An International, Multicenter Feasibility Study on Active and Continuous Irrigation With Cerebrospinal Fluid Exchange for Improving Outcomes in Cerebral Ventriculitis.

BACKGROUND AND OBJECTIVES: Cerebral ventriculitis remains a challenging neurosurgical condition because of poor outcomes including mortality rates of nearly 80% and a prolonged course of treatment in survivors. Despite current conventional management, outcomes in some cases remain unsatisfactory, with no definitive therapeutic guidelines. This feasibility study aims to explore the use of a novel active, continuous irrigation and drainage system (IRRAflow [IRRAS AB]) combined with intraventricular drug delivery for patients with cerebral ventriculitis. METHODS: We conducted a multicenter, international, retrospective study of patients with ventriculitis who were treated with use of the IRRAflow system. Data collected included patient demographics, comorbidities, admission Glasgow Coma Scale score, baseline modified Rankin Scale (mRS) score, and imaging findings. Catheter occlusions, infections, and shunt placement were recorded for outcome assessment, along with discharge mRS scores and in-hospital deaths. RESULTS: Four centers contributed data for a total of 21 patients who had IRRAflow placement for treatment of ventriculitis. Thirteen (61.9%) were men (mean age = 49.8 ± 14.87 years). The median baseline mRS score was 1. The median Glasgow Coma Scale score at admission was 13. The etiology of ventriculitis was iatrogenic in 12 (57.1%) patients and secondary to an abscess in 9 (42.9%). No cases reported hemorrhage or failure of IRRAflow placement. Antibiotics were administered through the IRRAflow system in 13 (61.9%) cases in addition to systemic dosing. Sixteen (76.2%) patients had significant clinical improvement and resolution of ventriculitis. Seven (33.3%) patients required shunt placement after resolution because of persistent hydrocephalus. There were 6 (28.6%) in-hospital deaths. CONCLUSION: The use of active irrigation with drainage for continuous delivery of intraventricular irrigation fluid with antibiotics led to dramatically low mortality. In our case series, it led to a marked improvement in neurological status, imaging findings, and cerebrospinal fluid profiles, making it a technically feasible and safe treatment for ventriculitis.

P2Y12 inhibitor use predicts hematoma expansion in patients with intracerebral hemorrhage.

OBJECTIVE: Hematoma expansion (HE) predicts disability and death after acute intracerebral hemorrhage (ICH). Aspirin and anticoagulants have been associated with HE. We tested the hypothesis that P2Y12 inhibitors predict subsequent HE in patients. We explored laboratory measures of P2Y12 inhibition and dual antiplatelet therapy with aspirin (DAPT). METHODS: We prospectively identified patients with ICH. Platelet activity was measured with the VerifyNow-P2Y12 assay. Hematoma volumes for initial and follow-up CTs were calculated using a validated semi-automated technique. HE was defined as the difference between hematoma volumes on the initial and follow-up CT scans. Nonparametric statistics were performed with Kruskal-Wallis H, and correction for multiple comparisons performed with Dunn's test. RESULTS: In 194 patients, 15 (7.7%) were known to take a P2Y12 inhibitor (clopidogrel in all but one). Patients taking a P2Y12 inhibitor had more HE compared to patients not taking a P2Y12 inhibitor (3.5 [1.2-11.9] vs. 0.1 [-0.8-1.4] mL, p = 0.004). Patients taking DAPT experienced the most HE (7.2 [2.6-13.8] vs. 0.0 [-1.0-1.1] mL, p = 0.04). The use of P2Y12 inhibitors was associated with less P2Y12 activity (178 [149-203] vs. 288 [246-319] P2Y12 reaction units, p = 0.005). INTERPRETATION: Patients taking a P2Y12 inhibitor had more HE and less P2Y12 activity. The effect was most pronounced in patients on DAPT, suggesting a synergistic effect of P2Y12 inhibitors and aspirin with respect to HE. Acute reversal of P2Y12 inhibitors in acute ICH requires further study.

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia.

OBJECTIVES: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature. MATERIALS AND METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients. RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia. CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

Background Subtraction Angiography with Deep Learning Using Multi-frame Spatiotemporal Angiographic Input.

