Towards Automatic Prediction of Outcome in Treatment of Cerebral Aneurysms.

Intrasaccular flow disruptors treat cerebral aneurysms by diverting the blood flow from the aneurysm sac. Residual flow into the sac after the intervention is a failure that could be due to the use of an undersized device, or to vascular anatomy and clinical condition of the patient. We report a machine learning model based on over 100 clinical and imaging features that predict the outcome of wide-neck bifurcation aneurysm treatment with an intrasaccular embolization device. We combine clinical features with a diverse set of common and novel imaging measurements within a random forest model. We also develop neural network segmentation algorithms in 2D and 3D to contour the sac in angiographic images and automatically calculate the imaging features. These deliver 90% overlap with manual contouring in 2D and 83% in 3D. Our predictive model classifies complete vs. partial occlusion outcomes with an accuracy of 75.31%, and weighted F1-score of 0.74.

Longer 6-mm Diameter Stent Retrievers Are Effective for Achieving Higher First Pass Success with Fibrin-Rich Clots.

First pass success (FPS) can be defined as in vitro retrieval of clot in a single pass during mechanical thrombectomy (MT) for acute large vessel occlusion (LVO). Despite advancements in MT technology, retrieval of fibrin-rich clots remains a challenge. Therefore, the effect of stent retriever length on FPS for fibrin-rich clots was investigated by using SolitaireTM 6 × 40 versus 6 × 30 mm devices with a balloon guide catheter (BGC) or distal access catheter (DAC) and sheath, in an in vitro model of anterior circulation neurovascular anatomy. Additionally, vascular safety of the SolitaireTM 6 × 40 versus 6 × 30 mm devices was evaluated in a porcine model for differences in: luminal thrombus, inflammation, endothelial coverage, fibrin deposits, smooth muscle cell loss, elastic lamina and adventitia disruption, intimal hyperplasia, and lumen reduction, at 0, 30, and 90 days post-treatment. In vitro overall FPS was measured as: SolitaireTM 6 × 40 (95%) and SolitaireTM 6 × 30 (67%). FPS for clot location in middle cerebral artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 100%; n = 8); (b) DAC with 088 sheath (6 × 40 mm: 83%; 6 × 30 mm: 33%; n = 12). FPS for clot location in internal carotid artery was: (a) BGC (6 × 40 mm: 100%; 6 × 30 mm: 80%; n = 11); (b) DAC with 088 sheath (6 × 40 mm: 100%; 6 × 30 mm: 67%; n = 10). Stent length had a significant effect (Fisher's exact test; p < 0.05) on FPS. In vivo evaluation in the porcine model showed no difference in vascular safety parameters between the SolitaireTM 6 × 40 and 6 × 30 mm devices (p > 0.05) at all time points in the study. Longer stent retrievers may be safe and effective in improving FPS for fibrin-rich clots in in vitro and in vivo models of LVO.

Diagnosis of Erdheim-Chester disease by using computerized tomography-guided stereotactic biopsy of a caudate lesion. Case report.

The authors present the case of a 27-year-old woman with Erdheim-Chester disease (ECD) and extensive intracranial involvement, in whom the initial diagnosis of ECD was established based on computerized tomography (CT)-guided stereotactic biopsy of a caudate lesion. Erdheim-Chester disease is a rare non-Langerhans cell histiocytosis of unknown origin that is clinically characterized by bone pain, diabetes insipidus, and exophthalmos. The radiological hallmarks of the disease include symmetrical sclerosis of the long bones with epiphysial sparing and increased tracer uptake in lesions seen on scintigraphic imaging. Erdheim-Chester disease is characterized histologically by the presence of infiltrating lipid-laden histiocytes that commonly involve the retroperitoneum, orbits, skin, pericardium, lungs, and long bones. Although the occurrence of diabetes insipidus often precedes the diagnosis of ECD by more than a decade in most patients, magnetic resonance imaging- and CT-documented central nervous system involvement is exceedingly rare. In the setting of neurological involvement, neurosurgical biopsy has been reported seven times in the literature, with only one of these biopsies being the basis for the initial diagnosis of the disease. The authors' case represents only the second time the disease has been diagnosed by means of neurosurgical biopsy, highlighting the diagnostic difficulties that patients with EDC present. Skeletal radiographs were confirmatory in this case and this modality should be emphasized as the simplest and most direct route to the diagnosis. The degree of neurological involvement further distinguishes the case presented from prior reports in the literature. The multiple bilateral intraaxial lesions were intensely enhancing on contrast CT scans, distributed infra- and supratentorially, involving both white and gray matter, and associated with diffuse cerebral edema. The case presented is also remarkable by virtue of the symmetrical involvement of the caudate nuclei, representing the first such example documented in the literature. The diagnosis, treatment, and outcome in this patient are discussed, and a review of the literature is presented.

