Initial clinical experience with the Bendit steerable articulating tip microcatheter for intracranial access and intervention.

BACKGROUND: The increasing complexity and sophistication of neurovascular implants and other therapeutic devices depend on access and delivery systems. Advancements in access technologies are required to improve minimally invasive endovascular procedures. Steerable catheters have been available in other disciplines, however, their implementation in neurovascular interventions has been a barrier previously due to issues with miniaturization and vascular caliber/complexity. METHODS: A retrospective review of the neurovascular stroke database was conducted in accordance with local IRB to identify patients that received neurointerventional endovascular procedures using a novel first iteration 0.021'' microcatheter with controlled articulating tip flexion. Indications, management, demographics, comorbidities, and clinical and technical outcomes were recorded and analyzed. Primary operator feedback on the novel catheter was collected and reviewed. RESULTS: Ten consecutive patients receiving treatment that involved a novel steerable 0.021'' microcatheter were identified and analyzed. No complications were reported. Novel useful features of the catheter were reported on a case-by-case basis. CONCLUSIONS: Initial clinical experience with the controlled articulation that permits flexion at the tip of the microcatheter demonstrated it to be safe. Access to difficult proximal origin curves, and distal clinoidal/ophthalmic segment anatomy may be improved due to the high torque transmission, and acute angulation of this microcatheter. Further experience with the delivery of therapeutic devices will be necessary to better understand the potential role that the present catheter may play in modern neurointerventional procedures.

Is Flow Diversion the Death of Simple Coiling or Stent-assisted Coiling? A Single-center Experience.

BACKGROUND: Since the introduction of endovascular methods to treat cerebral aneurysms, several technical advances have allowed a greater number of aneurysms to be treated endovascularly as opposed to open surgical clipping. These include flow diverting stents, which do not utilize coils and instead treat aneurysms by acting as an "internal bypass." We sought to investigate whether flow diversion is replacing coiling at our institution. METHODS: A retrospective chart review on five years of data was conducted to investigate the possible increasing use of flow diversion devices compared to traditional simple or stent-assisted coiling. RESULTS: Over five years, the population revealed a trend toward an increased proportion of female patients, increased frequency of basilar tip and internal carotid artery (ICA) aneurysm location, increased hospital volume, and increased volume of patients treated by dual-trained neurosurgeons over interventional radiologists. Patients were stratified by aneurysm location and statistically significant differences were observed. Flow diversion devices were used with increasing frequency when treating aneurysms arising from the proximal internal carotid artery (Odds ratio (OR)=1.24, 95% CI: 1.02-1.50; p = 0.03), and middle cerebral artery (OR=2.60, 95% CI: 1.38-4.88; p = 0.003). Distal internal carotid artery aneurysm location came close to achieving statistical significance (OR=1.3, 95% CI: 0.99-1.72; p = 0.063). CONCLUSION: In our single center experience at Houston Methodist Hospital, flow diversion devices are being used more frequently for aneurysms arising from the proximal ICA, MCA, and likely distal ICA (though this third location barely failed to achieve statistical significance.

Recurrent Cerebral Hemorrhage in Normal Pregnancy Secondary to Mycotic Pseudoaneurysms Related to Choriocarcinoma.

BACKGROUND: Choriocarcinoma coexisting with or after normal pregnancy is extremely rare. To our knowledge, our case report is the first time cerebral mycotic pseudoaneurysms from choriocarcinoma have been proven angiographically. CASE DESCRIPTION: A 38-week pregnant 26-year-old woman presented with an acute left frontal hemorrhage. She underwent emergency cesarean section, followed by hematoma evacuation and resection of what grossly appeared to be a medium-sized arteriovenous malformation at the time of surgery. Angiogram before and after resection showed no obvious vascular pathology. One month later, she returned with status epilepticus, and an acute parenchymal hematoma posterior to the surgical resection cavity was identified. Angiography showed a multilobulated pseudoaneurysm along the left middle cerebral artery. This was resected and found on histopathology to have choriocarcinoma within and around the blood vessels. Serum human chorionic gonadotrophin levels increased daily. Pan computed tomography showed a left lung lobular mass. The diagnosis was stage 4 World Health Organization score 9 high-risk metastatic choriocarcinoma requiring radiation followed by multiagent chemotherapy. Two weeks later, she had another seizure. An angiogram showed an unruptured pseudoaneurysm along the right posterior cerebral artery, which was embolized. CONCLUSIONS: Metastatic choriocarcinoma is rarely considered during a viable pregnancy but is almost always fatal if unrecognized. Early recognition enhances the chances of cure with chemotherapy. Arteriovenous malformations are typically considered in young women with intracerebral hemorrhages and have higher risk of rupture in pregnant women, but physicians should also be aware of metastatic choriocarcinoma and the development of mycotic aneurysms in peripartum women with intracerebral hemorrhages.

Anterior Skull Base Glomangioma-Induced Osteomalacia.