Catheter Digital Subtraction Angiography (DSA) is markedly degraded by all voluntary, respiratory, or cardiac motion artifact that occurs during the exam acquisition. Prior efforts directed toward improving DSA images with machine learning have focused on extracting vessels from individual, isolated 2D angiographic frames. In this work, we introduce improved 2D + t deep learning models that leverage the rich temporal information in angiographic timeseries. A total of 516 cerebral angiograms were collected with 8784 individual series. We utilized feature-based computer vision algorithms to separate the database into "motionless" and "motion-degraded" subsets. Motion measured from the "motion degraded" category was then used to create a realistic, but synthetic, motion-augmented dataset suitable for training 2D U-Net, 3D U-Net, SegResNet, and UNETR models. Quantitative results on a hold-out test set demonstrate that the 3D U-Net outperforms competing 2D U-Net architectures, with substantially reduced motion artifacts when compared to DSA. In comparison to single-frame 2D U-Net, the 3D U-Net utilizing 16 input frames achieves a reduced RMSE (35.77 ± 15.02 vs 23.14 ± 9.56, p < 0.0001; mean ± std dev) and an improved Multi-Scale SSIM (0.86 ± 0.08 vs 0.93 ± 0.05, p < 0.0001). The 3D U-Net also performs favorably in comparison to alternative convolutional and transformer-based architectures (U-Net RMSE 23.20 ± 7.55 vs SegResNet 23.99 ± 7.81, p < 0.0001, and UNETR 25.42 ± 7.79, p < 0.0001, mean ± std dev). These results demonstrate that multi-frame temporal information can boost performance of motion-resistant Background Subtraction Deep Learning algorithms, and we have presented a neuroangiography domain-specific synthetic affine motion augmentation pipeline that can be utilized to generate suitable datasets for supervised training of 3D (2d + t) architectures.

Fixed- Versus Variable-Dose Prothrombin Complex Concentrate for the Emergent Reversal of Vitamin K Antagonists: A Systematic Review and Meta-Analysis.

OBJECTIVES: Four-factor prothrombin complex concentrate (4-PCC) is recommended for rapid reversal of vitamin K antagonists (VKAs) such as warfarin, yet optimal dosing remains uncertain. DATA SOURCES: A systematic review was conducted of PubMed, Embase, and Ovid MEDLINE (Wolters Kluwer) databases from January 2000 to August 2023 for clinical studies comparing fixed- vs. variable-dose 4-PCC for emergent VKA reversal with at least one reported clinical outcome. STUDY SELECTION: Abstracts and full texts were assessed independently and in duplicate by two reviewers. DATA EXTRACTION: Data were extracted independently and in duplicate by two reviewers using predefined extraction forms. DATA SYNTHESIS: The analysis comprised three randomized trials and 16 cohort studies comprising a total of 323 participants in randomized trials (161 in fixed dosage and 162 in variable dosage) and 1912 patients in cohort studies (858 in fixed-dose and 1054 in variable dose). Extracranial bleeding was the predominant indication, while intracranial hemorrhage varied. Overall, a fixed-dose regimen may be associated with a lower dose of 4-PCC and results in a reduction in 4-PCC administration time compared with a variable-dose regimen. A fixed-dose regimen also likely results in increased clinical hemostasis. While there is no clear difference between the two regimens in terms of achieving a goal international normalized ratio (INR) less than 2, a fixed-dose regimen is less likely to achieve a goal INR less than 1.5. High certainty evidence indicates that the fixed-dose regimen reduces both mortality and the occurrence of thromboembolic events. Additional subgroup analyses provides exploratory data to guide future studies. CONCLUSIONS: A fixed-dose regimen for 4-PCC administration provides benefits over a variable-dose regimen in terms of dose reduction, faster administration time, improved clinical hemostasis, and reduced mortality and thromboembolic events. Further studies are warranted to better refine the optimal fixed-dose regimen.

Charlson Comorbidity Index and Frailty as Predictors of Resolution Following Middle Meningeal Artery Embolization for Chronic Subdural Hematoma.