Perineural spread of malignant melanoma of the head and neck: clinical and imaging features.

BACKGROUND AND PURPOSE: Extension of malignant melanoma along cranial nerves is a little-known complication of malignant melanoma of the head and neck. We describe the clinical and MR imaging findings of perineural spread of malignant melanoma to cranial nerves, emphasizing that this entity occurs more commonly with desmoplastic histology and may have a long latent period following primary diagnosis. METHODS: At two institutions, we identified and retrospectively reviewed eight cases of malignant melanoma of the head and neck that had MR imaging evidence of perineural spread of disease. All patients underwent confirmatory tissue sampling. RESULTS: Seven patients had melanomas of the facial skin or lip, and one patient had a primary sinonasal lesion. By histopathology, these melanomas included five desmoplastic, two mucosal, and one poorly differentiated melanotic spindle-cell tumor. All patients developed symptomatic cranial neuropathy an average of 4.9 years from the time of initial diagnosis. MR imaging demonstrated postgadolinium enhancement of at least one branch of the trigeminal nerve in all cases and of at least one other cranial nerve in five cases. Other findings included abnormal contrast enhancement and soft tissue thickening in the cavernous sinus, Meckel's cave, and/or the cisternal segment of the trigeminal nerve. CONCLUSION: Although perineural spread of disease occurs most commonly with squamous cell carcinoma and adenoid cystic carcinoma, malignant melanoma must also be included in this differential diagnosis, particularly if the patient's pathology is known to be desmoplastic. Similarly, any patient with malignant melanoma of the head and neck who undergoes MR imaging should receive an imaging assessment focused on the likely routes of perineural spread.

Neurophysiological monitoring in the endovascular therapy of aneurysms.

BACKGROUND AND PURPOSE: Endovascular aneurysm therapy has associated risks of ischemic complications. We undertook this study to evaluate the efficacy of neurophysiological monitoring (NPM) techniques in the detection of ischemic changes that may be seen during endovascular treatment of cerebral aneurysms. METHODS: Thirty-five patients underwent NPM during endovascular treatment of cerebral aneurysms. The patients underwent a total of 50 endovascular procedures, including balloon test occlusion (19 patients), GDC embolization (22 patients), and permanent vessel occlusion (nine patients). NPM included electroencephalography, somatosensory evoked potentials, and/or brain stem auditory evoked potentials, depending on the location of the aneurysm. RESULTS: NPM changes were seen in nine (26%) of 35 patients and altered the management in five (14%) of 35 patients. In three of the five cases, NPM changes were observed without corresponding neurologic physical examination changes after balloon test occlusion (performed while the patients were under general anesthesia in two cases). In the two other cases in which NPM changes altered management, ischemia was detected at the time of intra-aneurysmal therapy while the patients were under general anesthesia. Overall, 18 of 35 patients underwent a total of 19 balloon test occlusion procedures. Of the 17 remaining patients, 13 underwent aneurysm coiling, two were not treated because of inability to safely place coils, and two were treated for distal aneurysms. Two patients developed transient neurologic deficits without concurrent NPM changes, representing false-negative NPM test results. CONCLUSION: NPM is a valuable adjunct to endovascular treatment of cerebral aneurysms. Our study suggests that these monitoring techniques may reduce ischemic complications and can be used to help guide therapeutic decisions.