A Diagnostic Biomarker for Cervical Myelopathy Based on Dynamic Magnetic Resonance Imaging.

STUDY DESIGN: Multicenter prospective observational study. OBJECTIVE: Diffusion tensor imaging in flexion extension improves the diagnosis of degenerative cervical myelopathy (DCM). We aimed to provide an imaging biomarker for the detection of DCM. SUMMARY OF BACKGROUND DATA: DCM is the most common form of spinal cord dysfunction in adults; however, imaging surveillance for myelopathy remains poorly characterized. PATIENTS AND METHODS: Symptomatic DCM patients were examined in maximum neck flexion-extension and neutral positions in a 3T-magnetic resonance imaging scanner and allocated to 2 groups: (1) Patients with visible intramedullary hyperintensity (IHIS) on T2-weighted imaging (IHIS+, n = 10); and (2) Patients without IHIS (IHIS-, n = 11). Range of motion, space available for the spinal cord, apparent diffusion coefficient (ADC), axial diffusivity (AD), radial diffusivity, and fractional anisotropy were measured and compared between the neck positions and between the groups as well as between control (C2/3) and pathologic segments. RESULTS: Significant differences between the control level (C2/3) and pathologic segments were appreciated for the IHIS+ group at neutral neck position in AD; at flexion in ADC and AD; and at neck extension in ADC, AD, and fractional anisotropy values. For the IHIS- group, significant differences between the control level (C2/3) and pathologic segments were found only for ADC values in neck extension. When comparing diffusion parameters between groups, radial diffusivity was significantly different in all 3 neck positions. CONCLUSION: Significant increases in ADC values between the control and pathologic segments were found for both groups in neck extension only. This may serve as a diagnostic tool to identify early changes in the spinal cord related to myelopathy to indicate potentially reversible spinal cord injury and support the indication for surgery in select circumstances.

Case report: Experience with the Cube Navigation System in complex access routes during CT-guided lumbosacral infiltration therapy.

Purpose: Computed tomography (CT)-guided infiltrations are a mainstay in the treatment of lower back pain. Needle placement is usually performed using the free-hand method, where the translation from the planned needle angle to the actual needle insertion angle is estimated. However, the free-hand method is especially challenging in cases where a double-oblique access route (out-of-plane) rather than an in-plane route is necessary. In this case series, we report our experience with the patient-mounted Cube Navigation System to guide needle placement for complex access routes in lumbar pain therapy. Research design and methods: We retrospectively analyzed the cases of five patients in whom a double-oblique access route was necessary for CT-guided lumbar infiltration pain treatment. Each of those procedures was done using the Cube Navigation System to provide navigational guidance. The mean patient age was 69 ± 13 years (range 58-82 years; all females). Technical success, procedure time, and number of control scans were determined retrospectively. Results: Technical success (i.e., positioning and accuracy) was obtained in all cases. Mean procedure time was 15 ± 7 min (10-22 min); on average, 2 ± 1 CT control scans were performed. There were no complications or material failures reported in the present study. Conclusion: Double-oblique punctures with the Cube Navigation System in this initial case series of complex access routes at the lumbar spine were accurate and the procedure was time efficient. In the authors' view, the Cube Navigation System has the potential to improve needle guidance for complex access routes, especially considering the ease of use of the device.

Risk of intracranial aneurysm recurrence after microsurgical clipping based on 3D digital subtraction angiography.

OBJECTIVE: Current knowledge of recurrence rates after intracranial aneurysm (IA) surgery relies on 2D digital subtraction angiography (DSA), which fails to detect more than 75% of small aneurysm remnants. Accordingly, the discrimination between recurrence and growth of a remnant remains challenging, and actual assessment of recurrence risk of clipped IAs could be inaccurate. The authors report, for the first time, 3D-DSA-based long-term durability and risk factor data of IA recurrence and remnant growth after microsurgical clipping. METHODS: Prospectively collected data for 305 patients, with a total of 329 clipped IAs that underwent baseline 3D-DSA, were evaluated. The incidence of recurrent IA was described by Kaplan-Meier curves. Risk factors for IA recurrence were analyzed by multivariable Cox proportional hazards and logistic regression models. RESULTS: The overall observed proportion of IA recurrence after clipping was 2.7% (9 of 329 IAs) at a mean follow-up of 46 months (0.7% per year). While completely obliterated IAs did not recur during follow-up, incompletely clipped aneurysms (76 of 329) demonstrated remnant growth in 11.8% (3.4% per year). Young age and large initial IA size significantly increased the risk of IA recurrence. CONCLUSIONS: The findings support those in previous studies that hypothesized that completely clipped IAs have an extremely low risk of recurrence. Conversely, the results highlight the significant risk posed by incompletely clipped IAs. Young patients with initial large IAs and incomplete obliteration have an especially high risk for IA recurrence and therefore should be monitored more closely.

