Joshua W. Osbun
University of Washington
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Featured researches published by Joshua W. Osbun.
Journal of NeuroInterventional Surgery | 2015
John D. Nerva; Ryan P. Morton; Michael R. Levitt; Joshua W. Osbun; Manuel Ferreira; Louis J. Kim
Background Blood blister type aneurysms (BBAs) and pseudoaneurysms create a unique treatment challenge. Despite many advances in open surgical and endovascular techniques, this subset of patients retains relatively high rates of morbidity and mortality. Recently, BBAs have been treated with flow-diverting stents such as the Pipeline Embolization Device (PED) with overall positive results. Methods Four patients presented with dissecting internal carotid artery (ICA) aneurysms treated with the PED (two BBAs presenting with subarachnoid hemorrhage (SAH), two pseudoaneurysms after injury during endoscopic trans-sphenoidal tumor surgery). Results Three patients had a successful angiographic and neurological outcome. One patient with a BBA re-ruptured during initial PED placement, again in the postoperative period, and later died. Primary PED treatment involved telescoping stents in two patients and coil embolization supplementation in one patient. Conclusions The PED should be used selectively in the setting of acute SAH. Dual antiplatelet therapy can complicate hydrocephalus management, and the lack of immediate aneurysm occlusion creates the risk of short-term re-rupture. PED treatment for iatrogenic ICA pseudoaneurysms can provide a good angiographic and neurological outcome.
Neurosurgery | 2014
Eric D. Peterson; Brian W. Hanak; Ryan Morton; Joshua W. Osbun; Michael R. Levitt; Louis J. Kim
BACKGROUND In the endovascular treatment of wide-necked unruptured aneurysms, there is controversy over which adjunctive device (stent vs balloon) is appropriate. At the payer level it has been posited that stents and balloons treat the same aneurysms, and, as such, the more expensive stents should not be reimbursed. OBJECTIVE We challenge this assertion, and instead hypothesize that aneurysms treated with stent assistance are morphologically different than those selected for balloon assistance. METHODS Retrospective review of unruptured aneurysms treated with an adjunctive device between 2008 and 2010. Morphological analysis was performed on the pretreatment 2-D catheter angiogram. The immediate posttreatment Raymond score was compared with that seen on the 12-month follow-up angiogram. RESULTS One hundred six unruptured aneurysms were treated with an adjunctive device and followed for a mean of 24.5 months. Morphological analysis revealed a lower dome-to-neck ratio (1.5 vs 1.2) and aspect ratio (1.44 vs 1.16) in the aneurysms treated with stent assistance vs balloon assistance. Of the 15.3% that were worse on follow-up angiography, there was no statistical difference between those treated with a stent vs a balloon (17.1% vs 14.2%). The overall re-treatment rate was 10.2% and was not statistically different between the 2 groups (12.7% vs 5.7%). CONCLUSION We found that unruptured aneurysms selected for treatment with stent-assisted coiling are morphologically different from those selected for treatment with balloon assistance. Despite the more challenging morphology, Raymond scores and re-treatment rates at 1 year were not statistically different between the 2 groups, suggesting an important role for stents in the treatment of unruptured aneurysms.
World Neurosurgery | 2013
Joshua W. Osbun; Louis J. Kim; Robert F. Spetzler; Cameron G. McDougall
BACKGROUND Sphenoid wing region dural arteriovenous fistulas (DAVFs) are rare lesions that are typically fed by middle meningeal artery feeders and that drain via the sphenoparietal sinus or middle cerebral vein. We describe a unique case of a medial sphenoid wing fistula draining exclusively via the basal vein of Rosenthal. METHODS A 55-year-old man presented with progressive right temporal homonymous hemianopsia. Cerebral angiography revealed a DAVF that rapidly filled into the deep venous system via the basal vein of Rosenthal with a large venous varix compressing the optic nerve. The sphenoid wing DAVF was not amenable to endovascular embolization due to direct ophthalmic artery feeders and was therefore treated with surgical obliteration. A right pterional craniotomy with orbitozygomatic osteotomy was performed. RESULTS The fistula was clip ligated, and the venous varix was incised and drained. Intraoperative angiography demonstrated complete obliteration of the fistula. CONCLUSIONS Sphenoid wing DAVFs may drain via the deep venous system and have a complex arterial feeding network. Key features of the fistula, including deep venous drainage, presence of venous varices, and retrograde leptomeningeal venous drainage, make this an aggressive lesion with a high risk of rupture based on the available natural history data.
World Neurosurgery | 2013
Michael R. Levitt; Joshua W. Osbun; Louis J. Kim
The ability to expand and innovate on current practices, such as genetic subtyping of gliomas, personalized medicine, and stem cell research, may be impacted. On one hand, greater global access to genetic knowledge could help to disseminate neurosurgical expertise across nations. On the other hand, would these innovations continue to enjoy intellectual property protection, and if not, how would that affect progress on Parkinson disease or knowledge of central nervous system tumor biology?
World Neurosurgery | 2014
Laligam N. Sekhar; Farzana Tariq; Joshua W. Osbun
ntradural vascular and neoplastic lesions of the skull base at the foramen magnum and the craniocervical junction area I are difficult to treat, primarily because of the complex anatomy of the area, with multiple cranial nerves, arteries and veins, and the spino-medullary junction crowded into a small area. When lesions involve the anterior or anterolateral space of the foramen magnum or the spino-medullary junction, they are more difficult to expose adequately and treat.
