High-frequency optical coherence tomography for endovascular management of cerebral aneurysms.

Endovascular management of intracranial aneurysms has become the mainstay of treatment in recent years; however, retreatment rates remain as high as 1 in 5. High-frequency optical coherence tomography (HF-OCT) is an emerging imaging modality for the assessment, treatment and follow-up of cerebral aneurysms. EMBASE and SCOPUS databases were searched for studies relating to the management of intracranial aneurysm with OCT. A combination of keywords were used including 'cerebral aneurysm', 'intracranial aneurysm', 'high-frequency optical coherence tomography', 'optical coherence tomography', and 'optical frequency domain imaging'. There were 23 papers included in this review. For the assessment of intracranial aneurysm, OCT was able to accurately assess aneurysm morphology as well as detailed analysis of arterial wall layers. During IA treatment, OCT was used to assess and troubleshoot stent placement to optimise successful isolation from the circulation. In the follow-up period, endothelial growth patterns were visualised by OCT imaging. OCT shows promise for the treatment of IAs at all stages of management. Due to the novel development of HF-OCT, there is limited longitudinal data in human studies. Further research in this area is required with a focus specifically on long-term treatment outcomes in humans.

Preoperative coil localization for spinal surgery is accurate, safe and effective: a single-centre initial experience.

OBJECTIVE AND STUDY DESIGN: This is a retrospective, descriptive study of consecutive patients undergoing novel preoperative pushable coil localization for spinal surgery, in order to evaluate its feasibility, safety and accuracy. METHODS: Consecutive patients who underwent pre-operative coil marking for spinal surgery at our institution from May 2018 to July 2021 were included. Data were collected for coil placement, accuracy, complications and fluoroscopy usage. Patient demographic and relevant perioperative and procedural data were also collected. RESULTS: A total of 34 patients were identified of which 32 (94%) had complete data and imaging at last clinical follow up, with a mean duration of 13.9 months. There were no incorrect level surgeries performed. There were no coil-related complications found in our cohort. CONCLUSIONS: Preoperative coil placement is an accurate, safe and well-tolerated method for level localization in spinal surgeries.

Occult contrast retention post-thrombectomy on 24-h follow-up dual-energy CT: Associations and impact on imaging analysis.

BACKGROUND: Following reperfusion treatment in ischemic stroke, computed tomography (CT) imaging at 24 h is widely used to assess radiological outcomes. Even without visible hyperattenuation, occult angiographic contrast may persist in the brain and confound Hounsfield unit-based imaging metrics, such as net water uptake (NWU). AIMS: We aimed to assess the presence and factors associated with retained contrast post-thrombectomy on 24-h imaging using dual-energy CT (DECT), and its impact on the accuracy of NWU as a measure of cerebral edema. METHODS: Consecutive patients with anterior circulation large vessel occlusion who had post-thrombectomy DECT performed 24-h post-treatment from two thrombectomy stroke centers were retrospectively studied. NWU was calculated by interside comparison of HUs of the infarct lesion and its mirror homolog. Retained contrast was quantified by the difference in NWU values with and without adjustment for iodine. Patients with visible hyperdensities from hemorrhagic transformation or visible contrast retention and bilateral infarcts were excluded. Cerebral edema was measured by relative hemispheric volume (rHV) and midline shift (MLS). RESULTS: Of 125 patients analyzed (median age 71 (IQR = 61-80), baseline National Institutes of Health Stroke Scale (NIHSS) 16 (IQR = 9.75-21)), reperfusion (defined as extended-Thrombolysis-In-Cerebral-Infarction 2b-3) was achieved in 113 patients (90.4%). Iodine-subtracted NWU was significantly higher than unadjusted NWU (17.1% vs 10.8%, p < 0.001). In multivariable median regression analysis, increased age (p = 0.024), number of passes (p = 0.006), final infarct volume (p = 0.023), and study site (p = 0.021) were independently associated with amount of retained contrast. Iodine-subtracted NWU correlated with rHV (rho = 0.154, p = 0.043) and MLS (rho = 0.165, p = 0.033) but unadjusted NWU did not (rHV rho = -0.035, p = 0.35; MLS rho = 0.035, p = 0.347). CONCLUSIONS: Angiographic iodine contrast is retained in brain parenchyma 24-h post-thrombectomy, even without visually obvious hyperdensities on CT, and significantly affects NWU measurements. Adjustment for retained iodine using DECT is required for accurate NWU measurements post-thrombectomy. Future quantitative studies analyzing CT after thrombectomy should consider occult contrast retention.

