Cranial Procedures For Closed Head Injury14, 15

*If no CT scan is available, an accurate neurological examination must be obtained for the purposes of localizing the lesion. A skull X-ray may improve localization in cases of skull fracture or penetrating brain injury.*

*Proper positioning of the patient is essential.*

1. Avoid any compression of the neck to assure unhindered jugular venous outflow. Temporary removal of cervical collar is recommended as well as the use of a generous shoulder bump to allow semi-lateral positioning without the need for severe head rotation.
2. The head should be positioned slightly higher than the chest to reduce venous congestion and decrease bleeding.
3. Rotate the head 30-40° off midline such that the side being operated on is highest.
4. Mark the midline of the scalp, as well as the location of anticipated burr hole and craniotomy incisions, prior to draping the head. The planned craniotomy should encompass any penetrating injury, if present. It is critical that the planned hemi-craniotomy/craniectomy should achieve adequate dimensions of decompression (15cm AP length, 12cm width, taken to the floor of the middle fossa to decompress the temporal lobe). Equally important is avoidance of iatrogenic superior sagittal sinus injury through inadvertent craniectomy too close to the midline.
5. A single myocutaneous flap should be elevated forward from the cranial surface using cautery and periosteal elevators. Multiple incisions have been described to achieve adequate exposure for optimal cranial decompression. The temporalis is divided superior to the root of the zygoma and dissected anteriorly with its pedicle deep to the zygoma. The flap is secured with skin hooks or suture, permitting access to the middle cranial fossa. Scalp hemorrhage can be extreme and should be meticulously controlled with Raney clips, suture, cautery, or hemostats.

*If pre-operative imaging is not available, exploratory burr holes should be made over the frontal, temporal and parietal convexities using the cranial drill for the purposes of identifying a hematoma. Electric drills are carried by some Role 2 teams. Manual drill/saw with Hudson Brace and Gigli saw is an extremely time-consuming and energy intensive process*

1. The dura can be opened carefully through the burr hole following cauterization if hemorrhage is subdural.
2. If there is evidence of acute epidural/subdural bleeding (bleeding is not controlled), or if the hematoma is not fully evacuated, a craniectomy should be performed.
3. Burr holes alone are unlikely to be helpful in the setting of severe TBI caused by penetrating trauma, acute subdural hematoma, or an acute epidural hematoma; while they are not therapeutic, they are diagnostic for localization of the bleed in the absence of preoperative imaging. Craniectomies should NOT be performed if no subdural or epidural hematoma is encountered, unless there is external evidence of ipsilateral penetrating injury.

*Once the decision to proceed with craniectomy is made, the dura must be carefully separated from the inner table of the skull (Penfield 1-3 instruments) and the burr holes connected with the Gigli saw or electric drill using either a side-cutting bit or a “matchstick” bit.*

1. An appropriately sized hemi-craniectomy is usually at least 15cm long in the sagittal plane and 12cm in height in the coronal plane, a smaller craniectomy is not advisable in the far-forward setting.
2. Take care to stay >2.5cm from midline in-order-to avoid injury to the superior sagittal sinus.
3. If the hematoma is epidural, it must be evacuated and the bleeding source cauterized.
4. If subdural, the dura must be opened, the hematoma evacuated, and if visible, the bleeding source cauterized.
5. DO NOT replace the bone. For U.S. Service Members, the bone should be discarded with planned future cranioplasty with custom implant.
6. If not visible, do not search for a hemorrhage source in order to minimize risk of further injury.
7. If subdural pathology, do not close the dura. The dura may be loosely reapproximated over the cerebral hemisphere. Dural allograft (e.g., Duragen), if available, should be placed over the decompressed cerebral hemisphere for improved cerebrospinal fluid (CSF) control and to assist with future cranioplasty. Alternative hemostatic agents (e.g., Gelfoam, Surgicel) or pericranium autograft can be used to create a barrier between cerebral cortex and scalp.
8. An intracranial monitor (external ventricular drain (EVD) or parenchymal intracranial pressure (ICP) monitor) should be placed if available and the surgeon is adequately trained to perform the procedure. EVD is preferred as it is both a diagnostic and therapeutic device.
9. In all circumstances, the scalp must be closed (interrupted 2-0 Vicryl to reapproximate Temporalis fascia, interrupted 2-0 Vicryl to close galea, running staple line for skin).

*If the brain herniates rapidly after dural opening, close the scalp immediately due to risk of cyclical and catastrophic extracranial herniation, which is associated with a high mortality *