The pEGASUS-HPC stent system for intracranial arterial stenosis: a single-center case series.

BACKGROUND: Intracranial arterial stenting is a technique for the treatment of symptomatic stenosis. In this single-center retrospective case series we evaluated a novel low profile laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC, Phenox GmbH, Bochum, Germany) for the treatment of intracranial stenosis in the setting of acute ischemic stroke and elective cases. METHODS: All patients treated with pEGASUS-HPC for one or more intracranial arterial stenoses at our institution were retrospectively included. Clinical, imaging and procedural parameters as well as clinical and imaging follow-up data were collected. RESULTS: We performed 43 interventions in 41 patients with 42 stenoses in our neurovascular center between August 2021 and February 2024. Twenty-one patients (51.2%) were female and the mean±SD age was 71±10.8 years. Thirty-seven (86.1%) procedures were performed in the setting of endovascular acute ischemic stroke treatment. Technical or procedural complications occurred in seven patients (16.3%), six in the thrombectomy group and one in the elective group. One stent-related hemorrhagic complication (subarachnoid hemorrhage) occurred in emergency cases and symptomatic intracerebral hemorrhage occurred in one patient treated in an elective setting. Overall stenosis reduction following pEGASUS-HPC stent implantation was 53.0±18.0%. On follow-up imaging, which was available for 16 patients (37.2%) after an average of 32±58.6 days, 62.5% of the stents were patent. CONCLUSION: Our single-center case series demonstrates the feasibility of using the pEGASUS-HPC stent system, especially in emergency situations when thrombectomy fails.

Enhancing thromboresistance of neurovascular nickel-titanium devices with responsive heparin hydrogel coatings.

BACKGROUND: Neurointerventional devices, particularly laser-cut thin-strut stents made of self-expanding nickel-titanium alloy, are increasingly utilized for endovascular applications in intracranial arteries and dural venous sinuses. Preventing thrombosis and stroke necessitates systemic anticoagulant and antiplatelet therapies with the risk of bleeding complications. Antithrombotic coatings present a promising solution. METHODS: In this study, we investigated the potential of hydrogels composed of four-armed poly(ethylene glycol) (starPEG) and heparin, with or without coagulation-responsive heparin release, as coatings for neurovascular devices to mitigate blood clot formation. We evaluated the feasibility and efficacy of these coatings on neurovascular devices through in vitro Chandler-Loop assays and implantation experiments in the supra-aortic arteries of rabbits. RESULTS: Stable and coagulation-responsive starPEG-heparin hydrogel coatings exhibited antithrombotic efficacy in vitro, although with a slightly reduced thromboprotection observed in vivo. Furthermore, the hydrogel coatings demonstrated robustness against shear forces encountered during deployment and elicited only marginal humoral and cellular inflammatory responses compared with the reference standards. CONCLUSION: Heparin hydrogel coatings offer promising benefits for enhancing the hemocompatibility of neurointerventional devices made of self-expanding nickel-titanium alloy. The variance in performance between in vitro and in vivo settings may be attributed to differences in low- and high-shear blood flow conditions inherent to these models. These models may represent the differences in venous and arterial systems. Further optimization is warranted to tailor the hydrogel coatings for improved efficacy in arterial applications.

Non-ischemic cerebral enhancing (NICE) lesions after flow diversion for intracranial aneurysms: a multicenter study.

BACKGROUND: Non-ischemic cerebral enhancing (NICE) lesions have been reported as a rare complication of various neuroendovascular procedures, but information on their incidence after flow diversion is scant. It is unclear if specific devices or novel coating technologies may impact their occurrence. METHODS: We conducted a multicenter study on the incidence of NICE lesions after flow diverter (FD) implantation for cerebral aneurysm treatment. RESULTS: Eight centers identified 15 patients and provided detailed data. The clinical presentation ranged from asymptomatic to hemiplegia and cognitive impairment. The mean time to diagnosis after treatment was 65.1±101.5 days. Five centers disclosed information on all of their 1201 FD procedures during the inclusion period (2015-2022), during which 12 patients were diagnosed with NICE lesions in these institutions-that is, an incidence of 1%. FD coatings did not increase the incidence (6/591 patients (1%) treated with surface-modified FD vs 6/610 patients (1%) treated with bare FD; P=1.00). Significantly increased rates of 3.7% (6 cases in 161 procedures; P<0.01) and 3.3% (5 cases in 153 procedures; P<0.01) were found with stents of two specific product lines. The use of one product line was associated with a significantly lower incidence (0 cases in 499 procedures (0%); P<0.01). CONCLUSIONS: Novel stent coatings are not associated with an increased incidence of NICE lesions. The incidence rate of 1% suggests that these lesions may occur more often after flow diversion than after other endovascular treatments. We found a concerning accumulation of NICE lesion cases when FDs from two product families were used.