Evaluation of techniques to improve a deep learning algorithm for the automatic detection of intracranial haemorrhage on CT head imaging.

BACKGROUND: Deep learning (DL) algorithms are playing an increasing role in automatic medical image analysis. PURPOSE: To evaluate the performance of a DL model for the automatic detection of intracranial haemorrhage and its subtypes on non-contrast CT (NCCT) head studies and to compare the effects of various preprocessing and model design implementations. METHODS: The DL algorithm was trained and externally validated on open-source, multi-centre retrospective data containing radiologist-annotated NCCT head studies. The training dataset was sourced from four research institutions across Canada, the USA and Brazil. The test dataset was sourced from a research centre in India. A convolutional neural network (CNN) was used, with its performance compared against similar models with additional implementations: (1) a recurrent neural network (RNN) attached to the CNN, (2) preprocessed CT image-windowed inputs and (3) preprocessed CT image-concatenated inputs. The area under the receiver operating characteristic curve (AUC-ROC) and microaveraged precision (mAP) score were used to evaluate and compare model performances. RESULTS: The training and test datasets contained 21,744 and 491 NCCT head studies, respectively, with 8,882 (40.8%) and 205 (41.8%) positive for intracranial haemorrhage. Implementation of preprocessing techniques and the CNN-RNN framework increased mAP from 0.77 to 0.93 and increased AUC-ROC [95% confidence intervals] from 0.854 [0.816-0.889] to 0.966 [0.951-0.980] (p-value = 3.91 × 10-12). CONCLUSIONS: The deep learning model accurately detected intracranial haemorrhage and improved in performance following specific implementation techniques, demonstrating clinical potential as a decision support tool and an automated system to improve radiologist workflow efficiency. KEY POINTS: • The deep learning model detected intracranial haemorrhages on computed tomography with high accuracy. • Image preprocessing, such as windowing, plays a large role in improving deep learning model performance. • Implementations which enable an analysis of interslice dependencies can improve deep learning model performance. • Visual saliency maps can facilitate explainable artificial intelligence systems. • Deep learning within a triage system may expedite earlier intracranial haemorrhage detection.

Tranexamic acid as a novel adjunct in the management of vessel perforation complicating Endovascular Clot Retrieval.

AIM: To assess the safety and utility of tranexamic acid (TXA) as an adjunct salvage therapy in iatrogenic vessel perforation complicating endovascular clot retrieval. Iatrogenic vessel perforation and extravasation are known and potentially fatal complications of endovascular clot retrieval (ECR). Various methods of establishing haemostasis post perforation have been reported. TXA is widely utilised intraoperatively to reduce bleeding in various surgical specialities. The use of TXA in endovascular procedures has not been previously described in the literature. METHODS: Retrospective case control study of all cases that underwent ECR. Cases where arterial rupture occurred were identified. Details of management and functional status at 3 months were recorded. Modified Rankin score (mRS) 0-2 was considered a good functional outcome. Comparison of proportions analysis was performed. RESULTS: Of 1378 cases of ECR, rupture complicated 36 (2.6%). TXA was administered in addition to standard care in 11 cases (31%). At 3 months, 4 of 11 cases (36%) where TXA was administered had a good functional outcome compared to 3 of 22 (12%) in the standard care group (P=0.09). Mortality at 3 months occurred in 4 of 11 cases (41.7%) where TXA was administered compared to 16 of 25 (64%) where it was not (P=0.13). CONCLUSION: Tranexamic acid administration in iatrogenic vessel rupture was associated with a lower mortality rate and a larger proportion of patients achieving a good functional outcome at 3 months. This effect trended towards but was not statistically significant. TXA administration was not associated with adverse effects.

