Circulating tumor DNA for malignant peripheral nerve sheath tumors in neurofibromatosis type 1.

PURPOSE: The leading cause of early death in patients with neurofibromatosis type 1 (NF1) is malignant peripheral nerve sheath tumor (MPNST). The principles of management include early diagnosis, surgical clearance and close monitoring for tumor recurrence. Current methods for diagnosis, detection of residual disease and monitoring tumor burden are inadequate, as clinical and radiological features are non-specific for malignancy in patients with multiple tumors and lack the sensitivity to identify early evidence of malignant transformation or tumor recurrence. Circulating tumor DNA (ctDNA) is a promising tool in cancer management and has the potential to improve the care of patients with NF1. In the following article we summarise the current understanding of the genomic landscape of MPNST, report on the previous literature of ctDNA in MPNST and outline the potential clinical applications for ctDNA in NF1 associated MPNST. Finally, we describe our prospective cohort study protocol investigating the utility of using ctDNA as an early diagnostic tool for MPNSTs in NF1 patients.

Minimally invasive neurosurgical access techniques to facilitate endovascular treatment of dural arteriovenous fistulae.

We report two cases of dural arteriovenous fistulae treated endovascularly, where percutaneous venous or arterial access was not suitable. In both cases, a different surgical access technique was used to allow transcranial cannulation of the appropriate venous sinus or of the varix to gain access and occlude the fistula.

Routine but risky: a multi-centre analysis of the outcomes of cranioplasty in the Northeast of England.

BACKGROUND: Cranioplasty is undertaken as a routine secondary operation following craniectomy. At a time when decompressive craniectomy is being evaluated by several large trials, we aimed to evaluate the morbidity associated with cranioplasty and investigate its potential effect on outcome. METHODS: The outcomes of 166 patients undergoing cranioplasty at two centres in the United Kingdom between June 2006 and September 2011 were retrospectively analysed. Outcome measures included mortality, morbidity and functional outcome determined by the modified Rankin score (mRS) at last follow-up. A logistic regression analysis was performed to model and predict determinants related to neurological outcome following cranioplasty. RESULTS: Sixty-seven out of 166 patients (40.4 %) experienced at least one complication during a median follow-up time of 15 months (inter-quartile range 5-38 months). Thirty six patients (21.7 %) developed infection requiring antibiotics, with 27 (16.3 %) requiring removal of the cranioplasty. Nine of 25 patients (36 %) with bi-frontal defects developed an infection whereas 21 of the 153 patients (16.4 %) with a defect other than bi-frontal developed an infection (Chi square p = 0.009). Further surgery in the two groups was required in 16.4 % and 11.7, % respectively. Pseudomeningocoele (9 %), seizures (8.4 %) and poor cosmesis (7.2 %) were also commonly observed. Logistic regression analysis identified initial operation (p < 0.03), mRS at the time of cranioplasty (p < 0.0001) and complications (p < 0.04) as being predictive of neurological outcome at last follow-up. Age at the time of cranioplasty and the timing of cranioplasty were not predictive of last mRS score at follow-up. CONCLUSIONS: Cranioplasty harbours significant morbidity, a risk that appears to be higher with a bifrontal defect. The complications experienced influence subsequent functional outcome. The timing of cranioplasty, early or late, after the initial operation does not impact on the ultimate outcome. These findings should be considered when making decisions relating to craniectomy and cranioplasty.

Has the impact of the working time regulations changed neurosurgical trainees' attitudes towards the European working time directive 5 years on?

We report the results from a survey of the British Neurosurgical Trainees' Association which aimed to assess current rota patterns and their compliance with the government's working time regulations. The survey questioned whether trainees felt that shift working, imposed as a result of the European working time directive, is continuing to impact on patient care and training opportunities in neurosurgery. The responses to this survey indicate that neurosurgical trainees remain concerned with the impact that the current working time regulations have on all facets of their work: training, work- life balance, and the provision of patient care. The survey comments show that the majority would support a change in legislation to allow greater flexibility in the working time regulations.

Transcortical Approach to Deep-Seated Intraventricular and Intra-axial Tumors Using a Tubular Retractor System: A Technical Note and Review of the Literature.

BACKGROUND: Retraction of white matter overlying a brain lesion can be difficult without causing significant trauma especially when using traditional methods of bladed retractors. These conventional retractors can produce regions of focal pressure resulting in contusions and areas of infarct. METHODS: In this article, we present a retrospective case series of six patients with deep-seated intraventricular and intra-axial tumors that were approached using a ViewSite Brain Access System (tubular retractor). The authors describe a unique method of creating a pathway using a dilated glove. We shall also review the relevant literature that reports this type of surgery. Cases included three cases with third ventricular colloid cysts, one case of a third ventricular arachnoid cyst, one case with a lateral ventricular neurocytoma, and a case with a deeply seated intra-axial metastatic tumor. RESULTS: Gross total resection was achieved in five cases with small residual in the central neurocytoma operation, with no documented neurological deficit in any case. One case had persistent memory problems and one case had continuing decline from the metastatic disease. CONCLUSION: The introduction of tubular-shaped retractor systems has offered the advantage of reducing retraction pressures and distributing any remaining force in a more even and larger distributed area, thus reducing the risk of previous associated morbidity while also permitting great visualization of the target lesion.

Cerebral aneurysms and accelerated atherosclerosis in Russell-Silver syndrome: a new subtype? Case report.

The authors describe the case of a 32-year-old woman known to have Russell-Silver syndrome who presented with repeated aneurysmal subarachnoid hemorrhage. Multiple intracranial aneurysms and advanced peripheral vascular disease were demonstrated. The authors postulate a link between these vascular features and the patient's genetic condition.