Citations

Abstract Background/Objective: Maintaining acid-base balance within the central nervous system (CNS) is essential for neuronal homeostasis. Disruptions in this balance can result in respiratory disturbances, elevated intracranial pressure, or coma. These disturbances can occur concurrently with stroke, or CNS infection. However, they are augmented by various neurosurgical procedures involving CSF manipulation, either through direct ventricular irrigation during endoscopic neurosurgical procedures or by CSF exchange technologies. The IRRAflow active cerebrospinal fluid (CSF) exchange system (IRRA flow ) manages acid-base balance changes in the ventricular system through continuous irrigation with fluids and medications and removal of endogenous CSF. We describe a novel clinical syndrome of iatrogenic metabolic acidosis and respiratory compensation in response to exogenous fluid introduction in the ventricular fluid system using IRRAflow. The syndrome was previously seen with endoscopic neurosurgical procedures that require irrigation with normal saline. We also recommend fluid alternatives for more effective use of the IRRAflow system or different endoscopic procedure and increased awareness of CSF derangements. Methods We describe 2 cases involving patients with subarachnoid hemorrhage who developed a syndromic response characterized by tachypnea, conjunctival hyperemia, encephalopathy, and fluctuating language deficits due to continuous 0.9% normal saline irrigation. Results Both patients exhibited reproducible symptoms that persisted despite stable neuroimaging until normal saline was replaced with lactated Ringer solution, after which clinical parameters normalized within 3 hours. We named this condition SALT-CRAMD syndrome (saline acidosis leading to tachypnea, central respiratory alkalosis, and metabolic derangements). Pathophysiologic analysis based on the literature suggests that normal saline induced central hyperchloremia and dilutional acidosis, leading to heightened chemoreceptor activation in the medulla oblongata, triggering excessive respiratory drive and compensatory hypocapnia. Conclusion Awareness of SALT-CRAMD syndrome is crucial for understanding the profound pathophysiologic concepts of CSF dynamics, whether induced during treatment with active CSF exchange, endoscopic neurosurgical procedures, stroke, or CNS infections.

Abstract Introduction Intracerebral hemorrhage (ICH) carries higher morbidity and mortality than ischemic stroke. Recent studies have demonstrated improved patient outcomes by applying ultra-early bundled interventions including blood pressure management, coagulopathy reversal, and osmotic therapy. Effective strategies to deliver these ultra-early treatment options are currently being explored. On December 19th, 2022, the Mayo Clinic Comprehensive Stroke Center (CSC) launched the “ICH Phases” communication system to accelerate ICH patient care. Objective To evaluate adherence to the AHA/ASA guidelines in acute ICH care following the implementation of our novel-tiered paging system. Methods We retrospectively reviewed patients admitted with spontaneous ICH during 2024 and 2025. We excluded traumatic cases. We extracted clinical data such as time to imaging, documentation of ICH score, blood pressure control, reversal of anticoagulation, venous thrombo-embolism (VTE) prophylaxis and discharge disposition. Results Among 67 patients, 68.7% underwent CT imaging within 25 minutes. We documented the ICH score within 6 hours in 82.9% of patients. Nearly 94.7% of patients with SBP>140 mm Hg received antihypertensive therapy, yet only 18% reached target BP within 60 minutes. We completed the reversal of anticoagulation within 120 minutes in 75% of patients. VTE prophylaxis was initiated within 24 hours in 91% of patients. Discussion Our novel system demonstrated adherence to the AHA/ASA guidelines, and time sensitive benchmarks in neuroimaging, reversal of anticoagulation, and VTE prophylaxis. Early BP control remains a challenge, that highlights the discrepancy between guidelines and real-ground implementation. Conclusion A novel tiered paging system is effective for enhancing early ICH care. Such a holistic system remains critical for sustained improvement in quality of care.

