Continual cerebrospinal fluid sampling in the neonatal domestic piglet for biomarker and discovery studies

Background: Longitudinal access to cerebrospinal fluid (CSF) is useful for biomarker discovery in neurological disorders or diseases affecting CSF composition. Here, we aim to test a new method for insertion of a permanent intrathecal catheter, facilitating longitudinal collection of CSF. New method: We surgically placed a permanent intrathecal catheter into the cisterna magna of anesthetized neonatal piglets. The thecal sac was accessed at the L5-S1 spinal level and a radiopaque catheter was inserted under fluoroscopic x-ray guidance to position the tip at the cisterna magna. A titanium access port was connected to the catheter and anchored subcutaneously. Immediately after surgery, we confirmed CSF flow through the catheter and port via needle aspiration. Catheter patency over a two-month study period was determined through periodic CSF collection from the port. Results: Frequent (up to 3 times weekly), longitudinal sampling of CSF was achievable in neonatal piglets up to 60 days after implantation. CSF was readily accessible through the port without major adverse events. Catheterized piglets demonstrated slower, but normal, weight gain compared to control piglets. Post-operative complications were managed with standard access precautions and medications. There were no complications involving the implanted hardware. Comparison with existing method(s): This method fills a critical gap in the existing methods for longitudinal CSF sampling through an implanted intrathecal catheter system in neonatal piglets. Conclusions: This novel method is both safe and effective for longitudinal CSF access in the domestic piglet. Catheter patency and access to CSF is maintained over multiple months without major adverse events.