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Dangers of collapsible ventricular drainage systems

Technical note

Andrew H. Kaye and David Wallace

✓ Ventricular drainage systems employing a collapsible plastic bag for fluid collection were postulated to cause an increasing back-pressure produced in part by the elasticity of the bag. This postulate was shown to be correct in an experimental situation. There was a logarithmic rise in cerebrospinal fluid pressure as the bag filled. By increasing the size of the bag, the problem was overcome.

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Transnasal stereotactic biopsy of a clivus tumor

Technical note

Jeffrey V. Rosenfeld, David Wallace, Geoffrey L. Klug, and Andrew Danks

✓ Computerized tomography-guided transnasal stereotactic tissue diagnosis of a lytic lesion in the clivus was performed successfully using the Cosman-Roberts-Wells frame, thus avoiding a major craniotomy. The authors recommend stereotaxis as the preferred technique for biopsy in this region.

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Cerebellar astrocytoma presenting with precocious puberty in a girl

Case report

Vivek Anand Josan, Craig Douglas Timms, Christian Rickert, and David Wallace

✓Central precocious puberty in girls is uncommon and tends to be idiopathic in most cases. In about 20 to 30% of cases there is an intracranial mass lesion. The common lesions are hypothalamic hamartomas, optic nerve gliomas, supra-sellar arachnoid cysts, hydrocephalus, germinomas, and other sellar/suprasellar lesions. Central precocious puberty secondary to a cerebellar astrocytoma is extremely rare. The authors report the first case in a girl who presented with several episodes of bleeding per vaginum. There was no clinical or radiological evidence of raised intracranial pressure.

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Surgery for Occult Aneurysms

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The angiosome territories of the spinal cord: exploring the issue of preoperative spinal angiography

Laboratory investigation

Michael K.-Y. Hong, Matthew K.-H. Hong, Wei-Ren Pan, David Wallace, Mark W. Ashton, and G. Ian Taylor


The angiosome concept has been the subject of extensive research by the senior author (G.I.T.), but its specific applicability to the spinal cord was hitherto unknown. The aim of this study was to see if the spinal cord vasculature followed the angiosome concept and to review the usefulness of preoperative spinal angiography in surgery for spinal disorders. Spinal cord infarction and permanent paraplegia may result from inadvertent interruption of the artery of Adamkiewicz. Spinal angiography, which may enable avoidance of this catastrophic complication, is still not commonly used.


Two fresh cadavers were injected with a gelatin–lead oxide mixture for detailed comparative study of spinal cord vasculature. One cadaver had insignificant vascular disease, whereas the other had extensive aortic atherosclerosis, presenting a unique opportunity for study. After removal from each cadaver, radiographs of the spinal cords were obtained, then photographed, and the vascular territories of the cords were defined.


Four angiosome territories were defined: vertebral, subclavian, posterior intercostal, and lumbar. These vascular territories were joined longitudinally by true anastomotic channels along the anterior and posterior spinal cord. Anastomosis between the anterior and posterior vasculature was poor in the thoracolumbar region. The anterior cord relied on fewer feeder arteries than the posterior, and the anterior thoracolumbar cord depended on the artery of Adamkiewicz for its supply. In chronic aortic disease with intercostal artery occlusion at multiple levels, a rich collateral circulation supporting the spinal cord was found.


The arterial supply of the spinal cord follows the angiosome concept. The atherosclerotic specimen supports the suggestion that the blood supply is able to adapt to gradual vascular occlusion through development of a collateral circulation. Nevertheless, the spinal cord is susceptible to ischemia when faced with acute vascular occlusion. This includes inadvertent interruption of the artery of Adamkiewicz. The authors recommend the use of preoperative spinal angiography to prevent possible paraplegia in removal of thoracolumbar spinal tumors.

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Postgraduate publishing output in pediatric neurosurgery: correlation with fellowship site and individual scholars

Sonia Ajmera, Ryan P. Lee, Andrew Schultz, David S. Hersh, Jacob Lepard, Raymond Xu, Hassan Saad, Olutomi Akinduro, Melissa Justo, Brittany D. Fraser, Mustafa Motiwala, Pooja Dave, Brian Jimenez, David A. Wallace, Olufemi Osikoya, Sebastian Norrdahl, Jennings H. Dooley, Nickalus R. Khan, Brandy N. Vaughn, Cormac O. Maher, and Paul Klimo Jr.


The objective of this study was to analyze the publication output of postgraduate pediatric neurosurgery fellows for a 10-year period as well as identify 25 individual highly productive pediatric neurosurgeons. The correlation between academic productivity and the site of fellowship training was studied.


Programs certified by the Accreditation Council for Pediatric Neurosurgery Fellowships that had 5 or more graduating fellows from 2006 to 2015 were included for analysis. Fellows were queried using Scopus for publications during those 10 years with citation data through 2017. Pearson correlation coefficients were calculated, comparing program rankings of faculty against fellows using the revised Hirsch index (r-index; primary) and Hirsch index (h-index; secondary). A list of 25 highly accomplished individual academicians and their fellowship training locations was compiled.


Sixteen programs qualified with 152 fellows from 2006 to 2015; 136 of these surgeons published a total of 2009 articles with 23,735 citations. Most publications were pediatric-specific (66.7%) clinical articles (93.1%), with middle authorship (55%). Co-investigators were more likely from residency than fellowship. There was a clustering of the top 7 programs each having total publications of around 120 or greater, publications per fellow greater than 12, more than 1200 citations, and adjusted ir10 (revised 10-year institutional h-index) and ih10 (10-year institutional h-index) values of approximately 2 or higher. Correlating faculty and fellowship program rankings yielded correlation coefficients ranging from 0.53 to 0.80. Fifteen individuals (60%) in the top 25 (by r5 index) list completed their fellowship at 1 of these 7 institutions.


Approximately 90% of fellowship-trained pediatric neurosurgeons have 1 or more publications, but the spectrum of output is broad. There is a strong correlation between where surgeons complete their fellowships and postgraduate publications.

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Oral Presentations 2014 AANS Annual Scientific Meeting San Francisco, California • April 5–9, 2014

Published online June 1, 2015; DOI: 10.3171/2015.6.JNS.AANS2014abstracts