Retained intracranial splinters : a follow up study in survivors of low intensity military conflicts.
With improvements in the ballistic physics, patient evacuation, imaging, neurosurgical management and intensive care facilities, there has been overall improvement in the survival of patients with missile injuries of the brain. Patients with retained intracranial fragments have been followed up and the sequelae of such fragments were analysed. We present our observations in 43 such patients who had survived low velocity missile injuries of the brain during military conflicts and had retained intracranial fragments. Over a follow up period of 2 to 7 years, suppurative sequelae (brain abscess, recurrent meningitis) were seen in 6 patients, two of these progressing to formation of brain abscess. Three patients developed hydrocephalus and one seizures. Patients with orbitocranial or faciocranial wound of entry had a higher incidence of suppurative complications (3 out of 4), while those with skull vault entry had a lower incidence of such sequelae (7 out of 30). Nine patients were lost to follow up. Other determinants of suppurative complications were postoperative CSF leak and intraventricular lodgement of the fragment.
The literature on missile injuries of the brain sustained
in war is more extensive than the one dealing with
such injuries sustained during peacetime. While high
velocity missile injuries (HVMIs) are almost
invariably fatal, majority of the survivors would have
sustained low velocity missile (LVM) injuries. Source
of LVMs is generally a shrapnel from a grenade,
rocket or improvised explosive device (IED) etc. With
rapid evacuation of such patients to neurosurgical
centres, availability of computed tomography (CT),
improved understanding of missile ballistics and
better neurosurgical techniques and postoperative
care, there has been overall improvement in the
survival of these patients. This has also resulted in
more survivors with retained intracranial splinters,
who have been followed up over a period of years and
the sequelae and outcome of retained splinters have
been analysed. We present our observations in 43 such
patients with retained intracranial splinters. Relevant
literature is briefly reviewed.
A total of 18 patients with low velocity missile
injuries (LVMIs) of the brain were seen among the
Indian Army personnel during Sri Lanka operations in
1987-1989, and 92 patients were treated in Jammu
and Kashmir from 1990-1996. The sources of
missiles were IEDs, grenades, rockets and rifle
bullets. There were 28 orbitocranial and two frontoorbitomaxillary
injuries. All the injuries were
Assessment and Initial Management : Patients were
evacuated to the nearest Base Hospital after the injury,
within half an hour to more than 24 hours. Triage was
carried out and priority allotted. After resuscitation,
patients with brain injuries were neurologically
evaluated; this examination formed the baseline for all
subsequent neurological evaluation. Head was shaved
and open wounds were dressed. Intravenous mannitol,
frusemide and antibiotics were administered. All
patients had skull radiographs taken. CT brain could
be done in 23 patients before surgery.
Initial Surgery : Ninety patients underwent surgery.
Eight patients died in the hospital prior to surgery, and
nine patients with small puncture wounds and no
neurological deficit, were not operated upon and
followed up. Craniectomy was done at the site of
entry/exit wounds. Debridement was done till normal
looking brain was seen and cavity did not collapse.
Metallic splinters were removed only if they were
seen during the course of debridement.
Retained Intracranial Splinters : Forty three survivors
had retained intracranial splinters. Out of these, in the
postoperative period, two patients with orbitocranial
injury and ten patients with skull vault injury had CSF
leak from the wound for a period of 3-12 days. The
distribution of these patients is as given in [Table I].
These patients have been followed up for over a
period varying between one year to ten years. Nine
patients (two non-operated cases with puncture
wounds and seven operated cases) were lost to follow
up. The sequelae of retained splinters in the remaining
34 is as given in [Table II]. It is observed that three out
of four patients with orbitocranial injury and 7 out of
30 cases with skull vault injury had suppurative
sequelae. Recurrent meningitis was followed by
hydrocephalus, which required ventriculoperitoneal
shunting. In one of these patients with puncture
wound and no neurological deficit, there was
intraventricular lodgement of the splinter [Figure - 1].
Brain abscess was seen in two cases who earlier had
recurrent bouts of meningitis [Figure - 2]. Abscesses were
excised in both the cases together with the retained
missile fragments, which was seen adherent
to/embedded in the abscess wall. No abscess was seen
in skull vault group. One of these, however, developed
temporal lobe seizures requiring antiepileptic
medication. These patients are being followed up and
have remained stable. No sequelae have been noted in
the remaining 23 patients with retained intracranial
splinters on follow up [Figure - 3] and [Figure - 4].
In the past, military neurosurgeons believed it was
imperative to remove all intracranial bone and metal
pieces in a patient with splinter injury of the brain.
Reoperation was advocated if retained fragments were
evident after initial debridement., One of the
primary histological concerns with a less aggressive
approach has been the fear of intracerebral abscess
formation.4 Martin and Campbell5 recorded a
parenchymatous infection rate of 16% based on their
World War II experience. They believed that infection
was 10 times more likely to occur in the presence of
retained bone fragments than in their absence.
Nevertheless, the complication rate of secondary
procedures is high and consists of increased
neurological deficit, enhancement of cerebral oedema,
infection and deaths.
Others,, have advocated a more conservative
approach. Brandvold et al reported 83 patients with
splinter injury to brain with retained metal or bone
fragments. At follow up, there were no suppurative
sequelae. The low incidence of brain abscess and
inconsistent presence of retained fragments in patients
presenting with abscess has been confirmed by the
Vietnam head injury study (VHIS). In an analysis of
127 war inflicted missile injuries sustained in North-
Eastern Croatia, Vrankovic et al, reported an
incidence of retained fragments in 76.8% of the
patients, with intracranial infection rate of 10% in
these patients. In a recently concluded exhaustive
study on splinter injuries to brain during Iran-Iraq
war,11 it has been brought out that retained bone and
metal fragments were less important factors in CNS
infections after military head wounds.
The factors consistently leading to suppurative
a) Facio-orbital wound of entry, traversing the air
filled sinuses :The intracranial contents are in
communication with potentially infected mucus
secreting spaces, with higher risk of intracranial
b) CSF leak : Persistent CSF leak, especially more
than 24 hours old, is fraught with danger of meningitis
c) Intraventricular lodgement of the missile fragment.
Although the possible epileptogenic effects of
retained metal fragments - especially copper - have
been mentioned, there is no definite indication for
pursuing metallic fragments beyond those that are
readily accessible. The single exception is metallic
migrating fragment. Intraparenchymal bullets
generally do not migrate; intraventricular fragments
are the ones that do and these should be removed by
endoscopic manoeuvers or by stereotaxy.
With improvement in evacuation of patients with
missile injury to the brain, better understanding of the
pathology, improved imaging modalities, surgical
facilities and postoperative care, there will be more
patients surviving the initial injury. Missile fragments
need not be specially searched for during debridement
so as to avoid aggravation of neurological damage.
The fragments should be removed only if they are
visible. Retained intracranial fragments do not,
predispose the patient to suppurative complications.
On the other hand, other factors like postoperative
brain swelling and CSF leak, orbitocranial trajectory
and intraventricular lodgement are associated with
increased incidence of such complications. Patients
with retained intracranial missile fragments should be
on regular follow up so that such complications are
recognized and treated as they occur.