Blood vessel cannulation

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 and analgesia 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. The use of a subcutaneous access port may be more appropriate because they eliminate the need for tethering during periods when the animal is not being sampled from. 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 sange 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 use 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

  • Abrasions on the skin in contact with the jacket.
  • The tightness of the jacket.
  • Signs of infection/bruising/swelling/haemorrhage around the wound site.
  • The patency of the cannula.
  • The weight of the mouse (for recovery work).

Summary

Number of samples 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 up to five days after surgery, and daily animal observations post-surgery.
Adverse effects
  • Infection 5-10%
  • Haemorrhage 5-10%
  • Poor recovery after surgery 5-10%
  • Blocked cannula 5-10%
  • Swelling around the jacket 5-10%
  • Skin sores from the jacket 5-10%
Other 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