Abstract Background aneurysmal subarachnoid hemorrhage (aSAH) is neurological emergency associated with substantial mortality and disability. Current grading systems such as the modified Fisher Scale (mFS) and World Federation of Neurological Societies (WFNS) score, rely on semiquantitative and examination based assessments. Hence, they demonstrate limited predictive precision. The enhanced subarachnoid hemorrhage (eSAH) score is a simplified quantitative model integrating age, Glasgow Coma Scale (GCS), and cisternal subarachnoid hemorrhage volume (SAHV) to predict clinical outcomes after aSAH. Methods We performed a retrospective multicenter cohort study that included 1088 patients across three tertiary-care centers the United States. Predictive performance for unfavorable functional outcome, in-hospital mortality and delayed cerebral ischemia (DCI) was evaluated using receiver operating characteristic (ROC) analysis and area under the curve (AUC). Comparative analyses were performed and compared to the WFNS and mFS grading systems. Results the eSAH score demonstrated excellent discrimination for unfavorable functional outcome at discharge ( AUC 0.89 ) and in-hospital mortality (AUC 0.87). The DCI subscore demonstrated good discriminatory performance for predicting DCI (AUC 0.77). Compared with conventional grading systems, this was superior to both the WFNS (AUC 0.75) and the mFS ( AUC 0.70). increasing eSAH scores were additionally associated with progressively higher rates of mortality and unfavorable functional outcomes. Conclusion the eSAH score demonstrates strong external validity, reproducibility and superior predictive performance compared with conventional grading systems in a large multicenter cohort. These findings support the clinical utility of quantitative hemorrhage burden integration for early risk stratification in patients with aSAH.

Abstract Objective Shunt-dependent hydrocephalus is a common and costly complication of aneurysmal subarachnoid hemorrhage (aSAH), affecting up to 28% of survivors. Existing prediction tools, including the Chronic Hydrocephalus Ensuing from SAH Score (CHESS), have limited discriminative accuracy. We developed the CHECKMATE score, a clinically practical tool to improve prediction of ventriculoperitoneal shunt dependency after aSAH. Methods In this multicenter retrospective cohort of 486 patients with aSAH from Mayo Clinic (January 1, 2006-December 31, 2021), we used multivariable logistic regression and machine learning to identify independent predictors of ventriculoperitoneal shunt placement. The CHECKMATE score was derived from 5 weighted variables: symptomatic hydrocephalus (10 points), intraventricular hemorrhage (5 points), SAH volume greater than 10 mL (3 points), neutrophil-to-lymphocyte ratio greater than 12 (2 points), and 10-year incremental age thresholds starting at older than 60 years (1 point each). Results Of 486 patients (mean age, 56.3 years; 64.6% female), 137 (28.2%) required ventriculoperitoneal shunt placement. The CHECKMATE score achieved an area under the curve of 0.808 (compared to 0.737 for CHESS), with a sensitivity of 0.85, specificity of 0.67, and negative predictive value of 0.92 at the optimal cutoff of 14 points. Conclusions The CHECKMATE score outperforms CHESS for predicting ventriculoperitoneal shunt dependency after aSAH and is easily used at the bedside. Its high negative predictive value helps identify low-risk patients who may benefit from earlier external ventricular drain weaning and shorter hospital stays.

Abstract Background and Objectives: Neurosurgery is a distinctive realm with a tight and strict margin of error. IRRAflow (IRRA flow ) is a US Food and Drug Administration–approved active cerebrospinal fluid exchange system that can irrigate up to 180 mL/h. The system is tightly secured, safe, and continuously monitors intracranial pressure, using a 9F dual-lumen catheter. Inserting an IRRAflow catheter is more complex than standard external ventricular drains, with a higher risk of cerebrospinal fluid leak or catheter displacement. Particularly, the extracranial component of the IRRAflow catheter insertion is prone to errors and necessitates dedicated training. We aimed to design an affordable, reusable, and easy-to-use 3-dimensional printed model that simulates the extracranial component of the IRRAflow catheter insertion. Methods: The IRRAsert simulator was designed according to recent publications. The skull was printed with polylactic acid, and the Kocher point was drilled. A mold was cast to make the scalp, and Dragon Skin FX-Pro Part A and Part B (Smooth-On, Inc) was used to create a skin flap to cover the drilled Kocher point. Results: The IRRAsert simulator replicated the external parts of the skull starting from the bone outward. It allowed measurements for designating the Kocher point, incising the skin to reveal the drilled Kocher point, tunneling under the scalp, and creating a 5-cm posterior exit incision. The endogenous property of the mixed 1:1 ratio between parts A and B allowed adhesion with the underlying skull due to the attraction between polylactic acid and silicone in a stick-and-peel fashion. This adhesion allowed for dissection of skin from the bone during tunneling for the catheter under the scalp, as well as lifting and rotating the scalp for the next user. The final cost of our simulator was $20 to print the skull permanently, with another $5 to produce the skin that can be rotated 3 times for 3 different users. Conclusion: IRRAsert is the result of multidisciplinary efforts to produce an affordable simulator for the extracranial component of IRRAflow catheter insertion.

