Abciximab is a glycoprotein IIb/IIIa receptor antagonist that functions to prevent platelet aggregation, thus reducing thrombus initiation and propagation. It has been widely used during percutaneous endovascular interventions, such as aneurysm coil embolization, angioplasty, atherectomy, and stent placement, as both a preventative and a salvage therapy. The use of abciximab in cardiac and neurosurgical procedures has been associated with a reduced incidence of ischemic complications and a decreased need for repeated intervention. In these settings, abciximab has been delivered transarterially via a microcatheter or infused intravenously for systemic administration. The authors describe novel in situ delivery of abciximab as an agent to dissolve “white clots,” which are composed primarily of platelets, during an intracranial superficial temporal artery to middle cerebral artery bypass in a 28-year-old woman with severe intracranial occlusive disease. Abciximab was able to resolve multiple platelet-based clots after unsuccessful attempts with conventional clot dispersal techniques, such as heparinized saline, tissue plasminogen activator, mechanical passage of a wire through the vessel lumen, and multiple takedowns and re-anastomosis. After abciximab was administered, patency was demonstrated intraoperatively using indocyanine green dye and confirmed postoperatively at 1 and 10 months via CT angiography. The in situ use of abciximab as an agent to disperse a thrombus during intracranial bypass surgery is novel and has not previously been described in the literature, and serves as an additional tool during intracranial vessel bypass surgery.
Ian A. Buchanan, Brian Lee, Arun P. Amar and Steven L. Giannotta
Brian Lee and Patrick C. Hsieh
Intradural, extramedullary schwannomas have long been treated with open midline incision, laminectomy, and dural opening to expose and resect the lesion. While this technique is well established, today new surgical techniques can be utilized to perform the same procedure while minimizing pain, size of incision, and trauma to adjacent tissues. In cases of intradural surgery, minimally invasive surgery limits the degree of soft tissue disruption. As a result, there is significant decreased dead space within the surgical cavity that may decrease the rate of CSF leak complications. Minimally invasive techniques have continuously improved over the years and have reached a point where they can be used for intradural surgeries. In this case presentation, we demonstrate a minimally invasive approach to the lumbar spine with resection of an intradural schwannoma. Surgical techniques and the nuances of the minimally invasive approach to intradural tumors compared to the standard open procedure will be discussed.
The video can be found here: http://youtu.be/XXrvAIq_H48.
Brian Lee, Yvette D. Marquez and Steven L. Giannotta
Lesions of the brainstem pose a technical challenge due to their close proximity to critical vascular structures, neural pathways, and nuclei. Hemangioblastomas are rare lesions of the central nervous system and can cause significant neurological dysfunction, primarily due to enlargement of the cystic component. This is especially relevant when hemangioblastomas occur in eloquent brainstem regions. However, the outcomes after hemangioblastoma resection are good if complete surgical resection of the tumor of the mural nodule, can be achieved. This video demonstrates the excision of a brainstem hemangioblastoma via a left retrosigmoid craniotomy under Stealth guidance.
The video can be found here: http://youtu.be/bCkuaPwMV20.
Taylor E. Purvis, Brian J. Neuman, Lee H. Riley III and Richard L. Skolasky
In this paper, the authors demonstrate to spine surgeons the prevalence and severity of anxiety and depression among patients presenting for surgery and explore the relationships between different legacy and Patient-Reported Outcomes Measurement Information System (PROMIS) screening measures.
A total of 512 adult spine surgery patients at a single institution completed the 7-item Generalized Anxiety Disorder questionnaire (GAD-7), 8-item Patient Health Questionnaire (PHQ-8) depression scale, and PROMIS Anxiety and Depression computer-adaptive tests (CATs) preoperatively. Correlation coefficients were calculated between PROMIS scores and GAD-7 and PHQ-8 scores. Published reference tables were used to determine the presence of anxiety or depression using GAD-7 and PHQ-8. Sensitivity and specificity of published guidance on the PROMIS Anxiety and Depression CATs were compared. Guidance from 3 sources was compared: published GAD-7 and PHQ-8 crosswalk tables, American Psychiatric Association scales, and expert clinical consensus. Receiver operator characteristic curves were used to determine data-driven cut-points for PROMIS Anxiety and Depression. Significance was accepted as p < 0.05.
In 512 spine surgery patients, anxiety and depression were prevalent preoperatively (5% with any anxiety, 24% with generalized anxiety screen-positive; and 54% with any depression, 24% with probable major depression). Correlations were moderately strong between PROMIS Anxiety and GAD-7 scores (r = 0.72; p < 0.001) and between PROMIS Depression and PHQ-8 scores (r = 0.74; p < 0.001). The observed correlation of the PROMIS Depression score was greater with the PHQ-8 cognitive/affective score (r = 0.766) than with the somatic score (r = 0.601) (p < 0.001). PROMIS Anxiety and Depression CATs were able to detect the presence of generalized anxiety screen-positive (sensitivity, 86.0%; specificity, 81.6%) and of probable major depression (sensitivity, 82.3%; specificity, 81.4%). Receiver operating characteristic curve analysis demonstrated data-driven cut-points for these groups.
PROMIS Anxiety and Depression CATs are reliable tools for identifying generalized anxiety screen-positive spine surgery patients and those with probable major depression.
Charles Y. Liu, Brian Lee, Nicholas Boulis and Ali R. Rezai
Alvin Y. Chan, John D. Rolston, Brian Lee, Sumeet Vadera and Dario J. Englot
Corpus callosotomy is a palliative surgery for drug-resistant epilepsy that reduces the severity and frequency of generalized seizures by disconnecting the two cerebral hemispheres. Unlike with resection, seizure outcomes remain poorly understood. The authors systematically reviewed the literature and performed a meta-analysis to investigate rates and predictors of complete seizure freedom and freedom from drop attacks after corpus callosotomy.
