Etiology and Mechanisms
Injuries can be caused by two types of objects: sharp objects (e.g., knives, axes, nails, bamboo spikes, needles) and blunt objects (e.g., iron rods, stones, wooden sticks). Sharp objects, with their pointed and sharp edges, easily incise or penetrate the scalp, skull, and meninges, entering brain tissue. The resulting wound tract is typically smooth and localized, causing minimal damage to surrounding areas. Blunt objects, however, vary in mechanism depending on their type. For example, iron rods or wooden sticks penetrating the skull may cause brain injuries similar to those from sharp objects, whereas open injuries caused by stones striking the head resemble the acceleration-induced brain injuries seen in closed craniocerebral trauma.
Clinical Manifestations
Consciousness Impairment
Sharp-object injuries typically cause localized brain damage at the impact site and rarely induce cerebral concussion or diffuse brain injury; thus, immediate post-injury consciousness impairment is uncommon. In contrast, blunt-object open injuries resemble closed injuries, often involving both localized damage at the impact site and diffuse brain injury, leading to immediate consciousness impairment in most patients. If combined with intracranial hematoma, a lucid interval (temporary improvement in consciousness) may occur.
Neurological Symptoms
Open injuries frequently involve severe localized brain damage, resulting in neurological deficits such as paralysis, sensory disturbances, aphasia, or hemianopia.
Vital Sign Changes
Limited open injuries caused by sharp objects often show no significant vital sign abnormalities. However, vital signs may markedly deteriorate if critical structures like the brainstem or hypothalamus are directly injured or if blunt objects cause extensive brain damage. Profuse bleeding from open head wounds may lead to hemorrhagic shock.
Cerebrospinal Fluid or Brain Tissue Leakage
Open craniocerebral injuries often present with cerebrospinal fluid and/or brain tissue leakage at the wound site.
Diagnosis
Patients with open craniocerebral injuries often present with head wounds, along with cerebrospinal fluid and/or brain tissue leakage. CT or X-ray imaging is used to assess intracranial injuries and detect secondary hematomas or the presence of foreign objects.
CT imaging helps determine the location and extent of brain injury, assess for the presence of secondary intracranial hematomas, brain edema, or swelling, and provide precise localization of retained bone fragments or foreign bodies. CT angiography (CTA) is valuable for identifying cerebrovascular injuries caused by intracranial foreign bodies or skull base fractures.
Treatment
The treatment of open craniocerebral injuries shares similarities with that of closed head injuries, such as close monitoring of the patient’s condition, maintaining airway patency, and preventing or managing brain edema or swelling. However, open injuries have unique considerations as well:
Shock Prevention and Management
Hemorrhagic shock is relatively common in open craniocerebral injuries due to significant blood loss at the site of trauma. Rapid control of bleeding, restoration of blood volume, and correction of shock are essential.
Management of Intracranial Foreign Bodies
Foreign objects penetrating the cranial cavity should not be moved or removed precipitously to avoid causing additional damage. Surgical intervention may only be performed after accurately identifying the location of the foreign object and its relationship to surrounding critical intracranial structures (such as blood vessels). During surgery, the foreign object and adjacent vital structures are exposed, the object is carefully removed, bleeding is controlled, the dura mater is repaired, and cerebrospinal fluid leakage is prevented.
Protection of Extruded Brain Tissue
When brain tissue extrudes through the wound, although this may temporarily relieve acute intracranial pressure, it also increases the risk of intracranial infection. Emergency management is required to protect the exposed brain tissue.
Debridement Surgery
Debridement surgery for open craniocerebral injuries should ideally be performed within 6–8 hours. The procedure progresses from superficial to deep layers, ensuring the thorough removal of hair, bone fragments, hematomas, contused brain tissue, and foreign bodies while achieving hemostasis. The dura mater should be meticulously sutured, with repair material obtained from autologous periosteum, temporal fascia, or fascia lata. Postoperative care includes enhanced anti-infection and anti-epileptic treatments.