BACKGROUND: Intraventricular hemorrhage and subarachnoid hemorrhage are associated with neuroinflammation and increased morbidity and mortality. Rapid clearance of blood from the cerebrospinal fluid space may mitigate neuroinflammatory cascades and improve clinical outcomes. This systematic review and meta-analysis aimed to compare the clinical effectiveness of active cerebrospinal fluid exchange, including neuroendoscopic lavage and IRRAflow systems, versus external ventricular drainage in patients with intraventricular hemorrhage or subarachnoid hemorrhage. METHODS: The study followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and thoroughly assessed databases, including PubMed, Embase, Scopus, Cochrane, and Web of Science, up to September 18, 2025. Statistical analysis, both fixed-effect and random-effect model analyses, was performed by the Comprehensive Meta-Analysis software. In addition, the Cochran Q test was conducted to determine the statistical heterogeneity. In terms of low heterogeneity, the fixed-effect model is reported. RESULTS: This review included 7 studies with a total sample size of 834. Our analysis showed that active cerebrospinal fluid exchange was associated with significantly higher hematoma clearance (odds ratio, 2.72 [95% CI, 1.22–6.08]; P =0.015), better functional outcomes (odds ratio, 1.66 [95% CI, 1.12–2.48]; P =0.012), lower shunt dependency (odds ratio, 0.22 [95% CI, 0.10–0.50]; P <0.001), and reduced infection rates (odds ratio, 0.22 [95% CI, 0.12–0.42]; P <0.001). Subgroup analysis showed that neuroendoscopic lavage was most effective for hematoma clearance, while IRRAflow reduced infection rates. Also, younger patients had better neurological recovery. CONCLUSIONS: Active cerebrospinal fluid exchange techniques demonstrated superior outcomes over external ventricular drainage in managing intraventricular hemorrhage and subarachnoid hemorrhage, particularly in clot resolution and neurological recovery. Large-scale trials are warranted.

ABSTARCT BACKGROUND: IRRAflow is a novel active cerebrospinal fluid (CSF) exchange system for the treatment of hemorrhagic strokes and intracranial infections. It is a closed system that irrigates various medications dissolved in irrigation solutions at a speed of up to 180 mL/h, expediting resolution. Disrupting this closed system to withdraw CSF samples or infuse medications is necessary in certain circumstances. We report our novel approach for maintaining the sterility of the closed IRRAflow system using a needleless extension and assess the compatibility and safety of this technology throughout treatment. METHODS: We used a needleless extension to withdraw CSF samples and deliver medications to 5 patients treated with the IRRAflow system. We used 1 stopcock with a 3-way valve, 2 neutral needleless connectors, and 2 antiseptic caps. The stopcock was connected between the irrigation and drainage ports of the catheter. The needleless connectors were mounted at the 12 o’clock position of the attached stopcock and the irrigation port with antiseptic caps covering the distal ends. To initiate fluid exchange, the 2 needleless connectors were separated. The extra stopcock valve was connected between the drainage arm, the cassette, and the irrigation arm. The needleless connectors remained mounted at the 12 o’clock position of the stopcock and irrigation port throughout treatment. RESULTS: The needleless connectors mounted on the 12 o’clock position of the stopcock and irrigation port on the drainage and irrigation arms, respectively, provided efficient management of fluid exchange, CSF fluid sampling, and medication delivery. Our needleless extension was compatible with the IRRAflow device and prevented secondary infections despite repeated CSF sampling and medication delivery. CONCLUSION: The needleless extension facilitated a simple and safe interaction with the closed IRRAflow system without compromising the sterile environment during CSF sampling and medication delivery.

