What is the Safe Observation Period for Image-Guided Percutaneous Liver Biopsies?

PURPOSE: Current observation period post-liver biopsy is typically 4 h. This study investigates the safety of reducing the observation period after percutaneous liver biopsy. METHODS: Patients who underwent percutaneous liver biopsy between 2017 and 2022 in the Radiology Department of a tertiary centre were included in this retrospective, institutional review board-approved study. Patient demographics, procedure details and complication data were collected from the electronic medical records. Complications were graded according to the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) classification. Conditional survival probabilities were calculated for the 4-h observation period. RESULTS: Among 1125 patients, 275 complications were seen; 255 grade 1, 15 grade 2 and five grade 3. Post-procedural pain represented 93% (256) of complications, whereas post-procedural haemorrhage occurred in 17 (6%) patients: 13 were of grade 2 severity requiring prolonged observation, and 4 were of grade 3 severity. Of these grade 3 complications, two required blood transfusion whereas two required embolization. A total of 215 (78%) complications occurred within 1 h, 244 (89%) within 2 h of observation. 16 (94%) of 17 post-procedural haemorrhages occurred within 2 h post-biopsy. If complication-free after 2 h, the probability of experiencing a complication within the next 2 h was 4%. CONCLUSION: The majority of complications were identified within 2 h of observation. Complications recognised after this period were largely pain-related, with only one grade 3 complication seen (post-procedural haemorrhage).Our findings suggest 2 h of post-procedural observation may be safe. LEVEL OF EVIDENCE: Level 2B, Retrospective Cohort Study.

Neuroradiological features of contrast-induced neurotoxicity: A systematic review and pooled analysis.

BACKGROUND: Contrast-induced neurotoxicity (CIN), is an increasingly recognised complication of endovascular procedures, presenting as a spectrum of neurological symptoms that mimic ischaemic stroke. The diagnosis of CIN remains a clinical challenge, and stereotypical imaging findings are not established. This study was conducted to characterise the neuroimaging findings in patients with CIN, to raise diagnostic awareness and improve decision making. METHODS: We performed a systematic review of PubMed and Embase databases from inception (1946/1947) to June 2023 for reports of CIN following administration of iodinated contrast media. Studies with a final diagnosis of CIN, which provided details of neuroimaging were included. All included cases were pooled and descriptive analysis was conducted. RESULTS: A total of 84 patients were included, with a median age of 64 years. A large proportion of patients had normal imaging (CT 40.8 %, MRI 53.1 %). CT abnormalities included cortical/subarachnoid hyperattenuation (42.1 %), cerebral oedema/sulcal effacement (26.3 %), and loss of grey-white differentiation (7.9 %). Frequently reported MRI abnormalities included brain parenchymal MRI signal change (40.8 %) and cerebral oedema (12.2 %), most commonly observed on FLAIR sequences (26.5 %). Characterisation of imaging findings according to anatomical location and clinical symptoms has been conducted. CONCLUSIONS: Neuroimaging is an essential part of the diagnostic workup of CIN. Analysis of the anatomical location and laterality of imaging abnormalities may suggest relationship between radiological features and actual clinical symptoms, although this remains to be confirmed with dedicated study. Radiological abnormalities, particularly CT, appear to be transient and reversible in most patients.

Clinical management of contrast-induced neurotoxicity: a systematic review.

BACKGROUND: Contrast-induced neurotoxicity (CIN) is an increasingly recognised complication following endovascular procedures utilising contrast. It remains poorly understood with heterogenous clinical management strategies. The aim of this review was to identify commonly employed treatments for CIN to enhance clinical decision making. METHODS: A systematic search of Embase (1947-2022) and Medline (1946-2022) was conducted. Articles describing (i) patients with a clinical diagnosis of CIN, (ii) with radiological exclusion of other pathologies, (iii) detailed report of treatments, and (iv) discharge outcomes, were included. Data relating to demographics, procedure, symptoms, treatment and outcomes were extracted. RESULTS: A total of 73 patients were included, with a median age of 64 years. The most common procedures were cerebral angiography (42.5%) and coronary angiography (42.5%), and the median volume of contrast administered was 150 ml. The most common symptoms were cortical blindness (38.4%) and reduced consciousness (28.8%), and 84.9% of patients experienced complete resolution at the time of discharge. Management included intravenous fluids to dilute contrast in the cerebrovasculature (54.8%), corticosteroids to reduce blood-brain barrier damage (47.9%), antiseizure (16.4%) and sedative (16.4%) medications. Mannitol (13.7%) was also utilised to reduce cerebral oedema. Intensive care admission was required for 19.2% of patients. No statistically significant differences were observed between treatment and discharge outcomes. CONCLUSIONS: The clinical management of CIN should be considered on a patient-by-patient basis, but may consist of aggressive fluid therapy alongside corticosteroids, as well as other supportive therapy as required. Further examination of CIN management is required to define best practice.

Pathophysiology of Contrast-Induced Neurotoxicity: A Narrative Review of Possible Mechanisms.

