Keywords
penetrating brain injury - orbital injury - traumatic cerebrovascular injury - traumatic
brain injury
Introduction
A transorbital intracranial penetrating injury (TOPI) is an unusual traumatic brain
injury (TBI) that could be fatal. From the literature review, TOPI was found in 0.04%
of all TBI cases.[1] TOPI leads to serious damage when a foreign object penetrates the cranium, thus
requiring multidisciplinary management. Traumatic cerebrovascular injury (TCVI), accounting
for 0.8 to 1.7% of TBI, is one of the injuries that should be concerned in TOPI.[2]
[3] The authors report on a case of TOPI due to a penetrating injury from a handmade
gun that caused a projectile to enter through the left orbit and compress the left
anterior cerebral artery.
Case Presentation
An 8-year-old male patient was transferred to our hospital because of TOPI caused
by a handmade gun that penetrated through the left orbit. Examination showed mild
ptosis with blindness in the left eye. There was no neurological deficit. A computerized
tomography (CT) scan of the brain revealed a round-shaped foreign body through the
left medial orbit plane that caused a left orbital fracture and entered the left frontal
lobe, as shown in [Fig. 1A]. In addition, CT angiography of the brain that was performed for evaluation of TCVI
demonstrated the foreign body had compressed the left anterior cerebral artery, as
shown in [Fig. 1B]. In addition, extravasation of contrast was not seen from images. We chose a transorbital
approach with an intraoperative transcranial approach on standby to remove the foreign
body. Firstly, enucleation of the left eye was performed by an ophthalmologist. Consequently,
the foreign body was observed on the medial side of the left orbit and removed by
a neurosurgeon, as shown in [Fig. 2A]. The foreign body was a marble 1.5 centimeter in diameter that was used as a projectile,
as shown in [Fig. 2B]. Fibrin glue was applied at the surgical site although no cerebrospinal fluid leakage
was apparent. After the procedure, antibiotics were administered continuously for
14 days, and there were no complications such as cerebrospinal fluid leakage. At a
3-month follow-up, the patient appeared to have had an uneventful recovery and there
was no delayed pseudoaneurysm on the CTA of the brain.
Fig. 1 Image of a patient injured by a handmade gun. (A) Axial computed tomography (CT) head bone-window image showing a round-shaped foreign
body through the left orbit that entered the left frontal lobe. (B) Three-dimensional (3D)-reconstruction CTA of the brain showing a foreign body (green
arrow) that caused a left orbital fracture and compressed left anterior cerebral artery
(red arrow).
Fig. 2 Image of intraoperative findings. (A) The projectile placed at the left medial orbit (arrow). (B) Marble projectile 1.5 centimeter in diameter removed via the transorbital approach.
Discussion
TOPI following a penetrating injury is uncommon in TBI. From a prior study, the incidence
of TOPI has been reported in 0.04% of TBI cases. Various foreign bodies have been
reported to have entered through the orbit to the cranium, including metal bars[4]
[5] and wooden sticks.[6] Complete ophthalmological and neurological examinations are important in TOPI. Because
patients with TOPI can present both obvious and occult ocular injuries, intracranial
injury cannot be excluded.[7]
CT scan imaging is important for the evaluation of the trajectory of a projectile
and orbitocranial injuries, while magnetic resonance imaging (MRI) of the brain is
useful for evaluating injuries caused by wooden foreign bodies.[4]
[8]
[9] Cerebral angiography should be concerned when a projectile or foreign body has entered
the adjacent base of the skull, orbit, and facial bones.[5]
[8]
[9] Therefore, TOPI is a high risk to TCVI from the penetrating mechanism. Moreover,
a foreign body is often positioned near intracranial vessels. In an acute setting,
less invasive investigations such as CT angiography may be appropriate for the initial
preoperative evaluation of TCVI.[10]
[11]
The most common trajectory of entry is the superior orbital roof, which may cause
injury to the frontal lobe and intracranial vessel. If such penetration has sufficient
force, deep intracranial structures may be damaged such as the cavernous sinus, temporal
lobe, and brainstem. Arslan et al reported a fatal case of TOPI, which involved a
long metal bar penetrating from the right orbit to the left occipital bone.[1]
Management of TOPI typically involves foreign body removal that may lead to serious
intracranial infection later. However, intraoperative bleeding from the intracranial
vessel should be considered because the foreign body compresses and adheres to vascular
structures during foreign body removal. Three surgical approaches have been described
to remove a foreign body: anterior orbitotomy, subcranial craniotomy, and frontotemporal
craniotomy.[8] The surgical approach is selected depending on the location of the foreign body.
In the present case, we removed the marble projectile via the transorbital approach
with a transcranial approach ready if active bleeding occurred following the removal
of the foreign body. If the foreign body mainly involves intracranial structures,
the transcranial approach would be preferable in this situation.[9]
[10] Additionally, debridement of bone fragments, hematoma evacuation, control bleeding,
and repair of dural defects are required to avoid potentially infectious complications
later.
Postoperative intensive broad-spectrum antibiotics should be administered to prevent
subsequent infection. Staphylococcus, Bacillus, and Clostridium species have been reported TOPI cases. Therefore, appropriate tetanus immunization
is needed.[12]
[13] For long-term complications, postoperative cerebral angiogram or less-invasive vascular
studies including MR angiography or CT angiography should be performed 1 to 3 months
after the injury to evaluate delayed pseudoaneurysm.[9]
[10]
