The where, who and how of adrenal vein sampling in Australia and New Zealand.

INTRODUCTION: Primary aldosteronism (PA) causes 10-15% of cases of hypertension, and it is increasingly recognised as being under-diagnosed. An interventional radiology procedure, adrenal vein sampling (AVS), is a necessary and important diagnostic procedure for complete workup of PA. There is an anticipated increase in demand for AVS as detection of PA improves. This study aims to describe the current landscape of AVS in Australia and New Zealand (NZ). METHODS: Two surveys exploring AVS methodology and performance were conducted of (i) Endocrinology Unit Heads and (ii) interventional radiologists who perform AVS, at public hospitals with Endocrinology Units across Australia and NZ. RESULTS: Responses were received from 48/53 Endocrinology Unit Heads (91%) and 35 radiologists from 26 sites (87% of AVS sites). AVS was provided at 28/48 Endocrinology sites (58%) across Australia and NZ. In Australia, sites were concentrated in Victoria, New South Wales and Queensland with none in the Northern Territory; in NZ, sites were more evenly distributed across the North and South Islands. AVS was performed by 1-2 dedicated radiologists at 24 sites, 2-3 radiologists at two sites and a rotating roster of radiologists at two sites. Responses to both surveys revealed significant variation in AVS methodology and interpretation of AVS results. CONCLUSION: There is significant heterogeneity in the availability of AVS, the procedural details and the interpretation of results across Australia and NZ, which potentially impacts the quality of patient care and ability to scale up AVS capacity to meet increasing demand.

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.

Saline suppression to distinguish the primary aldosteronism subtype: a diagnostic study.

OBJECTIVES: The saline suppression test (SST) serves to confirm the diagnosis of primary aldosteronism (PA), while adrenal vein sampling (AVS) is used to subtype PA as unilateral or bilateral. Criteria that can accurately identify those with bilateral PA based on SST results could reduce the need for AVS. We previously demonstrated that a combination of plasma aldosterone concentration (PAC) < 300 pmol L-1 and a reduction in aldosterone-to-renin ratio (ARR) following recumbent SST had high specificity for predicting bilateral PA in an Australian cohort of 92 patients with PA who have undergone AVS. We sought to validate our predictive criteria in larger, independent cohorts of patients with PA. DESIGN: An international, multi-centre cohort study. METHODS: Data from 55 patients at Monash Health, Victoria, Australia, 106 patients from the First Affiliated Hospital of Chongqing Medical University, China, and 105 patients from Nihon University Itabashi Hospital, Japan were analysed. RESULTS: A combination of PAC <300 pmol L-1 and a reduction in ARR following recumbent SST predicted bilateral PA with specificities of 88.2%, 97.0%, and 100.0% in Australian, Chinese, and Japanese cohorts, respectively. This criterion could allow 22%-38% of patients with PA to bypass AVS and proceed directly to medical treatment. CONCLUSION: In patients undergoing the recumbent SST, a post-saline PAC <300 pmol L-1 together with a reduction in ARR can predict bilateral PA with high specificity and may allow targeted treatment to be commenced without AVS in up to a third of patients.

Evaluation of aneurysm rupture risk based upon flowrate-independent hemodynamic parameters: a multi-center pilot study.

BACKGROUND: Specifying generic flow boundary conditions in aneurysm hemodynamic simulations yields a great degree of uncertainty for the evaluation of aneurysm rupture risk. Herein, we proposed the use of flowrate-independent parameters in discriminating unstable aneurysms and compared their prognostic performance against that of conventional absolute parameters. METHODS: This retrospective study included 186 aneurysms collected from three international centers, with the stable aneurysms having a minimum follow-up period of 24 months. The flowrate-independent aneurysmal wall shear stress (WSS) and energy loss (EL) were defined as the coefficients of the second-order polynomials characterizing the relationships between the respective parameters and the parent-artery flows. Performance of the flowrate-independent parameters in discriminating unstable aneurysms with the logistic regression, Adaboost, and support-vector machine (SVM) methods was quantified and compared against that of the conventional parameters, in terms of sensitivity, specificity, and area under the curve (AUC). RESULTS: In discriminating unstable aneurysms, the proposed flowrate-independent EL achieved the highest sensitivity (0.833, 95% CI 0.586 to 0.964) and specificity (0.833, 95% CI 0.672 to 0.936) on the SVM, with the AUC outperforming the conventional EL by 0.133 (95% CI 0.039 to 0.226, p=0.006). Likewise, the flowrate-independent WSS outperformed the conventional WSS in terms of the AUC (difference: 0.137, 95% CI 0.033 to 0.241, p=0.010). CONCLUSION: The flowrate-independent hemodynamic parameters surpassed their conventional counterparts in predicting the stability of aneurysms, which may serve as a promising set of hemodynamic metrics to be used for the prediction of aneurysm rupture risk when physiologically real vascular boundary conditions are unavailable.

