Introduction: Large defects of the anterior / central skull base are a niche pathology that infrequently occurs in the setting of traumatic head injuries, more specifically high impact motor vehicle accidents and self-inflicted gun shout wounds to the head.
Case Description: This 37-year-old otherwise healthy male presented to our level-1-trauma-center in 2012 after a self-inflicted gunshot wound to the face and head. He had an entrance wound in the submental region, with extensive comminuted facial fractures (involving the mandible, mid face, and anterior skull base). Initial CT scan demonstrated a severely comminuted mandible, palatal defect with associated comminuted midface fractures, and anterior skull base defect involving frontal sinus, cribriform plate and orbital roof. CT scan of the head showed an 11 cm subdural hematoma with midline shift and uncal herniation, for which he underwent emergent craniotomy and evacuation of subdural hematoma. His ICP drain was removed, but he developed massive CSF rhinorrhea as a result of his cranial base defect.
On day 10, he underwent an open-approach anterior skull base reconstruction using titanium mesh cranioplasty. He tolerated the procedure well, but recovery was complicated by development of cerebritis and brain abscess in the frontal lobe. He improved with drainage of the abscess and antibiotic treatment without initial improvement in cognitive function. Repeat CT after one month revealed persistent pneumocephalus in communication with the air space of the nasal and oral cavities. Exam under anesthesia demonstrated a 2.5 cm irregular palatal defect leading from the oral cavity to the nasal cavity, a tract leading to the left frontal sinus where exposed mesh titanium plate was visible. A stage 2 reconstruction was performed with composite free graft of cartilage/bone/mucosa. One month after, a flexible nasal endoscopy demonstrated a viable graft in place and a CT scan demonstrated resolution of pneumocephalus. After enduring cranionasal separation was achieved, the otorhinolaryngology team then repaired the extensively comminuted facial fractures based on CT-guided design of reconstruction plates for his midface fractures. In collaboration with oromaxillofacial surgery, nonviable portions of mucosa and underlying dentition, maxilla, and palate were removed. The resulting palatal defect was occluded with a temporary acrylic obturator. A dental prosthesis was fashioned to obdurate the palatal defect and bridge the maxilla. At the time of writing, the patient had experienced sufficient cognitive improvement for minimal assitance living at home.
Discussion: Cranioplasty is required in cranial trauma patients with large basal defects, for physiologic restoration of neurovascular structures, cosmesis and prevention of CSF leak. A number of materials can be used to reconstruct cranial defects, and choice should be guided by consideration of biocompatibility, MR- and CT-compatibility, malleability and ease of surgical manipulation, optimal structure, weight, and stress-bearing capability, and finally cost. In the setting of acute trauma, however, the choice of material is narrowed by time-sensitive conditions that necessitate efficient decision-making, surgical planning, and operative action. Titanium-mesh is ideal and allows for easy surgical manipulation and contouring to the cranial defect, increasing accuracy of graft reconstruction and reducing surgical morbidity and mortality.