Osteoplastic Frontal Sinusotomy and Extradural Microsurgical Repair of Traumatic Frontobasal Cerebrospinal Fluid Fistulas

Introduction: The choice of surgical approach and operative technique for the management of traumatic cerebrospinal fluid (CSF) fistulas if the anterior cranial fossa is still intact is controversial. Although “extracranial” and endoscopic transnasal approaches through the paranasal sinuses are becoming popular among otolaryngologists and maxillofacial surgeons, most neurosurgeons traditionally prefer the “intracranial” repair of CSF fistulas by a craniotomy. We present our experience in 93 patients with traumatic frontobasal injuries of the dura, which were treated microsurgically using an extradural osteoplastic approach through the frontal sinus (sinusotomy).

Material and Methods: The intervention, which was used in 93 patients between November 1991 and June 2006, can be divided into the following operative steps: (1) exposure of the anterior wall of the frontal sinus by a bicoronal incision; (2) excision of the anterior wall without frontal burr holes; (3) bilateral removal of the posterior wall of the frontal sinus; (4) extradural inspection of the dura behind the frontal sinus, above the cribriform plate, the ethmoidal roof, and orbital roof bilaterally; (5) closure of dural tears by direct suture and a periosteal graft; (6) insertion of a wide silicone tube through one nasofrontal duct to ensure nasofrontal communication; and (7) reinsertion and reconstruction of the anterior wall of the frontal sinus and fixation with titanium microplates.

Results: Ninety of the 93 operated patients were male, with a mean age of 32 years (15 to 74 yrs). The interval between craniofacial injury and surgery ranged from a few hours to 23 years with a mean of 4.5 days. In all patients a dural tear was found and closed. Additional intracranial injuries were found in 91.4% and additional midfacial fractures in 68.8% of the patients. A second frontobasal operation was necessary in 3 patients because of persisting or recurring CSF rhinorrhea. Further postoperative complications (infections) were observed in 2 patients, necessitating revision.

Conclusion: This technique affords atraumatic extradural inspection bilaterally behind the frontal sinus and repair of traumatic dural fistulas with no or minimal brain retraction. It therefore allows early repair of CSF fistulas also in patients with severe brain injury. We consider this approach and extradural closure of fistulas the method of choice, since the procedure allows an intradural extension and an optimal restoration and reconstruction of the anterior wall of the frontal sinus. Furthermore, the technique makes possible intraoperative cooperation with maxillofacial colleagues for the treatment of midfacial fractures.