Assessment of Reversibility of Transverse Venous Sinus Stenosis in Patients With Papilledema.

BACKGROUND: Bilateral transverse venous sinus stenosis (TVSS) or stenosis of a dominant venous sinus has been found to be very sensitive radiological findings in patients with intracranial hypertension (IH), yet there is still an ongoing debate whether they constitute reversible or permanent phenomena. Thus, the purpose of this study was to investigate the reversibility of TVSS in patients with IH, including conservatively treated patients with signs of IH as defined by the presence of papilledema. METHODS: This was a retrospective chart review of all patients diagnosed with IH between 2016 and 2022, assessed from 2 tertiary university-affiliated neuro-ophthalmology practices. Inclusion criteria were the presence of papilledema, as quantified by optical coherence tomography, and bilateral TVSS, which is considered typical of IH on neuroimaging. During follow-up, included patients must have had confirmation of papilledema resolution as well as subsequent neuroimaging after conservative treatment or cerebrospinal fluid flow diversion. Patients with dural sinus vein thrombosis or intrinsic stenosis from sinus trabeculations or significant arachnoid granulations were excluded from the study. Either CT venography or MRI/MR venography was reviewed by a fellowship-trained neuroradiologist, and the degree of stenosis was scored through the combined conduit score (CCS), as described by Farb et al. The primary outcome was to assess TVSS changes after resolution or improvement of papilledema. RESULTS: From 435 patients, we identified a subset of 10 who satisfied all inclusion criteria. Our cohort comprised entirely women with a median age of 29.5 years and a median BMI of 32.5 kg/m2. Treatment consisted of acetazolamide in 7 patients, of which 1 had additional topiramate and 2 underwent cerebrospinal fluid flow diversion. Furthermore, 6 patients demonstrated significant weight loss during follow-up. For the primary outcome, 5 of 10 patients exhibited no appreciable TVSS change, and 5 patients demonstrated significant improvement in TVSS, of which 4 received conservative treatment only. Papilledema resolution or improvement was statistically significantly associated with increasing average CCS, TVSS diameter, and grade. CONCLUSIONS: We were able to demonstrate that TVSS can be both irreversible and reversible in patients with resolved papilledema. The finding of TVSS reversibility from conservative treatment alone is novel and has important implications to optimize patient care. Future studies should work to identify factors associated with irreversible TVSS for subsequent targeted intervention and prevention.

Spontaneous intracranial hypotension due to CSF-venous fistula: Evaluation of renal accumulation of contrast following decubitus myelography and maintained decubitus CT to improve fistula localization.

PURPOSE: Presented here is a strategy of sequential lateral decubitus digital subtraction myelography (LDDSM) followed closely by lateral decubitus CT (LDCT) to facilitate cerebrospinal fluid (CSF)-venous fistula (CVF) localization. MATERIALS AND METHODS: This is a retrospective analysis of patients referred to our institution for evaluation of CSF leak. Patients with Type 1 and Type 2 leaks, and those not displaying MR brain stigmata of intracranial hypotension were excluded. All patients underwent consecutive LDDSM and LDCT. If the CVF was not localized on the first LDDSM-LDCT pair the patient returned for contralateral examinations. Images were reviewed for CVF and for accumulation of contrast within the renal pelvises expressed as a renal pelvis contrast score (RPCS) in Hounsfield units (HU). RESULTS: Twenty-two patients were included in this study. In 21 of 22 patients (95%) a CVF was identified yielding an RPCS for the LDDSM-LDCT pair ipsilateral to the CVF ranging from 71 to 423 with an average of 146 HU. An RPCS of the negative side LDDSM-LDCT pair contralateral to a CVF was available in 8 patients and averaged 51 HU. In 4 patients the initial bilateral LDDSM-LDCT pairs did not reveal the location of the CVF however in 3 of these 4 cases the CVF was revealed on a third LDDSM repeated ipsilateral to the higher RPCS. CONCLUSION: The strategy of sequential LDDSM-LDCT coupled with evaluation of renal accumulation of contrast agent appears to improve the rate of CVF localization and warrants further evaluation.

The presence of pachymeningeal hyperintensity on non-contrast flair imaging in patients with spontaneous intracranial hypotension.