BACKGROUND: Research on variables associated with chronic subdural hematoma (cSDH) resolution following middle meningeal artery embolization (MMAE) is limited. This study investigated the clinical utility of age-adjusted Charlson Comorbidity Index (ACCI) and modified 5-item Frailty Index (mFI - 5) for predicting cSDH resolution following MMAE. METHODS: We identified patients who underwent MMAE at our institution between January 2018 and December 2022, with at least 20 days of follow-up and one radiographic follow-up study. Patient demographics, characteristics, and outcomes were collected. Complete resolution was defined as absence of subdural collections on CT-scan at last follow-up. Nonage adjusted CCI (CCI), ACCI, and mFI - 5 scores were calculated. Univariate and multivariable logistic regression analyzed the relationship between cSDH resolution and variables. A receiver operating characteristic (ROC) curve established the utility of ACCI and mFI - 5 in predicting hematoma resolution. RESULTS: The study included 85 MMAE procedures. In univariate analysis, patients without resolution were older, had higher CCI, higher ACCI, higher mFI - 5, and were more likely to have diabetes mellitus. In multivarible analysis, CCI (OR: 0.66, 95% CI: 0.48, 0.91) was independently associated with resolution controlling for age and antithrombotic resumption. The area under the ROC (AUROC) curve was 0.75 (95% CI: 0.65-0.85) for ACCI and 0.64 (95% CI: 0.52-0.76) for mFI - 5. The optimal cutoffs for predicting resolution were ACCI ≥5 (sensitivity = 0.63, specificity = 0.77), and mFI - 5 > 0 (sensitivity = 0.84, specificity = 0.43). CONCLUSIONS: ACCI and mFI - 5 moderately predict MMAE resolution and may aid in medical decision-making.

Second Data Release from the European Pulsar Timing Array: Challenging the Ultralight Dark Matter Paradigm.

Pulsar Timing Array experiments probe the presence of possible scalar or pseudoscalar ultralight dark matter particles through decade-long timing of an ensemble of galactic millisecond radio pulsars. With the second data release of the European Pulsar Timing Array, we focus on the most robust scenario, in which dark matter interacts only gravitationally with ordinary baryonic matter. Our results show that ultralight particles with masses 10^{-24.0} eV≲m≲10^{-23.3} eV cannot constitute 100% of the measured local dark matter density, but can have at most local density ρ≲0.3 GeV/cm^{3}.

The Rates of Postmastectomy Immediate Breast Reconstruction during the Initial Months of the COVID-19 Pandemic.

Background: Coronavirus disease 2019 (COVID-19) pandemic-related changes may have led to changes in immediate breast reconstruction (IBR) rates. We aimed to evaluate these changes before, during, and after the initial wave of COVID-19. Methods: We retrospectively reviewed women who underwent mastectomy with or without IBR from January 1 to September 30, 2019 and from January 1 to September 30, 2020, and compared demographic, clinical, and surgical variables between defined time periods. Results: A total of 202 mastectomies were included. Fewer patients underwent IBR during the initial surge of COVID-19 (surge period) compared with the months before (presurge period; 38.46% versus 70.97%, P = 0.0433). When comparing the postsurge period with a year before (postsurge control), fewer patients underwent reconstruction even after the initial surge had passed (53.13% versus 81.25%, P = 0.0007). Those who underwent IBR were older than the year before (59.34 versus 53.06, P = 0.0181). The median number of postoperative visits in the postsurge period was 8.50 (interquartile range: 6-12) compared with 14 (interquartile range: 8-20.50) in the year before (P = 0.0017). The overall incidences of complications and unanticipated resource utilization were also significantly lower in the postsurge period compared with the year before [5.88% versus 30.77% (P = 0.0055), and 14.71% versus 28.85% (P = 0.0103), respectively]. Conclusions: IBR rates were lower even after the initial surge than at the year before. Furthermore, during the pandemic, IBR patients were older, had fewer follow-up visits, and fewer reported complications.

Frequency-Dependent Squeezed Vacuum Source for the Advanced Virgo Gravitational-Wave Detector.

