Responsive Neurostimulator (RNS)

Patient is positioned supine and intubated.  A gamma knife frame is secured to the patient's head.  All 4 pins are tightened.  The left anterior pin is removed along with the corresponding post.  An adapter is used to secure the frame to the Mayfield.  The Rosa robot is advanced until the arm is touching the Mayfield.  The Rosa attachment to which the frame is normally attached is removed.  The Rosa arm should be set at a 2.  Registration is accomplished with the laser attachment.  The arm is advanced to each lead entry point and markings are made on the skin.  A 3 cm incision is marked in the coronal plane at each entry point with the entry point at the midpoint of the incision.  The left incision is continued laterally, posteriorly, and then medially to complete a C shape.

The head is shaved liberally.  Lidocaine with epinephrine is used to infiltrate the incision.  Prep and drape in the usual fashion.  First, make a pair of 3 cm incisions surrounding each entry point down to bone.  Use a Weitlaner retractor to hold each incision open.  Bring in the Rosa and use a hand drill to make a small 3 mm hole in the bone.  Pierce the dura.  Mark the stylet to the appropriate length and pass it through the attachment of the Rosa to the appropriate length.  Withdraw the stylet from within the needle.  Pass the lead through the needle to the appropriate length then withdraw the needle from around the lead.  Withdraw the wire from within the lead.  Placed a wet clip around the lead just before the outer table of the skull.  Secure the lead to the skull with a long dog bone.  Use a sucker to tunnel the right lead to the left incision.  Remove the retractor from the left incision.  Complete the C shape incision on the left.  Use a Bovie to go down to the bone.  Dissect pericranium from the skull underneath the flap with the Bovie.  Hold the flap back with several stitches.  Take the template and trace its outline against the skull with a sterile pencil.  Make a bur hole with the perforator at the top right corner of the traced outline.  Use a craniotome to turn the craniotomy.  Drop a generator holder in place in the craniotomy and screw it in.  Placed the generator in the holder and attach the leads. Interrogate. Irrigate.  Close galea with 2-0 Vicryl's.  Close skin with running 3-0 nylon.  Keep SBP less than 160 and get a postop CT head with 1.3 mm slices.