Introduction
Endoscopic removal of foreign bodies from the nose and paranasal sinuses is well known. However, endoscopic removal of intracranial foreign bodies has rarely been reported in the literature.Reference Dodson, Bridges and Reiter1, Reference Cetinkaya, Okan and Pelin2 Most surgeons opt for the traditional anterior craniotomy approach, which is associated with significantly higher morbidity and mortality.
Here, we describe a case in which an air rifle pellet was successfully removed transnasally and endoscopically from the anterior cranial fossa.
We submit that endoscopic removal is an alternative to craniotomy for the removal of foreign bodies located in the anterior skull base, if access is possible and the surgeon is able to close the skull base defect to prevent a cerebrospinal fluid (CSF) leak, provided adequate neurosurgical facilities are close at hand.
Case report
A depressed 41-year-old man, under the influence of alcohol, presented to the accident and emergency department after having attempted suicide by shooting himself with an air rifle placed beneath his chin. He was conscious, alert and stable, with a Glasgow coma scale of 15/15 at presentation. He complained of a headache and pain in his right eye, without visual loss or restriction of eye movement. He had vomited twice. There was a history of a previous overdose with tricyclic antidepressants four years ago.
Examination showed an entry wound of the pellet in the submental region, which traversed through the floor of the mouth, tongue, and hard palate. There was no compromise of his airway, CSF leak or any neurological deficit. A computed tomography scan of his head revealed an air rifle pellet lodged in the bony floor of the anterior cranial fossa, superior to the posterior ethmoid sinuses, with free intracranial air (Figure 1). No intracranial haemorrhage was seen.
Fig. 1 Computed tomography scan showing airgun pellet located superior to the posterior ethmoid sinuses in the anterior cranial fossa.
The patient was admitted under the care of the neurosurgeons. The maxillofacial surgeons decided to treat the wounds conservatively.
We proceeded to remove the pellet endoscopically from the anterior cranial fossa under general anaesthetic. The nose was prepared with Moffat's solution. A right anterior and posterior ethmoidectomy with a right sphenoidotomy was performed to delineate the skull base. This revealed a defect superior to the posterior ethmoid sinuses. The defect was enlarged and then the pellet was identified and removed. The defect was closed in layers using bone and mucosal free grafts from the inferior turbinate, and further reinforced with oxidised cellulose to prevent a CSF leak and to reduce the risk of meningitis.
Regular neurological observations were conducted post-operatively. The patient made an uneventful recovery and was discharged the next day with a course of co-amoxyclav 375 mg thrice daily for one week.
Discussion
Intracranial foreign bodies occur as a result of accidents, self-harm or iatrogenic incident. Removal of the foreign body is often indicated, to prevent such consequences as CSF leak, meningitis, brain abscess, hydrocephalus, injuries to intracranial nerves and vessels, and even death.Reference Dodson, Bridges and Reiter1 However, the site of some intracranial foreign bodies may mean that surgery is contraindicated as the risk of their removal would outweigh the benefit. Closure of an anterior skull base defect and a CSF leak is also indicated to reduce the likelihood of developing meningitis.Reference Marshall, Jones and Robertson3 Foreign bodies such as pellets made of lead also involve the risk of causing lead poisoning in the long term, thus further warranting their removal.Reference Brinson, Senior and Yarbrough4
Intracranial foreign bodies have traditionally been removed via a craniotomy approach. However, this procedure is associated with significant morbidity and even mortality.Reference Marshall, Jones and Robertson3 A frontal craniotomy often results in a loss of the sense of smell. Uncommonly, but importantly, it may also be complicated by post-operative intracerebral haemorrhage, cerebral oedema, epilepsy, frontal lobe dysfunction with memory and concentration deficits, and osteomyelitis of the frontal flap bone. In addition, a craniotomy requires the patient to spend five to seven days in hospital, results in the loss of hair along the incision line, and requires the patient to not drive until they are judged to have recovered from the operation.
Endoscopic sinus surgery has been used to treat lesions of the anterior and central skull base.Reference Casler, Doolittle and Mair5 It has the benefits associated with reduced morbidity, such as decreased duration of hospital stay, lower levels of post-operative pain, preservation of olfaction, less blood loss and no visible scars.
The decision to remove an intracranial foreign body endoscopically would depend on the location of the foreign body, the skill and experience of the surgeon, and the availability of neurosurgical backup. Pre-operative imaging would be mandatory. Only foreign bodies located at or close to the skull base should be considered for endoscopic removal, in order to prevent damage to the adjacent brain. If the intracranial foreign body is removed successfully, the surgeon should have the ability to close the bony defect endoscopically in order to prevent CSF leak and subsequent risk of meningitis.Reference Jones6 Successful closure can be achieved using bone and mucosa from the inferior turbinate.Reference Mirsa, Thaper, McClelland and Jones7 If there is difficulty in locating the foreign body due to uncontrolled haemorrhage or swelling around the brain, then the procedure should be abandoned and the patient referred to the neurosurgeons.
• Intracranial foreign bodies are typically removed via a craniotomy, which carries significant peri-operative risks
• This paper describes a case in which nasal endoscopy was employed to remove an air rifle pellet from the anterior cranial fossa, with subsequent repair of the associated cerebrospinal fistula
• This approach carries significantly less morbidity than a neurosurgical craniotomy
As experience with endoscopic sinus surgery has grown, so has its extended applications. In cases of intracranial foreign bodies located close to the skull base, we feel an endoscopic approach for removal should be considered as an alternative to craniotomy, provided the surgeon is able to close any resultant CSF leak endoscopically. We also acknowledge the importance of adequate neurosurgical support in case nasal endoscopic removal of the intracranial foreign body is not possible or is unsuccessful. Considering this multidisciplinary approach, it is important that such a procedure is undertaken in places where neurosurgical facilities are easily accessible.
