The effect of direction of force to the craniofacial skeleton on the severity of brain injury in patients with a fronto-basal fracture.

The skull base is uniquely positioned to absorb force imparted to the craniofacial skeleton, thereby reducing brain injury. Less well understood is the effect of the direction of force imparted to the craniofacial skeleton on the severity of brain injury. Eighty-one patients from two UK major trauma centres who sustained a fronto-basal fracture were divided into two groups: those struck with predominantly anterior force and those by predominantly lateral force. The first recorded Glasgow Coma Score (GCS), requirement for intubation, and requirement for decompressive craniectomy were used as markers of the severity of brain injury. An average GCS of 5 was found in the lateral group and 14 in the anterior group; this difference was statistically significant (P<0.001). There was an increased need for both intubation and decompressive craniectomy in the lateral group compared to the anterior group (absolute risk difference 46.6% and 15.8%, respectively). These results suggest that the skeletal anatomy of the fronto-basal region influences the severity of head injury. The delicate lattice-like structure in the central anterior cranial fossa can act as a crumple zone, absorbing force. Conversely in the lateral aspect of the anterior cranial fossa, there is a lack of collapsible interface, resulting in an increased energy transfer to the brain.

Applied anatomy of the anterior cranial fossa: what can fracture patterns tell us?

The skull base is uniquely placed to absorb anteriorly directed forces imparted either via the midfacial skeleton or cranial vault. A variety of skull base fracture classifications exist. Less well understood, however, is fracture extension beyond the anterior cranial fossa (ACF) into the middle and posterior cranial fossae. The cases of 81 patients from two UK major trauma centres were studied to examine the distribution of fractures across the skull base and any relationship between the vector of force and extent of skull base injury. It was found that predominantly lateral force to the craniofacial skeleton produced a fracture that propagated beyond the ACF into the middle cranial fossa in 77.4% of cases, significantly more (P<0.001) than for predominantly anterior force (12.0%). Fractures were significantly more likely to propagate into the posterior fossa with a lateral vector of impact compared to an anterior vector (P=0.049). This difference in energy transfer across the skull base may, in part, be explained by the local anatomy. The more delicate central ACF acts as a 'crumple zone' in order to absorb force. Conversely, no collapsible interface exists in the lateral aspect of the ACF, thus the lateral ACF behaves like a 'buttress', resulting in increased energy transfer.

Linear trapdoor or "white-eye" blowout fracture of the orbit: not restricted to children.

The management of orbital blowout fractures remains controversial, particularly in patients with a white-eye or trapdoor-type injury. We report our experience with 10 such cases (mean age 19.6 years, range 4-53) and show, unlike previous reports, that this pattern of injury is not restricted to children. Although most patients had a white eye (70%), the presence of subconjunctival haemorrhage and periorbital bruising did not exclude this injury, and the patients often (60%) had serious autonomic symptoms such as nausea and vomiting. A high index of suspicion and cross-sectional imaging is required to confirm the diagnosis. Early intervention (less than 7 days) seems to be associated with better outcome, but patients benefitted from intervention up to 41 days after injury. The mechanism underlying this pattern of injury and the rationale behind early intervention is also discussed.

Lateral orbitotomy: a useful technique in the management of severe traumatic disruption of the lateral orbital skeleton.

Lateral orbitotomy is a well-recognized method of improving orbital access for the removal of orbital tumours and foreign bodies, and has been used in orbital decompression in dysthyroid eye disease. The technique has received less attention in the management of orbital trauma. Lateral orbitotomy is useful in the management of selected cases of orbital trauma, in particular severe disruption of the lateral orbit requiring extensive dissection in the region of the superior orbital fissure. It is used in patients with globe rupture, with lateral orbital disruption, in helping to reduce the amount of globe retraction when the lateral orbital fractures are reduced and fixed.

Resolution of diplopia after repair of the deep orbit.

The degree of resolution of diplopia after repair of a blow-out fracture of the orbital floor varies and depends on many factors. We present six patients, each of whom had extensive fractures of the floor of the orbit that extended posteriorly to its anatomical limit. The mean (range) time for the resolution of diplopia after reconstruction was 4.4 (1-7) months. We think that its slow resolution in these patients may require preoperative counselling, and also the postoperative management of patients with extensive disruptions of the floor of the orbit posterior to the anterior limit of the inferior orbital fissure (within the deep orbit) must be carefully planned.

Post-traumatic orbital reconstruction: anatomical landmarks and the concept of the deep orbit.

Dissection deep within the orbit is a cause for concern to surgeons because of the perceived risks of injuring critical structures such as the contents of the superior orbital fissure and the optic nerve. Although "safe distances" (those distances within which it is considered safe to dissect within the orbit) have been described, these are of limited value if the orbit is severely disrupted or is congenitally shallow. In addition, traumatic defects in the orbital floor, in particular, often extend beyond these distances. Reliable landmarks based on the relations between anatomical structures within the orbit, rather than absolute distances, are described that permit safe dissection within the orbit. We present the concept of the deep orbit and describe its relevance to repair of injuries.

Sphenoid wing meningioma en plaque: a clinical review.

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.

Extended transbasal approach with preservation of olfaction: ananatomical study.

Many craniofacial approaches to the sphenoethmoidal region, anterior fossa, and central skull base compartment have been described, a number of which involve the mobilization of the frontonasoorbital complex en bloc. Spetzler's modification incorporates osteotomies around the cribriform plate, to preserve olfaction. In this morphological study of three cadavers, photographs were used to show the technique and define its anatomical boundaries and limitations. The study illustrates access to a number of anatomical regions, particularly the exposure of the medial orbit, the cavernous sinus, the clivus, and the vertebrobasilar complex.