The pEGASUS-HPC stent system for stent-assisted coiling of cerebral aneurysms: a multicenter case series.

BACKGROUND: Stent-assisted coiling (SAC) is a well-established method for treatment of wide-necked intracranial aneurysms. In this multicenter, retrospective case series we evaluated SAC with a new low-profile, laser-cut stent with an antithrombogenic hydrophilic polymer coating (pEGASUS-HPC) for the treatment of intracranial aneurysms. METHODS: Patients treated with pEGASUS-HPC SAC for one or more intracranial aneurysms were retrospectively included. Clinical, imaging, and procedural parameters as well as clinical and imaging follow-up data were recorded. RESULTS: We treated 53 aneurysms in 52 patients in six neurovascular centers between August 2021 and November 2022. Thirty-seven patients (69.8%) were female. Mean age was 57 (±11.7) years. Twenty-nine patients were treated electively, 23 in the acute phase (22 with aneurysmal subarachnoid hemorrhage (SAH), and 1 with a partially thrombosed aneurysm causing ischemic events). One intraprocedural thromboembolic event and three postprocedural ischemic complications occurred in two (8.7 %) of the SAH patients and in one of the elective patients (3.45%). Overall aneurysm occlusion was Raymond Roy (RR) I in 36 (69.2%), RR II in 9, and RR III in 9 cases. Follow-up imaging was available for 23 patients after an average of 147.7 (±59.6) days demonstrating RR I occlusion in 22 (95.5%) and RR II in 1 patient. CONCLUSION: SAC with the pEGASUS-HPC stent system demonstrates rates of periprocedural safety and effectiveness that are comparable with previously reported series for stent-assisted coil embolization.

Flow diversion for compressive unruptured internal carotid artery aneurysms with neuro-ophthalmological symptoms: a systematic review and meta-analysis.

BACKGROUND: Data on the safety and efficacy of flow diverters (FD) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms (NOS) are scarce and comprise mainly small case series. METHODS: We performed a search of three databases and included series with ≥10 patients, with unruptured aneurysms of the ICA and NOS, treated with FD. Random-effects analysis of treatment results and safety was performed. RESULTS: A total of 22 studies reporting on 594 patients were included. Pooled proportions of NOS recovery, improvement, transient and permanent worsening were: 47.4% (95% CI 35.0% to 60.1%); 74.5% (95% CI 67.9% to 80.2%); 7.1% (95% CI 3.3% to 14.7%); and 4.9% (95% CI 3.2% to 7.4%), respectively. Rates of complete recovery and improvement in patients with isolated visual symptoms were 30.6% (95% CI 12.5% to 57.7%) and 56.6% (95% CI 42.3% to 69.9%). Isolated oculomotor symptoms recovered completely in 47.8% (95% CI 29.9% to 66.3%) and improved in 78% (95% CI 69.2% to 84.9%). Morbidity occurred in 5% (95% CI 2.8% to 9%) and mortality in 3.9% (95% CI 2% to 7.5%) of patients. An increased likelihood of symptom improvement was observed when treatment was performed early (<1 month) after symptom onset (OR=11.22, 95% CI 3.9% to 32.5%). CONCLUSION: Flow diversion promotes recovery or improvement of compressive symptoms in a large proportion of patients but is associated with significant rates of morbidity and mortality. Transient and permanent NOS worsening is not uncommon. Early treatment is of utmost importance, as it increases the likelihood of symptom improvement more than 10-fold.

Mechanical thrombectomy for acute ischemic stroke in COVID-19 patients: multicenter experience in 111 cases.

