1. Position the patient with head/torso at 45° angle relative to the floor.
2. Shave frontal scalp and mark Kocher point (approximately 11 cm from the nasion and 3 cm from the midpupillary line)
3. Prepp and drape patient in the usual sterile fashion.
4. Inject lidocaine at the marked site, and with a 15-blade scalpel, make a 2- to 3-cm vertical incision centered on the Kocher point.
5. Invert scalpel and with the blunt pointed end, strip the skull from the pericranium.
6. Insert a small, self-retaining retractor to maintain visualization of the cranium and to aid in hemostasis.
7. Perform a craniostomy using a hand drill with a 5.3-mm drill bit. Exercise caution to perforate inner table slowly, without exerting downward force on the dura.
8. After removing the hand drill, directly visualize craniostomy and evacuate any remaining bone pieces from the site with a pair of Adson forceps.
9. Using an 11-blade scalpel, incise the dura through the craniostomy in a cruciate fashion.
10. Slowly pass the catheter (Integra Large-Style Ventricular Catheter, 3-mm outer diameter) through the cranistomy into the frontal horn of the lateral ventricle.
11. The trajectory of the catheter in the coronal plain is the medial canthus of the ipsilateral eye and the external auditory canal in the sagittal plane.
12. Do not insert catheters deeper than 7 cm at the bone edge.
13. Once clear CSF is visualized, remove metal stylet and tunnel catheter subcutaneously approximately 2- to 3-cm away from the incision.
14. Close the incision with nylon suture and connect the ventricular catheter to the drainage system in a sterile manner. Secure catheter to the patient.
15. Perform a head CT to verify catheter position.
FREEHAND PASS TECHNIQUE OF EVD INSERTION
- The right frontal cerebral hemisphere is the preferred site of entry given its nondominance for language function in >90% of patients.
- HOB 45 degrees supine
- Remove hair with clippers, prepare scalp in sterile fashion
- create Burr hole at Kocher’s point
- avoid SSS and motor strip
- draw 1 line in midline from nasion to a point 10cm back and another from previous point to a site 3cm lateral, along the ipsilateral midpupillary line)
- Instill local anesthesia
- Make linear incision down to bone and scrape periosteum
- Penetrate cranium with twist drill in the trajectory determined for ventricular cannulation and pierce pia and dura with scalpel
- Prime ventricular catheter
- Pass no more than 7cm aiming in coronal plane towards medical canthus of ipsilateral eye and in anteropost plane toward 1.5cm anterior to ipsi tragus toward ipsi Foramen of Monro
- Transduce catheter once CSF flow visualized after removal of catheter stylet – obtain opening pressure
- Tunnel catheter through skin away from point of entry through separate incision, suture in place and connect to external drainage system
Kocher Point: 12-13 cm posterior to nation and 3cm lateral from the midline.
Kosty, Jennifer et al. “Iatrogenic Vascular Complications Associated With External Ventricular Drain Placement”. Operative Neurosurgery 72 (2013): ons208-ons213. Web.
Muralidharan, Rajanandini. “External Ventricular Drains: Management And Complications”. Surgical Neurology International 6.7 (2015): 271. Web.
Vincent, J. L, and Jesse B Hall. Encyclopedia Of Intensive Care Medicine. Berlin: Springer, 2011. Print.