The foramen ovale: a keyhole to the brain? Computer simulations of percutaneous FO punctures

Abstract Background The percutaneous cannulation of the foramen ovale (FO) is implemented in treating trigeminal neuralgia, diagnosing temporal lobe epilepsy and biopsy petroclival lesions. This study dealt with the question whether it is possible to reach intracerebral structures with a puncture beyond the Gasserian Ganglion (GG) without bone destruction or perforating vascularity. Methods We considered the FO a natural keyhole and performed computer-simulated punctures through the right and left FO to eight intracerebral structures. Therefore, we took the Hartel and Submandibular (SM) approach as a starting point and planned trajectories with stereotactic planning software by using brain scans of ten patients. Results The simulated punctures with the Hartel approach directly reached the hippocampus (20 out of 20 trajectories), the lateral ventricle (15/20) and the amygdala (2/20). The pons was reached (20/20); however, the pontine vascularity was within the course. The trajectories to the thalamus (13/20) ran through the hippocampus or the mesencephalon. The simulated punctures with the SM approach directly reached the amygdala (18/20), the lateral ventricle (5/20) and the putamen (20/20). The trajectories to the nucleus caudatus (20/20) pierced the hippocampus, the putamen or the maxillary artery. The courses to the thalamus (7/20) ran through the hippocampus or the mesencephalon. The sinus cavernosus could not be reached with the Hartel or SM approach. Conclusions This study indicates that a percutaneous approach to the hippocampus, the lateral ventricle, the amygdala and the putamen is possible without harming major vessels or bone destruction. For a possible implementation of these trajectories in a clinical setting, it is necessary to prove these simulated punctures in cadaveric studies

Ultrasonography for depiction of brachial plexus injury

Recent development of ultrasonographic equipment has allowed improved spatial resolution for visualizing normal and pathologic conditions of peripheral nerves. Regarding the brachial plexus, only ultrasonographic studies that have described the normal appearance have been reported. To the best of our knowledge, no case report regarding the ultrasonographic description of a brachial plexus lesion has been published. We report the ultrasonographic findings of a brachial plexus injury after extirpation of a suspected enlarged supraclavicular lymph node

Immediate flow disruption as a prognostic factor after flow diverter treatment long term experience with the pipeline embolization device

Objective: To report long-term results after Pipeline Embolization Device (PED) implantation, characterize complex and standard aneurysms comprehensively, and introduce a modified flow disruption scale. Methods: We retrospectively reviewed a consecutive series of 40 patients harboring 59 aneurysms treated with 54 PEDs. Aneurysm complexity was assessed using our proposed classification. Immediate angiographic results were analyzed using previously published grading scales and our novel flow disruption scale. Results: According to our new definition, 46 (78%) aneurysms were classified as complex. Most PED interventions were performed in the paraophthalmic and cavernous internal carotid artery segments. Excellent neurologic outcome (modified Rankin Scale 0 and 1) was observed in 94% of patients. Our data showed low permanent procedure-related mortality (0%) and morbidity (3%) rates. Long-term angiographic follow-up showed complete occlusion in 81% and near-total obliteration in a further 14%. Complete obliteration after deployment of a single PED was achieved in all standard aneurysms with 1-year follow-up. Our new scale was an independent predictor of aneurysm occlusion in a multivariable analysis. All aneurysms with a high flow disruption grade showed complete occlusion at follow-up regardless of PED number or aneurysm complexity. Conclusions: Treatment with the PED should be recognized as a primary management strategy for a highly selected cohort with predominantly complex intracranial aneurysms. We further show that a priori assessment of aneurysm complexity and our new postinterventional angiographic flow disruption scale predict occlusion probability and may help to determine the adequate number of per-aneurysm devices

Local image variance of 7 Tesla SWI is a new technique for preoperative characterization of diffusely infiltrating gliomas : correlation with tumour grade and IDH1 mutational status

Objectives To investigate the value of local image variance (LIV) as a new technique for quantification of hypointense microvascular susceptibility-weighted imaging (SWI) structures at 7 Tesla for preoperative glioma characterization. Methods Adult patients with neuroradiologically suspected diffusely infiltrating gliomas were prospectively recruited and 7 Tesla SWI was performed in addition to standard imaging. After tumour segmentation, quantification of intratumoural SWI hypointensities was conducted by the SWI-LIV technique. Following surgery, the histopathological tumour grade and isocitrate dehydrogenase 1 (IDH1)-R132H mutational status was determined and SWI-LIV values were compared between low-grade gliomas (LGG) and high-grade gliomas (HGG), IDH1-R132H negative and positive tumours, as well as gliomas with significant and non-significant contrast-enhancement (CE) on MRI. Results In 30 patients, 9 LGG and 21 HGG were diagnosed. The calculation of SWI-LIV values was feasible in all tumours. Significantly higher mean SWI-LIV values were found in HGG compared to LGG (92.7 versus 30.8; p < 0.0001), IDH1-R132H negative compared to IDH1-R132H positive gliomas (109.9 versus 38.3; p < 0.0001) and tumours with significant CE compared to non-significant CE (120.1 versus 39.0; p < 0.0001). Conclusions Our data indicate that 7 Tesla SWI-LIV might improve preoperative characterization of diffusely infiltrating gliomas and thus optimize patient management by quantification of hypointense microvascular structures. Key Points 7 Tesla local image variance helps to quantify hypointense susceptibility-weighted imaging structures. SWI-LIV is significantly increased in high-grade and IDH1-R132H negative gliomas. SWI-LIV is a promising technique for improved preoperative glioma characterization. Preoperative management of diffusely infiltrating gliomas will be optimized.(VLID)352400

Single-stage bone resection and cranioplastic reconstruction: Comparison of a novel software-derived PEEK workflow with the standard reconstructive method

The combined resection of skull-infiltrating tumours and immediate cranioplastic reconstruction predominantly relies on freehand-moulded solutions. Techniques that enable this procedure to be performed easily in routine clinical practice would be useful. A cadaveric study was developed in which a new software tool was used to perform single-stage reconstructions with prefabricated implants after the resection of skull-infiltrating pathologies. A novel 3D visualization and interaction framework was developed to create 10 virtual craniotomies in five cadaveric specimens. Polyether ether ketone (PEEK) implants were manufactured according to the bone defects. The image-guided craniotomy was reconstructed with PEEK and compared to polymethyl methacrylate (PMMA). Navigational accuracy and surgical precision were assessed. The PEEK workflow resulted in up to 10-fold shorter reconstruction times than the standard technique. Surgical precision was reflected by the mean 1.1 ± 0.29 mm distance between the virtual and real craniotomy, with submillimetre precision in 50%. Assessment of the global offset between virtual and actual craniotomy revealed an average shift of 4.5 ± 3.6 mm. The results validated the ‘elective single-stage cranioplasty’ technique as a state-of-the-art virtual planning method and surgical workflow. This patient-tailored workflow could significantly reduce surgical times compared to the traditional, intraoperative acrylic moulding method and may be an option for the reconstruction of bone defects in the craniofacial region