One-step orbit reconstruction using PMMA implants following hyperostotic sphenoid wing meningioma removal: Evolution of the technique in short clinical series

Purpose

To report our experience with patient specific implants for one-step orbit reconstruction following hyperostotic SWM removal and to describe the evolution of the technique through three surgical cases. Methods: Three cases of one-step SWM removal and orbit reconstruction are described. All cases are given consecutively to describe the evolution of the technique. Hyperostotic bone resection was facilitated by electromagnetic navigation and cutting guides (templates). Based on a 3D model, silicone molds were made using CAD/CAM. Then PMMA implant was fabricated from these molds. The implant was adjusted and fixed to the cranium with titanium screws after tumor removal. Results: Following steps of the procedure changed over these series: hyperostotic bone resection, implant thickness control, implant overlay features, anatomic adjustments, implant fixation. The proptosis resolved in all cases. In one patient the progressive visual acuity deterioration was recognized during the follow-up. No oculomotor disturbances and no tumor regrowth were found at the follow-up.

Conclusion

CAD/CAM technologies enable creation of implants of any size and configuration, and thereby, to increase the extent of bony resection and lower the risk of tumor progression. The procedure is performed in one step which decreases the risk of postoperative morbidity.

Middle cranial fossa non-cavernous sinus dural arteriovenous fistulas: 20 years of experience

Non-cavernous sinus (CS) dural arteriovenous fistulas (DAVFs) involving the sphenoid bone are rare entities that are easily confused with one another due to the complex structure and high variability of the venous system around the middle cranial fossa. We present a large retrospective study on middle cranial fossa non-CS DAVFs and review the literature on DAVF treatment in this location as well as relative anatomy. 15 patients had DAVFs involving the lesser sphenoid wing and 11 patients had DAVFs involving the greater sphenoid wing. Six patients presented with intracranial hemorrhage or subarachnoid hemorrhage (23.1%, 6/26). The most common symptoms were eye symptoms (38.5%, 10/26). Nineteen patients were treated with trans-arterial embolization (TAE) using liquid embolic agents and two patients were treated with transvenous embolization (TVE) using Onyx or in combination with coils. Surgical disconnection of the drainage veins was performed in five patients, with three cases experiencing unsuccessful TAE. Anatomic cure was achieved in 92.3% of the patients (24/26). Twelve patients had DSA and clinical follow-up from 3 to 27 months. There was one recurrence (8.3%) of the fistula in the patient two months after the initial complete occlusion. The majority of patients can be cured endovascularly. Laterocavernous sinus DAVFs may not be embolized by transvenous approach via the cavernous sinus because there is often no connection between them in most patients. A small percentage of patients may require surgical ligation to be cured.

Skull Base Meningiomas

Skull base meningiomas are among the most challenging meningiomas to treat clinically due to their deep location, involvement or encasement of adjacent essential neurovascular structures (such as key arteries, cranial nerves, veins, and venous sinuses), and their often-large size prior to diagnosis. Although multimodal treatment strategies continue to evolve with advances in stereotactic and fractionated radiotherapy, surgical resection remains the mainstay of treatment for these tumors. Resection of these tumors however is challenging from a technical standpoint, and requires expertise in several skull-base surgical approaches that rely on adequate bony removal, minimization of brain retraction, and respect for nearby neurovascular structures. These skull base meningiomas originate from a variety of different structures including, but are not limited to: the clinoid processes, tuberculum sellae, dorsum sellae, sphenoid wing, petrous/petroclival area, falcotentorial region, cerebellopontine angle, and foramen magnum. In this chapter, we will cover the common anatomical areas in the skull base from which these tumors arise, and the specific or optimal surgical approaches and other treatment modalities for meningiomas in these such locations.

Sphenoid wing meningiomas

Meningiomas that arise from the dura along the sphenoid wing can occur in globoid or en plaque forms. Radiographically they can be defined as occurring in the medial, middle, or lateral portions of the sphenoid wing. The medial group carries the highest neurologic risk for surgical treatment, while the hyperostosing en plaque type is the most difficult to remove completely because of orbital and bone involvement. This chapter addresses the clinical presentation and surgical treatment of sphenoid wing meningiomas with an emphasis on the most recent results from the literature.