PubMed, Web of Science, and Scopus were queried for primary studies examining seizure outcomes after corpus callosotomy published over 30 years. Rates of complete seizure freedom or drop attack freedom were recorded. Variables showing a potential relationship to seizure outcome on preliminary analysis were subjected to formal meta-analysis.
The authors identified 1742 eligible patients from 58 included studies. Overall, the rates of complete seizure freedom and drop attack freedom after corpus callosotomy were 18.8% and 55.3%, respectively. Complete seizure freedom was significantly predicted by the presence of infantile spasms (OR 3.86, 95% CI 1.13–13.23), normal MRI findings (OR 4.63, 95% CI 1.75–12.25), and shorter epilepsy duration (OR 2.57, 95% CI 1.23–5.38). Freedom from drop attacks was predicted by complete over partial callosotomy (OR 2.90, 95% CI 1.07–7.83) and idiopathic over known epilepsy etiology (OR 2.84, 95% CI 1.35–5.99).
The authors report the first systematic review and meta-analysis of seizure outcomes in both adults and children after corpus callosotomy for epilepsy. Approximately one-half of patients become free from drop attacks, and one-fifth achieve complete seizure freedom after surgery. Some predictors of favorable outcome differ from those in resective epilepsy surgery.
Claire F. Jones, Jae H. T. Lee, Brian K. Kwon and Peter A. Cripton
Spinal cord injury (SCI) often results in considerable permanent neurological impairment, and unfortunately, the successful translation of effective treatments from laboratory models to human patients is lacking. This may be partially attributed to differences in anatomy, physiology, and scale between humans and rodent models. One potentially important difference between the rodent and human spinal cord is the presence of a significant CSF volume within the intrathecal space around the human cord. While the CSF may “cushion” the spinal cord, pressure waves within the CSF at the time of injury may contribute to the extent and severity of the primary injury. The objective of this study was to develop a model of contusion SCI in a miniature pig and establish the feasibility of measuring spinal CSF pressure during injury.
A custom weight-drop device was used to apply thoracic contusion SCI to 17 Yucatan miniature pigs. Impact load and velocity were measured. Using fiber optic pressure transducers implanted in the thecal sac, CSF pressures resulting from 2 injury severities (caused by 50-g and 100-g weights released from a 50-cm height) were measured.
The median peak impact loads were 54 N and 132 N for the 50-g and 100-g injuries, respectively. At a nominal 100 mm from the injury epicenter, the authors observed a small negative pressure peak (median −4.6 mm Hg [cranial] and −5.8 mm Hg [caudal] for 50 g; −27.6 mm Hg [cranial] and −27.2 mm Hg [caudal] for 100 g) followed by a larger positive pressure peak (median 110.5 mm Hg [cranial] and 77.1 mm Hg [caudal] for 50 g; 88.4 mm Hg [cranial] and 67.2 mm Hg [caudal] for 100 g) relative to the preinjury pressure. There were no significant differences in peak pressure between the 2 injury severities or the caudal and cranial transducer locations.
A new model of contusion SCI was developed to measure spinal CSF pressures during the SCI event. The results suggest that the Yucatan miniature pig is an appropriate model for studying CSF, spinal cord, and dura interactions during injury. With further development and characterization it may be an appropriate in vivo largeanimal model of SCI to answer questions regarding pathological changes, therapeutic safety, or treatment efficacy, particularly where humanlike dimensions and physiology are important.
Brian Lee, Vivek A. Mehta, William J. Mack, Matthew S. Tenser and Arun P. Amar
Type 1 spinal dural arteriovenous fistula (dAVF) constitute the vast majority of all spinal vascular malformations. Here we present the case of a 71-year-old male with progressive myelopathy, lower-extremity weakness and numbness, and urinary incontinence. MRI imaging of the thoracic spine demonstrated cord edema, and catheter spinal angiography confirmed a type 1 spinal dAVF. The fistula was supplied by small dural branches of the left L-2 segmental artery. Angiographic cure was achieved with a one-stage procedure in which coils were used to occlude the distal segmental vessels, followed by balloon-assisted embolization with Onyx.
The video can be found here: http://youtu.be/8aehJbueH0U.
Brian Lee, Vivek A. Mehta, Arun P. Amar, Matthew S. Tenser and William J. Mack
Open surgical disconnection has long been the treatment of choice for dural arteriovenous fistulas (dAVFs) of the anterior cranial fossa. However, advanced patient age and the presence of medical comorbidities can substantially increase the risk of craniotomy and favor a less invasive endovascular approach. Optimal positioning within the distal ophthalmic artery, beyond the origin of the central retinal branch, is achievable using current microcatheter technology and embolic materials. Here we present the case of an 88-year-old female with an incidentally discovered dAVF of the anterior cranial fossa. Angiographic cure was achieved with one-stage Onyx embolization.
The video can be found here: http://youtu.be/KVE0fUIECQM.
Robert J. Weil, Zhengping Zhuang, Svetlana Pack, Shimareet Kumar, Lee Helman, Brian G. Fuller, Crystall L. Mackall and Edward H. Oldfield
✓ Molecular biological techniques have begun to transform modern medicine. These techniques have shown promise in the pathological diagnosis of difficult or uncommon tumors. Accurate molecular diagnosis of the small round-cell tumors, for example, is especially important because divergent therapies may be required to eradicate such disparate lesions as neuroblastoma, lymphoma, rhabdomyosarcoma, central primitive neuroectodermal tumors/medulloblastoma, or Ewing sarcoma (ES). The authors present an unusual case of a primary, extraosseous ES arising from the intramedullary spinal cord, in which molecular studies were required for specific diagnosis and therapeutic guidance.