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 deep learning-based automatic system for intracranial aneurysms diagnosis on three-dimensional digital subtraction angiographic images.

BACKGROUND: Intracranial aneurysms (IAs) are a life-threatening disease. Their rupture can lead to hemorrhagic stroke. Most studies applying deep learning for the detection of aneurysms are based on angiographic images. However, critical diagnostic information such as morphology and aneurysm location are not captured by deep learning algorithms and still require manual assessments. PURPOSE: Digital subtraction angiography (DSA) is the gold standard for aneurysm diagnosis. To facilitate the fully automatic diagnosis of aneurysms, we proposed a comprehensive system for the detection, morphology measurement, and location classification of aneurysms on three-dimensional DSA images, allowing automatic diagnosis without further human input. METHODS: The system comprised three neural networks: a network for aneurysm detection, a network for morphology measurement, and a network for aneurysm location identification. A cross-scale dual-path transformer module was proposed to effectively fuse local and global information to capture aneurysms of varying sizes. A multitask learning approach was also proposed to allow an accurate localization of aneurysm neck for morphology measurement. RESULTS: The cross-scale dual-path transformer module was shown to outperform other state-of-the-art network architectures, improving segmentation, and classification accuracy. The detection network in our system achieved an F2 score of 0.946 (recall 93%, precision 100%), better than the winning team in the Cerebral Aneurysm Detection and Analysis challenge. The measurement network achieved a relative error of less than 10% for morphology measurement, at the same level as human operators. Perfect accuracy (100%) was achieved on aneurysm location classification. CONCLUSIONS: We have demonstrated that a comprehensive system can automatically detect, measure morphology and report the aneurysm location of aneurysms without human intervention. This can be a potential tool for the diagnosis of IAs, improving radiologists' performance and reducing their workload.

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.

Impact of Intraprocedural Sedation on Adrenal Vein Sampling without Corticotropin Stimulation.

See also the editorial by Georgiades in this issue.

Retrieval of Displaced Woven EndoBridge Intrasaccular Flow Disruptor Using Solitaire Platinum Revascularization Device.

The Woven EndoBridge (WEB; MicroVention, Aliso Viejo, CA, USA) intrasaccular flow disruptor is a therapeutic option for wide neck bifurcation intracranial aneurysms that does not require the use of adjunctive techniques such as stents or balloon remodeling. As with other endovascular devices, displacement of the WEB is a recognized complication. Few reports have been published regarding the management of this type of complication. We describe a case of retrieval of a displaced WEB using a Solitaire Platinum revascularization device (Medtronic, Minneapolis, MN, USA). Interventionists should be aware of this option in the management of such a complication.

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.

Automated Machine Learning Model Development for Intracranial Aneurysm Treatment Outcome Prediction: A Feasibility Study.

Background: The prediction of aneurysm treatment outcomes can help to optimize the treatment strategies. Machine learning (ML) has shown positive results in many clinical areas. However, the development of such models requires expertise in ML, which is not an easy task for surgeons. Objectives: The recently emerged automated machine learning (AutoML) has shown promise in making ML more accessible to non-computer experts. We aimed to evaluate the feasibility of applying AutoML to develop the ML models for treatment outcome prediction. Methods: The patients with aneurysms treated by endovascular treatment were prospectively recruited from 2016 to 2020. Treatment was considered successful if angiographic complete occlusion was achieved at follow-up. A statistical prediction model was developed using multivariate logistic regression. In addition, two ML models were developed. One was developed manually and the other was developed by AutoML. Three models were compared based on their area under the precision-recall curve (AUPRC) and area under the receiver operating characteristic curve (AUROC). Results: The aneurysm size, stent-assisted coiling (SAC), and posterior circulation were the three significant and independent variables associated with treatment outcome. The statistical model showed an AUPRC of 0.432 and AUROC of 0.745. The conventional manually trained ML model showed an improved AUPRC of 0.545 and AUROC of 0.781. The AutoML derived ML model showed the best performance with AUPRC of 0.632 and AUROC of 0.832, significantly better than the other two models. Conclusions: This study demonstrated the feasibility of using AutoML to develop a high-quality ML model, which may outperform the statistical model and manually derived ML models. AutoML could be a useful tool that makes ML more accessible to the clinical researchers.