In this Letter, we present the design and performance of the frequency-dependent squeezed vacuum source that will be used for the broadband quantum noise reduction of the Advanced Virgo Plus gravitational-wave detector in the upcoming observation run. The frequency-dependent squeezed field is generated by a phase rotation of a frequency-independent squeezed state through a 285 m long, high-finesse, near-detuned optical resonator. With about 8.5 dB of generated squeezing, up to 5.6 dB of quantum noise suppression has been measured at high frequency while close to the filter cavity resonance frequency, the intracavity losses limit this value to about 2 dB. Frequency-dependent squeezing is produced with a rotation frequency stability of about 6 Hz rms, which is maintained over the long term. The achieved results fulfill the frequency dependent squeezed vacuum source requirements for Advanced Virgo Plus. With the current squeezing source, considering also the estimated squeezing degradation induced by the interferometer, we expect a reduction of the quantum shot noise and radiation pressure noise of up to 4.5 dB and 2 dB, respectively.

Clot composition and recanalization outcomes in mechanical thrombectomy.

BACKGROUND: Mechanical thrombectomy (MT) has become standard for large vessel occlusions, but rates of complete recanalization are suboptimal. Previous reports correlated radiographic signs with clot composition and a better response to specific techniques. Therefore, understanding clot composition may allow improved outcomes. METHODS: Clinical, imaging, and clot data from patients enrolled in the STRIP Registry from September 2016 to September 2020 were analyzed. Samples were fixed in 10% phosphate-buffered formalin and stained with hematoxylin-eosin and Martius Scarlett Blue. Percent composition, richness, and gross appearance were evaluated. Outcome measures included the rate of first-pass effect (FPE, modified Thrombolysis in Cerebral Infarction 2c/3) and the number of passes. RESULTS: A total of 1430 patients of mean±SD age 68.4±13.5 years (median (IQR) baseline National Institutes of Health Stroke Scale score 17.2 (10.5-23), IV-tPA use 36%, stent-retrievers (SR) 27%, contact aspiration (CA) 27%, combined SR+CA 43%) were included. The median (IQR) number of passes was 1 (1-2). FPE was achieved in 39.3% of the cases. There was no association between percent histological composition or clot richness and FPE in the overall population. However, the combined technique resulted in lower FPE rates for red blood cell (RBC)-rich (P<0.0001), platelet-rich (P=0.003), and mixed (P<0.0001) clots. Fibrin-rich and platelet-rich clots required a higher number of passes than RBC-rich and mixed clots (median 2 and 1.5 vs 1, respectively; P=0.02). CA showed a trend towards a higher number of passes with fibrin-rich clots (2 vs 1; P=0.12). By gross appearance, mixed/heterogeneous clots had lower FPE rates than red and white clots. CONCLUSIONS: Despite the lack of correlation between clot histology and FPE, our study adds to the growing evidence supporting the notion that clot composition influences recanalization treatment strategy outcomes.

Outpatient telemedicine in neurosurgery: 15,677 consecutive encounters in a comparative analysis of its effectiveness and impact on the surgical conversion rate.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has necessitated the use of telehealth visits (THVs). The effects on neurosurgical practice have not been well characterized, especially concerning new-patient THVs. Therefore, the authors of this study reviewed their institution's experience with outpatient clinic visits and THVs from before the COVID-19 pandemic to the present to focus on clinical metrics, rates of surgery, and the effects of implementing THVs in order to better understand their implications for clinical practice as more data emerge over time. METHODS: The authors reviewed 15,677 consecutive new outpatient in-person visits (IPVs), THVs, and neurosurgical procedures/cases proceeding from their institution between 2018 and 2022 for trends and associations related to THVs. RESULTS: Among spine patients, there was no difference in the proportion of encounters that led to surgery (surgical conversion rate) between THVs and IPVs (p = 0.49). Among cranial patients, THVs were negatively associated with conversion (OR 0.73, p = 0.03). On average, patients using THVs lived further from the hospital (p < 0.001); however, the patient catchment area appeared unchanged. The median distance to the hospital among THV patients was counterbalanced by a decreased distance for spine patients pursing IPVs (p < 0.001), with no significant change to case volume. There was no change in distance to the hospital among cranial patients. For both cranial and spine patients, surgical conversion was more likely among those who lived a great distance from the hospital if their initial encounter was an IPV (p = 0.007 and < 0.001, respectively). However, there was no relationship between distance from the hospital and surgical conversion among THV patients (p = 0.565). The availability of THVs did not significantly affect follow-up time (p = 0.837). For new patients at IPVs, there was no difference in time to the operating room between cranial and spine cases; for new patients at THVs, however, time to the operating room was significantly faster for cranial cases than for spine cases (p = 0.0018). CONCLUSIONS: Compared to IPVs, THVs lead to decreased surgical conversion for cranial patients but not spine patients. THVs do not appear to increase the catchment area. For patients who live far from the hospital, an IPV is associated with surgical conversion. Surgical conversion is faster following cranial THVs than after spine THVs. THVs did not increase the duration of follow-up.