Reversal of Visual Impairment Associated with Vasospasm After Resection of Sphenoclinoidocavernous Meningioma with Intra-Arterial Verapamil

BACKGROUND

Visual loss can be encountered in the immediate, early, or even delayed postoperative period after resection of skull base meningiomas involving the optic apparatus. Various mechanisms for visual loss can include mechanical injury, vascular insult, optic nerve and chiasm edema, and vasospasm of the blood supply to the visual apparatus.

CASE DESCRIPTION

In this article, we describe a patient who developed unilateral visual worsening in the early postoperative period after skull base resection of a sphenoclinoidocavernous meningioma that was compressing the ipsilateral optic nerve. After implementing hyperdynamic therapy and high-dose corticosteroids, catheter angiography showed severe vasospasm of the ipsilateral ophthalmic artery with delayed filling of the choroidal blush. Intra-arterial chemical angioplasty with verapamil was administered that resulted in angiographic improvement and clinical restoration of vision back to preoperative baseline. Vision remained stable in the postoperative course and continued to improve after discharge from the hospital.

CONCLUSIONS

To our knowledge, this is the first report of successful reversal of postoperative unilateral visual loss related to vasospasm after resection of a skull base sphenoclinoidocavernous meningioma. This may be a useful strategy to diagnose and treat possible vasospasm-induced visual loss after resection of skull base meningiomas involving the optic apparatus.

Prostate carcinoma mimicking a sphenoid wing meningioma

INTRODUCTION

We report here on a rare case of a large, lateral sphenoid wing tumor with radiographic and intraoperative findings highly suggestive of meningioma, yet pathology was in fact consistent with metastatic prostate adenocarcinoma.

PRESENTATION OF CASE

An 81 year-old male presented with expressive dysphasia, right-sided weakness and headaches. Imaging revealed a heterogeneously-enhancing lesion based on the left lateral sphenoid wing. The presumed diagnosis was strongly in favor of meningioma, and the patient underwent complete resection of the dural-based lesion. Final pathology confirmed the unexpected finding of a metastatic prostate adenocarcinoma. Although he tolerated surgery well, the patient was subsequently referred for palliative therapy given findings of widespread systemic disease.

DISCUSSION

Intracranial metastases may involve the dura, at times presenting with rare radiographic features highly suggestive for meningioma, as in our case here. This makes differentiation, at least based on imaging, a challenge. Elderly patients presenting with neurological deficits secondary to a newly-diagnosed, dural-based lesion should thus be considered for metastasis, prompting additional imaging studies (including body CT, MRI or PET) to rule out a primary lesion elsewhere. In some cases, this may affect the overall decision to proceed with surgical resection, or alternatively, to proceed directly to palliative therapy (the latter decision made in the context of widespread metastatic disease).

CONCLUSION

We conclude that dural-based metastatic lesions may mimic meningiomas, warranting thorough pre-operative work-up to exclude the possibility of metastasis. In certain cases, identification of widespread disease might preclude surgery and favor palliation, instead.

Sphenoid wing meningiomas: Surgical strategies and evaluation of prognostic factors influencing clinical outcomes

OBJECTIVE

To study microsurgical technique and prognostic factors influencing clinical outcomes in a series of 53 patients with sphenoid wing meningiomas (SWMs).

MATERIALS AND METHODS

The clinical materials of 53 patients with sphenoid wing meningiomas treated microsurgically between January 2008 and January 2012 were analyzed retrospectively. Follow-up period ranged from 6 to 62 months (median, 34 months). Clinical outcomes including postoperative quality of life and recurrence rate were evaluated. Univariate and multivariate statistical analysis were performed among factors that might influence postoperative quality of life.