PURPOSE: Traditionally, in the work-up of patients for spontaneous intracranial hypotension, T1 post-contrast imaging is performed in order to assess for pachymeningeal enhancement. The aim of this study is to assess whether pachymeningeal hyperintensity can be identified on a non-contrast FLAIR sequence in these patients as a surrogate sign for pachymeningeal enhancement. METHODS: The patient cohort was identified from a prospectively maintained database of patients with a clinical diagnosis of intracranial hypotension. Patients who had both a post-contrast T1 sequence brain as well as non-contrast FLAR sequence of the brain were reviewed. Imaging was retrospectively reviewed by three independent neuroradiologists. Each study was assessed for the presence or absence of pachymeningeal hyperintensity on the FLAIR sequence. RESULTS: From January 2010 to July 2022, 177 patients were diagnosed with spontaneous intracranial hypotension. In total, 121 were excluded as post-contrast imaging was not performed during their work-up. Twenty-four were excluded as the FLAIR sequence was performed after administration of contrast. Six were excluded as there was no pachymeningeal thickening present on T1 post-contrast imaging, although there were other signs of intracranial hypotension. The study group therefore consisted of 26 patients. Pachymeningeal thickening was correctly identified on the non-contrast FLAIR sequence in all patients (100%). CONCLUSION: Where present, diffuse pachymeningeal hyperintensity can be accurately identified on a non-contrast FLAIR sequence in patients with spontaneous intracranial hypotension. This potentially obviates the need for gadolinium base contrast agents in the work-up of these patients.

Digital Subtraction Myelography is Associated with Less Radiation Dose than CT-based Techniques.

PURPOSE: Both CT myelogram (CTM) and digital-subtraction myelogram (DSM) can be used to evaluate patients for possible cerebrospinal fluid (CSF) leaks. DSM is a relatively new technique. No data exists on the radiation dose associated with this procedure, and how it compares with CTM. MATERIALS AND METHODS: All patients who underwent DSM for spontaneous intracranial hypotension (SIH) refractory to blood patching from Dec 2016 - Sept 2019 were retrospectively assessed. DSM dose factors were then recorded (cumulative fluoroscopy time, total kerma area product (KAP, mGy.cm2), cumulative air kerma (mGy), as well as CTM dose factors (included CTDIvol (mGy) and dose-length product (DLP, mGy.cm). These indices were then used to calculate the effective dose for both procedures using standardized conversion factors. RESULTS: 61 DSMs were performed in 42 patients, 33 of which also underwent CTM. The median effective dose was 6.6 mSv per DSM study (range: 1.2 - 17.7). On a per-patient basis (i.e. those patients who underwent more than one DSM (as the initial one was negative), the median total effective dose was 13 mSv for their total DSM imaging (range: 2.6 -31.7). For the CTM, the median effective dose was 19.7 mSv (range: 3.2 - 82.4 mSv). CONCLUSION: The radiation dose with DSM appears to be significantly lower than that of CTM (p = 0.0005), when looking at CTM doses both from our institution and in the published literature.

Vertebral artery aneurysms and the risk of cord infarction following spinal artery coverage during flow diversion.

OBJECTIVE: Coverage of the anterior spinal artery (ASA) ostia is a source of considerable consternation regarding flow diversion (FD) in vertebral artery (VA) aneurysms due to cord supply. The authors sought to assess the association between coverage of the ASA, posterior spinal artery (PSA), or lateral spinal artery (LSA) ostia when placing flow diverters in distal VAs and clinical outcomes, with emphasis on cord infarction. METHODS: A multicenter retrospective study of 7 institutions in which VA aneurysms were treated with FD between 2011 and 2019 was performed. The authors evaluated the risk of ASA and PSA/LSA occlusion, associated thromboembolic complication, complications overall, aneurysm occlusion status, and functional outcome. RESULTS: Sixty patients with 63 VA and posterior inferior cerebellar artery aneurysms treated with FD were identified. The median aneurysm diameter was 7 mm and fusiform type was the commonest morphology (42.9%). During a procedure, 1 (61.7%) or 2 (33.3%) flow diverters were placed. Complete occlusion was achieved in 71.9%. Symptomatic thromboembolic complications occurred in 7.4% of cases and intracranial hemorrhage in 10.0% of cases. The ASA and PSA/LSA were identified in 51 (80.9%) and 35 (55.6%) complications and covered by the flow diverter in 29 (56.9%) and 13 (37.1%) of the procedures, respectively. Patency after flow diverter coverage on last follow-up was 89.2% for ASA and 100% for PSA/LSA, not significantly different between covered and noncovered groups (p = 0.5 and p > 0.99, respectively). No complications arose from coverage. CONCLUSIONS: FD aneurysm treatment in the posterior circulation with coverage of ASA or PSA/LSA was not associated with higher rates of occlusion of these branches or any instances of cord infarction.