Subclavian to carotid artery bypass for a case of ocular ischemic syndrome.

BACKGROUND: Ocular Ischemic Syndrome (OIS) is a rare, vision threatening condition associated with severe carotid artery disease. There are few cases of OIS reported in the literature. METHODS: We present the case of a 54-year-old male with history of multiple previous carotid interventions including a right carotid stent, who presented with right-sided OIS. RESULTS: CTA and angiogram showed a severe calcific plaque causing restenosis of the right carotid stent, with a patent right internal carotid artery (ICA) in the very distal neck. The right common carotid artery (CCA) was patent but diseased with ulcerated plaque extending proximally to below the level of the clavicle. The left CCA was chronically occluded from its origin all the way to the bifurcation. Given our patient's surgical history, the imperative to revascularize the ipsilateral carotid, and a diffusely diseased ipsilateral CCA, he was successfully treated with an ipsilateral subclavian to internal carotid bypass. CONCLUSION: There is paucity of data regarding the best approach for carotid revascularization in OIS. This case report discusses our unique perioperative decision making as well as relevant literature.

Unplanned readmission after carotid stenting versus endarterectomy: analysis of the United States Nationwide Readmissions Database.

BACKGROUND: Hospital readmissions are costly and reflect negatively on care delivered. OBJECTIVE: To have a better understanding of unplanned readmissions after carotid revascularization, which might help to prevent them. METHODS: The Nationwide Readmissions Database was used to determine rates and reasons for unplanned readmission following carotid endarterectomy (CEA) and carotid artery stenting (CAS). Trends were assessed by annual percent change, modified Poisson regression was used to estimate risk ratios (RR) for readmission, and propensity scores were used to match cohorts. RESULTS: Analysis yielded 522 040 asymptomatic and 55 485 symptomatic admissions for carotid revascularization between 2010 and 2015. Higher 30-day readmission rates were noted after CAS versus CEA in both symptomatic (9.1% vs 7.7%, p<0.001) and asymptomatic (6.8% vs 5.7%, p<0.001) patients. Readmission rates trended lower over time, significantly so for 90-day readmissions in symptomatic patients undergoing CEA. The most common cause for 30-day readmission was stroke in both symptomatic (5.5%) and asymptomatic (3.9%) patients. Factors associated with a higher risk of readmission included age over 80; male gender; Medicaid health insurance; and increases in severity of illness, mortality risk, and comorbidity indices. Analysis of matched cohorts showed that CAS had higher readmission than CEA (RR=1.14 (95% CI 1.06 to 1.22); p<0.001) only in asymptomatic patients. Adverse events during initial admission which predicted 30-day readmission included acute renal failure and acute respiratory failure in asymptomatic patients; hematoma and cardiac events were additional predictive adverse events in symptomatic patients. CONCLUSIONS: Readmission is not uncommon after carotid revascularization, occurs more often after CAS, and is predicted by baseline factors and by preventable adverse events at initial admission.

Correlation of von Willebrand factor and platelets with acute ischemic stroke etiology and revascularization outcome: an immunohistochemical study.