Spontaneous Intracranial Hypotension and Spinal Epidural CSF Leaks: Diagnosis and Management.

Spontaneous intracranial hypotension from spinal cerebrospinal fluid leak is a condition that often presents as orthostatic headaches. Diagnosis and localisation of spinal CSF leaks remain difficult despite multiple imaging modalities that can be used to aid identification. These include traditional CT myelography and MRI as well as newer techniques such as dynamic and digital subtraction myelography. Leaks can be classified into types and optimal localisation and management techniques vary by type of leak. Localisation of a leak can aid in targeting treatment such as an epidural blood patch if conservative measures fail. Where unsuccessful, repeated blood patches and novel techniques can be used to improve patient symptoms. Much of this condition is not well understood and evidence is lacking, with many avenues for potential research.

Radioembolization for Treatment of Hepatocellular Carcinoma: Current Evidence and Patterns of Utilization.

Primary liver malignancy, of which hepatocellular carcinoma (HCC) is the most common type, is the second most common cause of death due to cancer worldwide. Given the historically poor prognosis of liver cancer, there has been major research on its treatment options, with significant advancements over the last decade. Transarterial radioembolization (TARE) is a locoregional treatment option for HCC that involves transarterial delivery of the ß-emitter yttrium-90 via resin or glass microspheres to arterialized tumor vasculature, delivering a tumoricidal dose to the tumor. The recent 2022 update of the Barcelona Clinic Liver Cancer (BCLC) treatment algorithm features a more prominent role for locoregional treatment, including the incorporation of radioembolization for very-early-stage (BCLC-0) and early-stage (BCLC-A) diseases. This review provides a contemporary summary of the evolving role of TARE in treatment of HCC in light of recent and upcoming trials.

Sustainability in interventional radiology: are we doing enough to save the environment?

BACKGROUND: Healthcare waste contributes substantially to the world's carbon footprint. Our aims are to review the current knowledge of Interventional Radiology (IR) waste generation and ways of reducing waste in practice, to quantify the environmental and financial impact of waste generated and address green initiatives to improve IR waste management. METHODS: A systematic literature search was conducted in July 2022 using the Medline and Embase literature databases. The scope of the search included the field of IR as well as operating theatre literature, where relevant to IR practice. RESULTS: One-hundred articles were reviewed and 68 studies met the inclusion criteria. Greening initiatives include reducing, reusing and recycling waste, as well as strict waste segregation. Interventional radiologists can engage with suppliers to reformulate procedure packs to minimize unnecessary items and packaging. Opened but unused equipment can be prevented if there is better communication within the team and increased staff awareness of wasted equipment cost. Incentives to use soon-to-expire equipment can be offered. Power consumption can be reduced by powering down operating room lights and workstations when not in use, changing to Light Emitting Diode (LED) and motion sensor lightings. Surgical hand wash can be replaced with alcohol-based hand rubs to reduce water usage. Common barriers to improving waste management include the lack of leadership, misconceptions regarding infectious risk, lack of data, concerns about increased workload, negative staff attitudes and resistance to change. Education remains a top priority to engage all staff in sustainable healthcare practices. CONCLUSION: Interventional radiologists have a crucial role to play in improving healthcare sustainability. By implementing small, iterative changes to our practice, financial savings, greater efficiency and improved environmental sustainability can be achieved.

A Systematic Review of Neuropsychological Outcomes After Treatment of Intracranial Aneurysms.