Treatment of anterior cerebral artery and anterior communicating artery aneurysms with flow-diversion devices: a systematic review and meta-analysis.

INTRODUCTION: To assess the early safety and efficacy of anterior cerebral artery (ACA) and anterior communicating artery (ACoA) aneurysm treatment with flow-diversion devices (FDDs), we performed a systematic review and meta-analysis for these aneurysms. EVIDENCE ACQUISITION: A literature search was performed by a reference librarian, and, after screening, eight case series were included for meta-analysis. We estimated from each study the cumulative incidence (event rate) and 95% confidence interval (CI) for each outcome. Event rates were pooled in a meta-analysis across studies using the random-effects model; descriptive statistics were reported when relevant. EVIDENCE SYNTHESIS: 129 ACA and ACoA aneurysms from 8 series were included. Technical success rate of 96% (95% CI: 0.93 to 1.00) and a technical complication rate was 3% (95% CI: 0.00 to 0.06). Perioperative rates of ischemic stroke, hemorrhagic stroke, morbidity, and mortality were 3% (95% CI: 0.00 to 0.06), 5% (95% CI: 0.01 to 0.08), 3% (95% CI: 0.00 to 0.06 and 2% (95% CI: 0.00 to 0.05), respectively. The rate of treatment-related, long-term neurological deficit was 4% (95% CI: 0.01 to 0.07). Complete occlusion rate at last radiological follow-up was 79% (95% CI: 0.68 to 0.91). CONCLUSIONS: FDDs are an acceptable tool for the treatment of ACA and ACoA aneurysms with high rates of technical success and low rates of periprocedural morbidity and mortality. Comparative studies with longer-term follow-up are needed to clarify the role of these devices in the management of ACA and ACoA aneurysms in patients with challenging comorbidities.

A Lesson from Cardiology: The Argument for Ultrasound-Guided Femoral Artery Access in Interventional Neuroradiology.

PURPOSE: The transfemoral approach is widely used by neurointerventionalists for accessing the femoral artery in patients undergoing diagnostic and therapeutic endovascular procedures. In patients with more difficult anatomy, duplex ultrasonography (US) may be a valuable adjunct for femoral vascular access. We aimed to assess the evidence for the effectiveness of duplex US-guided femoral access within interventional neuroradiology. METHODS: We searched MEDLINE, Scopus, and EMBASE and included 5 randomized controlled trials. Odds ratios (ORs) and mean differences were pooled using the random-effects model. RESULTS: Meta-analysis of 5 RCTs that included 784 US-guided patients and 769 non-US-guided patients found that the US-guided approach was significantly favored in terms of time-to-access (weighted mean difference: 24.90 minutes, 95% confidence interval [CI] 12.41-37.38), first-pass success rate (OR 2.97; 95% CI 1.49-5.92), and total complication rate (OR 0.42, 95% CI 0.23-0.77). There were no statistically significant differences in technical success rate, number of attempts, or individual complications. CONCLUSIONS: US-guided femoral artery access for endovascular procedures is a safe and effective adjunct for visualizing the femoral artery during vascular access for endovascular procedures. Neurointerventionalists should consider a low threshold for its use, especially for patients with challenging anatomy or at high-risk of bleeding complications.

#Fake news: a systematic review of mechanical thrombectomy results among neurointerventional stroke surgeons on Twitter.