BACKGROUND: Platelets and von Willebrand factor (vWF) are key components of acute ischemic stroke (AIS) emboli. We aimed to investigate the CD42b (platelets)/vWF expression, its association with stroke etiology and the impact these components may have on the clinical/procedural parameters. METHODS: CD42b/vWF immunostaining was performed on 288 emboli collected as part of the multicenter STRIP Registry. CD42b/VWF expression and distribution were evaluated. Student's t-test and χ2 test were performed as appropriate. RESULTS: The mean CD42b and VWF content in clots was 44.3% and 21.9%, respectively. There was a positive correlation between platelets and vWF (r=0.64, p<0.001**). We found a significantly higher vWF level in the other determined etiology (p=0.016*) and cryptogenic (p=0.049*) groups compared with cardioembolic etiology. No significant difference in CD42b content was found across the etiology subtypes. CD42b/vWF patterns were significantly associated with stroke etiology (p=0.006*). The peripheral pattern was predominant in atherosclerotic clots (36.4%) while the clustering (patchy) pattern was significantly associated with cardioembolic and cryptogenic origin (66.7% and 49.8%, respectively). The clots corresponding to other determined etiology showed mainly a diffuse pattern (28.1%). Two types of platelets were distinguished within the CD42b-positive clusters in all emboli: vWF-positive platelets were observed at the center, surrounded by vWF-negative platelets. Thrombolysis correlated with a high platelet content (p=0.03*). vWF-poor and peripheral CD42b/vWF pattern correlated with first pass effect (p=0.03* and p=0.04*, respectively). CONCLUSIONS: The vWF level and CD42b/vWF distribution pattern in emboli were correlated with AIS etiology and revascularization outcome. Platelet content was associated with response to thrombolysis.

Low-molecular-weight Heparin (enoxaparin) versus unfractionated heparin for venous thromboembolism prophylaxis in patients undergoing craniotomy.

OBJECTIVE: To explore the difference in post-operative DVT, PE, and ICH complications following administration of prophylactic UFH or enoxaparin in patients undergoing craniotomy. METHODS: A retrospective chart review was conducted for 542 patients at our institution receiving either 5000units/0.5 mL UFH (BID or TID; 180 patients) or single daily 40 mg/0.4 mL enoxaparin (362 patients) following craniotomy. Multivariate linear regression models were developed comparing rates of postoperative DVT, PE, and reoperation for bleeding in patients given enoxaparin versus UFH prophylaxis while controlling for age at surgery, history of VTE, surgery duration, number of post-operative hospital days, reoperation, post-operative infections, and reason for surgery (tumor type, genetics, etc.). Mann Whitney U tests were subsequently performed comparing rates of postoperative DVT, PE, and ICH for each group. RESULTS: Patients receiving prophylactic enoxaparin, when compared to UFH, exhibited similar rates of postoperative DVT (22 % vs 20.6 %, p = 0.86), PE (9.7 % vs 8.9 %, p = 0.86), and reoperation for bleeding (0.4 % vs 0.2 %, p = 0.58), while controlling for the factors described above. CONCLUSION: In patients undergoing craniotomy, rates for DVT, PE, and ICH were similar between patients treated with either prophylactic enoxaparin or UFH. Further studies are needed to understand whether a certain subset of patients demonstrate improved benefit from either prophylactic anticoagulant.

Search for Subsolar-Mass Binaries in the First Half of Advanced LIGO's and Advanced Virgo's Third Observing Run.

We report on a search for compact binary coalescences where at least one binary component has a mass between 0.2 M_{⊙} and 1.0 M_{⊙} in Advanced LIGO and Advanced Virgo data collected between 1 April 2019 1500 UTC and 1 October 2019 1500 UTC. We extend our previous analyses in two main ways: we include data from the Virgo detector and we allow for more unequal mass systems, with mass ratio q≥0.1. We do not report any gravitational-wave candidates. The most significant trigger has a false alarm rate of 0.14 yr^{-1}. This implies an upper limit on the merger rate of subsolar binaries in the range [220-24200] Gpc^{-3} yr^{-1}, depending on the chirp mass of the binary. We use this upper limit to derive astrophysical constraints on two phenomenological models that could produce subsolar-mass compact objects. One is an isotropic distribution of equal-mass primordial black holes. Using this model, we find that the fraction of dark matter in primordial black holes in the mass range 0.2 M_{⊙}

Ethical Considerations in Surgical Decompression for Stroke.