BACKGROUND: Aneurysmal subarachnoid hemorrhage is a cause of profound morbidity and mortality. Its effects extend beyond functional neurological status to neurocognitive and psychological functioning. Endovascular treatment is becoming more prevalent after increasing evidence for its safety and efficacy; however, there is a relative paucity of evidence specific to neurocognitive status after treatment. OBJECTIVE: To assess and compare neuropsychological outcomes after the treatment of ruptured and unruptured intracranial aneurysms. METHODS: A systematic review of the literature was conducted searching for articles assessing the neuropsychological and cognitive outcomes after the treatment of ruptured and unruptured intracranial aneurysms. Inclusion criteria were English language, publication between January 2000 and October 2020, and discussion of neuropsychological outcomes in adequate detail. Outcomes were categorized into 8 domains: 5 Neurocognitive (Language, Executive Function, Complex Attention, Memory and Learning, and Perceptual motor function), Intelligence Quotient, Affect, and Quality of Life. RESULTS: Twenty-four articles were included comprising 2236 patients (924 surgical clipping, 1095 endovascular coiling, and 217 controls). These studies reported that most tests revealed no significant difference [n = 356/421 (84.56%)] between treatment modalities. More studies reported significantly superior test scores in the fields of language, executive function, and memory and learning after coiling [n = 53/421 tests (12.59%)] compared with clipping [n = 12/421 tests (2.85%)]. CONCLUSION: The current available data and published studies demonstrate a trend toward improved neurocognitive and psychological outcomes after endovascular treatment. Although these findings should be considered when deciding on the optimal treatment method for each patient, drawing definitive conclusions is difficult because of heterogeneity between patients and studies.

Clipping versus coiling: A critical re-examination of a decades old controversy.

BACKGROUND: Two major studies, The International Subarachnoid Aneurysm Trial and the Barrow Ruptured Aneurysm Trial, compare the long-term outcomes of clipping and coiling. Although these demonstrated coiling's initial benefits, rebleeding and retreatment rates as well as converging patient outcomes sparked controversy regarding its durability. This article will critically examine the available evidence for and against clipping and coiling of intracranial aneurysms. Critics of endovascular treatment state that the initial benefit seen with endovascular coiling decreases over the duration of follow-up and eventually functional outcomes of both treatment modalities are similar. Combined with the increased rate of retreatment and rebleeding, these trials reveal that coiling is not as durable and not as effective as a long-term treatment compared to clipping. Also, due to the cost of devices following endovascular treatment and prolonged hospitalization following clipping, the financial burden has been considered controversial. SUMMARY/KEY MESSAGES: Short-term outcomes reveal better morbidity and mortality outcomes following coiling. Despite the higher rates of retreatment and rebleeding with coiling, there was no significant change in functional outcomes following retreatment. Furthermore, examining more recent trials reveals a decreased rate of recurrence and rebleeding with improved technology and expertise. Functional outcomes deteriorate for both cohorts over time while recent results revealed improved long-term cognitive outcomes and levels of health-related quality of life after coiling in comparison to clipping. The expense of longer hospital stays following clipping must be balanced against the expense of endovascular devices in coiling.

Intracranial pure arterial malformations.

Pure arterial malformations (PAMs) are rare vascular lesions often detected incidentally on brain imaging. They are characterised by a mass of arterial loops containing arteries that are tortuous, overlapping and dilated without any associated arteriovenous shunting. The incidence of PAMs have been rising due to the increasing use of non-invasive angiographic imaging for the diagnosis of neurovascular disorders. This article will present the clinical course of two cases of PAM, both of which demonstrated a stable appearance on surveillance imaging despite the lack of surgical or endovascular intervention.

Clinical Outcomes Following Rectal Artery Embolisation for the Treatment of Internal Haemorrhoids: A Systematic Review and Meta-Analysis.

