CC
You are called by the trauma team to evaluate a 25-year-old male status post-high-speed motor vehicle collision and to manage his facial trauma.
HPI
The patient was the unrestrained driver in a high-speed, head-on collision with another vehicle. No air bag was deployed, and there was subsequent significant steering wheel and windshield damage. The patient was found unconscious and was not arousable. He was intubated at the scene because of a Glasgow Coma Scale (GCS) score of 7 (high index of suspicion for a severe intracranial injury) and was brought to your Level I trauma center by air medical transport for evaluation and treatment.
PMHX/PDHX/medications/allergies/SH/FH
All history is unknown. (When possible, the history should be obtained from available family members.)
Examination
Primary survey
The primary survey is accomplished via the Advanced Trauma Life Support protocol. The patient is sedated and intubated with spontaneous respirations. A transport cervical collar is in place (correctly sized and positioned), and his pupils are equal and reactive. His GCS score is 10T on arrival. He is otherwise hemodynamically stable.
Secondary survey
Vital signs. Blood pressure is 115/64 mm Hg, heart rate is 115 bpm (tachycardia), respirations are 12 breaths per minute, and temperature is 37.6°C.
Maxillofacial. There is a 10-cm stellate laceration through the frontalis muscle in the left forehead and supraorbital region. Bony crepitus and step deformities are noted on palpation of the supraorbital rims, nasal bones, and frontal bone (indicative of comminuted fractures). There is a flow of clear, blood-tinged fluid from the left naris (possible cerebrospinal fluid [CSF] rhinorrhea). The maxilla is stable. The dental occlusion is difficult to assess secondary to oral endotracheal intubation.
Eyes. Bilateral pupils are equal, round, and reactive to light (5–2 mm; direct and consensual light reflexes intact bilaterally). There is bilateral subconjunctival hemorrhage and no evidence of hyphema (blood in the anterior chamber of the eye, which may be difficult to detect in a supine patient). Fundoscopic examination shows mild papilledema in the right eye (optic disc edema secondary to increased intracranial pressure). The bilateral intraocular pressures measured with a portable tonometer are normal at 16 mm Hg.
Imaging
The imaging modality of choice for evaluation of frontal sinus injuries is a noncontrast axial computed tomography (CT) scan with 1 mm or less slice thickness. However, CT is not a reliable predictor of nasofrontal duct injury.
In the current patient, head and facial helical CT scans were obtained after the primary and secondary surveys. The head CT scan revealed a 3-cm × 1-cm left subarachnoid hemorrhage with no midline shift and two 1-cm × 1-cm areas of hyperdensity in the left frontal lobe. (Frontal sinus fractures are commonly associated with intracranial injury.) Axial views of the facial CT scan revealed a displaced, comminuted frontal bone fracture involving both the anterior and posterior tables of the bilateral frontal sinuses ( Fig. 54.1 A). There were also fractures of the nasal bones, bilateral supraorbital rims, and left infraorbital rim. Three-dimensional reconstruction allows assessment of the overall fracture patterns and orientation of fracture segments ( Fig. 54.1 B). A plain radiographic trauma series also was obtained, including cervical spine, anteroposterior chest, and anteroposterior pelvis views, which were all negative. (The incidence of facial fractures accompanied by spinal injuries is a significant concern for craniomaxillofacial surgeons.)
Labs
Standard laboratory tests for the evaluation of multisystem trauma patients include a complete blood cell count, complete metabolic panel, arterial blood gas analysis, urinalysis, and coagulation studies (prothrombin time, partial thromboplastin time, and international normalized ratio). A urine drug screen and blood alcohol level are indicated in patients with decreased mental status.
For the current patient, laboratory values were within normal limits except for a slightly low hemoglobin and hematocrit (secondary to blood loss from the scalp laceration and fluid resuscitation). One milliliter of the blood-tinged transudate from the patient’s left naris was collected and sent for laboratory analysis. The sample tested positive for β 2 transferrin (diagnostic of CSF).
Assessment
Subarachnoid hemorrhage with left frontal lobe intracerebral contusion; bilateral comminuted frontal sinus fracture with significant displacement of the anterior and posterior tables; bilateral nasal bone, left infraorbital rim, and bilateral supraorbital rim fractures; left frontal stellate skin laceration, evidence of CSF rhinorrhea, possible nasofrontal duct injury or obstruction, possible elevated ICP; Facial Injury Severity Scale score of 10 (displaced frontal sinus fracture [5], bilateral supraorbital rim fractures [2], left infraorbital rim fracture [1], nasal bone fracture [1], and forehead laceration >10 cm [1]).