OBJECTIVE: Twitter is a popular social media platform among physicians. Neurointerventionalists frequently document their lifesaving mechanical thrombectomy cases on Twitter with very favorable results. We fear that there may be some social media publication bias to tweeted mechanical thrombectomy cases with neurointerventionalists being more likely to tweet cases with favorable outcomes. We used these publicly documented cases to analyze post-intervention Twitter-reported outcomes and compared these outcomes with the data provided in the gold standard literature. METHODS: Two reviewers performed a search of Twitter for tweeted cases of acute ischemic strokes treated with mechanical thrombectomy. Data were abstracted from each tweet regarding baseline characteristics and outcomes. Twitter-reported outcomes were compared with the Highly Effective Reperfusion Evaluated in Multiple Endovascular Stroke (HERMES) trial individual patient meta-analysis. RESULTS: When comparing the tweeted results to HERMES, tweeted cases had a higher post-intervention rate of modified Thrombolysis In Cerebral Infarction (mTICI) scale score of 2c/3 (94% vs 71%, respectively; p<0.0001) and rate of National Institutes of Health Stroke Scale (NIHSS) score ≤2 (81% vs 21%, respectively; p<0.0001). There were no reported complications; thus, tweeted cases also had significantly lower rates of complications, including symptomatic intracerebral hemorrhage (0% vs 4.4%, respectively; p<0.0001), type 2 parenchymal hemorrhage (0% vs 5.1%, respectively; p<0.0001), and mortality (0% vs 15.3%, respectively; p<0.0001). CONCLUSIONS: There is a significant difference between social media and reality even within the 'MedTwitter' sphere, which is likely due to a strong publication bias in Twitter-reported cases. Content on 'MedTwitter', as with most social media, should be accepted cautiously.

Orbital Infarction Syndrome Following Mechanical Thrombectomy Secondary to Embolization in New Territory.

BACKGROUND: Orbital infarction syndrome (OIS) is a rare entity defined as ischemia of all intraorbital and intraoccular structures including the optic nerve, extraocular muscles, and orbital fat. This entity is rare due to rich anastomotic orbital vascularization from both the internal carotid artery and external carotid artery. We report a case of a patient who suffered emboli to previously nonaffected territories to the ophthalmic artery and external carotid artery, which resulted in orbital infarction syndrome, and describe techniques to avoid such complications. CASE DESCRIPTION: A 66-year-old male presented to our institution with an acute ischemic stroke secondary to occlusion of the internal carotid artery terminus and M1 segment. The vessel was revascularized after 1 pass using a stent retriever. Postoperative angiography demonstrated sluggish flow in the distal right ophthalmic artery, as well as occlusion of the distal external carotid artery. Twenty-four hours following the procedure, the patient was noted to have complete ophthalmoplegia of the right eye, proptosis, and conjunctival chemosis. Computed tomography angiography demonstrated persistent occlusion of the distal right ophthalmic artery and external carotid artery. The right optic nerve was swollen, as were all extraocular muscles. A final diagnosis of orbital infarction syndrome was made given the clinical presentation, imaging findings, and occlusion of all vascular supply to the orbit on both conventional angiography and 24-hour computed tomography angiography. CONCLUSIONS: OIS is a rare entity that has not been previously described as a complication of mechanical thrombectomy for acute ischemic stroke. OIS should be considered when patients present with blindness, orbital pain, and total ophthalmoplegia post thrombectomy.

Prophylactic Placement of Internal Iliac Balloons in Patients with Abnormal Placental Implantation: Maternal and Foetal Outcomes.

PURPOSE: To report on outcomes following the use of prophylactic internal iliac artery occlusion balloons in patients with abnormal placental implantation. METHODS: A retrospective analysis was undertaken of patients with abnormal placental implantation who underwent prophylactic iliac balloon placement prior to delivery in a University Maternity Hospital. Various clinical and technical factors were analysed, including technical success of balloon placement, blood loss and number of blood units transfused, duration of surgery, length of stay, hysterectomy rates, complications related to the balloon insertion, foetal pH and infant Apgar scores. RESULTS: Twenty-two patients with placenta accreta or a variant thereof underwent caesarean section after first undergoing prophylactic placement of bilateral internal artery balloons. Average follow-up duration was 2.08 years. The average gestational age was 37 weeks 6 days, and the mean gravidity was 2.8. The mean number of previous caesarean sections was 2.4, while the mean maternal age was 35 years. The mean intraoperative blood loss was 1.4 L, and the mean number of blood units transfused was 2. Mean duration of surgery was 90 min, mean total length of hospital stay 7.5 days, while the mean duration of ICU/HDU stay was 1.2 days. The balloons were inflated in 60% of cases and two patients (2/22-9%) underwent subsequent hysterectomy. There were no major maternal complications due to the procedure. CONCLUSION: Prophylactic placement of arterial balloons prior to caesarean section in patients with placenta accreta is well tolerated and leads to satisfactory maternal and foetal outcomes with minimal complications.