BACKGROUND: Data on the frequency and outcome of mechanical thrombectomy (MT) for large vessel occlusion (LVO) in patients with COVID-19 is limited. Addressing this subject, we report our multicenter experience. METHODS: A retrospective cohort study was performed of consecutive acute stroke patients with COVID-19 infection treated with MT at 26 tertiary care centers between January 2020 and November 2021. Baseline demographics, angiographic outcome and clinical outcome evaluated by the modified Rankin Scale (mRS) at discharge and 90 days were noted. RESULTS: We identified 111 out of 11 365 (1%) patients with acute or subsided COVID-19 infection who underwent MT due to LVO. Cardioembolic events were the most common etiology for LVO (38.7%). Median baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early CT Score were 16 (IQR 11.5-20) and 9 (IQR 7-10), respectively. Successful reperfusion (mTICI ≥2b) was achieved in 97/111 (87.4%) patients and 46/111 (41.4%) patients were reperfused completely. The procedure-related complication rate was 12.6% (14/111). Functional independence was achieved in 20/108 (18.5%) patients at discharge and 14/66 (21.2%) at 90 days follow-up. The in-hospital mortality rate was 30.6% (33/108). In the subgroup analysis, patients with severe acute COVID-19 infection requiring intubation had a mortality rate twice as high as patients with mild or moderate acute COVID-19 infection. Acute respiratory failure requiring ventilation and time interval from symptom onset to groin puncture were independent predictors for an unfavorable outcome in a logistic regression analysis. CONCLUSION: Our study showed a poor clinical outcome and high mortality, especially in patients with severe acute COVID-19 infection undergoing MT due to LVO.

Flow diversion for internal carotid artery aneurysms with compressive neuro-ophthalmologic symptoms: clinical and anatomical results in an international multicenter study.

BACKGROUND: Scientific data on the safety and efficacy of flow diverter stents (FDS) for the treatment of unruptured internal carotid artery (ICA) aneurysms with compressive neuro-ophthalmological symptoms are scarce. We studied this subject in a retrospective international multicenter series, pooling data of 9 tertiary care neurointerventional departments. OBJECTIVE: To investigate, in a retrospective, multicentric cohort of patients presenting with visual or oculomotor symptoms attributed to a compressive carotid artery in an unruptured intracranial aneurysm, the safety and efficacy profiles of FDS, by analyzing neuro-opthalmologic symptom evolution following FDS placement, complications, and aneurysm obliteration rates. METHODS: All patients treated since 2015 with a FDS for an unruptured aneurysm of the ICA with signs of compressive cranial nerve symptoms (CN II, III, IV, VI) were included. RESULTS: We treated 55 patients with 55 aneurysms; 21 (38.2%) patients had oculomotor and 15 (27.3%) visual symptoms only; 19 (34.5%) presented with a combination of both. Treatment-related morbidity/mortality occurred in 7.2% and 3.6%, respectively. At last imaging follow-up (13.1±10.5 months) rates of complete aneurysm occlusion, neck remnant, and aneurysm remnant were 72%, 14%, and 14%, respectively. At last clinical follow-up after 13±10.5 months, 19/51 (37.3%) patients had recovered completely and 18/51 (35.3%) had recovered at least partially from their neuro-ophthalmological symptoms. In multivariable models, a longer delay between symptom onset and treatment was associated with higher odds for incomplete recovery and lower odds for any improvement (aOR 1.03 (95% CI 1.01 to 1.07), p=0.047 and 0.04 (0-0.81), p=0.020). Incomplete recovery was independently associated with older age and fusiform aneurysms. CONCLUSION: FDS are effective to treat patients with compressive aneurysms of the ICA causing neuro-ophthalmological symptoms, especially when treatment is initiated early after symptom onset, and aneurysm occlusion is adequate. However, serious complications are not rare.

Mechanical thrombectomy for basilar artery occlusion: efficacy, outcomes, and futile recanalization in comparison with the anterior circulation.

