Evaluation of intracranial stenting in a simulated training and assessment environment for neuroendovascular procedures

PurposeGiven the inherent complexity of neurointerventional procedures and the associated risks of ionizing radiation exposure, it is crucial to prioritize ongoing training and improve safety protocols. The aim of this study is to assess a training and evaluation in-vitro environment using a vascular model of M1 stenosis, within a clinical angiography suite, without relying on animal models or X-ray radiation.Materials and methodsUsing a transparent model replicating M1 stenosis, we conducted intracranial stenting procedures with four different setups (Gateway & Wingspan, Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse). A video camera was integrated with the angiography system’s monitor for real-time visualization, while a foot switch was employed to simulate live fluoroscopy. Three neuroradiologists with varying levels of expertise performed each procedure for three times. The total duration of fluoroscopy as well as the time from passing the stenosis with the wire to completion of the procedure were recorded using a dedicated software designed for this experimental setup.ResultsCompared to the Gateway & Wingspan procedure, the total fluoroscopy time reduced significantly with the Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse procedures by 51.56 s, 111.33 s, and 144.89 s, respectively (p < 0.001). Additionally, physicians with under 2 years and over 5 years of experience reduced FT by 62.83 s and 106.42 s, respectively, (p < 0.001), compared to a novice physician. Similar trends were noted for the time of wire distal to stenosis, with significant reductions for Neurospeed & Acclino and Pharos Vitesse compared to both Gateway & Wingspan as well as Gateway & Enterprise (all p < 0.001).ConclusionProcedures requiring wire exchange maneuvers exhibited nearly twice the fluoroscopy time in comparison to balloon-mounted stenting or stent-placement via PTA balloon catheters. The more experienced neuroradiologist demonstrated significantly quicker performance in line with expectations in a real-life clinical setting, when compared to the less experienced interventionalist. This in-vitro setup allowed the evaluation of alternative technical approaches and differences in experience of operators without the use of animal models or X-ray. The setup combines advantages of simulators and silicone vessel models in a realistic working environment

Angiographic CT with intravenous administration of contrast medium is a noninvasive option for follow-up after intracranial stenting

Intracranial angioplasty and stenting (ICAS) is a therapeutic option in symptomatic intracranial atherosclerotic disease. Adequate follow-up examination is necessary to exclude in-stent restenosis. Conventional intraarterial digital subtraction angiography (ia-DSA) is the current gold standard, but it is an invasive technique and carries the risk of neurological complications. Angiographic CT (ACT) is a new technique that provides a volume dataset of the highest spatial resolution and high contrast resolution derived from a rotational acquisition of a c-arm-mounted flat-panel detector. The feasibility of ACT with intravenous administration of contrast medium (iv-ACT) for follow-up after ICAS is demonstrated. In two patients iv-ACT was performed as a follow-up examination 12 months after ICAS. High-resolution volume data from the rotational acquisitions were processed to provide delineation of the stent lumen as well as imaging of the brain parenchyma and vessels. In both patients the patency of the stent lumen was assessed successfully. In addition, all other brain vessels were displayed in a manner similar to their appearance on CT angiograms. The brain parenchyma was also adequately imaged in a manner similar to its appearance on CT images. We demonstrated the feasibility and diagnostic value of iv-ACT for follow-up imaging after ICAS. This new application has the potential to become the imaging method of choice after ICAS since it not only enables visualization of the patency of the stent lumen but also is minimally invasive and provides additional information about all brain arteries and the brain parenchyma

Neoplastic Meningitis from Breast Cancer: Feasibility and Activity of Long-term Intrathecal Liposomal Ara-C Combined with Dose-dense Temozolomide

Background: Patients with neoplastic meningitis (NM) from breast cancer have a median survival of 4-8 months with specific treatment. Here, good tolerance and long-term stabilization with combined intrathecal liposomal cytarabine (Ara-C), which is probably the most promising drug for intrathecal chemotherapy to date, near-continuous temozolomide and radiotherapy is reported in two patients with leptomeningeal and solid central nervous system (CNS) mefastases from breast cancer. Case Reports: A 42- and a 43-year-old female presented with NM and disseminated CNS metastases from human epidermal growth factor receptor type 2 (Het-2)-positive breast cancer. After irradiation of the symptomatic sites, intrathecal liposomal Ara-C every 2-4 weeks was combined with temozolomide 100 mg/m(2) day 1-5/7. Cerebrospinal fluid (CSF) cytology and neurological symptoms improved in both patients and stabilized for several months. The patients survived 10 and 17 months after diagnosis of NM, without signs of neurological toxicity. Conclusion: Intensive treatment is complicated by extensive pre-treatment and the lack of active CNS-penetrating systemic drugs. The long-term results with up to 17 intrathecal injections of liposomal AraC show that this treatment regimen is feasible and well-tolerated. The stabilization of both patients indicates activity of this combined intrathecal and systemic regimen that is based on long-term exposure of the tumour cells to both Ara-C and temozolomide. The results need to be confirmed prospectively

Trajektorienorientierte Modellierung für Milchvieh-Ackerbaubetriebe zur Einhaltung der Stoffstrombilanzverordnung

Die Stoffstrombilanzverordnung verpflichtet landwirtschaftliche Betriebe zur Bilanzierung aller stickstoff- und phosphorhaltigen Betriebsmittel und Erzeugnisse. Zusätzlich zu geeigneten Dokumentationssystemen werden Entscheidungshilfen ("Navis") erforderlich, die die Produktion und die innerbetrieblichen Stoffströme allokationsoptimal steuern und bereits bei der Planung die gesetzlich vorgeschriebenen Stoffstromsalden simultan berücksichtigen. Wir erläutern den Aufbau eines trajektorienorientierten, die praktischen Entscheidungsentitäten möglichst realistisch abbildenden "action rooms" mit der Vorüberlegung, dass simultane mehrperiodige Modelle der gemischt-ganzzahligen Linearen Programmierung für diese Planungsaufgabe besonders geeignet sind