Fractures of the floor of the anterior cranial fossa. The selection of patients for dural repair

Late manifestations of traumatic lesions of the anterior skull base

The authors review their experience in detecting occult traumatic dural lesions. In a retrospective study covering the period from January 1, 1984 to December 31, 1996, 23 patients were evaluated for occult traumatic dural lesions. Clinical presentation, diagnostic work-up, and management of the dural lesions were analyzed.The clinical presentations of the previously undetected dural lesions of the anterior skull base were meningitis in eight cases, cerebrospinal fluid (CSF) rhinorrhea in eight cases, both meningitis and CSF rhinorrhea in five cases, and a pulsating swelling in the region of the right upper eyelid in one case. In another case a fracture of the posterior frontal wall was detected incidentally on the preoperative CT scan performed prior to surgery for chronic sinusitis. One patient had a CSF fistula of the lateral skull base in addition to the frontobasal fistula. The interval between trauma and diagnosis varied from 1 to 48 years. Dural lesions were localized by high-resolution CT, fluorescein nasal endoscopy, CT cisternography, and MRI. Intraoperative exposure of the dural lesions and duraplasty were possible in all cases. During the first attempt successful repair of the dural lesions was accomplished in 22 (95.7%) of the 23 patiants. Two interventions were necessary to close a CSF leak of the cribriform plate.Modern clinical and radiologic diagnostic methods should be employed to search for an occult dural lesion in patients with recurrent meningitis, meningitis caused by upper airway pathogens, or CSF rhinorrhea. The patient will remain at risk of potentially fatal meningitis until the lesion is appropriately repaired by duraplasty.

Severe craniofacial fractures with frontobasal involvement and cerebrospinal fluid fistula: indications for surgical repair

BACKGROUND

The management of posttraumatic cerebrospinal fluid (CSF) fistulae is a controversial topic. Although recent literature shows that endoscopic repair of CSF fistula is efficacious and minimally invasive, in specific conditions open operative approach remains imperative.

METHODS

A series of 36 patients underwent surgery for posttraumatic CSF fistula according to specific selection criteria. These criteria included: bone displacement more than 1 cm (5 cases), location of fracture in proximity to the midline (6 cases), involvement of cribriform plate (12 cases), presence of encephalocele (3 cases), and failure of the conservative treatment (10 cases). The dural defect was closed using vascularized pericranium and fibrin glue. Closure of the basal bone defect was necessary in very large fractures or in special localization of the fistula, such as near the optic nerve. Mean clinical follow-up was 5.7 years.

RESULTS

Two patients presented meningitis without sequelae, and 12 with hyposmia. One patient died of the severity of the primary brain injury and associated extracranial lesions. None of the patients had recurrence.

CONCLUSIONS

Our results indicate that surgical dural repair in selected cases is related to low morbidity and mortality preserving from delayed risks such as recurrence and infections.

Supraorbital Keyhole Surgery for Optic Nerve Decompression and Dura Repair

Supraorbital keyhole surgery is a limited surgical procedure with reduced traumatic manipulation of tissue and entailing little time in the opening and closing of wounds. We utilized the approach to treat head injury patients complicated with optic nerve compression and cerebrospinal fluid leakage (CSF). Eleven cases of basal skull fracture complicated with either optic nerve compression and/or CSF leakage were surgically treated at our department from February 1995 to June 1999. Six cases had primary optic nerve compression, four had CSF leakage and one case involved both injuries. Supraorbital craniotomy was carried out using a keyhole-sized burr hole plus a small craniotomy. The size of craniotomy approximated 2 x 3 cm2. The optic nerve was decompressed via removal of the optic canal roof and anterior clinoid process with high-speed drills. The defect of dura was repaired with two pieces of tensa fascia lata that were attached on both sides of the torn dural defect with tissue glue. Seven cases with optic nerve injury included five cases of total blindness and two cases of light perception before operation. Vision improved in four cases. The CSF leakage was stopped successfully in all four cases without complication. As optic nerve compression and CSF leakage are skull base lesions, the supraorbital keyhole surgery constitutes a suitable approach. The supraorbital keyhole surgery allows for an anterior approach to the skull base. This approach also allows the treatment of both CSF leakage and optic nerve compression. Our results indicate that supraorbital keyhole operation is a safe and effective method for preserving or improving vision and attenuating CSF leakage following injury.

Persistent posttraumatic cerebrospinal fluid leakage

OBJECT

Persistent posttraumatic cerebrospinal fluid (CSF) leakage frequently complicates skull base fractures. Although many CSF leaks will cease without treatment, patients with CSF leaks that persist greater than 24 hours may be at increased risk for meningitis, and many will require surgical intervention. The authors reviewed their 15-year experience with posttraumatic CSF leaks that persisted longer than 24 hours.