Contemporary Treatment of Intracranial Blood Blister Aneurysms - A Systematic Review.

INTRODUCTION: Blood blister aneurysms (BBAs) are rare aneurysms affecting non-branched points of intracerebral arteries. Due to their small size and fragility, BBAs are prone to rupture, and can be challenging to diagnose and treat. Several treatment options have been suggested yet there is no consensus regarding the best modality to reduce morbidity and mortality. MATERIALS AND METHODS: A systematic review of the literature was conducted searching for articles discussing the treatment of BBAs. Inclusion criteria included: articles published between January 2010 and August 2020, English language, with each paper including at least 15 patients. Studies included required detailed reporting of patient demographics, treatment, and patient outcomes (including complications, recurrence, neurologic functional status, and mortality). RESULTS AND DISCUSSION: A total of 25 studies with 883 patients were included. Most were female (n = 594, 67.3%) and aneurysms were overwhelmingly located in the supraclinoid internal carotid artery (99%). Aneurysms were variable in size and mostly presented with subarachnoid haemorrhage. Endovascular treatment (n = 518, 58.7%) was more common than microsurgery (n = 365, 41.1%) while only 2 patients were managed conservatively. Complications were more common in patients treated microsurgically. Microsurgical procedures had an unfavorable outcome (mRS 4-6, GOS 1-3) rate of 27.8% (n = 100/360) while that of endovascular procedures was 14.7% (n = 70/477). Endovascular procedures had a lower mortality rate than microsurgical interventions (8.4% vs 11%). CONCLUSION: This review demonstrates that endovascular treatment of blood blister aneurysm has reduced morbidity and mortality when compared with microsurgical treatment. Small sample sizes and substantial study heterogeneity makes strong conclusions difficult.

Endovascular Treatment of Intracranial Aneurysms Using the Novel Low Profile Visualized Intraluminal Support EVO Stent: Multicenter Early Feasibility Experience.

PURPOSE: Low-profile, self-expandable stents have broadened therapeutic options available for definitive treatment of intracranial aneurysms. The novel Low-Profile Visualized Intraluminal Support (LVIS) EVO stent extends upon the success of its predecessor, the LVIS Jr stent, aiming to enable higher visibility and greater opening ability within a self-expandable and fully retrievable microstent system. In this study, we aim to report the early safety and feasibility experience with the LVIS EVO stent. MATERIALS AND METHODS: A multicenter, retrospective, observational study was conducted on patients who had intracranial aneurysms treated with the LVIS EVO stent across 3 Australian neurovascular centers between February 2020 and September 2020. Short-term technical and clinical outcomes were evaluated. RESULTS: A total of 22 LVIS EVO stents were successfully implanted to treat 15 aneurysms (3 ruptured, 12 unruptured) in 15 patients. Aneurysms ranged from 2 mm to 35 mm in dome height. The LVIS EVO stent was used for stent-assisted coiling in 11 patients and flow diversion in 4 patients. There were no device-related procedural complications. There were 2 cases of peri-procedural symptomatic thromboembolic complications and no procedure-related mortality. At early radiological follow up, 10 patients had complete occlusion, 4 patients had small neck remnants, and 1 patient who was managed with flow diversion had a residual aneurysm. CONCLUSION: Early experience with the LVIS EVO stent demonstrated safety and feasibility for stent-assisted coiling as well as flow diversion for intracranial aneurysms. In this heterogeneous cohort, including ruptured, complex, and large aneurysms, all cases were technically successful.

Flow diverter modeled as heterogeneous and anisotropic porous medium: Simulation, experimental validation and case analysis.