Testing the applicability and performance of Auto ML for potential applications in diagnostic neuroradiology.

To investigate the applicability and performance of automated machine learning (AutoML) for potential applications in diagnostic neuroradiology. In the medical sector, there is a rapidly growing demand for machine learning methods, but only a limited number of corresponding experts. The comparatively simple handling of AutoML should enable even non-experts to develop adequate machine learning models with manageable effort. We aim to investigate the feasibility as well as the advantages and disadvantages of developing AutoML models compared to developing conventional machine learning models. We discuss the results in relation to a concrete example of a medical prediction application. In this retrospective IRB-approved study, a cohort of 107 patients who underwent gross total meningioma resection and a second cohort of 31 patients who underwent subtotal resection were included. Image segmentation of the contrast enhancing parts of the tumor was performed semi-automatically using the open-source software platform 3D Slicer. A total of 107 radiomic features were extracted by hand-delineated regions of interest from the pre-treatment MRI images of each patient. Within the AutoML approach, 20 different machine learning algorithms were trained and tested simultaneously. For comparison, a neural network and different conventional machine learning algorithms were trained and tested. With respect to the exemplary medical prediction application used in this study to evaluate the performance of Auto ML, namely the pre-treatment prediction of the achievable resection status of meningioma, AutoML achieved remarkable performance nearly equivalent to that of a feed-forward neural network with a single hidden layer. However, in the clinical case study considered here, logistic regression outperformed the AutoML algorithm. Using independent test data, we observed the following classification results (AutoML/neural network/logistic regression): mean area under the curve = 0.849/0.879/0.900, mean accuracy = 0.821/0.839/0.881, mean kappa = 0.465/0.491/0.644, mean sensitivity = 0.578/0.577/0.692 and mean specificity = 0.891/0.914/0.936. The results obtained with AutoML are therefore very promising. However, the AutoML models in our study did not yet show the corresponding performance of the best models obtained with conventional machine learning methods. While AutoML may facilitate and simplify the task of training and testing machine learning algorithms as applied in the field of neuroradiology and medical imaging, a considerable amount of expert knowledge may still be needed to develop models with the highest possible discriminatory power for diagnostic neuroradiology.

Aspirin treatment prevents inflammation in experimental bifurcation aneurysms in New Zealand White rabbits.

BACKGROUND: Aneurysm wall degeneration is linked to growth and rupture. To address the effect of aspirin (ASA) on aneurysm formation under various wall conditions, this issue was analyzed in a novel rabbit bifurcation model. METHODS: Bifurcation aneurysms created in 45 New Zealand White rabbits were randomized to vital (n=15), decellularized (n=13), or elastase-degraded (n=17) wall groups; each group was assigned to a study arm with or without ASA. At follow-up 28 days later, aneurysms were evaluated for patency, growth, and wall inflammation at macroscopic and histological levels. RESULTS: 36 rabbits survived to follow-up at the end of the trial. None of the aneurysms had ruptured. Patency was visualized in all aneurysms by intraoperative fluorescence angiography and confirmed in 33 (92%) of 36 aneurysms by MRI/MRA. Aneurysm size was significantly increased in the vital (without ASA) and elastase-degraded (with and without ASA) groups. Aneurysm thrombosis was considered complete in three (50%) of six decellularized aneurysms without ASA by MRI/MRA. Locoregional inflammation of the aneurysm complex was significantly reduced in histological analysis among all groups treated with ASA. CONCLUSION: ASA intake prevented inflammation of both the periadventitial tissue and aneurysm wall, irrespective of initial wall condition. Although ASA prevented significant growth in aneurysms with vital walls, this preventive effect did not have an important role in elastase-degraded pouches. In possible translation to the clinical situation, ASA might exert a potential preventive effect during early phases of aneurysm formation in patients with healthy vessels but not in those with highly degenerative aneurysm walls.

