Samantha Hettige

Indocyanine green video-angiography as an aid to surgical treatment of spinal dural arteriovenous fistulae

PurposeTo illustrate the use of indocyanine green (ICG) video-angiography to confirm abolition of spinal dural arteriovenous fistula (SDAVF) and preserve the normal vascular anatomy intraoperatively.MethodsA 73-year-old woman presenting with progressive myelopathy was diagnosed with an SDAVF, where the origin of the fistula was in close proximity to the origin of the posterior spinal artery. ICG was injected intravenously. Using a filter on the microscope, dynamic filling of the abnormal vasculature was visualised.ResultsAfter applying a clip to the fistulous connection, we were able to see the successful interruption of the dural fistula, on-table in real time.ConclusionICG video angiography confirmed interruption of the fistula and preservation of the associated posterior spinal artery. We find the application of this relatively new technology has the potential to shorten operating times, gives additional reassurance of completeness of surgical treatment and preservation of normal spinal vasculature.

Malignant transformation in craniopharyngiomas.

BACKGROUND Craniopharyngiomas are successfully managed with surgery and/or adjuvant chemoradiotherapy but have been documented to undergo malignant transformation (MT), albeit very rarely, with only 23 reported cases. The exact cause and pathogenesis of this MT are unknown, although the literature has suggested a possible correlation with radiotherapy. OBJECTIVE To review the reported cases of malignancy, in particular looking at the incidence, tumor characteristics, previous treatment modalities, and median survival. METHODS We conducted a PUBMED, SCOPUS, OVID SP, and INFORMA search with a combination of key words: craniopharyngioma, malignancy, transformation, neoplasm, radiation therapy, and anaplastic. We identified 23 cases relevant to our study. RESULTS Median age at the time of diagnosis of malignant craniopharyngiomas was 31 years (range, 10-66 years); 52.6% of the patients were female. Histologically, the most common tumor types were squamous cell carcinoma (80.96%), with adamantinomatous cell type being the most common morphology (89.47%). We found that 21.7% of the cases were diagnosed as malignant craniopharyngioma at first biopsy. Of the rest, the median time from initial benign diagnosis to MT was 8.5 years (range, 3-55 years). Median overall survival after MT was 6 months (range, 2 weeks-5 years). Using the Spearman rank correlation, we found no correlation between the use of radiation therapy (correlation coefficient, -0.25; P < .05) or its dosage (correlation coefficient, -0.26; P < .05) and MT. CONCLUSION Malignant craniopharyngiomas are rare and are associated with a poor prognosis. MTs occur years after the initial benign craniopharyngioma diagnosis and are associated with multiple benign craniopharyngioma recurrence. Results also show that, contrary to widespread belief, there is a poor correlation between radiotherapy and MT.

A review of spontaneous intracranial extradural hematoma in sickle-cell disease

Sickle-cell disease is common among patients of Afro-Caribbean origin. Though it can precipitate neurological conditions, it only rarely causes neurosurgical problems, with very few reported cases. We describe the case of a 7-year-old girl with a background of sickle-cell disease (SCD) brought into an acute neurosurgical unit in extremis, signs of a raised ICP, and with no history of recent trauma. Following further investigations, an acute drop in the hemoglobin and hematocrit levels were noted, with the cause of her presentation being attributed to a sickling crisis causing skull convexity infarction and resulting in spontaneous bilateral extradural hematomas requiring emergency evacuation. We review the current literature and propose the pathophysiological mechanism behind this phenomenon.

Raising the ethical standards in neurosurgery

The historically aware neurosurgeon cannot but be astounded by the remarkable progress of the specialty since the early 1900s. Around that time, the neurologist David Ferrier described neurosurgery as ‘a sort of polite way of committing suicide’ [1]. Today, spectacular neuroimaging techniques, neuroanaesthesia, neurostimulation and brain-computer interfaces, the prospect of neural transplantation using stem cells, and advances in operating microscopes, surgical instruments and technique are only some of the developments that reflect the evolution of the specialty. Progress in medicine, however, often presents new ethical challenges, and neurosurgery is no exception. Our ability to manipulate and interfere with the brain, and the implications of such an ability on personal identity, consciousness and wellbeing, have raised such an array of ethical issues that a new branch of bioethics has emerged to address them: neuroethics [4, 9]. While we can open the closed box of the skull with greater ease and safety than ever before, it is not infrequent for neurosurgeons to approach an operation, be it an awkwardly placed petroclival meningioma, a large infiltrating highgrade glioma or an unpredictable cerebral aneurysm, knowing that there is a chance that their patients may die or be so cognitively impaired as a result of the operation or its complications that they may no longer be able to make decisions. The invasiveness of many intracranial operations and the risks of neurological deficit distinguish neurosurgery from other specialties. It seems sensible, given these features, that neurosurgeons not only inform patients of the possible outcomes of high-risk operations, but also offer competent patients the possibility to discuss what they would like to happen if they lose the ability to make decisions (“some patients in your situation have views on what they would want if their condition deteriorates after the operation. The chances of this happening are low, but some patients appreciate the opportunity to make plans. Do you have any views on this?”) [3]. Depending on the patient’s answer, the surgeon could mention the possibility of creating a Durable Power of Attorney (or, in the UK, a Lasting Power of Attorney), which would allow patients to appoint a person (or several persons) to make decisions on their behalf if unable to do so themselves. Alternatively, patients may want to make an advance directive (formally called an ‘advance decision’ in the UK), specifying what treatment they would not want to receive in the future. If the patient has preferences but does not wish to record them in such a formal manner, the surgeon can document them in the notes. This will provide some indication of the patient’s views and wishes that may be of future use. It is important to raise the subject in this preoperative encounter (rather than wait to see how the situation evolves) for it may be the last time the surgeon sees the patient when he or she still has capacity. If patients accept the offer to have this discussion (and doubtless some patients would rather not), it will allow clinicians to continue respecting their autonomy when they D. K. Sokol (*) Lecturer in Medical Ethics and Law, St George’s, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom e-mail: daniel.sokol@talk21.com