Simulation of flow diverter (FD) treated aneurysm can evaluate treatment efficacy and aid treatment planning. However, explicit modeling of thin wires of FD impose extremely high demand of computational resources and time, which limit its use in time-sensitive presurgical planning. One alternative approach is to model FD as homogenous porous medium, which saves time but with compromise in accuracy. We proposed a new method to model FD as heterogeneous and anisotropic porous medium whose properties were determined from local porosity. The new method was validated by comparing with PIV measurement from an in-vitro phantom. Simulation result was in good agreement with experimental measurement. Four patient cases were further analyzed to compare the new method with the homogenous porous media method. Results showed that in patient cases with curved artery, new method was preferred over the homogenous method, as the assumption of homogenous porosity led to overpredicted flow reduction effect by as much as 87.9%, which may lead to overoptimistic decision making and poor prognosis. Our new method can provide timely and accurate simulation to aid in the treatment planning of aneurysms.

Imaging triage of acute stroke patients for endovascular clot retrieval: Effect of increased therapeutic window on the utilization of CT perfusion.

INTRODUCTION: Recent randomized trials showing improved outcomes for later-presenting acute ischaemic stroke (AIS) patients with large vessel occlusion (LVO) treated with endovascular clot retrieval (ECR) may result in substantial increases in CTP utilization. This 3-hospital, single-institution cohort study aimed to compare 2017 and 2018 patient cohorts for the following: CTP use in AIS. Prevalence of LVO in all patients having CTP. Number and clinical characteristics of patients triaged to ECR. Number of patients receiving CTP relative to similar-acuity total ED presentations. METHODS: Inclusion criteria: Consecutive adult emergency (ED) patients receiving CTP for suspected AIS. Study period 1:1 January-30 June 2017; Period 2:1 January-30 June 2018. DATA COLLECTION: age, gender, triage category, NIHSS (National Institute of Health Stroke Score), symptoms/signs, time elapsed since last seen well (TESLSW) to triage, disposition (home/other). RESULTS: A 38.7 % increase in CTP (512 in 2017, 710 in 2018) occurred with 39/512 (7.6%) and 72/710 (10.1%) having intended ECR. CTPs per intended ECR declined from 13.1 to 9.9. 36/512 (7.0%) and 58/710 (8.2%) patients had ECR (61.1% increase) and 22/36 (61.1%) and 25/58 (43.1%) of these were discharged home in 2017 and 2018, respectively, an increase of 3/22(14%). CONCLUSION: Despite a 38.7% increase in CTP utilization, we experienced a reduction in the number of CTPs performed/patient triaged to ECR. This did not reflect higher LVO prevalence among later presenters but may reflect changed selection criteria for CTP and/or decision making about suitability for ECR.

A preliminary investigation of radiomics differences between ruptured and unruptured intracranial aneurysms.

OBJECTIVES: Prediction of intracranial aneurysm rupture is important in the management of unruptured aneurysms. The application of radiomics in predicting aneurysm rupture remained largely unexplored. This study aims to evaluate the radiomics differences between ruptured and unruptured aneurysms and explore its potential use in predicting aneurysm rupture. METHODS: One hundred twenty-two aneurysms were included in the study (93 unruptured). Morphological and radiomics features were extracted for each case. Statistical analysis was performed to identify significant features which were incorporated into prediction models constructed with a machine learning algorithm. To investigate the usefulness of radiomics features, three models were constructed and compared. The baseline model A was constructed with morphological features, while model B was constructed with addition of radiomics shape features and model C with more radiomics features. Multivariate analysis was performed for the ten most important variables in model C to identify independent risk factors. A simplified model based on independent risk factors was constructed for clinical use. RESULTS: Five morphological features and 89 radiomics features were significantly associated with rupture. Model A, model B, and model C achieved the area under the receiver operating characteristic curve of 0.767, 0.807, and 0.879, respectively. Model C was significantly better than model A and model B (p < 0.001). Multivariate analysis identified two radiomics features which were used to construct the simplified model showing an AUROC of 0.876. CONCLUSIONS: Radiomics signatures were different between ruptured and unruptured aneurysms. The use of radiomics features, especially texture features, may significantly improve rupture prediction performance. KEY POINTS: • Significant radiomics differences exist between ruptured and unruptured intracranial aneurysms. • Radiomics shape features can significantly improve rupture prediction performance over conventional morphology-based prediction model. The inclusion of histogram and texture radiomics features can further improve the performance. • A simplified model with two variables achieved a similar level of performance as the more complex ones. Our prediction model can serve as a promising tool for the risk management of intracranial aneurysms.

COILUMICA: coil embolization of a coronary artery to pulmonary artery fistula via novel dual lumen micro catheter technique.

