Medications

• 2 g IV Ancef
• 10 mg IV dexamethasone
• 1000 mg IV Keppra
• 0.5 g/kg IV mannitol
• Adenosine 0.3 to 0.4 mg/kg if necessary to induce asystole in the setting of uncontrollable bleeding from aneurysm rupture

Monitoring

SSEPs, transcranial motors, and EEG.

Retractors

You will need a Layla bar, Greenburg, and fish hooks. Place the Layla bar attachment on the side of the bed contralateral to the pathology, as high up as it will go. 

 Marking

Place your hand on the side of the patient's head with the thumb on the midline and the index finger along the side. The index finger will find the groove or depression posterior to the lateral orbital rim that approximates the level of the sphenoid ridge. Draw the incision such that it is bisected by the line described by your index finger. 

Mark the hairline (red) then mark the incision a few mm behind the hairline (green). Allow the ends of the incision to curve together slightly, this allows for better tissue retraction. 

Patient Positioning

Turn bed 180 degrees such that the feet are at anesthesia. 

Pull the patient up in the bed until the shoulders are just past the break in the bed. 

Place a thin purple foam on the inside of the patient's arms, between the arms and the body. 

Gather up the sheet, wrap the patient, and tape with 3-inch tape. 

 Wrist for Intra-op Angiogram

Pull the right wrist out of the wrapped sheet. Supinate the hand then start taping with the tape against the thenar eminence, go below the bed, come back over the hand and this time let the tape fall between the index finger and thumb before securing to the underside of the bed. 

 Pinning

Pin after the head of the bed has been removed. 

Always use a radiolucent head holder in case of need for intraoperative angiogram. 

Double pin in the axial plane, low on the occiput. Bias slightly towards ipsilateral ear such that the pin is just above and behind the pinna. Single pin at the forehead hairline, at about the level of the mid-pupillary line. 

Head Positioning

MCA Bifurcation Aneurysm

1. Thrust head forward
2. Extend the neck by tilting the chin backward
3. Rotate to the side opposite the pathology by about 20 degrees. The goal is to get the surface of the brain approximately perpendicular with your line of sight. 

Prep

Inject the incision liberally with 0.5% lidocaine with epinephrine. 

Draping

Two to four blue towels surrounding the cranial incision. Keep the towels relatively close to the incision, within a few millimeters. Staple the towels to the skin liberally. 

Four blue towels in a square around the planned angiogram wrist site.

Ioban on both sites. 

Start with a thyroid drape over the wrist site, short end towards the head. Follow this with a crani drape over the cranial incision that is pulled down to just shy of the wrist site, leaving the wrist site uncovered. Finally, place a down sheet on top of everything and staple the border opposite the wrist site to the underlying drapes. Leave unstapled the border of the drape ipsilateral to the wrist site so that the drape can be pulled back to expose the wrist during an intraoperative angiogram. In so doing, all the instrument cords are pulled away from the field of view of the x-ray, which minimizes view clutter. 

Attach the Greenburg retractor C clamp such that the short arm is away from the operator. Attach the Layla bar such that it is low, the elbow is towards the head, and the arm is pointed towards the feet. 

Approach

Make skin incision with a 15 blade, just through the dermis. 

Grab the skin edge at the top of the incision with toothed forceps and poke through the galea with Metzenbaum scissors. Spread the scissors to develop the subgaleal plane. Point the scissors towards the feet, spread them wide, and pull the scalp away from the temporalis. Ask your assistant to Bovie through the galea. Carry this down to the lower limit of the incision. Undercut the galea somewhat at the top and bottom of the incision. 

Use a Ray-Tec to sweep the loose areolar connective tissue off the temporalis fascia anteriorly only. You need very little to no posterior fascia exposure. 

Pull the skin edge anteriorly with three fish hooks. 

Feel for the superior temporal line. Plan the horizontal fascial incision a few millimeters below and parallel with the superior temporal line. Use a 15 blade to make an incision through both layers of the deep temporalis fascia at the superior anterior corner of the exposure. At this level, there will be a fat pad between the two layers. Keep going until you see muscle, but do not cut the muscle. Use Metzenbaum scissors to complete the fascial incision drawn below. Dissect the fascia off the muscle then retract forward and down with a fish hook attached to the Layla bar. 