Intraoperative Spinal Angiography during Microsurgical Occlusion of Spinal Dural Arteriovenous Fistula within the Hybrid Operation Room.

BACKGROUND: Spinal dural arteriovenous fistula (SDAVF) is a rare cause of progressive myelopathy in predominantly middle-aged men. Treatment modalities include surgical obliteration and endovascular embolization. In surgically treated cases, failure of obliteration is reported in up to 5%. The aim of this technical note is to present a safe procedure with complete SDAVF occlusion, verified by intraoperative digital subtraction angiography (DSA). METHODS: We describe four patients with progressive leg weakness who underwent surgical obliteration of SDAVF with spinal intraoperative DSA in the prone position after cannulation of the popliteal artery. All surgeries took place in our hybrid operating room (OR) and were accompanied by electrophysiologic monitoring. Surgeries and cannulation of the popliteal artery were performed in the prone position. Ultrasound was used to guide the popliteal artery puncture. A 5-Fr sheath was inserted and the fistula was displayed using a 5-Fr spinal catheter. Spinal intraoperative DSA was performed prior to and after temporary clipping of the fistula point as well after the final SDAVF occlusion. RESULTS: The main feeder of the SDAVF fistula in the first patient arose from the right T11 segmental artery, which also supplied the artery of Adamkiewicz. The second patient initially underwent endovascular treatment and deteriorated 5 months later due to recanalization of the SDAVF via a small branch of the T12 segmental artery. The third and fourth cases were primarily scheduled for surgical occlusion. Access through the popliteal artery for spinal intraoperative DSA proved to be beneficial and safe in the hybrid OR setting, allowing the sheath to be left in place during the procedure. During exposure and after temporary and permanent occlusion of the fistulous point, intraoperative indocyanine green (ICG) video angiography was also performed. In one case, the addition of intraoperative DSA showed failure of fistula occlusion, which was not visible with ICG angiography, leading to repositioning of the clip. Complete fistula occlusion was documented in all cases. CONCLUSION: Spinal intraoperative DSA in the prone position is a feasible and safe intervention for rapid localization and confirmation of surgical SDAVF occlusion.

Spontaneous regression of multiple flow-related aneurysms following treatment of an associated brain arteriovenous malformation: A case report.

Introduction: There is no consensus in the treatment strategy of intracranial aneurysms (IAs) associated with brain arteriovenous malformation (BAVM). In particular, it is unknown if a more aggressive approach should be considered in patients harboring a BAVM, in whom multiple aneurysms or a history of aneurysmal subarachnoid hemorrhage (aSAH) is present. Case presentation: We report on an elderly woman harboring multiple aneurysms with a history of SAH due to rupture of an unrelated IA. On evaluation, she was also found to harbor a contralateral, left parietal convexity BAVM. Following resection of the latter, spontaneous regression of two large flow-related aneurysms was encountered. Discussion: We discuss the therapeutic decision-making, risk stratification, and functional outcome in this patient with regard to the pertinent literature on the risk of hemorrhage in IAs associated with BAVM.

The Shape grading system: a classification for growth patterns of pituitary adenomas.

BACKGROUND: Long-term tumor control of pituitary adenomas may be achieved by gross total resection (GTR). Factors, which influence the extent of resection, are invasiveness, tumor size, and possibly tumor shape. Nevertheless, the latter factor has not been assessed so far and there is no classification for the different shapes. The aim of this study was to evaluate the impact of different tumor shapes on GTR rates and outcome according to our proposed "Shape grading system." METHODS: In this retrospective single center study, the radiological outcome of nonfunctioning pituitary adenomas was assessed with respect to the following previously defined growth patterns: spherical (Shape I), oval (Shape II), dumbbell (Shape III), mushroom (Shape IV), and polylobulated (Shape V). RESULTS: A total of 191 patients were included (Shape I, n = 28 (15%); Shape II, n = 91 (48%); Shape III, n = 37 (19%); Shape IV, n = 12 (6%); Shape V, n = 23 (12%)). GTR was achieved in 101 patients (53%) with decreasing likelihood of GTR in higher shape grades (Shape I, n = 23 (82%); Shape II, n = 67 (74%); Shape III, n = 9 (24%); Shape IV, n = 2 (17%); Shape V, n = 0 (0%)). This correlated with larger tumor remnants, a higher risk of tumor recurrence/regrowth and therefore necessity of re-surgery and/or radiotherapy/radiosurgery. CONCLUSION: The "Shape grading system" may be used as a predictor of the outcome in nonfunctioning pituitary adenomas. The higher the "Shape grade," the higher the likelihood for lower GTR rates, larger tumor remnants, and need for further therapies.