BACKGROUND: Management of coronary artery fistula (CAF) is based on obliterating the fistula communication between the cardiac arteries and other thoracic vessels. CASE PRESENTATION: We describe the presentation of an 85-year-old female with progressive exertional dyspnea on a background of a long standing left anterior descending diagonal to pulmonary artery fistula. We utilized neuro-interventional techniques to perform coil embolization via use of a Scepter XC dual lumen micro catheter. CONCLUSIONS: Dual lumen balloon catheters allow for super-selective artery interrogation, stability of balloon positioning, with less trauma to vessel architecture and accurate embolization. There were no complications and the patient reported improvement of symptoms on review.

Environmental sustainability in neurointerventional procedures: a waste audit.

BACKGROUND: Operating rooms contribute between 20% to 70% of hospital waste. This study aimed to evaluate the waste burden of neurointerventional procedures performed in a radiology department, identify areas for waste reduction, and motivate new greening initiatives. METHODS: We performed a waste audit of 17 neurointerventional procedures at a tertiary-referral center over a 3-month period. Waste was categorized into five streams: general waste, clinical waste, recyclable plastic, recyclable paper, and sharps. Our radiology department started recycling soft plastics from 13 December 2019. Hence, an additional recyclable soft plastic waste stream was added from this time point. The weight of each waste stream was measured using a digital weighing scale. RESULTS: We measured the waste from seven cerebral digital subtraction angiograms (DSA), six mechanical thrombectomies (MT), two aneurysm-coiling procedures, one coiling with tumour embolization, and one dural arteriovenous fistula embolization procedure. In total, the 17 procedures generated 135.3 kg of waste: 85.5 kg (63.2%) clinical waste, 28.0 kg (20.7%) general waste, 14.7 kg (10.9%) recyclable paper, 3.5 kg (2.6%) recyclable plastic, 2.2 kg (1.6%) recyclable soft plastic, and 1.4 kg (1.0%) of sharps. An average of 8 kg of waste was generated per case. Coiling cases produced the greatest waste burden (13.1 kg), followed by embolization (10.3 kg), MT (8.8 kg), and DSA procedures (5.1 kg). CONCLUSION: Neurointerventional procedures generate a substantial amount of waste, an average of 8 kg per case. Targeted initiatives such as engaging with suppliers to revise procedure packs and reduce packaging, digitizing paper instructions, opening devices only when necessary, implementing additional recycling programs, and appropriate waste segregation have the potential to reduce the environmental impact of our specialty.

Utility of adrenocorticotropic hormone in adrenal vein sampling despite the occurrence of discordant lateralization.

BACKGROUND: Adrenal vein sampling (AVS) is crucial for accurate lateralization of aldosterone excess but it is technically challenging due to the difficulty of adrenal vein cannulation. The use of adrenocorticotropic hormone (ACTH) to improve cannulation success is controversial and can lead to discordant lateralization outcomes. OBJECTIVE: To evaluate the utility of ACTH in two centres with different levels of AVS expertise and formulate a strategy for interpreting discordant results. DESIGN: A retrospective cross-sectional analysis of AVS results and postoperative patient outcomes. SETTING: Two large tertiary hospitals with harmonized AVS protocols where adrenal venous samples are collected both before and after ACTH stimulation. MEASUREMENTS: Cannulation success (measured by selectivity index, SI), lateralization (measured by lateralization index, LI) and postoperative biochemical cure. RESULTS: Number of AVS procedures judged to have successful bilateral adrenal vein cannulation increased from 53% pre- to 73% post-ACTH. The increase in cannulation success was significantly higher in centre where AVS was performed by multiple radiologists with a lower basal success rate. In both centres, the proportion of cases deemed to display lateralization significantly decreased with the use of ACTH (70% pre- to 52% post-ACTH). Based on postoperative outcomes of patients with discordant results who underwent unilateral adrenalectomy, the combination of LI >3 pre-ACTH and LI >2 post-ACTH was predictive of a biochemical cure. CONCLUSION: Adrenocorticotropic hormone can increase the rate of cannulation success during AVS at the expense of reduced lateralization. The criteria for lateralization should be carefully determined based on local data when ACTH is used.

Correction to: Venous pathologies in paediatric neuroradiology: from foetal to adolescent life.

The original version of this article unfortunately contained a referencing omission. Figure 11 is reused from the original publication of Figure 10 of Gunny and Lin [1].