Long-term access to blood vessels for sampling, administering drug compounds and other substances, or measuring blood pressure in laboratory animals is facilitated by implanting catheters.
Using catheters can reduce the stress and discomfort involved with repeated restraint and venepuncture. They also permit access to deep, normally inaccessible vessels (e.g. the hepatic portal vein) and can allow continuous ambulatory infusions. Recent technical developments have made automated blood sampling possible in animals with implanted catheters (1).
The ethical review of research protocols proposing to use implanted catheters should carefully analyse the benefits against the costs of the surgical procedures required to implant catheters (e.g. potential pain, discomfort and distress) and the risk of long term complications, such as infection, thrombosis and reactions to implant materials (2).
The main challenges to successful long term vascular access are:
- Preventing thrombosis, which can lead to catheter and vessel blockage (occlusion).
- Using apppropriate catheter material, design and construction.
- Preventing catheter-related infection and managing cutaneous exit sites.
Good planning and experimental design are essential to ensure optimised research outcomes from animals with vascular catheters.
Resources on each of these challenges are available:
Resources and references
- Holmberg A & Pelletier R (2009) Automated blood sampling and the 3Rs. London: NC3Rs.
- Morton DB et al. (2001) Refining procedures for the administration of substances. Laboratory Animals 35(1): 1-41.
- Guiding principles for preparing for and undertaking aseptic surgery: A report by the LASA Education, Training and Ethics section.
- Methods in vascular infusion biotechnology in research with rodents.
- Refining procedures for the administration of substances.
- Removal of blood from laboratory animals and birds.