Data from the medical literature suggest that surgical revascularisation is a safe intervention for paediatric MMS and most treated patients derive some symptomatic benefit. However, paucity of data on selection criteria and more global outcome measures means that the impact of surgical revascularisation on natural history remains uncertain. Direct and/or combined procedures provide better revascularisation, but this is not associated with differences in symptomatic outcome. International standardisation of the clinical approach to the treatment of paediatric MMS is urgently needed to critically evaluate the optimal indications for and timing of surgical revascularisation.

BackgroundThe embryology of the bony craniovertebral junction (CVJ) is reviewed with the purpose of explaining the genesis and unusual configurations of the numerous congenital malformations in this region. Functionally, the bony CVJ can be divided into a central pillar consisting of the basiocciput and dental pivot and a two-tiered ring revolving round the central pivot, comprising the foramen magnum rim and occipital condyles above and the atlantal ring below. Embryologically, the central pillar and the surrounding rings descend from different primordia, and accordingly, developmental anomalies at the CVJ can also be segregated into those affecting the central pillar and those affecting the surrounding rings, respectively.DiscussionA logical classification of this seemingly unwieldy group of malformations is thus possible based on their ontogenetic lineage, morbid anatomy, and clinical relevance. Representative examples of the main constituents of this classification scheme are given, and their surgical treatments are selectively discussed.

In the management of craniosynostosis subdural intracranial pressure (ICP) monitoring has proved a useful and safe means of identifying those children with raised ICP who are at risk from its long-term sequelae and who would benefit from early surgical intervention. Overnight subdural ICP recordings have been obtained in 136 unoperated cases of craniosynostosis. Fifteen patients were studied both before and after cranial vault remodelling procedures. ICP was raised (> 15 mmHg) in 35%, borderline (10-15 mmHg) in 37% and normal (< 10 mmHg) in 27% of cases. Raised ICP was present in 28/53 of the syndromic craniofacial dysostosis cases and in 20/83 non-syndromic craniosynostosis cases investigated (P < 0.001). Raised mean ICP and periodic plateaux of sustained ICP during sleep were particularly associated with the syndromic cases. Of the 15 patients studied following cranial vault surgery, 9 showed a reduction in ICP, 3 were unchanged and 3 had higher ICP postoperatively. The results of ICP monitoring can contribute significantly to formulating a rational and staged surgical management plan incorporating the need to normalise ICP and correct the frequently severe functional and cosmetic consequences of these disorders.

Based on their findings, the authors assert that in children with complex forms of craniosynostosis in whom other factors, such as hydrocephalus, are absent, abnormalities of venous drainage that particularly affect the sigmoid-jugular sinus complex produce a state of venous hypertension that, in turn, is responsible for the majority of cases of raised ICP. The incidence of these changes is unknown, but an analysis of the ages of the children in this study indicated that the period of particular vulnerability to the effects of venous hypertension lasts until the affected child is approximately 6 years old. After that age the collateral venous drainage through the stylomastoid plexus will likely become sufficient to allow ICP to normalize.

The indications for surgical correction of craniosynostosis in which there is involvement of only one of the cranial vault sutures have traditionally been based upon the cosmetic merits of the deformity alone. Whilst it is now appreciated that intracranial hypertension is commonly associated with the more complex forms of craniosynostosis, this aspect has not previously been addressed in detail among cases of single-suture craniosynostosis. This retrospective study reports our experience of overnight subdural intracranial pressure monitoring in 74 children with premature closure of a single cranial suture. A single coronal suture was involved in 37 patients, the sagittal suture in 25 and the metopic suture in 12. Intracranial pressure was raised in 13 (17%), borderline in 28 (38%) and normal in 33 (45%). Elevated intracranial pressure was seen more commonly where a midline suture was involved (sagittal or metopic) than when a single coronal suture was fused. We conclude that intracranial hypertension occurs in a significant proportion of children with single-suture craniosynostosis and suggest that this factor should be borne in mind during the initial assessment of these children so as to enable timely intervention where required and appropriate counselling of parents.