Extensive Convexity Flattening of a Synthetic Skull Implant the Overcome Major Scalp Deficiency After Multiple Craniotomies.

ABSTRACT: Multiple craniofacial surgeries and postoperative recalcitrant infections frequently can lead to secondary scalp tissue scarring and skin retraction. Although there are different methods of reducing and optimizing scalp skin tension, the authors describe a last resort treatment method of cranioplastic procedure, which despite of its unfavorable cosmetic outcome, relieves the skin tension through extensive flattening of the polyetheretherketone curvature. Thereby, a custom-made cranioplastic bone flap was extensively flattened in the curvature of the fronto-parietal area with consideration of the related brain hemisphere extension. The extent of bone curvature flatting reduced the skin tension significantly and allowed for plain and simple tension-free wound closure in a chronic smoker patient with poor skin quality and brain atrophy. Although brain extension was sufficient, the cosmetic outcome was unfavorable with regard to skull symmetry, but well accepted and satisfactory for the patient due to preoperative discussion outcome expectation from surgery. Thus, extensive polyetheretherketone curvature flattening is a straightforward and simple last resort treatment option for tension-free skin closure in high-risk patients with extensive skin scarring and retraction and previous reconstructive plastic skin relief procedures. However, this method is limited in patients with normal brain hemisphere extension.

Long-term apparent diffusion coefficient value changes in patients undergoing radiosurgical treatment of meningiomas.

PURPOSE: A noninvasive method to predict the progress or treatment response of meningiomas is desirable to improve the tumor management. Studies showed that apparent diffusion coefficient (ADC) pretreatment values can predict treatment response in brain tumors. The aim of this study was to analyze changes of intratumoral ADC values in patients with meningiomas undergoing conservative or radiosurgery. METHOD: MR images of 51 patients with diagnose of meningiomas were retrospectively reviewed. Twenty-five patients undergoing conservative or radiosurgery treatment, respectively, were included in the study. The follow-up data ranged between 1 and 10 years. Based on ROI analysis, the mean ADC values, ADC10%min, and ADC90%max were evaluated at different time points during follow-up. RESULTS: Baseline ADC values in between both groups were similar. The ADCmean values, ADC10%min, and ADC90%max within the different groups did not show any significant changes during the follow-up times in the untreated (ADCmean over 10 years period: 0.87 ± 0.05 × 10-3 mm2/s) and radiosurgically treated (ADCmean over 4 years period: 1.02 ± 0.12 × 10-3 mm2/s) group. However, statistically significant difference was observed when comparing the ADCmean and ADC90%max values of untreated with radiosurgically treated (p < 0.0001) meningiomas. Also, ADC10%min revealed statistically significant difference between the untreated and the radiosurgery group (p < 0.05). CONCLUSIONS: ADC values in conservatively managed meningiomas remain stable during the follow-up. However, meningiomas undergoing radiosurgery reveal significant change of the mean ADC values over time, suggesting that ADC may reflect a change in the biological behavior of the tumor. These observations might suggest the value of ADC changes as an indicator of treatment response.

MRI and 18FET-PET Predict Survival Benefit from Bevacizumab Plus Radiotherapy in Patients with Isocitrate Dehydrogenase Wild-type Glioblastoma: Results from the Randomized ARTE Trial.

