A review of 59 consecutive patients with lesions of the anterior cranial base operated on using the subcranial approach

Subcranial Approach for Management of Secondary Frontal Bone Deformity

Abstract

Secondary correction for aesthetic purposes can be more challenging as the fractured segments may be united in abnormal positions and would require osteotomy procedures before mobilizing the segments for reconstruction. Such maneuvers require adequate exposure and visibility. The subcranial approach is an effective alternate to classical approaches, which required frontal lobe retraction.

Conclusion

Subcranial approach is a viable alternative to posttraumatic deformity of frontal bone.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Access to the skull base: modular facial disassembly

Access to the skull base is not new. The different modules of the facial skeleton can be removed to give access to the skull base based on target zones, which were first described by Grime et al in 1991. However, the vertical plane is not considered, and this article adds to the original classification and develops a decision-making algorithm for preferred access to identified lesions of the skull base.

Subcranial craniotomy approach for frontobasal fracture correction

OBJECTIVE

Frontobasilar fracture types and the outcome of patients after management with the subcranial approach technique were evaluated.

MATERIAL AND METHODS

A retrospective analysis of 48 patients (45 males, mean age 38,5 years; range 16-82 years) who had a subcranial approach for frontal base fracture correction between April 1996 and April 2011 at a tertiary care academic hospital in Turku, Finland.

RESULTS

Sixteen (33%) patients had fractures including all frontobasilar fracture types (Type I-IV) i.e. fractures that involved frontal sinuses, orbital roofs, ethmoidal region, cribriform plate and sphenoidal region. Twenty-seven (56%) patients were considered to have had brain damage at presentation. Forty percent of patients were suffering from synchronous trauma. Peroperatively, 31 (65%) patients had exposure or defect of the dura due to bone dehiscence but only two patients suffered from cerebrospinal fluid (CSF) fistula following surgery. CSF fistulae were covered by pericranium in most of the cases (68%). There was no postoperative meningitis. Thirty-eight percent of the patients needed further operation with a subcranial craniotomy following primary reconstruction. At the last follow-up visit 35% were suffering from permanent neurological problems following brain injury.

CONCLUSIONS

Subcranial approach seemed successful in the management of all frontobasilar fractures in this series with reasonably low complication rate. Therefore, we would recommend it as the technique of choice in multiple and even in the most complicated frontal base fractures.

Anterior cranial fossa traumas: clinical value, surgical indications, and results-a retrospective study on a series of 223 patients

Objective Frontobasal fractures are relatively common traumas but surgical indications are still discussed. The authors report their results on patients showing anterior cranial fossa fractures; clinical data, surgical indications, and results are reported and critically analyzed. Methods From 1991 to 2010, 223 patients were admitted in our institution with diagnosis of anterior cranial fossa fracture. Fractures were classified as type A-fracture of the anterior wall of the frontal sinus; type B-fracture of the posterior wall of the frontal sinus; and type C-frontobasal traumas without involvement of the frontal sinus. All patients entered a follow-up program consisting in periodic controls. Results A total of 105 patients were conservatively treated, while 118 patients underwent surgical intervention. The presence of pneumocephalus (p < 0.0001) and rhinoliquorrhea (p = 0.001) were the factors influencing the surgical indication. In the fractures of group B with signs of pneumocephalus and or rhinoliquorrhea, full sinus cranialization represents the variable mainly influencing the outcome (p < 0.001). Conclusion Patients with frontobasal traumas should be carefully evaluated to choose the best treatment option. Clinical and radiological data suggest that patients with frontobasal fractures with massive pneumocephalus and/or rhinoliquorrhea should be always surgically treated.

Anterior fossa schwannoma mimicking an olfactory groove meningioma: case report and literature review

Intracranial schwannomas not associated with cranial nerves account for less than 1% of surgically treated schwannomas of the central and peripheral nervous system. With only 45 cases reported to date, subfrontal schwannomas are very rare tumors, leaving the issue of their origin controversial. A 66-year-old woman presented with a 1-year history of progressive headaches. Clinical examination revealed hypoesthesia of the nasal tip. CT-scan and MRI studies revealed a large subfrontal tumor thought preoperatively to be a meningioma. Intraoperatively, a large extra-axial tumor arising from the floor of the right frontal fossa was encountered. Histopathology identified the tumor as a schwannoma. This current case gives strong clinical presumption of an origin from the anterior ethmoidal nerve. We reviewed the literature in order to establish the epidemiology of these tumors, from which there appear to be divergent profiles depending on tumor origin and histology. Despite close similarities with olfactory groove meningiomas, patient history and radiological findings provide substantial evidence for differential diagnosis.

Management and outcome of pediatric skull base fractures

OBJECTIVE

The management of skull base fractures in the pediatric age group continues to be a major challenge even for experienced multidisciplinary teams. This retrospective study was undertaken at a tertiary care academic hospital to evaluate the management and outcome of pediatric skull base fractures.

METHODS

Retrospective analysis covering a period of 13.5 years (from 1996 to 2009) and 63 patients (mean age 10.7 years; range 1-18 years) was performed.