Background We automated subarachnoid hemorrhage volume (SAHV) calculation with artificial intelligence (SAHVAI) and created 3‐dimensional volumetric images (SAHVAI‐3D) using noncontrast head computed tomography data for patients with aneurysmal SAH. We also defined 4‐dimensional SAHVAI (SAHVAI‐4D), representing SAHV over time. We aimed to compare automated SAHVAI values and computational times to manual SAHV measurement methods, explore the potential of imaging biomarkers to identify at‐risk brain regions for delayed cerebral ischemia and explore potential insights in future neurotherapeutic interventions for patient recovery after SAH. Methods A training set of 10 consecutive patients with aneurysmal SAH was used to manually compute SAHV, SAHVAI‐3D, and SAHVAI‐4D, including 92 noncontrast computed tomography scans (182 slices each). The SAHVAI deep learning algorithm generated automated SAHV values in cubic centimeters. A 3‐dimensional SAH brain map was created for each patient for the SAHVAI and manual evaluations. Blood volumetric outputs were analyzed and compared to neurologic outcomes at discharge, including delayed cerebral ischemia events, symptomatic vasospasm, and areas with the thickest SAH blood concentration. Results SAHVAI quantified SAHV in a mean of 6.7 seconds per scan, significantly faster than the manual method, which took >60 minutes per scan (Fisher exact test, P <0.001). SAHVAI demonstrated an accuracy of 99.8%, Dice score of 0.701, false‐positive rate of 0.0005, and negative predictive value of 0.999. The mean absolute error between SAHVAI and manual methods was 5.67 mL. SAHVAI‐3D brain map and total SAHV at admission were inversely associated with Glasgow Coma Scale (R 2 = 0.23, P = 0.017) and directly associated with length of hospital stay (R 2 = 0.175, P = 0.004), especially in regions with dense blood concentration. Conclusion SAHVAI‐3D and SAHVAI‐4D brain mapping techniques represent innovative imaging biomarkers for SAH. These advancements enable rapid evaluation and targeted interventions, potentially improving patient care in SAH management.

Background We developed a simplified ABC/2‐derived method to estimate total subarachnoid hemorrhage volume (SAHV) on noncontrast computed tomography in patients with aneurysmal SAH and compared the clinical and radiographic outcomes. Methods and Results In this retrospective observational cohort study, we analyzed 277 patients with SAH admitted to our Comprehensive Stroke Center between 2012 and 2022. We derived a mathematical model (model 1) by measuring SAH basal cisternal blood volume using an ABC/2‐derived ellipsoid formula (A=width/thickness, B=length, C=vertical extension) on head noncontrast computed tomography in 5 major SAH cisternal compartments. We compared model 1 against a manual segmentation method (model 2) on noncontrast computed tomography. Data were analyzed using logistic regression analysis, t test, receiver operator characteristic curves, and area under the curve analysis. There was no significant difference in cisternal SAHV analysis between the 2 models ( P =0.14). Mean SAHV by the simplified method was 7.0 mL (95% CI, 5.89–8.09) for good outcome and 16.6 mL (95% CI, 13.49–19.77) for poor outcome. Patients with delayed cerebral ischemia had higher SAHV, with a cutoff value of 10 mL. Conclusions Our simplified ABC/2‐derived method to estimate SAHV is comparable to manual segmentation and can be performed in low‐resource settings. Higher total SAHV was associated with worse outcomes and higher risk of delayed cerebral ischemia. A potential dose–response relationship was observed, with SAHV >10 mL predicting worse outcomes and higher risk of DCI.