BACKGROUND: Performing mechanical thrombectomy (MT) in patients with basilar artery occlusion (BAO) is currently not evidence-based. OBJECTIVE: To compare patients' outcome, relative merits of achieving recanalization, and predictors of futile recanalization (FR) between BAO and anterior circulation large vessel occlusion (ACLVO) MT. METHODS: In the multicenter BEYOND-SWIFT registry (NCT03496064), univariate and multivariate (displayed as adjusted Odds Ratios, aOR and 95% confidence intervals, 95%-CI) outcome comparisons between BAO (N=165) and ACLVO (N=1574) were performed. The primary outcome was favorable outcome at 90 days (modified Rankin Scale, mRS 0-2). Secondary outcome included mortality, symptomatic intracranial hemorrhage (sICH) and FR. The relative merits of achieving successful recanalization between ACLVO and BAO were evaluated with interaction terms. RESULTS: MT in BAO was more often technically effective and equally safe in regards to mortality and sICH when compared to ACLVO. When adjusting for baseline differences, there was no significant difference between BAO vs ACLVO regarding rates of favorable outcome (aOR 0.986, 95%-CI 0.553 - 1.758). However, BAO were associated with increased rates of FR (aOR 2.146, 95%-CI 1.267 - 3.633). Predictors for FR were age, stroke severity, maneuver count and intracranial stenting. No significant heterogeneity on the relative merits of achieving successful recanalization on several outcome parameters were observed when comparing BAO and ACLVO. CONCLUSIONS: In selected patients, similar outcomes can be achieved in BAO and ACLVO patients treated with MT. Randomized controlled trials comparing patient selection and interventional strategies seem warranted to avoid FR. TRIAL REGISTRATION NUMBER: NCT03496064.

Intracranial aneurysms treatment with Barricade coils: Safety and 1-year efficacy in a prospective, single-center series.

BACKGROUND AND PURPOSE: Barricade coils (Blockade/Balt, Montmorency, France) are bare platinum coils, electrically detached existing in different shapes, softnesses, and sizes. This series is analyzing the safety (procedural complications) and efficacy (anatomical results at 1-year) of these coils in a prospective, single-center series. MATERIALS AND METHODS: All patients with aneurysms treated with Barricade coils, without associated treatment (flow diverter, flow disrupter, or surgery) or parent artery occlusion were included. Peri-operative complications were evaluated. Anatomical results at 1-year were analyzed for patients that completed the 1-year digital subtraction angiographic follow-up and were independently evaluated by an expert neuroradiologist. RESULTS: During the study period (October 2013-October 2017), 132 patients (female: 88/132, 66.7%; median age: 50 years) with 141 aneurysms treated with Blockade coils were included. Aneurysm rupture, thromboembolic complication, and technical problems occurred in 9 aneurysms (6.3%), 8 aneurysms (5.6%), and 8 aneurysms (5.6%), respectively. Clinical consequences were variable; morbidity was reported in 5 patients (3.8%) and mortality in 2 patients (1.5%). Post-operatively aneurysm occlusion was complete in 117 aneurysms (83.0%), neck remnant in 16 aneurysms (11.3%), and aneurysm remnant in 8 aneurysms (5.7%). At 1-year aneurysm occlusion was complete in 53 aneurysms (51.5%), neck remnant in 34 aneurysms (33.0%), and aneurysm remnant in 16 aneurysms (15.5%). Retreatment in the year following the initial treatment was reported in 10 aneurysms (9.7%). CONCLUSION: Treatment of ruptured, unruptured, and recanalized aneurysms with Barricade coils is associated with a good safety and 1-year efficacy.

Can early neurological improvement after mechanical thrombectomy be used as a surrogate for final stroke outcome?

