The Great Contrast Shortage of 2022-Lessons learnt in Australia.

INTRODUCTION: Computed tomography (CT) imaging is one of the most commonly used diagnostic tools. Iodine-based contrast media (IBCM) are frequently administered intravenously to improve soft tissue contrast in a wide range of CT scans. Supply chain disruptions triggered by the SARS-CoV-19 pandemic led to a global shortage of IBCM in mid-2022. The purpose of this study was to explore the impact of this shortage on the delivery of healthcare in Western Australia. METHODS: We performed a single-centre retrospective analysis of the provision of CT studies, comparing historical patterns to the shortage period. We focussed our attention on the total number of CT scans (noncontrast CT [NCCT] and contrast-enhanced CT [CECT]) and also specifically CT pulmonary angiogram (CTPA) and CT neck angiogram with or without inclusion of circle of Willis (CTNA) examinations. We also examined whether a decrease was compensated by increasing frequency of alternate examinations such as ventilation/perfusion (V/Q) scans, carotid Doppler ultrasound studies and Magnetic Resonance Angiograms (MRAs). RESULTS: Since 2012, there has been an approximate linear increase in the frequency of CT examinations. During the period of contrast shortage, there was an abrupt drop-off by approximately 50% in the CECT, CTPA and CTNA groups compared with the preceding 6 weeks (49%, 55% and 44%, respectively, with P < 0.001 in all cases). During the contrast shortage, the frequency of V/Q scans increased fivefold (from 13 to 65; P < 0.001). However, the provision of carotid Doppler ultrasound studies and MRAs remained approximately stable in frequency across recent time intervals. CONCLUSION: Our findings demonstrate that the IBCM shortage crisis had a very significant impact on the delivery of healthcare. While V/Q scans could (partially) substitute for CTPA studies in suspected pulmonary emboli, there appeared to be no valid alternative for CTNA studies in stroke calls. The unexpected and critical shortage of IBCM forced healthcare professionals to conserve resources, prioritise indications, triage patients based on risk, explore alternate imaging strategies and prepare for similar events recurring in the future.

Embolization for the treatment of intractable epistaxis: 12 month outcomes in a two centre case series.

OBJECTIVE: Embolization is a treatment option for intractable epistaxis; however, concerns regarding tissue necrosis, stroke and blindness persist in the literature. METHODS: A retrospective review of patients from September 2010 to January 2016 treated with embolization for epistaxis was performed. No patient was excluded. Follow-up was 12 months and no patient was lost. RESULTS: 62 embolizations on 59 patients occurred. 21 cases were taking anticoagulants, P2Y12 inhibiting agents or had a systemic coagulopathy. Embolized territories typically involved bilateral distal internal maxillary arteries with unilateral or bilateral facial arteries with polyvinyl alcohol particles. 60 cases had procedural general anaesthesia. There were no major complications. Six died of unrelated causes. Of the surviving 53 patients, excluding the 3 patients with hereditary haemorrhagic telangiectasia, 5 had recurrent epistaxis post-embolization. Four were taking P2Y12 inhibiting and/or anticoagulants, none of which required surgery, prolonged packing or repeat embolization. This group had a propensity to recur compared with cases taking aspirin only or no antiplatelet/anticoagulant (77.8 vs 97.1%, p = 0.04). The fifth underwent repeat embolization after previously only having ipsilateral distal internal maxillary and facial arteries treated. CONCLUSION: Embolization for epistaxis is safe and effective. Of those who had recurrent epistaxis post embolization, most were taking P2Y12 inhibition and/or anticoagulation. We prefer bilateral distal internal maxillary artery and unilateral facial artery embolization under general anaesthesia for optimal safety and efficacy. Advances in knowledge: Embolization with this technique seems to facilitate superior outcomes without complications despite the large proportion of patients taking anticoagulating or P2Y12 inhibiting agents.

Outcomes of Endovascular Thrombectomy with and without Thrombolysis for Acute Large Artery Ischaemic Stroke at a Tertiary Stroke Centre.

