This approach continued throughout World War II and was refined by Dr. Donald Matson in his classic monograph published in 1958.² Matson described the principal tenets of performing initial lifesaving interventions, preventing infection, preserving neurological function, and restoring normal anatomy. These strategies hold as true today as then and have developed into modern advanced trauma life support (ATLS) guidelines,³ aseptic surgical techniques, prevention of secondary injury through neurocritical care, and craniofacial reconstruction.

Cushing’s strategy of débridement continued to be applied in both the Korean War and the Vietnam conflict where early experiences with less aggressive approaches were met with higher infection rates and increased mortality rates.⁴^–⁶ It was not until the Israel/Lebanon conflict of 1982, when computed tomography (CT) first became routine in the assessment of head injury, that a more conservative approach was advocated in favor of brain preservation. This approach was validated by 6 years of follow-up in the studies by Brandvolt and associates and Levi and colleagues and by 8 years of follow-up in a similar group of patients from the Iran-Iraq war of 1986 by Amirjamshidi and co-workers revealing no statistically significant increase in delayed infection or seizure disorders.⁷^–⁹ A report of early experience with conservative débridement in Operation Desert Storm continued to find similar results¹⁰ (Fig. 21.1).

FIGURE 21.1 A, Tangential penetrating injury with posterior entry. B, Patient was immediately taken for decompressive hemicraniectomy for elevated intracranial pressures. C and D, Axial noncontrast computed tomography (CT) scan demonstrating superficial scalp hematoma, with comminuted bony fracture and underlying hemorrhagic contusion. No midline shift, preservation of the basal cistern, without a focal mass lesion. E and F, Severe lateral temporofacial explosive blast injury with significant disruption of anatomical continuity, tissue loss, associated traumatic orbital injury, with left hemispheric edema, midline shift, obliteration of ambient cisterns, and focal temporal lobe hematoma. Patient responded well to left hemicraniectomy, evacuation of temporal lobe hematoma, left orbital enucleation, and staged skull base repair. Incision was placed in midline with large left posterior auricular curve toward the mastoid tip away from the zone of injury. After hemicraniectomy, duraplasty, skull base repair with split-thickness bone graft from the cranial plate of the hemicraniectomy, with tissue closed up to the zygoma separating the lateral facial component, followed by initial wound packing in the infratemporal portion, wound was later definitively closed after subsequent débridements.

In 1995, the Brain Trauma Foundation developed the first traumatic brain injury (TBI) guidelines with the assistance of international experts in the field to address the need for protocol-driven health care based upon the most current scientific literature. In 2001, guidelines for the care of PBI were created toward the same end with the support of the Brain Injury Association, the International Brain Injury Association, the American Association of Neurological Surgeons (AANS), and members of the Congress of Neurological Surgeons (CNS). These guidelines stand as the most comprehensive evidence-based evaluation of interventions specific to the care of PBI and are summarized in Table 21.2.¹¹ It is worth mentioning, however, that despite the exhaustive literature search used to develop the guidelines, no recommendation achieves a level beyond that of option and this underscores the need for further research. No level I or II data exist on the subject.

TABLE 21.2 2001 Guidelines for the Management of Penetrating Brain Injury

Topic	Conclusion	Recommendation Level
I. Antibiotic prophylaxis	The use of prophylactic broad-spectrum antibiotics is recommended for patients with PBI.	Option
II. Seizure prophylaxis	The use of prophylactic antiseizure medications in the first week after PBI is recommended to prevent early post-traumatic seizures.	Option
III. ICP monitoring	Early ICP monitoring is recommended when the clinician is unable to assess the neurological examination accurately or if CT scans suggest elevated intracranial pressure. The need to evacuate a mass lesion is unclear.	Option
IV. Management of CSF leaks	Surgical correction is recommended for CSF leaks that do not close spontaneously, or are refractory to temporary CSF diversion. During the primary surgery, every effort should be made to close the dura and prevent CSF leaks.	Option
V. Neuroimaging	CT scanning of the head is strongly recommended. Angiography is recommended in PBI when a vascular injury is suspected. Routine MRI is not recommended for use in the acute management of missile-induced PBI.	Option
VII. Surgical management	Evacuation of hematomas with mass effect, conservative débridement of missile tract without retrieval of remote fragments, débridement of nonviable scalp, bone, or dura before primary closure, and watertight repair of open-air sinus injuries is recommended.	Option
VIII. Vascular complications	CT angiography and/or conventional angiography should be considered when vascular injury is suspected. If traumatic intracranial aneurysm (TICA) or arteriovenous fistula (AVF) is identified, surgical or endovascular management is recommended.	Option

CSF, cerebrospinal fluid; CT, computed tomography; ICP, intracranial pressure; MRI, magnetic resonance imaging; PBI, penetrating brain injury.