BACKGROUND AND PURPOSE: We aimed to identify the best definition of early neurological improvement (ENI) at 2 and 24 hours after mechanical thrombectomy (MT) and determine its ability to predict a good functional outcome at 3 months. METHODS: This retrospective analysis was based on a prospectively collected registry of patients treated by MT for ischemic stroke from May 2010 to March 2017. We included patients treated with stent-retrievers with National Institute of Health Stroke Scale (NIHSS) score before treatment and at 2 and/or 24 hours after treatment and modified Rankin Score (mRS) at 3 months. Receiver operating characteristic curve analysis was performed to estimate optimal thresholds for ENI at 2 and 24 hours. The relationship between optimal ENI definitions and good outcome at 3 months (mRS 0-2) was assessed by logistic regression. RESULTS: The analysis included 246 patients. At 2 hours, the optimal threshold to predict a good outcome at 3 months was improvementin the NIHSS score of >1 point (AUC 0.83,95% CI 0.77 to 0.87), with sensitivity and specificity 78.3% (62.2-85.7%) and 84.6% (77.2-90.3%), respectively, and OR 12.67 (95% CI 4.69 to 31.10, p<0.0001). At 24 hours, the optimal threshold was an improvementin the NIHSS score of >4 points (AUC 0.93, 95% CI 0.89 to 0.96), with sensitivity and specificity 93.8% (87.7-97.5%) and 83.2% (75.7-89.2%), respectively, and OR 391.32 (95% CI 44.43 to 3448.35, p<0.0001). CONCLUSIONS: ENI 24 hours after thrombectomy appears to be a straightforward surrogate of long-term endpoints and may have value in future research.

Hilar en bloc resection for hilar cholangiocarcinoma in patients with limited liver capacities-preserving parts of liver segment 4.

BACKGROUND: A right trisectionectomy with portal vein resection represents the conventional approach for hilar cholangiocarcinoma. Here, we present a technical modification of hilar en bloc resection in order to increase the remnant volume by partially preserving liver segment 4. METHODS: The caudal parenchymal dissection line starts centrally between the left lateral and left medial segments. Cranially, the resection line switches to the right towards Cantlie's line and turns again upwards perpendicularly. Hence, segment 4a and subtotal segment 4b are partially preserved by this novel technique. The left hepatic duct is dissected at the segmental ramification and reconstruction is performed as a single hepaticojejunostomy. The feasibility of the novel parenchyma-sparing approach for hilar cholangiocarcinoma was proven in a case series and medical records were reviewed retrospectively. RESULTS: Ten patients (6 male, 4 female) underwent segment 4 partially preserving right trisectionectomy for hilar cholangiocarcinoma. Estimated future liver remnant volume was significantly increased (FLRV 38.3%), when compared to standard right trisectionectomy (FLRV 23.9%; p < 0.01). Three of 10 liver resections were associated with major surgical complications (≥IIIb; n = 3); categorized according to the Dindo-Clavien classification. No patient died due to complications associated with postoperatively impaired liver function. Tumor-free margins could be achieved in 8 patients while median overall survival and disease-free survival were 547 and 367 days, respectively. CONCLUSION: This novel parenchyma-sparing modification of hilar en bloc resection by partially preserving segment 4 allows to safely increase the remnant liver volume without neglecting principles of local radicality.

Correction to: Hilar en bloc resection for hilar cholangiocarcinoma in patients with limited liver capacities-preserving parts of liver segment 4.

[This corrects the article DOI: 10.1007/s10353-017-0507-8.].

Treatment of recurrent aneurysms using the Woven EndoBridge (WEB): anatomical and clinical results.

BACKGROUND: The safety and efficacy of the Woven EndoBridge (WEB) for the treatment of naïve intracranial aneurysms has been confirmed. PURPOSE: To analyze the safety and efficacy of the WEB in the treatment of recurrent aneurysms. METHODS: Anatomical and clinical results in consecutive patients with a recurrent aneurysm, who were treated using the WEB device in two French neurointerventional centers, were evaluated. RESULTS: Seventeen patients with 17 aneurysms were included. Treatment was feasible in 16 patients. In seven patients (41.2%), ancillary devices were used. Permanent morbidity due to a thromboembolic complication occurred in one patient (5.9%). There was no mortality. Follow-up angiographic studies were available for 15 patients after a mean of 12.1±6.1 months. Rates of complete occlusion, neck remnant, and aneurysm remnant were 33.3%, 40.0%, and 26.7%, respectively. CONCLUSIONS: Treatment of recurrent aneurysms using the WEB device may be reasonably safe and effective.

Peritumoral Brain Edema in Meningiomas Depends on Aquaporin-4 Expression and Not on Tumor Grade, Tumor Volume, Cell Count, or Ki-67 Labeling Index.