BACKGROUND AND PURPOSE: Endovascular thrombectomy (EVT) improves the functional outcome when added to best medical therapy, including alteplase, in patients with acute ischaemic stroke secondary to large vessel occlusion (LVO) in the anterior circulation. However, the evidence for EVT in alteplase-ineligible patients is less compelling. It is also uncertain whether alteplase is necessary in patients with successful recanalization by EVT, as the treatment effect of EVT may be so powerful that bridging alteplase may not add to efficacy and may compromise safety by increasing bleeding risks. We aimed to survey the proportion of patients suitable for EVT who are alteplase-ineligible and to compare the safety and effectiveness of standard care of acute large artery ischaemic stroke by EVT plus thrombolysis with that of EVT alone in a tertiary hospital clinical stroke service. METHODS: We performed a retrospective analysis of acute ischaemic stroke patients treated with EVT at our centre between October 2013 and April 2016, based on a registry with prospective and consecutive patient collection. Individual patient records were retrieved for review. Significant early neurological improvement was defined as a NIHSS score of 0-1, or a decrease from baseline of ≤8, at 24 h after stroke onset. RESULTS: Fifty patients with acute ischaemic stroke secondary to LVO in the anterior circulation received EVT in this period, of whom 21 (42%) received concurrent alteplase and 29 (58%) EVT alone. The 2 groups had similar baseline characteristics and similar outcomes. Significant neurological improvement at 24 h occurred in 47.6% of the patients with EVT and bridging alteplase and in 51.7% of the patients with EVT alone (p = 0.774). Mortality during acute hospitalization was 20% for the bridging alteplase group versus 7.1% for EVT alone (p = 0.184). Intracranial haemorrhage rates were 14.3% for bridging alteplase versus 20.7% for EVT alone (p = 0.716). Local complications, groin haematoma (23.8 vs. 10.3%) and groin pseudoaneurysms (4.8 vs. 0%) (p = 0.170), were not significantly different. CONCLUSION: Our study highlights the relatively large proportion of patients suitable for EVT who have a contraindication to alteplase and raises the hypothesis that adding alteplase to successful EVT may not be necessary to optimize functional outcome. The results are consistent with observational data from other endovascular centres and support a randomised controlled trial of EVT versus EVT with bridging alteplase.

Mechanical thrombectomy for anterior circulation stroke: 5-year experience in a statewide service with differences in pretreatment time metrics across two hospitals sites.

OBJECTIVE: To audit our institutional mechanical thrombectomy (MT) outcomes for acute anterior circulation stroke and examine the influence of workflow time metrics on patient outcomes. METHODS: A database of 100 MT cases was maintained throughout May 2010-February 2015 as part of a statewide service provided across two tertiary hospitals (H1 and H2). Patient demographics, stroke and procedural details, blinded angiographic outcomes, and 90-day modified Rankin Scale (mRS) scores were recorded. The following time points in stroke treatment were recorded: stroke onset, hospital presentation, CT imaging, arteriotomy, and recanalization. Statistical analysis of outcomes, predictors of outcome, and differences between the hospitals was carried out. RESULTS: Thrombolysis in Cerebral Infarction (TICI) 2b/3 reperfusion was 79%. Forty-nine per cent of patients had good clinical outcomes (mRS 0-2). In a subgroup analysis of 76 patients with premorbid mRS 0-1 and first CT performed ≤4.5 h after stroke onset, 60% had good clinical outcomes. Patient and disease characteristics were matched between the two hospitals. H1 had shorter times between hospital presentation and CT (32 vs 55 min, p=0.01), CT and arteriotomy (33 vs 69 min, p=0.00), and stroke onset and recanalization (198 vs 260 min, p=0.00). These time metrics independently predicted good clinical outcome. Median days spent at home in the first 90 days was greater at H1 (61 vs 8, p=0.04) than at H2. A greater proportion of patients treated at H1 were independent (mRS 0-2) at 90 days (54% vs 42%); however, this was not statistically significant (p=0.22). CONCLUSIONS: Outcomes similar to randomized controlled trials are attainable in 'real-world' settings. Workflow time metrics were independent predictors of clinical outcome, and differed between the two hospitals owing to site-specific organizational differences.