For the muscle cut, leave a few millimeter cuff of muscle showing from under the edge of the fascia. Use a Bovie to make the muscle cut straight down to bone, in the axial plane as far anteriorly as the lateral orbital rim and posteriorly a few millimeters beyond the edge of the fascial incision (i.e. undercut the muscle below the fascia at the posterior edge). 

Dissect the muscle away from the bone starting at the top edge and working down. Use a Penfield 1 to start then transition to a broad periosteal. Move the fish hook that was previously retracting the fascia to the plane below the muscle to retract it anteriorly. Add the final fifth fish hook to retract the muscle inferiorly and secure to the spoke of the Greenburg retractor C clamp. 

Use the perforator to place a single burr hole at the posterior border of the exposure, at about the level of the sphenoid ridge. Use a Woodson to dissect the dura then use a Penfield 3 to complete the dissection. Feel free to take some bites with a Kerrison to widen the burr hole and make it easier to dissect the dura. Take time with this step, a durotomy is bad form. 

Use the B1 with the foot plate to turn the crani below. Make sure that the cuts starting in the burr hole go straight up and straight down and start at the posterior border of the burr hole. Have an assistant retract the muscle and soft tissue to maximize the crani. The foot plate will have trouble going over the sphenoid ridge from the angle available, so you will often have to score the bone with the unfooted B1 before cracking the deep part of the sphenoid ridge. 

Use a Penfield 1 to dissect the frontal and temporal dura away from the sphenoid ridge to the level of the meningoorbital band. You will not have to take down the band. 

Once the sphenoid ridge is exposed, use an eye rongeur to bite it down as much as possible. 

Then, use the M8 to drill down the sphenoid ridge until it is flush with the orbit. The goal is to make a smooth bony transition between anterior and middle cranial fossae. Do not go into the orbit. Violation of the orbit will give the patient a black eye which significantly reduces the likelihood that they will be comfortable with home discharge on postop day 1. 

To minimize the risk of orbital violation, the drill should be oriented on a trajectory along the lesser wing of the sphenoid, not pointing towards the orbit. Your hand should be resting on the orbital rim and the drill pointing straight into the skull. Do not rest your hand on the squamous temporal bone and point the drill anteriorly towards the orbit. 

Open dura in a C shape and tack up with 4-0 Nurolons on both the flap and the dural edge. Use plenty of tackups on the flap to ensure that the dura is as flat as possible against the drilled edge of the sphenoid ridge. 

Once the dura is open and tacked up, go under scope. 

Begin the Sylvian fissure split by using an 11 blade to nick the arachnoid in several places. Use the fine micro scissors to carry the arachnoid dissection to the aneurysm. 

Closure

Take down the dural tack ups then reapproximate the dura with interrupted 4-0 Nurolon suture. This is not a water-tight closure. 

After obtaining epidural hemostasis, place a single large piece of Nu-Knit over the dura. 

Plate the bone flap as below. Tuck the dog bones back against the burr hole cover to reduce the size of the flap during placement. Once the flap is in place, hinge the dog bones out and secure to the skull. 

Inject bupivicaine into the temporalis muscle before closing the muscle. This reduces postop pain.

For muscle closure, pull the temporalis anteriorly, towards the orbital rim, such that it is biased towards the front of the head. This is done to maximize muscle bulk anteriorly and reduce the likelihood of a cosmetic defect. Close the temporalis fascia on top of the muscle normally, i.e. not biased towards the front. Use 2-0 Polysorb suture. 

Close the galea with 2-0 Polysorb suture. 

Close skin with a running subcuticular 3-0 barbed absorbable suture if available. If unavailable, use a running subcuticular 3-0 Biosyn monofilament suture. Do not use skin glue. 

Dress with a row of Steri-strips oriented perpendicular to the incision. Do not place a single Steri-strip longitudinally over the incision. 

Postop Orders

All patients go to the ICU postop. 

CTA head to verify the vessels are not occluded. 

Goal normotension.

Routine pain medication, Keppra for 7 days, no steroids. 

Most patients go home the next day.