OBJECTIVES: Haemorrhoidal disease (HD) is a common anorectal disorder which can substantially impair quality of life. Rectal artery embolisation (RAE) is a recently described technique for the management of HD, however, its clinical efficacy and safety are unclear at present. The objective of this systematic review and meta-analysis is to evaluate the clinical outcomes following RAE. METHODS: The PubMed, MEDLINE and EMBASE databases were searched for studies specifying the management of haemorrhoids with RAE from January 2000 to October 2021. Primary outcomes were: French bleeding score (FBS), Visual analogue scale (VAS) for pain, general quality of life (QoL) score, and the Goligher prolapse score (GPS). Secondary outcomes were technical success, clinical success, postoperative complications, and technical outcomes. A random-effects meta-analysis was conducted. Study heterogeneity was evaluated, and sensitivity analysis was performed. RESULTS: Thirteen eligible studies were identified including 381 patients. Rectal artery embolisation was associated with improvements in the FBS (mean difference [MD] 2.66; 95% confidence interval [CI] 2.10-3.23), VAS (MD 1.92; 95% CI 1.58-2.27) and QoL (MD 1.41; 95% CI 1.20-3.80), although the grade of internal haemerrhoids increased with uncertain clinical significance (MD 0.30; 95% CI 0.23-0.36). Technical success was achieved in almost all procedures (99%; 95% CI 94-100%) however clinical efficacy was lower (82%; 95% CI 73-89%). Procedural duration and radiation exposure were heterogeneous. No major complications occurred. CONCLUSION: RAE demonstrates early clinical efficacy with low rates of peri-procedural complications or morbidity. RAE is a promising addition to the treatment options available for HD and warrants ongoing research.

Which test is the best? An updated literature review of imaging modalities for acute ankle diastasis injuries.

Ankle diastasis injuries, or ankle syndesmotic injuries, are common among athletes who usually experience a traumatic injury to the ankle. Long-term complications are avoidable when these injuries are diagnosed promptly and accurately treated. Whilst ankle arthroscopy remains the gold standard diagnostic modality for ankle diastasis injuries, imaging modalities are still widely utilised due to the treatment having greater accessibility, being less invasive and the most cost effective. There are various imaging modalities used to diagnose diastasis injuries, varying in levels of specificity and sensitivity. These observation methods include; X-ray, computed tomography (CT), magnetic resonance imaging (MRI) and ankle arthroscopy. This article uncovers common criteria and parameters to diagnose diastasis injuries through the implementation of different imaging modalities. The conclusions addressed within this article are deduced from a total of 338 articles being screened with only 43 articles being selected for the purposes of this examination. Across most articles, it was concluded that that plain X-ray should be used in the first instance due to its wide availability, quick processing time, and low cost. CT is the next recommended investigation due to its increased sensitivity and specificity, ability to show the positional relationship of the distal tibiofibular syndesmosis, and reliability in detecting minor diastasis injuries. MRI is recommended when ankle diastasis injuries are suspected, but not diagnosed on previous imaging modalities. It has the highest sensitivity and specificity compared to X-ray and CT.

A Systematic Review and Meta-analysis of Patient Survival and Disease Recurrence Following Percutaneous Ablation of Pulmonary Metastasis.

BACKGROUND: Pulmonary metastasectomy has been widely adopted in the treatment of metastatic disease. In recent years image guided ablation has seen increased use in the treatment of thoracic malignancies. The objective of this study was to evaluate oncological outcomes following percutaneous ablation (PA) of pulmonary metastasis. METHODS: A comprehensive search of the PubMed, MEDLINE and EMBASE databases from January 2000 to August 2021 was performed to identify studies evaluating patient survival following ablation of lung metastasis. Pooled outcomes have been presented with a random effects model to assess primary outcomes of overall survival, progression free survival and 1-year local control. Secondary outcomes included procedural mortality, major complications, and the incidence of pneumothorax. RESULTS: A total of 24 studies were identified. The pooled median overall survival was 5.13 [95% confidence interval (CI): 4.37-6.84] years, and the 1-, 3-, 5-year progression free survival rates were 53%, 26% and 20% respectively. The 1-year local control rate was 91% (95%CI: 86-95%). Periprocedural mortality was rare (0%; 95%CI: 0-1%), as were major complications excluding pneumothorax (1%; 95%CI: 1-2%). Pneumothorax developed in 44% of ablation sessions, although only half of these required chest tube placement. Most patients were able to be discharged day one post-procedurally. CONCLUSION: PA demonstrates high overall, progression free and local tumour survival in patients with lung metastasis. Complications and mortality are also rare. Consideration of its use should be made in a tumour board meeting in conjunction with surgical and radiotherapy perspectives for targeted local control of metastases.