Stroke is a major cause of morbidity and mortality. Neurosurgical decompression is often considered for the treatment of malignant infarcts and intraparenchymal hemorrhages, but this treatment can be frought with ethical dilemmas. In this article, the authors outline the primary principles of bioethics and their application to stroke care, provide an overview of key ethical issues and special situations in the neurosurgical management of stroke, and highlight methods to improve ethical decision-making for patients with stroke. Understanding these ethical principles is essential for stroke care teams to deliver appropriate, timely, and ethical care to patients with stroke.

Small Bowel Obstruction with a Transition Point in a Patient on Peritoneal Dialysis.

Small bowel obstruction (SBO) is a rare complication of peritoneal dialysis (PD) that is usually seen in patients with encapsulating peritoneal sclerosis. We present a case of SBO that was caused by mechanical obstruction from omental adhesions around the PD catheter. This is the case of 71-year-old female with end-stage renal disease who was recently started on PD and presented with recurrent syncopal episodes and altered mental status. During hospitalization, the patient began experiencing incomplete drainage of the PD solution. Abdominal computerized tomography revealed SBO with a transition point near the PD catheter. The patient then underwent laparoscopy, which revealed omental adhesions around the PD catheter near the obstruction area, but no adhesion of the intestine was observed. The adhesions were dissected by laparoscopy, and the PD catheter was removed. This case highlights the challenges of PD access.

Continued Dominance of Carotid Endarterectomy over Stenting in the United States: Volumes, Outcomes, and Complications from the National Inpatient Sample (1997-2015).

BACKGROUND: The introduction of carotid stenting (CAS) has led to numerous comparative trials with carotid endarterectomy (CEA). OBJECTIVE: The objective of the study was to review real-world volumes, outcomes, and complications following CEA versus CAS over an extended period to identify durable changes in practice. METHODS: Data were extracted from the National Inpatient Sample. Trends were assessed by annual percent change (APC), and adjusted risk ratios were calculated across the last 5 years of the study period. RESULTS: During 1997-2015, 199,330 symptomatic and 1,995,637 asymptomatic patients underwent carotid revascularization. In symptomatic patients, CEA declined (1997-2004; APC = -7.68%, P < 0.001) and CAS rose (1997-2008; APC = 15.48%, P < 0.001) during the first decade, subsequently becoming more muted. In asymptomatic patients, CEA decreased, whereas CAS initially increased (1997-2006; APC = 20.27%, P < 0.001) and then decreased (2007-2015; APC = -4.52%, P < 0.001). Routine discharge after symptomatic revascularization declined in CEA after 2003 and in CAS after 2006 (APC = -1.72% and -3.11%, respectively, P < 0.001 for both), corresponding to increasing patient comorbidity; similar trends were seen in asymptomatic patients. Death decreased after CEA (symptomatic and asymptomatic; APC = -4.85% and -3.53%, respectively, P < 0.001 for both) and CAS (asymptomatic only, APC = -2.53%, P = 0.04). CAS remained associated with a higher adjusted risk ratio for death, venous thromboembolism, and seizures in all patients and stroke and nonroutine discharge in symptomatic patients, during the last 5 years of the study period. CONCLUSIONS: Mortality has improved, but routine discharge has decreased following both CEA and CAS, congruent with increasing patient comorbidity. Trends in volumes, outcomes, and complication rates continue to favor CEA in real-world practice.

Holohemispheric Prostate Carcinoma Dural Metastasis Mimicking Subdural Hematoma: Case Report and Review of the Literature.

Prostate carcinomas are the most common malignancy to metastasize to the dura. These metastases can commonly mimic subdural hematomas and may similarly present with brain compression. The optimal management and outcomes after surgical management are not well characterized. We present a case of prostate carcinoma metastatic to the dura that was initially thought to be a large isodense subdural hematoma and was treated with surgical decompression. We also review the literature regarding prostate dural metastases mimicking subdural hematomas and discuss the relevant imaging findings, treatments, and outcomes. Dural metastasis should be considered when a patient with known metastatic prostate cancer presents with imaging evidence of a subdural mass.