METHODS

The authors reviewed the medical records of 51 patients treated between 1984 and 1998 with CSF leaks that persisted for 24 hours or longer after traumatic head injury. In 27 patients (55%) spontaneous resolution of CSF leakage occurred at an average of 5 days posttrauma. In 23 patients (45%) surgery was required to resolve the leakage. Eight patients (16%) with occult CSF leaks presented with recurrent meningitis at an average of 6.5 years posttrauma. Forty-three (84%) patients with CSF leaks sustained a skull fracture, most commonly involving the frontal sinus, whereas parenchymal brain injury or extraaxial hematoma was demonstrated in only 18 patients (35%). Delayed CSF leaks, with an average onset of 13 days posttrauma, were observed in eight patients (16%). Among patients with clinically evident CSF leakage, the frequency of meningitis was 10% with antibiotic prophylaxis, and 21% without antibiotic prophylaxis. Thus, prophylactic antibiotic administration halved the risk of meningitis. A variety of surgical approaches was used, and no significant neurological morbidity occurred. Three (13%) of 23 surgically treated patients required additional surgery to treat continued CSF leakage.

CONCLUSIONS

A significant proportion of patients with CSF leaks that persist greater than 24 hours will require surgical intervention. Prophylactic antibiotic therapy may be effective in this group of patients. Patients with skull base or frontal sinus fractures should be followed to detect the occurrence of delayed leakage. Surgery-related outcome is excellent.

Compound anterior cranial base fractures: classification using computerized tomography scanning as a basis for selection of patients for dural repair

OBJECT

A classification is proposed to organize anterior cranial base fractures systematically according to their location and size. The goal of this study was to determine whether these two variables, irrespective of cerebrospinal fluid (CSF) rhinorrhea, are related to the long-term risk of posttraumatic meningitis and, hence, to standardize decision making concerning surgical repair of associated CSF fistulas.

METHODS

With the aid of high-resolution thin-section coronal computerized tomography (CT) scanning, anterior cranial base fractures were classified into the following four major types: I, cribriform; II, frontoethmoidal; III, lateral frontal; and IV, complex (any combination of the other three types). Fractures with a maximum bone displacement that extended farther than 1 cm in any plane were classified as "large" and those less than 1 cm as "small." The authors used this classification in a study of 48 patients who were treated by conservative (20 patients) or surgical (28 patients) means. The results showed a gradation of risk: the fracture most likely to develop infection was a large cribriform (Type I) and the least likely was a small lateral frontal (Type II). Statistical analysis showed that the trend for an increased infection rate was related to the cumulative effect of three variables in the following order: 1) prolonged duration of rhinorrhea (analysis of variance [ANOVA], p = 0.017); 2) large size of fracture displacement (ANOVA, p = 0.079); and 3) fracture's proximity to the midline (ANOVA, p = 0.015).

CONCLUSIONS

In this series, microsurgical repair was accompanied by a minimum complication rate. Hence, the authors recommend that patients with fractures that combine the aforementioned variables should be considered to have a high long-term risk of infection and their injury should be surgically repaired as soon as the posttraumatic edema has subsided. This applies to the following fractures: large cribriform (Type I) with transient rhinorrhea lasting 5 to 8 days and large frontoethmoidal (Type II) with prolonged rhinorrhea lasting longer than 8 days. Furthermore, the authors conclude that this classification can improve the management of posttraumatic CSF fistulas of the anterior cranial base and may provide insights into the mechanisms underlying their spontaneous repair and susceptibility to meningitis.

Diagnosis and treatment of frontobasal skull fractures

During a five-year-period (January 1990 to December 1994) a total of 67 patients were operated on for frontobasal skull fractures. The indication for surgical treatment was based on the evidence of fractures encroaching paranasal sinuses or the cribriform plate on high-resolution axial or coronal CT scans. The following clinical signs indicating frontobasal trauma were observed: 25 patients (37%) showed rhinoliquorrhea, 14 (21%) had raccoon's eyes, and 2 (3%) had meningitis. Distinct dura laceration was observed intraoperatively in 64 of 67 patients (96%). In our experience, high resolution CT has proven to be a sensitive diagnostic tool for frontobasal skull fractures. With respect to the high coincidence of fractures and dura lacerations, the indication for surgical treatment based on CT findings seems to be justified.