PURPOSE: The aim of this study was to investigate to which degree the peritumoral brain edema in patients with meningiomas depends on aquaporin-4 (AQP4) expression, tumor grade, tumor volume, Ki-67 expression, and cell count. PROCEDURES: Thirty-three patients (25 women, 8 men; mean age 56.6 ± 16.0 years) with an intracranial meningioma underwent a standardized magnetic resonance (MR) examination prior to surgical resection. Edema indices (EIs) and tumor volumes were measured on the MR images. Tumor grade was classified according to the World Health Organization, and the proliferation index was estimated on Ki-67 antigen-stained specimens. Tumor cell count was evaluated. Eighteen specimens were stained for AQP4 expressioon. RESULTS: Significant intergroup differences between AQP4 expression grades and EIs were observed (P = 0.03), and a positive correlation was detected between EIs and AQP4 expression grades (r = 0.54; P < 0.05). A ROC analysis with EI as a test variable revealed an AUC of 0.77 (95 % CI 0.55-0.99) for the prediction of a moderate-to-strong AQP4 expression. An EI ≥1.5 predicted a moderate-to-high AQP4 expression with a sensitivity of 77 % and a specificity of 60 %. EI values of 2.2 and 3.5 reached sensitivity/specificity values of 69/80 % and 54/100 %, respectively. The AQP4 expression did not show any significant correlations with tumor grading, tumor volume, Ki-67 expression, or cell count. Moreover, we observed no significant positive or negative correlations between the EI and tumor grading (P = 0.7), tumor volume (P = 0.19), Ki-67 index (P = 0.9), and cell count (P = 0.34). CONCLUSION: Peritumoral brain edema in patients with meningiomas may depend on AQP4 expression grades and not on tumor grade, tumor volume, Ki-67 expression, and cell count. The amount of edema predicted AQP4 expressions with moderate-to-good sensitivity and specificity.

Correlations Between DCE MRI and Histopathological Parameters in Head and Neck Squamous Cell Carcinoma.

BACKGROUND: Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) can characterize perfusion and vascularization of tissues. DCE MRI parameters can differentiate between malignant and benign lesions and predict tumor grading. The purpose of this study was to correlate DCE MRI findings and various histopathological parameters in head and neck squamous cell carcinoma (HNSCC). PATIENTS AND METHODS: Sixteen patients with histologically proven HNSCC (11 cases primary tumors and in 5 patients with local tumor recurrence) were included in the study. DCE imaging was performed in all cases and the following parameters were estimated: Ktrans, Ve, Kep, and iAUC. The tumor proliferation index was estimated on Ki 67 antigen stained specimens. Microvessel density parameters (stained vessel area, total vessel area, number of vessels, and mean vessel diameter) were estimated on CD31 antigen stained specimens. Spearman's non-parametric rank sum correlation coefficients were calculated between DCE and different histopathological parameters. RESULTS: The mean values of DCE perfusion parameters were as follows: Ktrans 0.189 ± 0.056 min-1, Kep 0.390 ± 0.160 min-1, Ve 0.548 ± 0.119%, and iAUC 22.40 ± 12.57. Significant correlations were observed between Kep and stained vessel areas (r = 0.51, P = .041) and total vessel areas (r = 0.5118, P = .043); between Ve and mean vessel diameter (r = -0.59, P = .017). Cell count had a tendency to correlate with Ve (r = -0.48, P = .058). In an analysis of the primary HNSCC only, a significant inverse correlation between Ktrans and KI 67 was identified (r = -0.62, P = .041). Our analysis showed significant correlations between DCE parameters and histopathological findings in HNSCC.

The Cerebral Surfactant System and Its Alteration in Hydrocephalic Conditions.

