A rat spinal subarachnoid continuous infusion device

In this paper we describe a method for the continuous infusion of putative repair-enhancing substances into the rat spinal cord subarachnoid space, thereby allowing investigation of the process of naturally occurring and graft assisted repair of the spinal cord. Solutions are delivered into the rat CSF from an osmotic mini-pump via a purpose-made fine-silicone catheter. Under general anaesthesia a T13 to L2 laminectomy is performed to expose the dura covering the spinal cord. The osmotic mini-pump is placed in a subcutaneous pouch in the left thoracolumbar region with the silicone catheter looping forward in the subcutaneous plane before entering the subarachnoid space through a durotomy in the rostral extent of the exposed dura. A technique of fixation has been developed which prevents migration, disconnection or kinking of the mini-pump and catheter assembly. Dye infusion, post-mortem and histological studies have been used to validate the method and its reliability.