Fractures of the floor of the anterior cranial fossa

We treated 28 patients with anterior cranial fossa floor fractures. Computed tomography (CT) scans adjusted to bone density disclosed three fracture types: (1) penetrating fractures through the orbita or ethmoid sinus; (2) simple or multiple linear fractures; and (3) extensive comminuted anterior cranial fossa floor fractures. Thirteen patients underwent emergent surgery for treatment of open depressed fractures (most common in type 3 fractures), for foreign bodies (in type 1 fractures), and for optic canal decompression. Large dural lacerations were always present in patients with type 3 fractures, and repairs were made with dural substitutes. Only one patient developed postoperative cerebrospinal fluid leakage. Nine (32%) of the patients in our series had visual involvement, but visual acuity recovered or improved in six patients. Our study shows that initial neuroradiologic evaluation with CT scans is important in patients with frontobasal fractures, and that secure dural repair during primary operation helps prevent cerebrospinal fluid leakage.

Delayed complications of ethmoid fractures: a "growing fracture" phenomenon

Delayed complications of ethmoid fractures are considered relatively rare. However, meningitis, recurrence of previously ceased cerebrospinal fluid rhinorrhea and delayed onset of cerebrospinal fluid rhinorrhea are possible even years after trauma. We report 10 consecutive patients with delayed complications of ethmoid fractures, whom we treated over the past 11 years. All patients had previously sustained a closed head injury and had remained anosmic. Variously after trauma (ranging from 2 months to 31 years), these patients were re-admitted because of meningitis (6 cases), recurrence of previously ceased cerebrospinal fluid rhinorrhea (3 cases), and delayed onset of cerebrospinal fluid rhinorrhea (1 case). In all cases the delayed complications were associated with relatively large defects of the ethmoid bone. These bone lesions were now evident even in those patients whose radiological assessments had been normal after trauma. All patients underwent a successful surgical repair and remained well during the follow-up. We discuss the possibility that delayed complications of ethmoid fractures are due to a mechanism like that of "growing fractures" in children.

Fractures of the middle third of the face and cerebrospinal fluid rhinorrhoea

The incidence of cerebrospinal fluid (CSF) rhinorrhoea in patients with facial fractures is about 25%. Although the management of facial fractures is well documented, its timing and role in the presence of CSF leak is still open to debate. This study evaluates facial manipulation in 89 facial fractures associated with CSF rhinorrhoea, with a mean follow-up of 4 years. The facial fractures were reduced in 26 patients (29%) and the CSF fistula was repaired in 75 (84%). Twenty-three (25.8%) had both facial manipulation and dural repair with no deaths, post operative infection, failure or recurrence of CSF leak. On the other hand, when facial manipulation or dural repair was performed alone, the CSF rhinorrhoea either persisted or recurred in a significant number of patients requiring further intervention. Although this is a retrospective analysis of patients treated over several years and, there has been a change in the methods of investigation and treatment of these patients, one can conclude that manipulation of facial fractures and surgical dural repair can be carried out at the same sitting without increasing the surgical morbidity and mortality.

Combined injuries of the cranium and face

The neurosurgeon and plastic surgeon are increasingly called upon to manage the care of patients with combined injuries of the cranium and face. The authors briefly review the pathogenesis and classification of craniofacial fractures and outline historical approaches to them. Current principles of management are then discussed. Experience with 167 patients is presented with emphasis on surgical technique, the sequence of repair and early primary reconstruction. The controversial issue of fontal sinus fracture repair is addressed. The authors favour preservation of the frontal sinus cavity, where possible, and do not obliterate the nasofrontal duct. With injuries to the floor of the sinus, the base of the sinus and frontonasal duct are sealed with bone graft and a vascularised soft tissue flap and the sinus is cranialised. Immediate bone grafts, using split skull or rib, are used to reconstruct areas of bony destruction or loss. Ninety-eight patients required 402 grafts. Immediate bone grafting resulted in few complications and low incidence of secondary deformities needing correction.