The Woven EndoBridge Device for the Treatment of Intracranial Aneurysms: Initial Clinical Experience within an Australian Population.

PURPOSE: Advances in endovascular technology have expanded the treatment options for intracranial aneurysms. Intrasaccular flow diversion is a relatively new technique that aims to disrupt blood inflow at the neck of the aneurysm, hence promoting intrasaccular thrombosis. The Woven EndoBridge device (WEB; MicroVention, Aliso Viejo, CA, USA) is an US Food and Drug Administration approved intrasaccular flow diverter for wide-necked aneurysms. We report the early interim clinical and radiological outcomes of patients with both ruptured and unruptured intracranial aneurysms (IAs) treated using the WEB device in an Australian population. MATERIALS AND METHODS: A retrospective analysis was done of patients with ruptured or unruptured IAs who received treatment with WEB across 5 Australian neuroendovascular referral centers between May 2017 and November 2020. Angiographic occlusion was assessed with time-of-flight magnetic resonance angiography. Complications were recorded and clinical outcomes were assessed using the modified Rankin scale at follow-up. RESULTS: In total, 66 aneurysms were treated in 63 patients, with successful deployment of the WEB device in 98.5% (n=65). Eighteen (26.9%) ruptured aneurysms were included. Failure of deployment occurred in a single case. Adjunct coiling and/or stenting was performed in 20.9% (n=14) cases. Sixty-two patients with 65 aneurysms using a WEB device were followed up (mean=9.1 months), and 89.4% of these had complete aneurysm occlusion while 1.5% remained patent. Functional independence was achieved in 93.5% of cases. CONCLUSION: Early results following the use of WEB devices in Australia demonstrate safety and adequate aneurysm occlusion comparable to international literature.

STABILISE; treatment of aortic dissection, a single Centre experience.

PURPOSE: To outline the process of the STABILISE technique and its use; reporting patient outcomes and midterm follow up for complicated aortic dissection. MATERIALS AND METHODS: Single centre retrospective analysis from January 2011 to January 2021 using the STABILISE technique which utilises balloon assistance to facilitate intimal disruption and promote aortic relamination. RESULTS: Sixteen patients underwent endovascular aortic repair with the STABILISE technique for aortic dissection over the study period. Fourteen patients (14/16; 88%) had acute dissection. Two of 16 (12%) were chronic. The median age of the patient cohort was 61 years (range 32-80 years) and consisted of a male majority (n = 11; 69%). The median time from diagnosis to intervention was 5 days (1-115 days; IQR 1-17.3). More than half (56%) had surgical repair of a acute type A aortic dissection prior to radiological intervention. The procedure was technically successful with no procedural mortality. Two patients were lost to follow up and two died in the post-operative period. Twelve patients had ongoing follow up with an average number of 2.9 ± 1.6 scans performed. Follow up was available in thirteen patients (81%) with a median follow up period of 1097 days (IQR 707-1657). The rate of re-intervention (n = 2/16; 13%) requiring additional stenting was in line with published re-intervention data (15%). Follow up showed a reduction in false lumen size following treatment with total luminal dimensions remaining stable over the follow-up period. CONCLUSION: The STABILISE technique as a procedure for complicated aortic dissection, either acute or chronic, appears safe with stable mid-term aortic remodelling and patient outcomes. LEVEL OF EVIDENCE: Level 3, Retrospective cohort study.

Association of Onset-to-Treatment Time With Discharge Destination, Mortality, and Complications Among Patients With Aneurysmal Subarachnoid Hemorrhage.

