prefill Hamilton syringe with 14 µL of 500 units/mL of heparinized saline in 50% glycerol.
Wipe septum of vial with 70% ethanol swab and let air dry for 00:00:30 prior to puncturing septum.
30s
Use 1mL syringe with 23-gauge needle attachment to pull ~100 µL of 500 units/mL of heparinized saline in 50% glycerol.
Remove plunger from Hamilton and insert needle of filled syringe into the back of the Hamilton syringe and fill until the liquid can be seen in a drop at the tip of the Hamilton syringe.
Remove needle from the back of the Hamilton syringe and reinsert plunger, ensuring no air is in the Hamilton syringe.
With the remainder of the 500 units/mL of heparinized saline in 50% glycerol in the 1mL syringe, fill the pinport injector such that no air is present.
Connect the Hamilton syringe to the pinport injector, then lower the plunger to 14 µL .
Use paper towel to dab away excess liquid from the pinport tip.
Between mice, fill a new pinport attachment with 500 units/mL of heparinized saline in 50% glycerol, then pull Hamilton syringe plunger up to 14 µL , then swap to the newly filled pinport attachment while ensuring no air in the syringe.
Prepare mouse for catheter maintenance
Prepare mouse for catheter maintenance
Place mouse cage in a fume hood with prepared syringes and remove the lid.
Place mouse in container on scale and record body weight.
Do a health assessment per IACUC protocol and continue if mouse meets criteria to proceed.
(Optional) Anesthetize mouse
(Optional) Anesthetize mouse
3m
3m
Place mouse in isoflurane chamber and induce mouse at 4% isoflurane in oxygen at a rate of 0.8L per minute for about 00:03:00 .
Note
Ensure the mouse is immobile with a slowed breathing rate (~55-100 breaths per minute) before proceeding.
3m
Remove anesthetized mouse and ensure mouse is in the appropriate anesthetic plane with toe pinch and by noting slowed respiration rate.
Note
If mouse shows signs of wakefulness such as movement, increased respiration, or response to toe pinch during the maintenance procedure, then return the mouse to the isoflurane chamber and wait for about 3 minutes or until it is unresponsive before trying again.
Perform catheter maintenance
Perform catheter maintenance
Position mouse for optimal VAB (Vascular Access Button) access.
If anesthetized, place mouse on paper towel.
If awake, place mouse on grid of food hopper.
Remove the VAB cap with forceps and fingers.
Note
Forceps should grip the base of the VAB while fingers grip the cap before pulling the cap from the VAB.
Sanitize the top of the VAB with a 70% ethanol swab and allow to air dry for 5-10 seconds.
Insert empty withdrawal syringe with pinport attached and remove lock solution from VAB.
Note
Note: A small amount of blood should be seen to indicate locking solution has been removed. If no blood is withdrawn, this could indicate catheter patency issues. Patency can sometimes be recovered by filling a syringe with ~50 µL saline and then perform a rapid flush quickly followed by a gentle pull.
Remove and discard withdrawal syringe.
Attach prefilled flush syringe and flush catheter with 50 µL of saline.
Remove flushing syringe while maintaining positive pressure on the plunger.
Maintain positive pressure by applying a small amount of force onto the plunger while removing it. If there is some liquid left in the syringe, some will be pushed out the tip as the syringe is removed.
Attach prefilled Hamilton syringe with heparinized saline in 50% glycerol and push all 14 µL into catheter and remove Hamilton syringe while maintaining positive pressure.
Maintain positive pressure with the Hamilton syringe by holding the plunger down while removing the syringe.
Return cap to VAB by gripping the base of the VAB with forceps and applying the cap with fingers. The cap should be pushed past the black rubber ring in the middle of the VAB to ensure it stays in place.
Recovery and takedown
Recovery and takedown
Return mouse to its cage.
If maintenance is performed under anesthesia:
Lay mouse on its side to allow for respiration while still under anesthesia.
Monitor mouse until it wakes up from anesthesia and confirm no issues are seen with mouse post catheter maintenance.
Ensure isoflurane gas flow is turned off.
Record catheter patency status.
Patent: The catheter is capable of infusing and withdrawing.
Partial patency: The catheter is capable of infusing solution but not capable of withdrawing blood.
Patency loss: The catheter is neither capable of infusion solution nor withdrawing blood.
Clean area and return cage to rack.