Modified from Aarabi B, Alden TD, Chestnut RM, et al. Management and prognosis of penetrating brain injury. J Trauma 2001;51:3-43.

Craniofacial injuries sustained during OEF and OIF have resulted in further modifications to the management of patients with severe PBI.¹²^–¹⁸ Although aggressive débridement of the brain is no longer used, early and aggressive cranial decompression with subsequent watertight dural closure is the current accepted practice (see Fig. 21.1).¹⁸ This strategy affords the patient protection from significant elevations in intracranial pressure (ICP) during the long flights, unaccompanied by neurosurgeons, from operative theaters back to the United States. This initial stabilization is then followed by protocol-driven neurocritical care aimed at preventing secondary neurological decline and maximizing neurological recovery. Though the data are still under review, preliminary analysis appears favorable^15,¹⁹ (Fig. 21.2).

FIGURE 21.2 A, Victim of a point blank attempted homicide evidenced by powder burns at the entry site. At the initial physical examination, this bihemispheric gunshot wound to the head (A and B) appears to cross the zona fatalis, but the computed tomography (CT) scan (C) instead reveals a more anterior trajectory. This information led to the appropriate course of decompression and aggressive management, subsequently resulting in a favorable outcome.

Prognosis

Civilian PBI has high mortality rates that remain refractory to medical and neurosurgical advances based on the most recent case series.^20,²¹ The mortality rate in most retrospective cohorts is greater than 70% owing in large part to the higher percentage of gunshot wounds (see Fig. 21.2), suicides, and the ubiquitous absence of cranial protection (helmets) compared to military injuries.²²^–²⁶ Other variables that differentiate these two groups are presented in Table 21.3. The reported civilian mortality rates from gunshot wounds to the head (GSWH) in the literature range from 23% to 92% with those series on the lower end including a number of cases without dural violation.²⁷^–²⁹ Death from PBI occurs shortly after injury with 70% of patients succumbing after the first 24 hours^23,²⁵ (Table 21.4).

TABLE 21.3 Comparison of Civilian and Military Penetrating Brain Injury

Factor	Civilian	Military
Population	Heterogeneous	Homogeneous (younger overall age)
Mechanism	Gunshot/suicide	Blast/shrapnel
Environment	Modern sanitation	Possibly contaminated
Prehospital care	Variable	Immediate
Tertiary care	Hours	Variable
Injury severity score (ISS)^∗	Low	High

TABLE 21.4 Prognostic Variables

Topic	Conclusion	Data Class
I. Age	Age > 50 years is associated with higher rate of mortality, but significance is unclear.	III
II. Cause of injury (suicide)	Self-inflicted GSWH carry a higher rate of mortality than those for other causes.	II
III. Mode of injury	Perforating wounds have a higher mortality rate than tangential or penetrating PBIs.	III
IV. Caliber of weapon	No demonstrated effect.
V. Hypotension	Hypotension is associated with increased mortality rate.	III
VII. Coagulopathy	Coagulopathy is associated with increased mortality rate.	III
VIII. Respiratory distress	Respiratory distress is associated with increased mortality rate.	III
IX. GCS	In civilian injuries, low GCS score correlates with higher mortality rate and unfavorable outcome. In military injuries, low GCS score correlates with unfavorable outcome.	I (civilian) III (military)
X. Pupil size and response	The presence of bilateral fixed and dilated pupils is highly predictive of fatal outcome.	III
XI. ICP	High ICP is predictive of higher mortality rate.	II

GCS, Glasgow Coma Scale; GSWH, gunshot wounds to the head; ICP, intracranial pressure; PBI, penetrating brain injury.

Modified from Aarabi B, Alden TD, Chestnut RM, et al. Management and prognosis of penetrating brain injury. J Trauma 2001;51:44-86.

Prognostic indicators were classified as a separate section in the 2001 PBI guidelines and are summarized in Table 21.4.¹¹ Of these factors and consistent with data in other forms of TBI, a postresuscitation Glasgow Coma Scale (GCS) score stands as the most reliable predictor of death and other unfavorable outcomes.³⁰ This measure is a consistent predictor for both civilian and military populations but appears to have the greatest correlation with civilian mortality. In series segregating out patients with poor presenting neurological function or upon subgroup analysis of those with GCS scores of 3 to 5, mortality rate rises to 87% to 100%.²⁵^–³¹ A recommended triage for both military and civilian patients is located in Figure 21.3.