Cancer survival rates and GDP expenditure on health: a comparison of England and Wales and the USA, Denmark, Netherlands, Finland, France, Germany, Italy, Spain and Switzerland in the 1990s.

Health funding is central to public health planning and clinical practice, hence this comparison of GDP health expenditure and five year post-diagnostic cancer survival rates of England and Wales with the USA and eight European countries. The three lowest proportional GDP health expenditures over the period 1980-1990 were Denmark, England and Wales, and Spain. The USA had the highest proportional GDP expenditure, followed by France, Germany, and The Netherlands. Overall the USA had the best cancer survival rates in the 14 sites reviewed, followed by Switzerland, The Netherlands, and Germany. The least successful were Spain, England and Wales, and Italy. In respect to the high incidence cancers, colorectal, lung, and female breast cancers, England and Wales survival rates were the poorest of all ten countries, followed by Denmark and Spain. Higher GDP health expenditure and longer survival rates for each gender were significantly correlated indicating a possible association between fiscal input and clinical outcomes, which poses problems for the development of effective public health.

Doppler sonography for the assessment of central mandibular blood flow.

In this study we evaluated the role of Doppler sonography in the assessment of central mandibular blood flow. We assessed the characteristics of blood flow in the mental artery, the larger terminal branch of the inferior alveolar artery, in 30 healthy volunteers equally distributed in the age groups 20-39, 40-59 and over 60 years. We used a DWL Multi-Dop X4(R) Doppler sonography machine (DWL GmbH) with an 8 MHz probe applied intraorally. The variables analysed were patency, time averaged maximum velocity (TAMV), pulsatility index (PI), discomfort and the duration of the procedure. All the arteries analysed were patent. The TAMV and PI decreased as age increased and there were significant differences between the age groups: TAMV (P = 0.01), PI (P = 0.006). Pair-wise comparisons also showed significant differences (P< 0.05) between the 20-39 and the over 60 age group, 40-59 and the over 60 age group for TAMV, and between the 20-39 and over 60 age group for PI. The difference in measurements between the right and left sides in individual patients was not significant. The assessment took about 20 minutes and caused little discomfort. The technique is simple and could potentially be used to influence clinical decisions.

The extended transbasal approach: a quantitative anatomical and histological study.

Since 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. An 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. The 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 10 mms below the cribriform plate.

The extended transbasal approach: clinical applications and complications.

OBJECTIVES: 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. To 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. METHODS: Prospective data recording and clinical chart review. RESULTS: 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. CONCLUSIONS: 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 patient's expectations and which address his quality of life in order to validate the benefits of these procedures.

Craniofacial access in children.

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 patient's 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.

Quantitative separation of 4-hydroxyproline from skeletal muscle collagen by micellar electrokinetic capillary electrophoresis.

The phenylthiohydantoin (PTH) derivatives of 3- and 4-hydroxyproline (Hyp) were separated using micellar electrokinetic capillary electrophoresis (MEKC). The separation protocol was also used to determine Hyp content of bovine skeletal perimysial collagen preparations and whole muscle samples. Amino acids from hydrolyzed tissues were labeled using a two step procedure that involved initial reaction with o-phthalaldehyde (OPA) to modify primary amines followed by their precipitation under acidic conditions. In the second step, imino acids were reacted with phenyl isothiocyanate (PITC). This labeling method was rapid and the Hyp values determined in these biological samples were found to be in close agreement with conventional methods and other published reports.

The effect of orbitozygomatic access for ruptured basilar and related aneurysms on management outcome.

BACKGROUND: Despite increasing use of craniofacial access for complex intracranial and skull base pathology, there have been no reports detailing the impact of improved access on clinical outcome. METHODS: Orbitozygomatic access was used in 32 patients with an aneurysm of the basilar bifurcation, superior cerebellar, or posterior cerebral arteries over a 9-year period. RESULTS: Operative mortality was 0%, overall management mortality 9% and management morbidity was 9%. This approach was selected for these patients because of the anatomy of the aneurysm and its relationship to the terminal basilar complex and the dorsum sellae/posterior clinoid process. The flexibility achieved by the access allowed intraoperative use of multiple corridors of access. Morbidity directly attributable to the use of orbitozygomatic access was minimal. CONCLUSIONS: While management outcome after aneurysmal subarachnoid hemorrhage relates directly to the severity of the initial hemorrhage, rather than the surgical approach chosen, in selected patients we recommend the use of this approach as a valuable adjunct to the armamentarium of the vascular neurosurgeon.

A nationwide study to investigate current opinion amongst maxillo-facial and neurological surgeons with regard to access surgery for neurosurgical procedures.

Over the past two decades there has been much interest in the use of craniofacial disassembly techniques to improve difficult access to some neurosurgical lesions, However, it is not known to what extent these techniques have been adopted throughout the UK. The aim of this study was to establish how many maxillofacial surgeons and neurosurgeons are currently involved in this type of collaborative surgery and to determine current opinion regarding the use of these procedures. A self-completion questionnaire was sent to all consultant maxillofacial surgeons and neurosurgeons within the UK. The results of the questionnaire suggest that there is a high level of interest in this type of collaborative surgery within the UK. It has demonstrated some interesting differences of emphasis regarding possible advantages and disadvantages of these procedures, and the areas to which access can be particularly improved. In addition, the future of this type of collaborative surgery and some of the difficulties involved in its organization were highlighted.

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.