Oncogenic osteomalacia (OO) is an uncommon but treatable cause of osteomalacia related to tumor production of FGF23, usually caused by benign mesenchymal neoplasms. Paranasal sinus glomangiomas are a rare cause of OO, with only one previously reported case. Here we describe a second case (first reported in English) of paranasal sinus glomangioma-induced osteomalacia in a 42-year-old man. He presented with weakness and multiple spontaneous fractures, and was found to have an ethmoid sinus glomangioma with intracranial extension. The tumor was removed via endoscopic endonasal approach to the anterior skull base, which resulted in complete resolution of symptoms and no further evidence of disease 1 year postoperatively.

Three-dimensional printing of anatomically accurate, patient specific intracranial aneurysm models.

OBJECTIVE: To develop and validate a method for creating realistic, patient specific replicas of cerebral aneurysms by means of fused deposition modeling. METHODS: The luminal boundaries of 10 cerebral aneurysms, together with adjacent proximal and distal sections of the parent artery, were segmented based on DSA images, and corresponding virtual three-dimensional (3D) surface reconstructions were created. From these, polylactic acid and MakerBot Flexible Filament replicas of each aneurysm were created by means of fused deposition modeling. The accuracy of the replicas was assessed by quantifying statistical significance in the variations of their inner dimensions relative to 3D DSA images. Feasibility for using these replicas as flow phantoms in combination with phase contrast MRI was demonstrated. RESULTS: 3D printed aneurysm models were created for all 10 subjects. Good agreement was seen between the models and the source anatomy. Aneurysm diameter measurements of the printed models and source images correlated well (r=0.999; p<0.001), with no statistically significant group difference (p=0.4) or observed bias. The SDs of the measurements were 0.5 mm and 0.2 mm for source images and 3D models, respectively. 3D printed models could be imaged with flow via MRI. CONCLUSIONS: The 3D printed aneurysm models presented were accurate and were able to be produced inhouse. These models can be used for previously cited applications, but their anatomical accuracy also enables their use as MRI flow phantoms for comparison with ongoing studies of computational fluid dynamics. Proof of principle imaging experiments confirm MRI flow phantom utility.

Quantification of speed-up and accuracy of multi-CPU computational flow dynamics simulations of hemodynamics in a posterior communicating artery aneurysm of complex geometry.

BACKGROUND: Towards the translation of computational fluid dynamics (CFD) techniques into the clinical workflow, performance increases achieved with parallel multi-central processing unit (CPU) pulsatile CFD simulations in a patient-derived model of a bilobed posterior communicating artery aneurysm were evaluated while simultaneously monitoring changes in the accuracy of the solution. METHODS: Simulations were performed using 2, 4, 6, 8, 10 and 12 processors. In addition, a baseline simulation was obtained with a dual-core dual CPU computer of similar computational power to clinical imaging workstations. Parallel performance indices including computation speed-up, efficiency (speed-up divided by number of processors), computational cost (computation time × number of processors) and accuracy (velocity at four distinct locations: proximal and distal to the aneurysm, in the aneurysm ostium and aneurysm dome) were determined from the simulations and compared. RESULTS: Total computation time decreased from 9 h 10 min (baseline) to 2 h 34 min (10 CPU). Speed-up relative to baseline increased from 1.35 (2 CPU) to 3.57 (maximum at 10 CPU) while efficiency decreased from 0.65 to 0.35 with increasing cost (33.013 to 92.535). Relative velocity component deviations were less than 0.0073% and larger for 12 CPU than for 2 CPU (0.004 ± 0.002%, not statistically significant, p=0.07). CONCLUSIONS: Without compromising accuracy, parallel multi-CPU simulation reduces computing time for the simulation of hemodynamics in a model of a cerebral aneurysm by up to a factor of 3.57 (10 CPUs) to 2 h 34 min compared with a workstation with computational power similar to clinical imaging workstations.

HER2-specific T cells target primary glioblastoma stem cells and induce regression of autologous experimental tumors.

PURPOSE: Glioblastoma multiforme (GBM) is the most aggressive human primary brain tumor and is currently incurable. Immunotherapies have the potential to target GBM stem cells, which are resistant to conventional therapies. Human epidermal growth factor receptor 2 (HER2) is a validated immunotherapy target, and we determined if HER2-specific T cells can be generated from GBM patients that will target autologous HER2-positive GBMs and their CD133-positive stem cell compartment. EXPERIMENTAL DESIGN: HER2-specific T cells from 10 consecutive GBM patients were generated by transduction with a retroviral vector encoding a HER2-specific chimeric antigen receptor. The effector function of HER2-specific T cells against autologous GBM cells, including CD133-positive stem cells, was evaluated in vitro and in an orthotopic murine xenograft model. RESULTS: Stimulation of HER2-specific T cells with HER2-positive autologous GBM cells resulted in T-cell proliferation and secretion of IFN-gamma and interleukin-2 in a HER2-dependent manner. Patients' HER2-specific T cells killed CD133-positive and CD133-negative cells derived from primary HER2-positive GBMs, whereas HER2-negative tumor cells were not killed. Injection of HER2-specific T cells induced sustained regression of autologous GBM xenografts established in the brain of severe combined immunodeficient mice. CONCLUSIONS: Gene transfer allows the reliable generation of HER2-specific T cells from GBM patients, which have potent antitumor activity against autologous HER2-positive tumors including their putative stem cells. Hence, the adoptive transfer of HER2-redirected T cells may be a promising immunotherapeutic approach for GBM.