CT perfusion in acute stroke calls: A pictorial review and differential diagnoses.

CT perfusion is increasingly utilised in hyperacute stroke to facilitate diagnosis and patient selection for reperfusion therapies. This review article demonstrates eight examples of how CT perfusion can be used to diagnose stroke mimics and small volume infarcts, which can be easily missed on non-contrast CT, and to suggest the presence of an ischaemic penumbra. Radiologists involved in stroke management must understand the importance of rapid imaging acquisition and be confident in the prospective interpretation of this powerful diagnostic tool as we move into a new era of hyperacute stroke care.

Vertebrobasilar insufficiency.

Vertebrobasilar insufficiency presents with characteristic symptoms and signs due to impaired perfusion of the cerebellum, the brain stem, and the occipital cortex. This may be due to reduced perfusion usually due to atherosclerosis or thromboembolism. Choice of treatment depends on understanding the different underlying pathophysiologic mechanisms. Antiplatelet therapy; reduction of risk factors such as diabetes, hypertension, hypercholesterolemia, and cigarette smoking; and a healthy lifestyle form the first line of management. Systemic anticoagulation in the short term also has a key role in selected cases. In patients with refractory symptoms on maximal medical therapy and underlying focal stenotic lesions, endovascular revascularization using stents and balloon angioplasty may be indicated. Bypass surgery is another option if there are factors that render endovascular therapy unsuitable.

Incidental discovery of a dural arteriovenous fistula in a patient with activated protein C resistance.

A dural arteriovenous fistula was discovered incidentally in a 58-year-old man with activated protein C resistance who underwent routine outpatient cerebral angiography for workup of multiple intracranial aneurysms.

Basilar trunk occlusion during endovascular treatment of giant and fusiform aneurysms of the basilar artery.

Giant and fusiform aneurysms of the basilar artery (BA) are difficult to manage surgically, and they still present a challenge for the neurosurgeon despite progress in posterior fossa surgery. Guglielmi detachable coils have provided an alternative approach to treatment, but they have their own difficulties. We present a series of three patients with BA aneurysms treated with endovascular occlusion of the aneurysm and basilar trunk. Our experience suggests that, in select cases, BA occlusion may be not only safe but also necessary for the effective treatment of these aneurysms.

Dural carotid cavernous fistula: definitive endovascular management and long-term follow-up.

PURPOSE: To describe the endovascular treatment and clinical outcome in patients with indirect carotid cavernous fistulas (CCFs) over a 15-year period. To our knowledge, this is the largest series in the medical literature. DESIGN: Interventional case series. METHODS: A retrospective evaluation of 135 consecutive patients who underwent examination and treatment for indirect CCF was performed. Patients received independent evaluations by ophthalmologists, neurologists, or neuro-ophthalmologists before, during, and after endovascular treatment. Patients initially received noninvasive imaging followed by cerebral arteriography for definitive diagnosis and stratification by angiographic risk factors. Endovascular treatment was performed in 133 (98%) patients and clinical follow-up was achieved in 135 (100%) patients on an average of 56 +/- 4.3 months (range: 2 months-14 years). Angiographic follow-up was performed in 72 (54%) patients with ongoing symptoms or a history of fistula with high-risk angiographic features. Arteriographic cure with long-term clinical outcome is summarized by modified Rankin scale (mRS) and Barthel index (BI). RESULTS: At a mean follow-up of 56 months, 121 (90%) patients were clinically cured. At latest clinical follow-up, 131 (97%) patients showed good recovery (mRS, 1-2; BI 90-100), one (1%) had moderate disability (mRS, 3; BI, 50-60), and three (2%) (mRS, 4; BI, 40-50) were severely disabled. Procedure-related permanent morbidity was 2.3%. There was no operative mortality. CONCLUSIONS: With the observed favorable outcomes and low rate of procedural morbidity in this patient population with long-term angiographic and clinical follow-up, endovascular therapy should be the primary treatment for patients with indirect (dural) fistulas of the cavernous sinus.