EEA

Last modified by XWikiGuest on 2023/11/10 16:41

Pre-op

Before the case begins, know the pathology and approach for prior resections.  Know what kind of reconstruction was done for prior EEA's.  Pay particular attention to medications the patient is on including steroids, DDAVP, and Synthroid.  If the patient is on steroids they will need stress dosing, usually 100q8 hydrocortisone, to be given prior to induction of anesthesia.  Gardner also likes a preinduction arterial line to be placed.

Monitoring

For all cases, pre-position SSEPs are obtained if the patient is older than 60 years old. Always place a Foley.

Positioning

Patient begins positioned supine on the operating table and is intubated. The bed is rotated, the head is always to the right of anesthesia (as if positioning for a right sided crani) and the feet are to the left. The foot of the bed is kicked out, away from anesthesia, to a 45 degree angle. The bed is moved such that the left axilla is just above the metal cross In the tile the floor where the tiles meet.  The patient is moved up until the top of the shoulders is at the break between the headboard and the rest of the bed.  Patient is moved slightly to the right such that they are not lying exactly in the middle of the bed but are biased slightly to the patient's right, towards the operators.  The right arm is tucked.  A blanket is placed over the chest and the belly is left uncovered for a fat graft. If a fascia lata graft is possible, then the thigh is also left bare.  

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Fascia Lata

First, bend the knee and internally rotate the hip. Put a pink foam donut under the heel. Put a folded pillow under the knee. Put a thin purple foam over the lower leg and go around with 3-inch tape to secure the leg to the bed and hold it in an internally-rotated position. 

Mark the head of the fibula and the greater trochanter. When the leg is held in the internally-rotated position, the location of the IT band stands out on the lateral leg as a shallow linear depression (red arrows). 

Mark a 3-inch linear incision parallel to the IT band midway between the marks for the greater trochanter and fibular head in the rostral-caudal dimension. The mark should be midway between the IT band and the mid-sagittal line in the medial-lateral dimension. 

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Pinning

The head is pinned with 2 pins on the left and 1 on the right.  On both sides, 1 pin is placed at approximately the 10:30 position behind the pinna.  I.e., superior and posterior to the pinna.  On the side with 2 pins, that pin is the lower. The upper pin is positioned anterior, essentially at the superior temporal line. 

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The head of the bed is removed. Head positioning varies depending on approach (e.g. tumor in the sella vs cribriform plate).

General principles:

  1. Thrust the head forward and extend the chin
  2. Turn the head towards the operator
  3. Tilt the apex of the head away from the operator.  
  4. Lock the Mayfield such that the arm is beneath the head.  Attach to the outside attachment. 
  5. Attach the image guidance arm to the inside attachment

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Finally, drop the bed down until the head is approximately level with your arms held at a 90-degree angle.  Raise the legs slightly and raised the back of the bed until it is at 15 degrees with the floor. Use a level on your phone to verify that it is in fact at 15 degrees.  

Registration

Registration is done by the tech. Verify the registration against the teeth, nasion, sides of the nose, and skin of the frontal scalp, making sure the probe is in fact at the skin.

Eye Padding

Once the neurophysiologist finishes applying the leads to the face and eye, tape the eye closed with a single piece of vertically-oriented tape. Then, fold a 4x4 piece of gauze to the size of the orbit. Place the gauze on the orbit such that the folded parts are against the brow ridge and the nose. Secure in place with Tegaderms. 

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Afrin Pledgets

Placement of Afrin-soaked pledgets is usually done by ENT.  If you are asked to do it as the neurosurgery resident, this is how:

  1. Take 1 pledget at a time, hold open the nostril with the speculum, place the first pledget superiorly, aiming towards the eye, bury the pledget all the way in the nose, until no part of the cotton is showing, only string.  Do the other nostril.  
  2. Place the second pledget below the first one, do the other nostril.  
  3. Place the third pledget aiming straight back, parallel with the palate.  
  4. Use Betadine to prep the nose and upper lip and chlorhexidine to prep the belly. Remove the pledgets before draping.

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Draping

Draping is also usually done by ENT.  If you are asked to do this, it is done as follows:

  1. Use 3 blue towels to outline a triangle around the nose.  
  2. The first is applied over the upper lip, leaving 2 mm of upper lip showing.
  3. Two other blue towels are placed over the eyes to complete the triangle.  
  4. A down sheet is placed
  5. An Ioban is used to cover the nose.
  6. An Ioban is applied over the belly.  
  7. A thyroid drape is applied over the belly, then another over the nose. The nose thyroid drape is allowed to cover the window in the belly thyroid drape.  Later, when fat is harvested, a hole will be cut in the drape overlying the belly site.
  8. Cut a hole in the nose ioban to expose the nostrils

Quiz questions

  • What nerve is at risk of injury with a fascia lata harvest incision that is too high? 
    • Lateral femoral cutaneous nerve
  • What are the attachments of posterior clinoids?
  • Upper clivus, bone over paraclival carotid, and dorsum sellae

Antibiotics

As of 2023:

PackingRedoAntibiotics

Merocels

NoAncef for 48 hours then Ceftin until packing is removed
MerocelsYesAncef + Levaquin 500 q24 for 48 hours then just Ceftin until packing is removed 

Nasopores

NoAncef for 48 hours then Ceftin for 72 more hours for a total of 5 days on antibiotics
NasoporesYesAncef + Levaquin 500 q24 for 48 hours then just Ceftin for 72 more hours for a total of 5 days on antibiotics
DoylesAnyNo antibiotics

Discharge