Treatment
Three components of frontal sinus fractures must be considered when determining the proper treatment: the anterior sinus wall, posterior sinus wall, and nasofrontal outflow tract (NFOT). In general, fractures of the anterior or posterior table are considered significantly displaced when bony segments are found to be displaced greater than one table thickness. Indications for surgical management are given in the following sections. However, these indications are not absolute, and each case needs treatment planning on an individual basis.
Displaced anterior sinus wall fractures without nasofrontal outflow tract involvement
The goal of treatment in this clinical situation is to prevent cosmetic deformity. After reduction, internal fixation is completed with titanium or resorbable microplates. Surgical access may be accomplished through a coronal or local approach (existing lacerations, open sky incision). Endoscopic repair through a transnasal or transcutaneous approach (brow or coronal incisions) may be used for minimally displaced anterior table fractures. Bone grafting should be considered for avulsed fragments or extensive comminution. Isolated, nondisplaced anterior table fractures do not require surgical reduction and may be managed conservatively.
Nasofrontal outflow tract injury without significantly displaced posterior table fracture
The outflow tract is often uninjured with minimally displaced anterior table fractures; it more commonly presents with significantly displaced frontal sinus fractures or concomitant naso-orbito-ethmoid and Le Fort fractures. An untreated obstructed NFOT injury prevents evacuation of mucin from the frontal sinus and may lead to mucocele or mucopyocele formation, osteomyelitis, sinusitis, meningitis, or brain abscess. Treatment goals are complete debridement of sinus mucosa from the sinus and upper outflow tract, using a curette or high-speed burr, and obliteration of the frontal sinus and nasofrontal duct with various materials, including bone, temporalis muscle, fat, fascia, Gelfoam (Pfizer), and hydroxyapatite cement. The anterior table segments are replaced and stabilized with rigid fixation. For an isolated, mild NFOT injury, some authors advocate observation, NFOT reconstruction, or stenting; however, reobstruction has been reported in up to 30% of patients. Endoscopic frontal sinusotomy or a modified endoscopic Lothrop procedure may also be considered for a mild NFOT injury or persistent obstruction after conservative management. Less commonly used surgical techniques include trephination, a frontoethmoidectomy (Lynch or Knapp procedure), and a frontal sinus collapse (Reidel) procedure.
Displaced posterior table fractures
These fractures can present with intracranial injury or dural tear and CSF leakage. The goals of treatment are acute management of intracranial injury (often with a craniotomy), dural repair, and cranialization in open approaches (removal of the posterior table, allowing the brain parenchyma to occupy the frontal sinus). Increasing support and evidence can be found for transnasal endoscopic approaches in patients with displaced posterior table fractures who do not require simultaneous neurosurgical intervention. Injuries of the posterior table with CSF leaks can now maintain the frontal sinus drainage pathway with Draf IIb or Draf III techniques.
Nasofrontal outflow tract obliteration before cranialization is achieved with a variety of materials, including temporal fascia, temporal muscle, bone, and tissue sealants. A pedicled pericranial flap placed after cranialization facilitates separation of the brain from the nasal environment. Open reduction and internal fixation of the anterior table segments and reconstruction of the craniotomy defect with rigid fixation plates or mesh is completed. Management of isolated and minimally displaced fractures of the inner table without an obvious dural tear is more controversial, and conservative management or sinus obliteration may be considered.
The ability of the surgeon to evaluate the patency and function of the NFOT is critical. For fractures treated nonsurgically and those in which the nasofrontal ducts are not obliterated, interval CT imaging must be performed to assess duct function over time. Intraoperatively, patency may be assessed by injecting dye into the duct and observing its emergence in the nasal cavity. However, the accuracy of this test is questionable.
In the current patient, the presence of a displaced posterior table fracture, dural tears, and CSF leak warranted cranialization through a coronal flap in coordination with the neurosurgical team. A craniotomy was performed, the subarachnoid hematoma was evacuated, and an external ventriculostomy drain (EVD) was placed. The supraorbital rims and nasal bone were reconstructed and rigidly fixated with titanium plates ( Fig. 54.2 A). The posterior table was removed, and the dural tears were repaired by primary closure. (A fascial graft and fibrin glue may be used if primary closure is not possible.) The sinus mucosa was removed from the sinus and upper outflow tract using a pear-shaped burr. The remaining NFOT mucosa was inverted into the nose, and the outflow tracts were occluded with a small amount of free temporalis fascia. An anteriorly based pericranial flap (based on deep branches of the supratrochlear and supraorbital vessels) was placed into the frontal sinus ( Fig. 54.2 B). The anterior table was reduced and stabilized with titanium microplates ( Fig. 54.2 C).