INTRODUCTION: Pulmonary Surfactant reduces surface tension in the terminal airways thus facilitating breathing and contributes to host's innate immunity. Surfactant Proteins (SP) A, B, C and D were recently identified as inherent proteins of the CNS. Aim of the study was to investigate cerebrospinal fluid (CSF) SP levels in hydrocephalus patients compared to normal subjects. PATIENTS AND METHODS: CSF SP A-D levels were quantified using commercially available ELISA kits in 126 patients (0-84 years, mean 39 years). 60 patients without CNS pathologies served as a control group. Hydrocephalus patients were separated in aqueductal stenosis (AQS, n = 24), acute hydrocephalus without aqueductal stenosis (acute HC w/o AQS, n = 16) and idiopathic normal pressure hydrocephalus (NPH, n = 20). Furthermore, six patients with pseudotumor cerebri were investigated. RESULTS: SP A-D are present under physiological conditions in human CSF. SP-A is elevated in diseases accompanied by ventricular enlargement (AQS, acute HC w/o AQS) in a significant manner (0.67, 1.21 vs 0.38 ng/ml in control, p<0.001). SP-C is also elevated in hydrocephalic conditions (AQS, acute HC w/o AQS; 0.87, 1.71 vs. 0.48 ng/ml in controls, p<0.001) and in Pseudotumor cerebri (1.26 vs. 0.48 ng/ml in controls, p<0.01). SP-B and SP-D did not show significant alterations. CONCLUSION: The present study confirms the presence of SPs in human CSF. There are significant changes of SP-A and SP-C levels in diseases affecting brain water circulation and elevation of intracranial pressure. Cause of the alterations, underlying regulatory mechanisms, as well as diagnostic and therapeutic consequences of cerebral SP's requires further thorough investigations.

Diffusion-Weighted MRI Reflects Proliferative Activity in Primary CNS Lymphoma.

PURPOSE: To investigate if apparent diffusion coefficient (ADC) values within primary central nervous system lymphoma correlate with cellularity and proliferative activity in corresponding histological samples. MATERIALS AND METHODS: Echo-planar diffusion-weighted magnetic resonance images obtained from 21 patients with primary central nervous system lymphoma were reviewed retrospectively. Regions of interest were drawn on ADC maps corresponding to the contrast enhancing parts of the tumors. Biopsies from all 21 patients were histologically analyzed. Nuclei count, total nuclei area and average nuclei area were measured. The proliferation index was estimated as Ki-67 positive nuclei divided by total number of nuclei. Correlations of ADC values and histopathologic parameters were determined statistically. RESULTS: Ki-67 staining revealed a statistically significant correlation with ADCmin (r = -0.454, p = 0.038), ADCmean (r = -0.546, p = 0.010) and ADCmax (r = -0.515, p = 0.017). Furthermore, ADCmean correlated in a statistically significant manner with total nucleic area (r = -0.500, p = 0.021). CONCLUSION: Low ADCmin, ADCmean and ADCmax values reflect a high proliferative activity of primary cental nervous system lymphoma. Low ADCmean values-in concordance with several previously published studies-indicate an increased cellularity within the tumor.

Signal Intensities in Preoperative MRI Do Not Reflect Proliferative Activity in Meningioma.

BACKGROUND: Identification of high-grade meningiomas in preoperative magnetic resonance imaging (MRI) is important for optimized surgical strategy and best possible resection. Numerous studies investigated subjectively determined morphological features as predictors of tumor biology in meningiomas. The aim of this study was to identify the predictive value of more reliable, quantitatively measured signal intensities in MRI for differentiation of high- and low-grade meningiomas and identification of meningiomas with high proliferation rates, respectively. PATIENTS AND METHODS: Sixty-six patients (56 World Health Organization [WHO] grade I, 9 WHO grade II, and 1 WHO grade I) were included in the study. Preoperative MRI signal intensities (fluid-attenuated inversion recovery [FLAIR], T1 precontrast, and T1 postcontrast as genuine and normalized values) were correlated with Ki-67 expression in tissue sections of resected meningiomas. Differences between the groups (analysis of variance) and Spearman rho correlation were computed using SPSS 22. RESULTS: Mean values of genuine signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 323.9 ± 59, 332.8 ± 67.9, and 768.5 ± 165.3. Mean values of normalized (to the contralateral white matter) signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 1.5 ± 0.3, 0.8 ± 0.1, and 1.9 ± 0.4. There was no significant correlation between MRI signal intensities and WHO grade or Ki-67 expression. Signal intensities did not differ significantly between WHO grade I and II/III meningiomas. Ki-67 expression was significantly increased in high-grade meningiomas compared with low-grade meningiomas (P < 0.01). Objectively measured values of MRI signal intensities (FLAIR, T1 precontrast, and T1 postcontrast enhancement) did not distinguish between high-grade and low-grade meningiomas. Furthermore, there was no association between MRI signal intensities and Ki-67 expression representing proliferative activity.