BACKGROUND: Contrast-induced neurotoxicity (CIN) is an increasingly observed event following the administration of iodinated contrast. It presents as a spectrum of neurological symptoms that closely mimic ischaemic stroke, however, CIN remains a poorly understood clinical phenomenon. An appreciation of the underlying pathophysiological mechanisms is essential to improve clinical understanding and enhance decision-making. METHODS: A broad literature search of Medline (1946 to December 2022) and Embase (1947 to December 2022) was conducted. Articles discussing the pathophysiology of CIN were reviewed. SUMMARY: The pathogenesis of CIN appears to be multifactorial. A key step is likely blood-brain barrier (BBB) breakdown due to factors including ischaemic stroke, uncontrolled hypertension, and possibly contrast agents themselves, among others. This is followed by passage of contrast agents across the BBB, leading to chemotoxic sequelae on neural tissue. KEY MESSAGES: This review provides a clinically oriented review on the pathophysiology of CIN to enhance knowledge and improve decision-making among clinicians.

Current knowledge and perspectives of contrast-induced neurotoxicity: A survey of Australian clinicians.

BACKGROUND: Contrast-induced Neurotoxicity (CIN) is an increasingly recognised complication following endovascular procedures. It remains a relatively unexplored clinical entity, and we sought to characterise clinician perspectives towards CIN, as well as identify gaps in knowledge and provide directions for future research. METHODS: An online survey was distributed to members of the Australian and New Zealand Society of Neuroradiology, as well as several Australian tertiary hospitals. Questions related to clinical exposure to CIN, diagnosis, management and pathophysiology were explored. Descriptive analysis was conducted on survey responses, and statistical analysis was performed using Chi-square and Fisher's exact test as appropriate. RESULTS: A total of 95 survey responses were recorded (26.8% response rate). Only 28.4% of respondents were comfortable in diagnosing CIN, and even fewer (24.2%) were comfortable in independently managing CIN patients. Based on clinician opinion, symptoms including impaired consciousness and cortical blindness were thought to be most associated with CIN, whilst the radiological findings of parenchymal oedema and cortical enhancement were considered to be most indicative of CIN. Most clinicians agreed that further investigation is required related to pathophysiology (86.3%), diagnosis (83.2%), and treatment (82.1%). CONCLUSION: CIN is a poorly understood complication following endovascular procedures. Significant gaps in clinical understanding are evident, and further investigation is vital to improve diagnosis and management.

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.

Influence of comorbidities on treatment of unruptured intracranial aneurysms in the elderly.

Current evidence does not conclusively justify conservative management of unruptured intracranial aneurysms (UIA) in the elderly (age ≥ 65 years). To rationalise intervention, the authors investigated the role of age and comorbidity burden on treatment outcomes. A retrospective chart review for consecutive cases of UIAs treated in the elderly between 2007 and 2018 was performed. Preoperative Charlson Comorbidity Index (CCI) and Neurovascular Comorbidities Index (NCI) were calculated. Standard statistical methods with univariate and multiple logistic regression were used. A total of 123 patients (46 surgery, 77 endovascular) with 131 UIAs were treated. The mean age was 70.6 ±â€¯4.1 years, and 90 patients were female (73.1%). The mean aneurysm size was 8.6 ±â€¯5.0 mm, and the mean follow up period was 22.9 ±â€¯21.3 months. The rates of poor outcome (mRS > 1) at discharge, 6 weeks and 6 months were 9.8%, 5.8% and 3.6%, respectively. There was no difference in outcomes between surgical and endovascular treatment. Correlation and regression analyses revealed that aneurysm size, higher preoperative comorbidity index (CCI > 4), and endovascular treatment with a stent or flow diverter (p = 0.009, 0.02, and 0.005, respectively) were associated with a poor outcome. When adjusted in a multivariate analysis, only high comorbidity burden (CCI > 4) predicted unfavourable outcome (p = 0.01). Elderly patients who undergo treatment for UIAs are at high risk of postoperative deterioration. Careful preoperative case selection based on comorbidity burden, rather than chronological age, would be useful for improved risk stratification.

Safety and effectiveness of endovascular embolization or stent-graft reconstruction for treatment of acute carotid blowout syndrome in patients with head and neck cancer: Case series and systematic review of observational studies.

BACKGROUND: Indications for treatment and outcomes after endovascular management of carotid blowout syndrome for patients with head and neck cancer are not well defined. We investigated the safety and effectiveness of endovascular embolization and stent-graft reconstruction. METHODS: A literature review was performed for studies published between 2001 and 2015 with relevance to treatment outcomes. Our institutional database was examined to identify patients treated with endovascular techniques. RESULTS: A total of 266 patients were included. Rates of procedural stroke were higher after embolization of internal carotid artery (ICA)/common carotid artery (CCA) compared to stent graft (embolization 10.3%; stent graft 2.5%; P < .02). Stent graft of ICA/CCA was associated with higher rates of recurrent bleeding (embolization 9.1%; stent graft 31.9%; P < .01). CONCLUSION: Both embolization and stent grafts are safe therapeutic options for acute carotid blowout syndrome. Embolization for ICA/CCA carotid blowout syndrome was associated with higher risks of procedural stroke and lower recurrent bleeding compared to stent grafts.