The management of dural tear resulting from mid-facial fracture

This study examines the relative risks and benefits of conservative and surgical management of dural tear secondary to middle third facial fracture and ascertains the type of skull and facial injury most often associated with the development of posttraumatic meningitis. Two projects were undertaken. First, the histories of 247 cases of major middle third facial fracture were reviewed with a recent follow-up of those patients who also sustained a dural tear. Second, 280 cases of bacterial meningitis were reviewed and particular attention was given to cases of posttraumatic meningitis. Of the 247 cases of middle third facial fractures studied, 43% (107/247) had evidence of a dural tear; of this group, 76 patients were managed conservatively and 31 patients were managed surgically. In the former group, there were three instances of recurrent cerebrospinal fluid rhinorrhea (CFR). In the surgically managed group, 77% (24/31) sustained surgical complications including two cases of posttraumatic meningitis and 21 cases of neurological deficit. Of the 280 cases of bacterial meningitis, 48 patients had sustained dural tear following trauma. The prognosis for posttraumatic meningitis is considerably better than for other forms of meningitis. The preceding trauma involved the vault of the skull in 90% (43/48) of cases, and discrete middle third facial fracture in one case (2.1%). Posttraumatic meningitis followed a previous operative repair in 15% (7/48) of the patients. The results of this study indicate that dural tear subsequent to middle third facial fractures is a different proposition than dural tear subsequent to direct skull trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Traumatic, spontaneous and postoperative CSF rhinorrhea

CSF fistulas are a major complication of head injury but also occur spontaneously or symptomatically in connection with tumours of the skull base, empty sella syndrome, ethmoidal encephalomyelocele, intracranial hypertension or postoperatively in connection with operations on skull base tumours or ENT operations. Their main risk is the possibility of meningitis. The main clinical symptom is CSF leakage from the nose, but meningitis may be the first manifestation. Isotope cisternography and metrizamide CT cisternography are the most important methods for precise localization, sometimes also for verification of a suspected fistula. Most traumatic CSF fistulas of the frontal and ethmoidal region have to be treated operatively. The method of choice is the transfrontal approach and the closure of the fistula opening using a pedicled pericranial flap or fascia lata graft. Most sphenoidal fistulas have to be treated by packing the sphenoidal sinus with muscle. The treatment methods of the rare spontaneous and symptomatic CSF fistulas are also described. The results of operative treatment are satisfactory. About 6% recurrences, which as a rule can be cured by reoperation, and a mortality rate of about 1-3% seem to be an acceptable price for prevention of an otherwise unavoidable and oftenly deadly meningitis. Future efforts are necessary to improve the operative technique in order to reduce the incidence of anosmia. Our descriptions and advice are based not only on literature reports but also on our own experiences with a combined material of 237 cases operated on for rhinorrhea.

Residual complications in patients with major middle third facial fractures

Residual complications associated with middle third facial fractures have been poorly documented in the literature. In the present study, 240 patients with fractures of the middle third of the facial skeleton, who were treated at the Royal Melbourne Hospital, Victoria, between 1969 and 1976, were reviewed to determine the residual complications of these fractures. Cranial complications were relatively uncommon, and 60 % of cases of cerebrospinal fluid rhinorrhoea ceased within 3 days of fracture reduction and fixation. Persistent infraorbital sensory defects occurred in 22 % of patients with Le Fort II or Le Fort III fractures. Orbital complications included diplopia, which remained in 8 % of cases, and was often corrected by secondary surgery. Residual complications involving the nose or maxillary sinus were uncommon (less than 5 %). Occlusal disharmony was present as a residual problem in 19.6 % of cases, although this could be managed by simple means in 89 % of these cases so that primary surgery and simple secondary dental procedures a satisfactory result in 98 % of all patients. The low incidence of dental complications is most likely a result of the rigid fixation employed in the fracture management, allowing accurate control of the bone fragments.

Analysis of the treatment of basilar skull fractures with and without antibiotics

The efficacy of chemoprophylaxis in the treatment of basilar skull fractures was studied in 129 patients over a 2-year period; antibiotics were found ineffective in preventing central nervous system infections, and in some cases may have proved harmful. It is suggested that a more rational approach to the treatment of basilar skull fractures includes close observation of the patient for early signs of meningitis, and if these should develop, treatment with antibiotics appropriate to the organism involved.

Primary reconstruction of depressed frontal skull fractures including those involving the sinus, orbit, and cribriform plate

✓ Instead of discarding bone as in past practice with depressed skull fractures, fragments were soaked in Betadine, trimmed, reinserted into the skull defect, and covered with flaps of pericranium, muscle, or fascia. Of the 110 patients who had bone replaced, 65 had frontal fractures, which in 33 involved the frontal sinus, cribriform plate, or orbital rim. Fractures involving sinuses were treated by exenterating the sinus and packing it with muscle. The frontal and orbital rim region were reconstructed whenever possible with a mosaic of replaced bone. There were no deaths due to the minimal complications from the procedure. Despite severely macerated, contaminated, and in several instances, infected scalp wounds, most bone fragments have survived, and cranial defects have gradually filled with new bone. The authors believe that immediate bone replacement for depressed frontal fractures with or without orbital, sinus, or cribriform plate involvement is both practical and safe.