RESULTS

A road traffic accident was the most frequent etiological factor (38%). The most common skull base fracture type was temporal bone fracture (64%). Longitudinal temporal fractures were observed in 45% and transversal in 23% of these patients; in 10 cases (25%) the fracture was comminuted or mixed type. A fracture involving the spheno-ethmoidal complex was the second most common type of basilar skull fracture (41%) followed by fracture through the orbital bone (35%). Forty-three percent of the patients had a concomitant intracranial injury. Early neurological deficits were diagnosed in 21 patients (33%) and 10 patients (16%) had permanent neurological deficits. One patient died after 1 week of intensive care treatment. Fifty-four patients (86%) were discharged home and 8 patients (13%) were discharged for further rehabilitation. Glasgow Coma Scale score of 8 or lower correlated with moderate to poor outcome.

CONCLUSIONS

We conclude that skull base fracture is a rare injury in childhood. Mortality is uncommon, but this trauma is commonly associated with intracranial injury. Early neurological deficits are caused by traumatic brain injury and were observed in one-third of the patients. However, only less than one-sixth suffered from permanent neurological or neuropsychiatric disorders.

A modified midfacial degloving approach for the treatment of unilateral paranasal sinus tumours

PURPOSE

The midfacial degloving approach (MFDA) is the primary option for the removal of benign and malignant sinonasal tumours. However, the classic MFDA does not compensate for the fact that most benign and malignant paranasal sinus (PNS) tumours are unilateral and the incisions may lead to some unnecessary complications?. Surgical exposure is limited to the upper and deep part of the PNS. Modifications of the classical MFDA that minimize complications and improve surgical field exposure are warranted.

PATIENTS

The medical records of 27 consecutive patients who had undergone surgery using a modified MFDA for treatment of unilateral benign or malignant tumours from 2000 to 2006, were reviewed.

RESULTS

We developed and performed a modified MFDA utilizing a hemigingivobuccal incision, a transfixion incision, mucosal detachment of the pyriform aperture and separation of the upper lateral cartilage from the nasal bone in 27 patients with unilateral benign (85%) or malignant (15%) PNS neoplasms. Adequate surgical exposure was achieved in all cases. No technical problems and no intraoperative complications related to the surgical procedure were encountered.

CONCLUSION

Our modified MFDA provides sufficient surgical exposure for the removal of unilateral malignant or benign PNS tumours with few surgical or cosmetic complications.

CT measurement of the frontal sinus - gender differences and implications for frontal cranioplasty

OBJECTIVE

To describe frontal sinus anatomy and explore gender variations that may have significance for cranioplasty and sinus surgery.

METHODS

150 subjects who underwent maxillofacial computed tomography (CT) between 1/1/2008 and 6/11/2008 were enrolled. Frontal sinus dimensions and forehead measurements were taken at midline and at 10, 20, and 30 mm to the left and right of midline using sagittal, coronal, and axial images. The data was analyzed for significant differences between measurements made at the selected points in the frontal sinus, for left to right variations, and for gender variations.

RESULTS

Mean anterior table thickness ranged from 2.6 to 4.1 mm and was thinnest at 10 mm left and right of midline (2.9 and 2.6 mm). Mean anteroposterior depth of the frontal sinus ranged from 8.0 to 9.3 mm and did not vary significantly at any distance from midline. Frontal sinus height was greatest at midline (mean=24.5 mm) and progressively lessened at lateral distances. Mean total width at the level of the supraorbital ridge was 52.2 mm. For all measurements, no significant left to right variation was noted. Comparing the sexes, males were found to have greater dimensions in most frontal sinus measurements, though these differences were only found to be significant at or close to midline. The male forehead was marked by more acute nasofrontal angle (119.9° versus 133.5°) and a steeper posterior forehead inclination (-7.2° versus -3.5°). The glabella was wider in males (44.4 versus 33.9 mm) and more frequently protruded beyond the ideal forehead slope line (51% versus 30%).

CONCLUSIONS

Using CT imaging, forehead and frontal sinus dimensions have been described. Generally, males had larger overall frontal sinus dimensions, and this was most pronounced in the medial area of the supraorbital ridge known as the glabella.

A modified frontal-nasal-orbital approach to midline lesions of the anterior cranial fossa and skull base: technical note with case illustrations

The frontal-nasal-orbital craniotomy has been utilized for craniofacial abnormalities and resection of tumors involving the anterior skull base. We describe modifications of this technique to approach extra-axial and intradural midline lesions of the anterior fossa with or without involvement of the skull base. A craniotomy was planned with an endoscope and image guidance. A modified frontal-nasal-orbital craniotomy encompassing the entire frontal sinus complex was performed in conjunction with osteotomies incorporating the bilateral superior orbital ridges and nasal septum. Removal of the posterior wall of the frontal sinus was completed if necessary. Dural repair and final reconstruction are detailed. Our initial experience using this approach in five patients harboring lesions of the anterior skull base resulted in adequate exposure of the targeted pathology. There were no complications of the procedure. Cosmetic results were acceptable. We present a detailed account of this procedure via photographs and a video. The frontal-nasal-orbital craniotomy provides access to the floor of the anterior fossa while avoiding excessive brain retraction associated with facial incisions. In addition, this approach is associated with a lower incidence of complications, such as CSF leak, brain retraction edema, or infection. The frontal-nasal-orbital craniotomy is a useful technique for midline lesions of the anterior skull base, and it should be in the armamentarium of neurological surgeons.