Assessment Of Subcutaneous Radio-Telemetry Device Implantation In Cynomolgus Monkeys

By J.C. Queudot, J. Forget, S. Nechev, A. Celori, B. Megrath, T. Hernandez, and L. Tilley

A study was conducted to evaluate the feasibility of two telemetry device implantation methods (intra-abdominal vs. subcutaneous) in non-human primates (NHPs), aiming to reduce surgical trauma while maintaining data quality. Typically, telemetry devices are implanted intra-abdominally, a more invasive procedure requiring extensive post-operative care, whereas subcutaneous implantation involves a less invasive surgery with a shorter recovery period. Over a 6-week monitoring period, cardiovascular data, body temperature, rectal temperatures, and clinical pathology (hematology, coagulation, and serum chemistry) were assessed. No significant differences in cardiovascular readings, such as blood pressure, heart rate, and ECG, were observed between the two methods.

However, body temperature readings were notably lower for both implant sites compared to rectal temperatures, with intra-abdominal implants showing a 1.5-degree difference and subcutaneous implants showing a 3 to 4-degree difference. Minimal clinical pathology changes consistent with low-grade inflammation were seen in both groups post-implantation. The subcutaneous method’s feasibility was constrained by the size of the animals, as smaller primates lacked sufficient subcutaneous space to accommodate the device. Given that inflammation levels were similar between both methods and there were no differences in cardiovascular data, subcutaneous implants present a viable, less invasive alternative to intra-abdominal implants for appropriately sized NHPs.