Intrathecal Placement of Lumbar Drain: A Technique to Withdraw Cerebrospinal Fluid from the Lumbar Spine in Porcine Model

A lumbar puncture is performed by injecting a specialized needle into the spinal column's intrathecal space in the lower back region to withdraw a cerebrospinal fluid, or CSF, sample. To begin, place an anesthetized pig in a right lateral position on a surgical platform. Ensure the spine is flexed, which increases the gaps between the vertebrae.

Take a needle assembly consisting of an inlay needle fitted inside an introducer needle. Locate the space between the fourth and fifth lumbar vertebrae. Pierce the needle through the skin layers and deeper tissues. 

Remove the inlay needle and connect a saline-filled syringe to the introducer needle. Push the needle inward while injecting the saline into the spinal column. This step facilitates an easy passage of the needle into the epidural space located around the spinal cord. 

Replace the syringe with an inlay needle. Advance the needle to puncture the dura mater - the tissue layer covering the spinal cord. Remove the inlay needle and introduce a lumbar drain tube into the intrathecal space.

Aspirate a small amount of CSF sample to confirm the appropriate positioning of the tube and remove the needle. Suture the drain tube in its position and connect it to a CSF drainage system while monitoring its pressure.