PURPOSE: To explore a prognostic or predictive role of MRI and O-(2-18F-fluoroethyl)-L-tyrosine (18FET) PET parameters for outcome in the randomized multicenter trial ARTE that compared bevacizumab plus radiotherapy with radiotherpay alone in elderly patients with glioblastoma. PATIENTS AND METHODS: Patients with isocitrate dehydrogenase wild-type glioblastoma ages 65 years or older were included in this post hoc analysis. Tumor volumetric and apparent diffusion coefficient (ADC) analyses of serial MRI scans from 67 patients and serial 18FET-PET tumor-to-brain intensity ratios (TBRs) from 31 patients were analyzed blinded for treatment arm and outcome. Multivariate Cox regression analysis was done to account for established prognostic factors and treatment arm. RESULTS: Overall survival benefit from bevacizumab plus radiotherapy compared with radiotherapy alone was observed for larger pretreatment MRI contrast-enhancing tumor [HR per cm3 0.94; 95% confidence interval (CI), 0.89-0.99] and for higher ADC (HR 0.18; CI, 0.05-0.66). Higher 18FET-TBR on pretreatment PET scans was associated with inferior overall survival in both arms. Response assessed by standard MRI-based Response Assessment in Neuro-Oncology criteria was associated with overall survival in the bevacizumab plus radiotherapy arm by trend only (P = 0.09). High 18FET-TBR of noncontrast-enhancing tumor portions during bevacizumab therapy was associated with inferior overall survival on multivariate analysis (HR 5.97; CI, 1.16-30.8). CONCLUSIONS: Large pretreatment contrast-enhancing tumor mass and higher ADCs identify patients who may experience a survival benefit from bevacizumab plus radiotherapy. Persistent 18FET-PET signal of no longer contrast-enhancing tumor after concomitant bevacizumab plus radiotherapy suggests pseudoresponse and predicts poor outcome.

Outcome of nonneoplastic pituitary cysts during conservative monitoring and after surgery-a SwissPit study.

BACKGROUND: Nonneoplastic cysts of the pituitary are common incidental findings; however, best management remains controversial as they are often asymptomatic but eventually may cause symptoms. The aims of this study are to describe the course of conservative and surgical approaches, to assess timing and results of surgery, and to identify predictors for growth. METHODS: This retrospective study reviewed medical records from the Swiss Pituitary registry. Fifty patients (68% females; median 44 years old) fulfilled the criteria for inclusion. Three cohorts were defined: a conservative group (n = 28), a group who initially needed surgery (n = 18), and a group who had surgery during follow-up (n = 4). Transsphenoidal cyst evacuation was used in 95%; 68% had intraoperative MRI. All patients had standardized neuroradiological, endocrinological, and ophthalmological follow-up (mean 44 (7-151) months). RESULTS: Conservative follow-up of 30 (6-120) months showed cyst growth in 16% (4%/year) and spontaneous shrinkage in 19% (8%/year). Cyst-volumes changed - 0.95 to 1.45 cm3 per year. The probability of needing surgery was 5% per year. Larger cysts (> 1.4 cm3) and T1-hypo-/T2-hyper cyst contents were associated with higher probability for growth. Postoperatively, no remnant was seen in 82% during a follow-up of 53 months. Visual field deficiencies improved in 83%. Hypopituitarism recovered in up to 88%. But for a smaller complication rate, the outcome was not influenced by the use of the intraoperative MRI. CONCLUSIONS: Asymptomatic nonneoplastic pituitary cysts may be monitored; many lesions may shrink with time. Larger or T1-hypo-/T2-hyper cysts have higher growth rates. If indicated, surgery for nonneoplastic sellar cysts is a safe and efficient.

An endovascular assisted, nonocclusive cerebral bypass: a technical feasibility study in a rabbit model.

OBJECTIVE: Temporary parent vessel occlusion performed to establish a high-flow interpositional bypass carries the risk of infarcts. The authors investigated the feasibility of a novel technique to establish a high-flow bypass without temporary parent vessel occlusion in order to lower the risk of ischemic complications. METHODS: In 10 New Zealand white rabbits, a carotid artery side-to-end anastomosis was performed under parent artery patency with a novel endovascular balloon device. Intraoperative angiography, postoperative neurological assessments, and postoperative MRI/MRA were performed to evaluate the feasibility and safety of the novel technique. RESULTS: A patent anastomosis was established in 10 of 10 animals; 3 procedure-related complications occurred. No postoperative focal neurological deficits were observed. The MRI/MRA findings include no infarcts and bypass patency in 50% of the animals. CONCLUSIONS: The authors demonstrated the feasibility of an endovascular assisted, nonocclusive high-flow bypass. Future refinement of the device and technique in an animal model is necessary to lower the complication rate and increase patency rates.

Endovascular Temporary Balloon Occlusion for Microsurgical Clipping of Posterior Circulation Aneurysms.

