Verification of a simplified aneurysm dimensionless flow parameter to predict intracranial aneurysm rupture status.

OBJECTIVES: Aneurysm number (An) is a novel prediction tool utilizing parameters of pulsatility index (PI) and aneurysm geometry. An has been shown to have the potential to differentiate intracranial aneurysm (IA) rupture status. The objective of this study is to investigate the feasibility and accuracy of An for IA rupture status prediction using Australian based clinical data. METHODS: A retrospective study was conducted across three tertiary referral hospitals between November 2017 and November 2020 and all saccular IAs with known rupture status were included. Two sets of An values were calculated based on two sets of PI values previously reported in the literature. RESULTS: Five hundred and four IA cases were included in this study. The results demonstrated no significant difference between ruptured and unruptured status when using An ≥1 as the discriminator. Further analysis showed no strong correlation between An and IA subtypes. The area under the curve (AUC) indicated poor performance in predicting rupture status (AUC1 = 0.55 and AUC2 = 0.56). CONCLUSIONS: This study does not support An ≥1 as a reliable parameter to predict the rupture status of IAs based on a retrospective cohort. Although the concept of An is supported by hemodynamic aneurysm theory, further research is needed before it can be applied in the clinical setting. ADVANCES IN KNOWLEDGE: This study demonstrates that the novel prediction tool, An, proposed in 2020 is not reliable and that further research of this hemodynamic model is needed before it can be incorporated into the prediction of IA rupture status.

A Qualitative Systematic Review of Endovascular Management of Renal Artery Aneurysms.

PURPOSE: To perform a qualitative systematic review of endovascular management of renal artery aneurysms (RAAs). MATERIALS AND METHODS: A comprehensive electronic search of PubMed, MEDLINE, Embase, Google Scholar, and Cochrane databases from 2000 to 2022 was performed using the search terms "renal artery," "aneurysm," and "endovascular." Means of outcome measures were calculated with a primary end point focused on RAA-related mortality and rupture. Secondary end points included reintervention rate and renal infarction. RESULTS: Twenty-six, single-center, retrospective, observational studies were included. There were 454 RAAs treated in 427 patients using endovascular techniques. Mean age was 53.8 years, with a female predominance (62%). A variety of endovascular treatments of RAA were used with excellent technical success (96%), renal parenchymal preservation, and a low rate of moderate/severe adverse events (AEs). Primary coil embolization was the most commonly used technique (44.7%). There was an overall AE rate of 22.9%, of which 6.7% were moderate/severe and there was 0% periprocedural mortality. The most common AE was renal infarction (49 patients, 11.5%); however, renal function was preserved in 84% of patients. Nephrectomy rate was 0.4%. Computed tomography (CT) angiography was the most common imaging follow-up modality used in 72% of studies. Only 9 studies (34%) reported anticoagulant use. Although the risk of delayed aneurysm reperfusion warrants clinical and imaging surveillance, relatively few patients (3%) required reintervention in this cohort. CONCLUSIONS: Endovascular management of RAA is a technically feasible treatment option with low rates of AEs and reintervention. The present study highlights the techniques available for interventional radiologists, a need for standardization of AE reporting, anticoagulation therapy, and follow-up imaging.

Endovascular repair of a giant common hepatic aneurysm.

Hepatic artery aneurysms are a rare phenomenon but their diagnosis and prompt treatment are imperative due to a high risk of mortality and complications. Appropriate management depends on patient characteristics, anatomical location of the aneurysm, operative risk and collateral arterial supply. Management options include surgical and endovascular approaches. The endovascular approach has gained popularity over recent years as it is an effective and less invasive alternative to surgical management. In this case report, we present a giant common hepatic artery aneurysm and its successful endovascular management. The patient had a complete resolution of symptoms after the procedure and remained well 8 months postprocedure.

Current challenges in the prevention and management of post-thrombotic syndrome-towards improved prevention.

Post-thrombotic syndrome (PTS) is a common and potentially debilitating complication of deep vein thrombosis (DVT), affecting up to 50% of DVT patients. The consequence of this chronic condition includes reduced quality of life, increased use of the healthcare system and decreased productivity. The societal impact of this condition is projected to increase, given our ageing population and increased burden of thrombotic diseases. Despite significant recent advances in our understanding of PTS, many unanswered questions remain. Currently, there are few effective and proven options for established PTS; hence, the emphasis should be on instituting effective prevention to reduce the progression to PTS. Effective anticoagulation lowers the risk of PTS, with direct oral anticoagulants appearing to outperform vitamin-K antagonists. However, the evidence for elastic compression stockings and endovascular thrombolysis or thrombectomy techniques remains unclear. Accurate identification of individuals at high risk of developing PTS may also improve the targeting of preventative interventions. This review will examine the current body of evidence regarding PTS, with a focus on preventative strategies as well as novel biomarkers.

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.

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.

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.

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.

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.

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.

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.

Intracranial atherosclerotic disease and acute ischaemic stroke: A review of diagnosis and management.

Intracranial atherosclerotic disease is highly prevalent and a common cause of ischaemic stroke globally. With the increasing use of endovascular treatment for acute stroke management, computed tomography and magnetic resonance imaging have become an essential part of patient selection. In this review, we present the typical imaging findings of intracranial atherosclerosis and an overview of management as relevant to diagnostic and interventional radiologists.