Importance: Rapid access to specialized care is recommended to improve outcomes after aneurysmal subarachnoid hemorrhage (SAH), but understanding of the optimal onset-to-treatment time for aneurysmal SAH is limited. Objective: To assess the optimal onset-to-treatment time for aneurysmal SAH that maximized patient outcomes after surgery. Design, Setting, and Participants: This cohort study assessed 575 retrospectively identified cases of first-ever aneurysmal SAH occurring within the referral networks of 2 major tertiary Australian hospitals from January 1, 2010, to December 31, 2016. Individual factors, prehospital factors, and hospital factors were extracted from the digital medical records of eligible cases. Data analysis was performed from March 1, 2020, to August 31, 2021. Exposures: Main exposure was onset-to-treatment time (time between symptom onset and aneurysm surgical treatment in hours) derived from medical records. Main Outcomes and Measures: Clinical characteristics, complications, and discharge destination were extracted from medical records and 12-month survival obtained from data linkage. The associations of onset-to-treatment time (in hours) with (1) discharge destination of survivors (home vs rehabilitation), (2) 12-month survival, and (3) neurologic complications (rebleed, delayed cerebral ischemia, meningitis, seizure, hydrocephalus, and delayed cerebral injury) were investigated using natural cubic splines in multivariable Cox proportional hazards and logistic regression models. Results: Of the 575 patients with aneurysmal SAH, 482 patients (mean [SD] age, 55.0 [14.5] years; 337 [69.9%] female) who received endovascular coiling or neurosurgical clipping were studied. A nonlinear association of treatment delay was found with the odds of being discharged home vs rehabilitation (effective df = 3.83 in the generalized additive model, χ2 test P = .002 for the 4-df cubic spline), with a similar nonlinear association remaining significant after adjustment for sex, treatment modality, severity, Charlson Comorbidity Index, history of hypertension, and hospital transfer (likelihood ratio test: df = 3, deviance = 9.57, χ2 test P = .02). Both unadjusted and adjusted cox regression models showed a nonlinear association between time to treatment and 12-month mortality with the lowest hazard of death with receipt of treatment at 12.5 hours after symptom onset, although the nonlinear term became nonsignificant upon adjustment. The odds of being discharged home were higher with treatment before 20 hours after onset, with the probability of being discharged home compared with rehabilitation or other hospital increased by approximately 10% when treatment was received within the first 12.5 hours after symptom onset and increased by an additional 5% from 12.5 to 20 hours. Time to treatment was not associated with any complications. Conclusions and Relevance: This cohort study found evidence that more favorable outcomes (discharge home and survival at 12 months) were achieved when surgical treatment occurred at approximately 12.5 hours. These findings provide more clarity around optimal timelines of treatment with people with aneurysmal SAH; however, additional studies are needed to confirm the findings.

Development of a machine learning-based real-time location system to streamline acute endovascular intervention in acute stroke: a proof-of-concept study.

BACKGROUND: Delivery of acute stroke endovascular intervention can be challenging because it requires complex coordination of patient and staff across many different locations. In this proof-of-concept paper we (a) examine whether WiFi fingerprinting is a feasible machine learning (ML)-based real-time location system (RTLS) technology that can provide accurate real-time location information within a hospital setting, and (b) hypothesize its potential application in streamlining acute stroke endovascular intervention. METHODS: We conducted our study in a comprehensive stroke care unit in Melbourne, Australia that offers a 24-hour mechanical thrombectomy service. ML algorithms including K-nearest neighbors, decision tree, random forest, support vector machine and ensemble models were trained and tested on a public WiFi dataset and the study hospital WiFi dataset. The hospital dataset was collected using the WiFi explorer software (version 3.0.2) on a MacBook Pro (AirPort Extreme, Broadcom BCM43x×1.0). Data analysis was implemented in the Python programming environment using the scikit-learn package. The primary statistical measure for algorithm performance was the accuracy of location prediction. RESULTS: ML-based WiFi fingerprinting can accurately predict the different hospital zones relevant in the acute endovascular intervention workflow such as emergency department, CT room and angiography suite. The most accurate algorithms were random forest and support vector machine, both of which were 98% accurate. The algorithms remain robust when new data points, which were distinct from the training dataset, were tested. CONCLUSIONS: ML-based RTLS technology using WiFi fingerprinting has the potential to streamline delivery of acute stroke endovascular intervention by efficiently tracking patient and staff movement during stroke calls.