Based on the relationship between the posterior clinoid process and the basilar artery (BA) apex it may be difficult to obtain proximal control of the BA using temporary clips. Endovascular BA temporary balloon occlusion (TBO) can reduce aneurysm sac pressure, facilitate dissection/clipping, and finally lower the risk of intraoperative rupture. We present our experience with TBO during aneurysm clipping of posterior circulation aneurysms within the setting of a hybrid operating room (hOR). We report one case each of a basilar tip, posterior cerebral artery, and superior cerebellar artery aneurysm that underwent surgical occlusion under TBO within an hOR. Surgical exposure of the BA was achieved with a pterional approach and selective anterior and posterior clinoidectomy. Intraoperative digital subtraction angiography (iDSA) was performed prior, during, and after aneurysm occlusion. Two patients presented with subarachnoid hemorrhage and one patient presented with an unruptured aneurysm. The intraluminal balloon was inserted through the femoral artery and inflated in the BA after craniotomy to allow further dissection of the parent vessel and branches needed for the preparation of the aneurysm neck. No complications during balloon inflation and aneurysm dissection occurred. Intraoperative aneurysm rupture prior to clipping did not occur. The duration of TBO varied between 9 and 11 min. Small neck aneurysm remnants were present in two cases (BA and PCA). Two patients recovered well with a GOS 5 after surgery and one patient died due to complications unrelated to surgery. Intraoperative TBO within the hOR is a feasible and safe procedure with no additional morbidity when using a standardized protocol and setting. No relevant side effects or intraoperative complications were present in this series. In addition, iDSA in an hOR facilitates the evaluation of the surgical result and 3D reconstructions provide documentation of potential aneurysm remnants for future follow-up.

Pontine Neoplasm or Myelinolysis Despite Normal Sodium Levels.

An elderly woman was transferred for biopsy of a pontine lesion. Her condition, including gait disturbances, truncal ataxia, and dysarthria-presumed to be due to severe alcohol abuse-had deteriorated during treatment of ambulatory-acquired pneumonia. No electrolyte abnormalities were noted during hospitalization. However, the neuroimaging findings were in line with central pontine myelinolysis, typically sparing the peripheral pontine fibers. Although extremely rare, pontine myelinolysis can occur in the presence of normal electrolyte levels. Thus, imaging findings should not be misinterpreted as pontine neoplasms, and patients should not undergo stereotactic biopsy-a procedure that could result in disastrous morbidity.

Three-dimensional visualization of aneurysm wall calcification by cerebral angiography: Technical case report.

BACKGROUND: We describe on a 57-year-old man with an incidental middle cerebral artery (MCA) aneurysm in whom a preoperative standard three-dimensional rotational angiogram (3D-RA) was used to depict luminal morphology along with 3D density rendering to precisely locate aneurysm wall calcification. METHODS: To detect aneurysm calcification, a native 3D rotational angiogram was acquired for calcium density visualization, followed by an intraarterial contrast-enhanced 3D rotational angiogram in the same location. Both data sets were postprocessed obtaining a 3D calcium volume rendering on a 3D-RA. RESULTS: Depiction of both the MCA luminal aneurysm morphology as well as calcium-rich components in the aneurysm wall was valuable to determine treatment strategy towards surgery. CONCLUSION: Imaging of luminal morphology and calcification within the same angiographic procedure allows for a plain and simple estimation of the degree and distribution of brain aneurysm wall calcification with limited amount of additional radiation dosage.

Early Rupture of a Giant Basilar Artery Aneurysm after LEO Stenting: Case Report and Review of the Literature.

BACKGROUND: Advances in the endovascular armamentarium, such as flow diversion and stenting devices, provide treatment options for posterior circulation intracranial aneurysms (IAs) with complex angioarchitecture. Delayed IA rupture following flow diversion is a rare but often fatal complication. Giant IAs likely pose a higher risk because of the extensive clot formation and its suspected detrimental effect on the aneurysmal wall. However, mechanisms that lead to delayed rupture are poorly understood, and few cases provide thorough documentation of macroscopic and histologic findings. CLINICAL PRESENTATION: After our 60-year-old patient with a giant basilar aneurysm underwent treatment with a LEO stent, the postoperative clinical course remained uneventful until day 4 when he suffered an unexpected fatal subarachnoid hemorrhage (SAH). Autopsy demonstrated extensive hemorrhage, large intraluminal thrombus, and ruptured IA wall. The aneurysm, which ruptured linearly, was completely filled with a clot that seemed to have outgrown the thin aneurysm wall. Histologic specimens revealed thinning and degenerative changes of the aneurysm's wall, and sparse neutrophilic and histiocytic inflammatory infiltrate adjacent to the rupture site, a finding consistent with recently published cases of IA rupture. CONCLUSIONS: Our case report highlighting the clinical course and autopsy findings of a fatal SAH shortly after stenting this giant basilar artery aneurysm adds to the few previously reported fatal cases of IA rupture after endovascular treatment. Our macroscopic and histologic findings suggested that multimodal changes of inflammation, wall sheer tress (mechanical), and recanalization were involved.