RESULTS

In our group, the mean age of patients was 49 years. Mean tumor size was 3.9cm. Total tumor resection was achieved in 38 cases (71.7%), subtotal in 10 cases (18.9%) and partial resection in 5 cases (9.4%). Within the follow-up period, ten patients (18.9%) had recurrence and three patients (5.7%) died. In univariate analysis, we found the postoperative Karnofshky Performance Score (KPS) improvement was determined by various factors, including extent of tumor resection, peritumoral edema, tumor blood supply, size, adhesion, encasement and preoperative KPS. However, multivariate analysis showed that complete resection, rich blood supply, adhesion to adjacent structure, encasement of neurovascular were independent predictive factors for worse postoperative KPS.

CONCLUSIONS

With the improved requirement of postoperative quality of life in patients, intentional incomplete resection should be considered as an acceptable treatment option. Multivariate analysis confirmed that incomplete resection, poor blood supply, lack of adhesion or encasement of adjacent structure were independent predictive factors for favorable postoperative quality of life. An individual treatment strategy could help improved quality of life.

Results of surgical treatment of anterior clinoidal meningiomas - our experiences

OBJECTIVE

Presentation of our experience in the treatment of anterior clinoidal meningiomas, including evaluation of factors that may affect early and long-term treatment outcomes.

METHODS

Thirty patients were operated with strategy of complete tumor resection using fronto-orbito-zygomatic approach. Outcomes were assessed by Glasgow Outcome Scale at discharge and by Karnofsky Performance Scale at follow-up.

RESULTS

There were 6 tumors in group I, 20 in group II, and 4 in group III according to Al-Mefty classification. Complete tumor resection (Simpson I or II) was achieved in 19 patients, incomplete resection (Simpson IV) in 11: due to strict tumor adhesion to cerebral arteries in 5 and tumor extension to cavernous sinus in 6 cases. Operative mortality was 6.7%. Visual acuity improved in six among nine patients with impaired vision but in no one among nine patients with blindness. Normal life activity (80-100 KPS) could be carried out by 88% patients at follow-up. Recurrence was observed in two (11.8%) patients after radical removal and progression of residual tumor in two (25%) after subtotal resection.

CONCLUSIONS

Complete tumor removal is possible with an acceptable risk of death and severe neurological deficits, except for cases with tumor extension to the cavernous sinus or strict tumor adhesion to cerebral arteries. Visual acuity improvement may be expected in two thirds of patients with impaired vision, but not in cases of blindness. In cases of incomplete tumor removal, use of stereotactic radiosurgery immediately after surgery seems justified.

Preformed titanium cranioplasty after resection of skull base meningiomas - a technical note

INTRODUCTION

Meningiomas of the fronto-basal skull are difficult to manage as the treatment usually includes extensive resection of the lesion, consecutive reconstruction of the meninges and of the skull. Especially after removal of spheno-orbital and sphenoid-wing meningiomas, the cosmetic result is of utmost importance. In this technical note, we present our institutional approach in the treatment of skull base meningiomas, focussing on the reconstruction of the neurocranium with individually preformed titanium cranioplasty (CRANIOTOP(®), CL Instruments, Germany).

CASE REPORT

Two female patients (40 years, 64 years) are presented. Both patients presented with skull base lesions suggestive of meningiomas. The preoperative thin-sliced CT scan was processed to generate a 3D-model of the skull. On it, the resection was mapped and following a simulated resection, the cranioplasty was manufactured. Intra-operatively, the titanium plate served as a template for the skull resection and was implanted after microsurgical tumour removal, consecutively. The cosmetic result was excellent. Immediate postoperative CT scan revealed accurate fitting and complete tumour removal. Control Magnetic Resonance Imaging (MRI) within 12 weeks was possible without any artifacts.

DISCUSSION

The comprehensive approach described indicates only one surgical procedure for tumour removal and for reconstruction of the skull. The titanium plate served as an exact template for complete resection of the osseous parts of the tumour. Cosmetic outcome was excellent and control MRI was possible post operatively.

CONCLUSION

CRANIOTOP(®) cranioplasty is a safe and practical tool for reconstruction of the skull after meningioma surgery.