Penetrating skull injury with six inch fence rod.

In this study we are describing an unusual case of the boundary fence (6 inch long) penetrating through the skull vault and lodging into the middle cranial fossa. A 10 years old male child fell onto his house fence while playing on the terrace. The metal fence penetrated through the scalp, parietal bone, midbrain and the midface, fracturing the parietal and the midfacial bones. CT-scans were obtained to view the trajectory and the position of the fence. The amount of midbrain injury was also accessed. The degree of morbidity vis-à-vis the type of injury was surprisingly low. Safe access to the fence was made through a bicoronal incision and modified bifrontal craniectomy to retrieve the lodged portion of the fence. These kind of penetrating injuries are rare considering the thickness of the vault. Proper preoperative planning and team approach is required for the safe surgical removal of the objects.

INTRODUCTION

Penetrating skull injury in children is usually rare. A penetrating head injury is a head injury in which the dura mater is breached.[1] Penetrating injury can be caused by high velocity projectiles or objects of lower velocity such as knives, or bone fragments from a skull fracture that are driven into the brain. Head injuries caused by penetrating trauma are serious medical emergencies and may cause permanent disability or death. The injury in penetrating brain trauma is mostly focal.[2] This focal, or localized, damage occurs along the route the object has traveled in the brain. Symptoms vary depending on the part of the brain that is damaged.

Primary brain damage is the damage that is complete at the time of impact, which may include:

Skull fracture: breaking of the bony skull

Contusions/bruises: often occur right under the location of impact or at points where the force of the blow has driven the brain against the bony ridges inside the skull Hematomas/blood clots: occur between the skull and the brain or inside the brain itself

Lacerations: tearing of the frontal (front) and temporal (on the side) lobes or blood vessels of the brain (the force of the blow causes the brain to rotate across the hard ridges of the skull, causing the tears)

Nerve damage (diffuse axonal injury): arises from a cutting, or shearing, force from the blow that damages nerve cells in the brain's connecting nerve fibers

Secondary brain damage is the damage that evolves over time after the trauma, which may include:

Brain swelling (edema)

Increased pressure inside of the skull (intracranial pressure)

Epilepsy

Intracranial infection

Fever

Hematoma

Low or high blood pressure

Low sodium

Anemia

Too much or too little carbon dioxide

Abnormal blood coagulation

Cardiac changes

Lung changes

Nutritional changes

CASE REPORT

A 10-year-old male child was playing with his siblings on the terrace of his house from two floors height. He slipped off the terrace while playing and landed head-on on the fence of his house and tumbling down onto the ground unconscious with an impacted broken distal end of the fence in the parietal bone [Figure 1]. There were no seizure episodes.

Figure 1

Cut end of fence seen at skull vault

On examination in the emergency room, he was conscious, cardiovascularly stable, maintaining his airway adequately with no major hemorrhage and secretion pouring through the penetration site. His vitals were stable (pulse rate: 100/min, blood pressure 102/64 mm Hg, and respiratory rate 18/min). Neurologically, his Glasgow coma score (GCS) was 10/15 – E2M3V5. His left pupil was dilated and the fractured end of the fence was seen jutting out through the scalp. Patient had an episode of nausea and vomiting. There was peroral and pernasal bleed. There were no other injuries apart from few bruises. CT scan showed a spear-like radio-opaque object penetrating the mid-parietal bone and entering the structures below to end just above the palate [Figures 2 and 3].

Figure 2

CT scan showing the path of the projectile

Figure 3

CT coronal view

OPERATION

Antibiotics and mannitol were started immediately to avoid infection and decrease the cranial pressure. Orotracheal intubation was carried out and bicoronal flap was raised. A bicoronal approach was used and a modified bifrontal craniotomy was performed and the distal fragment of the fence was removed along with the bone flap [Figures 4 and 5]. The tip of the fence was seen to be six inch [Figure 6] inside the brain parenchyma. There was no vascular injury. Necrotic brain tissue, hematoma, and bone fragment were removed. The wound was closed after debridement of the track. There was significant brain edema [Figure 7]. Maxillofacial surgical team was on standby to deal with oral and nasal bleeds. The cranium was not fixed back at the primary surgery considering the edema. Primary closure of the scalp was performed with staples.

Figure 4

After removal

Figure 5

Modified bifrontal craniotomy

Figure 6

Six-inch rod

Figure 7

Post-op CT

The patient recovered uneventfully during the postoperative phase and was shifted to the ward from the neurologic ICU in 4 days. Patient complained of diminished vision in the left eye which could be due to injury to the optic chiasma. CT scan was taken on the 7th postoperative day [Figure 8] to look for intracranial hematoma or abscess formation. At the time of discharge his neurological examination was normal. He was kept under periodic follow-up. There has been no report of seizure till date.

Figure 8

Brain edema

DISCUSSION

Head trauma is exceedingly common in children due to fall,[3] but it rarely presents as a penetrating skull injury. Injuries caused by objects with an impact velocity less than 100 m/s are known as non-missile injuries.[4] A non-missile object causing penetrating skull injury are knife (most common) and rarely nails, keys, pencils, and chopsticks.[56789]

Penetrating skull injuries represent a life-threatening emergency. Immediate hospitalization and prompt treatment are keys to a favorable prognosis. A prophylactic wide-spectrum antibiotic treatment amenable to crossing the blood–brain barrier should be given as soon as possible to avoid the risk of infection. The use of anticonvulsant prophylactic agents is recommended in those cases in which traumatic brain lesions are evident, such as intracerebral hemorrhage, subdural hematoma, and depressed skull fracture and neurological deficits. Early diagnosis is based on clinical evaluation, X-ray skull, and CT-scan. MRI can be dangerous in cases of retained ferromagnetic objects due to possible movement in response to the magnetic torque. Non-missile injuries should undergo a preoperative angiogram to rule out any vascular injury.

Rapid removal of the foreign body and bone fragments along with focal debridement after achieving absolute hemostasis followed by meticulous dural and scalp closure are the goals of surgical treatment.[10] Multidisciplinary approach enables the best surgical outcome. Penetrating trauma is likely to cause infection,[11] cerebral contusion, intracranial hemorrhage and seizures. Penetrating head trauma also presents a risk of shock due to hemorrhage. Intracranial pressure is likely to increase due to swelling or bleeding, potentially crushing delicate brain tissue. Occasionally it may cause cerebrospinal fluid fistula and neuro-endocrine dysfunction. Most deaths from penetrating trauma are caused by damage to blood vessels, which can lead to intracranial hematomas and ischemia, which can in turn lead to a biochemical cascade called the ischemic cascade. The child was extremely fortunate to have survived such an injury which could have easily caused sagittal sinus bleeding.

To conclude, penetrating skull injuries in children are a rare entity. It is a serious injury that may lead to irreversible brain damage and death. Early intervention and multidisciplinary approach following trauma is important in penetrating skull injuries for favorable prognosis.