Neurophys

SSEPs

BSERs

Postop orders

-cap 150

-Ancef

-tylenol,oxy,dilaudid

-bowel reg

-abtiemetics

-no ketamine

-no imaging

-no steroids

Positioning/Pinning

-pins Left mastoid and STL, right STL

-mayfield tilted slightly up to help with flexing

-wrap arms before flipping after pre-positions

-prone on regular table with vertically oriented jelly rolls

-after taping in place, lock in head in flexed position

-Gardner does not necessarily tape shoulders as no fluoro shots, and patients usually younger and have laxity in tissues

Marking

-plan incision from inion to C2 spinous process, do not need to expose the all the way down to the inion or SP w dissection, but they are good tactile landmarks

-also mark with upside down triangle the occipital protuberance at the inion, should be at the top of the incision

Top of incision is occipital protuberance, bottom marked at C2 SP, important to be midline, can often feel bellies of the muscles and raphe at the midline (at least PAG says so)

Exposure

-stay midline, looking for muscle and connective tissue fibers too keep you oriented, this reduces bleeding and pain

-first dissect all the way down onto skull, this is safest to avoid durotomy and vert injury at foramen magnum

-extend exposure inferior until starting to get close to foramen (not all the way there), extend laterally in subpericranial plane the person whose side it is will retract and create tension with a broad periosteal elevator or a smaller, contralateral person uses bovie

-feel for C1 posterior tubercle, bovie down to midline and up to 1cm lateral (vert a. is out lateral), further out you can use a Pen 1 or bipol

-dissect soft tissue overlying the FM btw the skull and C1, going from sup. to inf. You can use a bipolar pulling from central to lateral to your own side, thicker fibers that don’t tear from Bipol can be cut w Mets once coagulated, or dissected bluntly with Mets by making a similarly central to lateral sweeping motion with the tines left slightly open. Lastly a Woodson can be used to dissect under and define the plane between soft tissue and dura, with a 15 blade cutting protected on top

-up going curette to define between bone and dura at both skull and c1

Craniectomy/laminectomy

-M8 bit to drill out a wide SOC, at least 3x3cm in size

-The cut across the occipital sinus at the top should be made last, you may need kerrisons to bite out depths of the keel

-kocher and pen3/curette to dissect free bone flap

-M8 for C1 laminectomy as well

Dural opening

-Y shaped with two tops superior, one midline incision lower, start with the two upper parts, ipsilareral person holding Woodson, contralateral 15 blade

-at the base of the V, use bipol w tongs around the dura to coagulate the occipital sinus all the way across

-continue bottom incision just until you see bottom of tonsils, otherwise difficult to make graft fit

• tack up dura with neurulons, make a figure-8 stitch around tip of occipital sinus to held coagulate it before tacking up with snap

Arachnoid dissection

-Gardner does NOT buzz or resect tonsils

-ipsilateral person retracts tonsil w pen 1/3, contralateral uses microscis to cut arachnoid

-goal is to visualize 4th ventricle

Expansion duraplasty

-use 5x4?? Pericardium graft

-to size the graft appropriately, you will likely need to “get creative”

-goal is a pseudo isocoles triangle with base superior, without too much tension (may need to make cut along diagnol, as that is the longest dimension of the graft)

-neurulons suture

-attach each corner with needle kept long

-start from top left going down to bottom, then up to top right, then across top to right again, locking your stitches, and overlapping each corner

-irrigate with micro before closing last corner

Closure

-0’s on muscle and fascia

-2-0’s on scarpa/deep dermal

-nylon on skin

-bacitracin/telfa stapled