Neurosurgical Focus | 2014
Michael R. Levitt; Joshua W. Osbun; John D. Nerva; Louis J. Kim
A 71-year-old woman presented with headache and dilated vessels on CTA. Angiography demonstrated a complex dural arteriovenous fistula with retrograde cortical venous hypertension, supplied by branches of internal and external carotids bilaterally into a fistulous pouch paralleling the left transverse and sigmoid sinuses, which was occluded at the jugular bulb. The patient refused treatment and was lost to follow-up, returning with sudden confusion and hemianopsia from left temporo-occipital hemorrhage. Transvenous endovascular embolization was performed using the dual-microcatheter technique with a combination of coiling and Onyx copolymer, completely occluding the sinus and fistula while preserving normal venous drainage. The video can be found here: http://youtu.be/u_4Oc7tSmDM .
Skull Base Surgery | 2017
Joshua W. Osbun; Philip D. Tatman; Sumanpreet Kaur; Carolina Parada; Tina Busald; Luis F. Gonzalez-Cuyar; Min Shi; Donald E. Born; Jing Zhang; Manuel Ferreira
Background Meningomas represent the most common primary intracranial tumor. The majority are benign World Health Organization (WHO) Grade I lesions, but a subset of these behave in an aggressive manner. Protein biomarkers are needed to distinguish aggressive from benign Grade I lesions. Materials and Methods Pooled protein lysates were derived from five clinically aggressive Grade I and five typically benign WHO Grade I tumors snap frozen at the time of surgery. Proteins were separated in each group using two‐dimensional gel electrophoresis (2DGE) and protein spots of interest were identified using liquid chromatography‐mass spectrometry (LC‐MS). Potential biomarker candidates were validated using western blot assays in individual tumor samples and by tissue microarray (TMA). Results Seven candidate biomarkers were obtained from the 2DGE and validated via western blot and TMA. Biomarker validation data allowed for the creation of predictive models using binary logistical regression that correctly identified 85.9% of aggressive tumors within the larger cohort of Grade I meningioma. Conclusion Simple protein separation by 2DGE and identification of candidate biomarkers by LC‐MS allowed for the identification of seven candidate biomarkers that when used in predictive models accurately distinguish aggressive from benign behavior in WHO Grade I meningioma.
Methodist DeBakey cardiovascular journal | 2014
Joshua W. Osbun; Louis J. Kim
Intracranial atherosclerotic disease is a significant cause of stroke in the United States. Much like coronary atherosclerosis, this disease leads to arterial stenosis secondary to the buildup of lipid-based plaques in intracranial vessels. Ischemic stroke may occur following thromboembolic events near the site of stenosis or from watershed ischemia secondary to cerebral hypoperfusion. While this disease has been treated with intracranial angioplasty and stenting and cerebrovascular bypass surgery, the current literature supports aggressive medical management with dual antiplatelet therapy, treatment of comorbidities such as hypertension, diabetes, and hyperlipidemia, and lifestyle modification. Intracranial angioplasty and stenting is reserved for cases of medical failure.
World Neurosurgery | 2012
Michael R. Levitt; Joshua W. Osbun; Louis J. Kim
pituitary cells was the generation of the appropriate ronment using the three-dimensional culture and th the hedgehog pathway, a known regulator of adeno velopment. The cells generated in culture include totrophs and corticotrophs. Upon transplantation of mouse with a nonfunctional pituitary, the cells w rescuing hormone deficiencies (Figure 1). The development of “cookbook” formulas or cock factors or signaling molecules for the generation o from embryonic stem cells will pave the way for the essentially any cell type in the near future. As the stud al. (1) demonstrates, a fundamental understanding o environment in the embryo can lead to great engine generation of cells with very specific phenotypic char upcoming challenge is going to be how to use scaffolds to
Scientific Reports | 2018
Carolina Parada; Joshua W. Osbun; Sumanpreet Kaur; Youssef Yakkioui; Min Shi; Catherine Pan; Tina Busald; Yigit Karasozen; Luis F. Gonzalez-Cuyar; Robert C. Rostomily; Jing Zhang; Manuel Ferreira
There is a need to better understand meningioma oncogenesis for biomarker discovery and development of targeted therapies. Histological or genetic criteria do not accurately predict aggressiveness. Post-translational studies in meningioma progression are lacking. In the present work, we introduce a combination of mass spectrometry-based phosphoproteomics and peptide array kinomics to profile atypical and anaplastic (high-grade) meningiomas. In the discovery set of fresh-frozen tissue specimens (14), the A-kinase anchor protein 12 (AKAP12) protein was found downregulated across the grades. AKAP12 knockdown in benign meningioma cells SF4433 increases proliferation, cell cycle, migration, invasion, and confers an anaplastic profile. Differentially regulated pathways were characteristic of high-grade meningiomas. Low AKAP12 expression in a larger cohort of patients (75) characterized tumor invasiveness, recurrence, and progression, indicating its potential as a prognostic biomarker. These results demonstrate AKAP12 as a central regulator of meningioma aggressiveness with a possible role in progression.