Blood vessel cannulation

Please read the general principles of blood sampling page and catheterisation pages before attempting any cannulation procedure.

Technique

Blood vessel cannulation should be considered when repeated samples are required, as it avoids multiple needle entries at any one site. It is suitable for use in all strains of mice and can be used to take blood from the carotid artery, vena cava and femoral vein. Surgery is required and appropriate anaesthesia, analgesia and aseptic technique should be used to minimise any pain caused. Mice should be allowed to regain their pre-operative body weight before blood samples are taken.

For recovery work, the cannula may be exteriorised at the nape of the neck through a jacket and tether system. The jacket can cause swelling and skin abrasion and mice require regular and detailed observation to identify any problems. Use of a subcutaneous access port may be more appropriate than exteriorisation because these eliminate the need for tethering and hence allow group housing. For terminal work, the cannula is not exteriorised.

Cannulated mice are usually housed singly. The caging, bedding and environmental enrichment need to be appropriate to prevent the tether becoming entangled and the wound contaminated. In addition, the bedding needs to be sand free.

The cannula used is small, which can promote blood clotting (larger cannulae can abrade the blood vessel wall). To prevent this, the cannula requires regular maintenance (e.g. flushing with an anticoagulant).

Using a cannula 0.01 - 0.02 ml of blood can be taken and, depending on the sample volume and scientific justification up to six samples may be taken in a 24-hour period. An aseptic technique should be used. Sterile saline with anticoagulant should be used to flush the cannula after blood sampling to prevent occlusion. A pin is then inserted into the exteriorised end of the cannula to stop the blood from flowing. A sterile locking solution can be used to lock the cannula after a series of samples have been taken, allowing flushing to be avoided for a number of days.

The following should be checked daily

  • Skin in contact with the jackets should be checked for abrasion.
  • The jacket should be checked for tightness.
  • Wound sites should be checked for infection/bruising/swelling/haemorrhage.
  • The cannula should be checked for patency (without blockage).
  • The weight of the mouse (remember weight will include that of the device).

Changes in any of the above may require veterinary advice or treatment, or may indicate that a humane endpoint has been reached and appropriate action should be taken.

Summary

Number of samples It is recommended up to six samples may be taken in a 24-hour period, depending on sample volume.
Sample volume 0.01 - 0.02 ml
Equipment 25G cannula
Staff resource One person is required to take the blood sample. Further staff resource is required for surgery, post-operative care for as long as necessary for the individual animal, and daily animal observations post-surgery.
Adverse effects and incidence
  • Infection 1-5%
  • Haemorrhage 1-5%
  • Poor recovery after surgery 1-5%
  • Blocked cannula 1-5%
  • Swelling around the jacket 1-5%
  • Skin sores from the jacket 1-5%

Be sure to use our advice on vascular catheters to reduce the incidence of adverse effects.

Further considerations Mice should be back at their pre-operative weight before blood sampling starts.

Resources and references

Blood vessel cannulation technique in other animals

Click here for information on blood vessel cannulation in the rat Click here for information on blood vessel cannulation in the guinea pig Click here for information on blood vessel cannulation in the ferret

All blood sampling techniques in the mouse

Click here for information on tail snip blood sampling in the mouseClick here for information on tail vessel microsampling in the mouseClick here for information on tail vein blood sampling in the mouseClick here for information on saphenous vein blood sampling in the mouseClick here for information on retro-orbital blood sampling techniques in the mouseClick here for information on abdominal/thoracic blood vessel blood sampling in the mouseClick here for information on cardiac puncture blood sampling in the mouseClick here for information on schedule 1 stunning followed by decapitation in the mouseClick here for information on decapitation blood sampling techniques in the mouse