10 Years' Experience of Using Low-Field Intraoperative MRI in Transsphenoidal Surgery for Pituitary Adenoma: Results of the Swiss Pituitary Registry (SwissPit).

BACKGROUND: For 20 years, several studies have reported intraoperative magnetic resonance imaging (iMRI) utility to achieve gross total resections in transsphenoidal pituitary adenoma surgery. Although few studies on low-field iMRI included >100 patients, data on hormonally active tumors remain scarce and follow-up times are <3 years. This is not sufficient to judge the long-term efficiency of the use of low-field iMRI. The aim of this retrospective study is to report the detailed outcome of iMRI-controlled transsphenoidal surgery in >200 patients during a follow-up exceeding 5 years. METHODS: Patients undergoing surgery for pituitary adenoma by iMRI-controlled, endoscopically assisted transsphenoidal surgery at the authors' institution between 2006 and 2016 were eligible for inclusion. Data were collected in the Swiss Pituitary Registry. A Polestar 0.15T-scanner was used. RESULTS: A total of 231 patients had surgery for 160 nonfunctioning adenomas; 28 hGH-, 27 PRL-, 10 ACTH-secreting and 6 mixed adenomas and were followed for 62 months (9-178). Additional iMRI-guided resections were possible in 54% and increased the gross total resection rate by 4% (P = 0.004). Remission rates were as follows: nonfunctioning adenoma, 53%; acromegaly, 61%; prolactinoma, 50%; Cushing disease, 90%. Tumor regrowth and recurrence was detected at a mean time of 24 and 63 months, respectively. Recovery of deficient hormone axes was detected in 22% to 27%. The risk for new postoperative hormonal deficiencies was 15%. Postoperative relieve of visual field and visual acuity deficiencies was seen in 94 (86%) and 73 (81%) patients, respectively. CONCLUSION: Judged by long-term follow-ups of >200 nonfunctioning/functioning pituitary adenomas, the use of low-field iMRI in transsphenoidal surgery increases resection rates and sustainably influences outcomes.

Comparison of Intra- and Postoperative 3-Dimensional Digital Subtraction Angiography in Evaluation of the Surgical Result After Intracranial Aneurysm Treatment.

BACKGROUND: Postoperative three-dimensional digital subtraction angiography (3D-DSA) is the gold standard in evaluating intracranial aneurysm (IA) remnants after clipping. Should intraoperative 3D-DSA image quality be equally good as postoperative 3D-DSA, it could supplant the latter as standard of care for follow-up of clipped IA. OBJECTIVE: To directly compare the quality of assessment of clipped IA by intraoperative and postoperative 3D-DSA. METHODS: From a prospective cohort of 221 consecutive patients who underwent craniotomy for IA treatment in a hybrid operating room, we retrospectively studied 26 patients who had both intraoperative and postoperative 3D-DSA imaging of their clipped aneurysm. Comparison of intraoperative and postoperative 3D-DSA images (blinded for review) included parameters that affected image quality and differences between the 2 periods. RESULTS: In the 26 patients with 32 clipped IAs, the mean interval was 11 ± 7 mo between intraoperative and postoperative imaging 3D-DSA examinations. Reconstruction with multiple clips was used in 14 (44%) cases. Of 15 remnants, 9 (60%) were small (<2 mm). In comparing intraoperative and postoperative 3D-DSA, no discordance or discrepancy in assessment of the surgical result was noted for any clipped IA, and overall imaging quality was excellent for both modalities. Factors affecting minor differences in image quality were not identified. CONCLUSION: Compared with postoperative 3D-DSA, intraoperative 3D-DSA images achieved equally high quality and effective, immediate interpretation of the surgical clipping result. With comparable imaging quality and no discordant findings, intraoperative 3D-DSA could replace postoperative 3D-DSA to become the standard of care in IA surgery.