Implantation of a Vascular Access Button for Chronic Blood Sampling and Drug Administration in the Rabbit

Abstract

Rabbits are commonly used for pharmacokinetic (PK) and toxicokinetic (TK) studies in the research setting, requiring repetitive venipuncture, which can be challenging in this species. The auricular vessels are commonly used for venipuncture in rabbits. The repetitive access of these delicate vessels can lead to trauma such as hematomas causing venipuncture to become more challenging as the study progresses. In turn, this leads to missed time points or insufficient blood samples. Surgical models for chronic vascular access in rabbits are common throughout the industry. Common models include exteriorized vascular catheters and implanted vascular access ports. However, these implants come with their own complications and restrictions when used in rabbits. Therefore, the authors evaluated the use of a vascular access button (VAB), an implant commonly used in small rodents, as a refinement to the current chronic models in use in the industry. Seventeen rabbits were implanted with either single or dual channel VABs. The catheters were implanted in the femoral artery and/or vein and then tunneled subcutaneously to the button on the dorsal thoracic area. Overall, the results were outstanding, and an established model was created. The average patency rate was 316 days with several implants still patent after 2 years. The authors feel the implantation and use of a vascular access button in rabbits for routine PK studies is an excellent refinement. The rabbits tolerate the buttons extremely well with minimal issues. The patency rate is equal to or better than vascular access ports and when used with the tethering system, provides a hands-off method for blood collection and intravenous administration in rabbits during PK studies.