S. Honeybul

Sphenoid wing meningioma en plaque: a clinical review.

Summary.Summary.Objective. To review the role of craniofacial resection and reconstruction in the treatment of patients with sphenoid wing meningioma en plaque.Design: 15 patients were reviewed. The presenting features, operative details and complications were documented. The adequacy of resection was reviewed and postoperative scans were analyzed to assess orbital reconstruction. Patients were assessed regarding aesthetics and craniofacial function. The Glasgow outcome scale and the SF36 questionnaire were used to assess outcome.Results: The majority (92%) presented with proptosis and had disease extending from the sphenoid wing into the orbital roof (71%) and the middle fossa (71%). The transzygomatic approach was the most commonly used approach (85%). 14 patients were examined on an outpatient basis, one patient has died. In the majority of patients visual acuity was unchanged (85%) and in most cases (85%) there was significant improvement in globe position. Ptosis (57%) and upper eyelid swelling (50%) were a persistent problem. Craniofacial function and cosmesis were well maintained. Two patients have had clinical recurrences (14%). 14 have had a good outcome adjudged by the Glasgow outcome scale and most patients have satisfactory outcomes adjudged by the SF36 questionnaire.Conclusions: Meningioma en plaque represents a difficult surgical challenge requiring a multidisciplinary approach. By using well established craniofacial techniques good disease control can be achieved with minimal morbidity and good functional and cosmetic results.

The orbitozygomatic infratemporal fossa approach: a quantitative anatomical study.

SummaryUsing detailed cadaveric dissections this study has demonstrated and quantified the increase in exposure and additional access gained by using the Orbitozygomatic infratemporal fossa approach for neurosurgical access.The surgical window of exposure can be increased by up to 300% when this technique is utilised to facilitate access via either a subtemporal (to access the P2 segment of the posterior cerebral artery) or transsylvian (to access the basilar bifurcation) approach. In addition the distance between the surgeon and the operative field can be decreased by approximately 2–3 cm.The orbitozygomatic infratemporal fossa approach is a relatively simple technique which can readily increase neurosurgical exposure of the skull base. It also provides simultaneous access to the infratemporal fossa, pterygopalatine fossa and the orbit.

Craniofacial Access in Children

Summary We have used craniofacial access in 20 children (age range 3/12–14 years) for complex skull base/intracranial pathology over the past 5 years. The majority of the patients had a tumour – 7 of the skull base, 5 extensive suprasellar lesions and 3 acoustic neuromas; 4 had an aneurysm or AVM and in 1 there was a congenital problem.This extended application of established adult techniques in a paediatric practice emphasises the fundamental point that the quintessence of good surgical practice is the construction of an operation for the individual patients pathology. We therefore used transzygomatic, orbital, transoral, transmandibular, petrous, transcondylar, translabyrinthine and transbasal access techniques. Good function and cosmesis with minimal complications were achieved. We have not observed complications with craniofacial growth and the majority of patients were able to return to normal school. The range of approaches used emphasise the importance of a multidisciplinary team with both paediatric and neurosurgical expertise, especially with complex vascular and skull base pathology, in dealing with these difficult problems. The case for specialist referral merits some discussion within the representative bodies of paediatric neurosurgeons.

The transzygomatic approach: an anatomical study

The transzygomatic approach has been utilised to facilitate neurosurgical access to the skull base for a number of years. Advocates of the technique claim the additional access gained provides wider exposure of the neurosurgical pathology and improved visualisation of adjacent vital neurovascular structures. The aim of this study was to photographically demonstrate the technique and to highlight the anatomical areas to which access can be improved. A morphological cadaver study was undertaken. Specific intracranial structures in the vicinity of the skull base were targeted and exposure was compared with and without the zygoma in position. This study demonstrates the increase in exposure of the basilar bifurcation (via a transsylvian approach) and the P2 segment of the posterior cerebral artery (via a subtemporal approach) that can be achieved and the improved access to adjacent anatomical compartments. It can be concluded that the transzygomatic approach is a relatively simple technique which can readily increase exposure of the skull base. It also provides simultaneous access to the superior pole of the infratemporal fossa, the pterygopalatine fossa and the orbit.

The Extended Transbasal Approach: A Quantitative Anatomical and Histological Study

Summaryu2003Since its introduction in 1972 the transbasal approach to the anterior fossa and sphenoethmoidal region has undergone a number of modifications. The extended transbasal approach with preservation of olfaction not only improves exposure of the anterior fossa, but also provides access to the clivus as far inferiorly as the foramen magnum.u2003An anatomical study has been undertaken to photographically demonstrate and quantify the varying degrees of exposure that this technique provides. The pituitary stalk was used as an intracranial target. The amount of exposure was compared using a standard subfrontal approach, a transbasal approach and an extended transbasal with preservation of olfaction. In addition, a histological study was carried out to investigate the level to which identifiable olfactory nerves extended into the nasal mucosa.u2003The anatomical study demonstrates the area of the “external window of exposure” can be doubled using a transbasal approach and more than quadrupled using the extended transbasal approach, when gaining access to the pituitary stalk. In addition, the study highlights the exposure of other anatomical areas, such as the medial orbit, the cavernous sinus, the clivus and the vertebrobasilar complex. The histological study establishes that the olfactory nerves extend only 10mms below the cribriform plate.

The extended transbasal approach: clinical applications and complications.

Summaryu2003Objectives. To describe in detail key technical aspects of the extended transbasal approach which involves en-bloc mobilisation of the supraorbital rim, the orbital roof and the nasoethmoidal complex. In some patients osteotomies were performed around the cribriform plate with a view to maintaining olfaction.u2003To review 18 patients with deep seated lesions located in the central skull base region (including 6 recurrences) to highlight patient selection, presentation, surgical morbidity and outcome.u2003Methods. Prospective data recording and clinical chart review.u2003Results. Outcome was assessed at a minimum of 1 year after operation using the Glasgow Outcome Score. Thirteen patients had made a good recovery, 1 was moderately disabled, 2 were severely disabled (both had been severely disabled before operation), and 2 died. By contrast, quality of life assessment indicated that only 7 of the surviving 14 adults had returned to normal levels of activity and perceived health; although 6 of the other 7 patients had resumed their former occupations, their follow up assessments showed a reduced quality of life. Of the 13 patients who had an olfaction preservation procedure, 6 showed appreciation of smell on formal testing.u2003Conclusions. In patients with progressive and extensive deep seated lesions this technique provides wide exposure in a shallow surgical field. Complication rates although acceptable were significantly higher in patients with intradural lesions. In some selected patients it was possible to preserve olfaction. Specific surgical outcome assessments pointed to satisfactory results, but failed to reflect the degree of patient disability. There is a need for outcome measures that take into account the patients expectations and which address his quality of life in order to validate the benefits of these procedures.

The transzygomatic approach: A long-term clinical review

SummaryThe transzygomatic approach has been utilised to improve access to the skull base, infratemporal fossa and orbit for a number of years. It provides a low anterolateral approach to the skull base, along the floor of the middle fossa. It allows both a transsylvian and subtemporal approach with a reduction in brain retraction and better exposure of adjacent neurovasculature structures. A long term review of 53 patients is presented highlighting outcome at two years post surgery and morbidity of the approach. It is concluded that the technique is versatile and can be used to improve exposure of a variety of anatomical locations. There is minimal long term morbidity attributable to the surgery of access and the majority of patients have had good outcomes.