Pre-operative embolization of a choroid plexus carcinoma: review of the vascular anatomy.

AIM: The purpose of this case is to highlight the benefits of preoperative embolization as well as to review the vascular anatomy that needs to be recognized in order to perform pre-operative embolization of choroid plexus tumors. METHOD: We achieve this by presenting the case of a 12-month-old female who had symptoms of raised intracranial pressure. MRI demonstrated a large vividly enhancing mass centered within the atria of the right lateral ventricle associated with hydrocephalus in keeping with a choroid plexus tumor. RESULT: Enlarged anterior and posterior choroidal arteries supplying the tumor were noted on the MRI scan. Pre-operative embolization was performed with NBCA glue via the anterior and posterior choroidal arteries. Subsequently, total surgical resection was achieved with only 200 cc of blood loss. Pathology confirmed a choroid plexus carcinoma. CONCLUSION: Pre-operative embolization can be useful in minimizing blood loss during excision of choroid plexus tumors. It is important to understand the anatomy of the anterior and posterior choroidal arteries to perform embolization of these tumors safely.

Intra-aneurysmal hemodynamics: evaluation of pCONus and pCANvas bifurcation aneurysm devices using DSA optical flow imaging.

BACKGROUND: Implantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging stents like Solitaire AB, can be used; however, bifurcation devices like pCONus and pCANvas are especially designed for WCT. These devices provide additional support for coil implantation owing to intraluminal nylon fibers (pCONus) or membranes (pCANvas) covering the intracranial aneurysm neck. OBJECTIVE: Assessment of the intra-aneurysmal hemodynamic impact of these three devices: a regular intracranial stent (Solitaire AB) and two bifurcation devices (pCONus and pCANvas). MATERIAL AND METHODS: An in vitro experiment was set up using a silicone model of a basilar tip aneurysm filled with blood mimicking fluid under a pulsatile circulation. Solitaire AB, pCONus, and pCANvas were successively implanted in the model for hemodynamic evaluation. High frame rate DSA series were acquired under various conditions. Intra-aneurysmal flow changes, including mean aneurysm flow amplitude ratio (R), were subsequently assessed by the optical flow method, measuring the detector velocity field before and after device implantations. RESULTS: pCONus and Solitaire minimally reduced the intra-aneurysmal flow (R=0.96, p=0.17 and R=0.91, p=0.01, respectively), whereas pCANvas strongly diminished the intra-aneurysmal flow (R=0.41, p=5×10-12). CONCLUSIONS: Waffle cone deployment of stents and technique-specific devices had no undesirable effect on the intra-aneurysmal flow. In particular, no increased flow was redirected into the aneurysm sac. The intraluminal membrane of the pCANvas strongly reduced the intra-aneurysmal flow, potentially preventing recanalization problems.

Current status of mechanical thrombectomy for acute stroke treatment.

Acute ischemic stroke is a morbid and disabling medical condition with a significant social and economic impact throughout the world. Intravenous thrombolysis (IVT) has been the first line treatment for patients presenting up to 4.5 hours after symptom onset for many years. Endovascular stroke treatment has been used successfully as rescue therapy after failed IVT; in patients with contraindications to rtPA or presenting outside the 4.5-hour window. The effectiveness of IVT is high for distal thrombi but significantly lower for proximal occlusions. Endovascular treatment has been revolutionized by the evolution from intra-arterial thrombolysis and first generation mechanical devices to the current generation of stent retrievers and aspiration systems with large bore catheters. These devices have been associated with excellent revascularization, improved clinical outcomes, shorter procedure times and reduced device and procedure related complications. We report the current literature, clinical standards and perspectives on mechanical thrombectomy in acute ischemic stroke.

Long-term MRI findings of muslin-induced foreign body granulomas after aneurysm wrapping. A report of two cases and literature review.

Muslin-induced foreign body granulomas are rare delayed complications after wrapping of intracranial aneurysms. Few small case series have been reported, with a paucity of documented MRI findings. In addition, there are no reports on long-term radiological appearances or temporal evolution of conservatively managed patients. We thus report on the long-term radiological and clinical follow-up of two patients with asymptomatic muslin-induced foreign body granulomas after wrapping of recurrent middle cerebral arterial aneurysms. Both patients were successfully managed conservatively and remain asymptomatic three and six years after diagnosis of their granulomas. A literature review confirms that MRI features of muslin-induced foreign body granuloma are typical. Features include focal areas of elevated T2 signal with increased diffusion-weighted signal and thin rim enhancement. To the best of our knowledge, this is the first report to confirm that there is a corresponding reduction in apparent diffusion coefficient, as typical in an intracranial abscess. Thus a history of aneurysm wrapping is critical for diagnosis. Accurate clinical recognition of this exuberant inflammatory response will avoid misdiagnosis as pyogenic abscess or tumor and prevent unnecessary or invasive treatment.