Diagnostic accuracy of a clinical carotid plaque MR protocol using a neurovascular coil compared to a surface coil protocol.

BACKGROUND: Carotid plaque imaging with MRI is becoming more commonplace, but practical challenges exist in performing plaque imaging with surface coils. PURPOSE: To compare the diagnostic performance of a carotid plaque MRI protocol using a standard neurovascular coil (Neurovascular Coil Protocol) to a higher-resolution carotid plaque MRI using carotid surface coils (Surface Coil Protocol) in characterizing carotid plaque. STUDY TYPE: Prospective study comparing two MR techniques in plaque characterization. POPULATION: Thirty-eight consecutive carotid artery disease patients. FIELD STRENGTH/SEQUENCE: Patients underwent 3T MRI using 1) a Neurovascular Coil Protocol including the following sequences: 3D-FSE T1 pre/postcontrast and precontrast 3D IR-FSPGR, and 2) a Surface Coil Protocol using standard multicontrast MRI sequences. ASSESSMENT: Plaque characteristics analyzed by two independent neuroradiologists included intraplaque hemorrhage (IPH), lipid-rich necrotic-core (LRNC), and thin/ruptured fibrous cap (TRFC). STATISTICAL TESTS: Diagnostic performance of the Neurovascular Coil Protocol was compared to the Surface Coil Protocol reference standard using receiver-operating curves. RESULTS: For IPH, sensitivity, specificity, and area under the curve (AUC) of the Neurovascular Coil Protocol were 91.1% (95% confidence interval [CI] = 78.8-97.5%), 87.0% (95% CI = 66.4-97.2%), and 0.92, respectively. For LRNC without IPH sensitivity, specificity, and AUC were 73.3% (95% CI = 44.9-92.2%), 85.7% (95% CI = 67.3-96.0%), and 0.84, respectively. For TRFC, sensitivity, specificity, and AUC were 35.3% (95% CI = 14.2-61.7%), 97.6% (95% CI = 87.4-99.9%), and 0.66 respectively. Interobserver agreement for IPH, LRNC, and TRFC using the Neurovascular Coil Protocol were k = 0.87 (95% CI = 0.75-0.99), k = 0.54 (95% CI = 0.29-0.80), and k = 0.41 (95% CI = 0.08-0.74), respectively. DATA CONCLUSION: Our Neurovascular Coil Protocol has high sensitivity, specificity, and accuracy in identifying IPH and LRNC but is limited in assessment of TRFC. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:1264-1272.

Adult blunt renal trauma: routine follow-up imaging is excessive.

OBJECTIVE: To determine the yield of follow-up imaging in patients sustaining renal trauma at our level-1 trauma center and hence, whether the 2013 European Association of Urology guidelines are clinically applicable. METHODS: All patients who attended Cork University Hospital with a diagnosis of renal injury from 2000-2012 were identified. Review of all medical records and radiologic imaging was undertaken. Injuries were graded using the American Association for the Surgery of Trauma Organ Injury Scale and were grouped as low-grade injuries (I, II, and III) or high-grade injuries (IV and V). RESULTS: One hundred and two patients (105 renal units) were identified with a median age of 23 years (interquartile range, 18-39 years). The mechanism of injury was blunt force in 98 of 102 cases (96%). Injuries were diagnosed at the time of admission using contrast-enhanced computed tomography (CT) imaging. Low-grade injuries accounted for 78 of 102 cases (77%); all were managed conservatively with a complication rate of 2 of 78 (3%). Twenty-four patients (23%) had high-grade injuries; 2 cases required nephrectomy, 22 of 24 (92%) were managed conservatively with a complication rate of 5 of 24 (21%). All patients with complications were symptomatic, prompting repeat imaging. Overall, 38 of 102 patients (37%) underwent at least 1 follow-up CT: 20 of 78 (25%) of low-grade injuries and 18 of 24 (75%) of high-grade injuries. Concurrent thoracoabdominal injuries mandated the need for repeat CT evaluation in 21 of 38 patients (55%). Thirty-one (30%) patients were reimaged by renal ultrasonography. CONCLUSION: Selective reimaging of renal injuries based on clinical and laboratory criteria would have detected all complications. The 2013 European Association of Urology guidelines on urologic trauma are clinically appropriate in a major tertiary-trauma unit.

Pulmonary fibrosis in systemic sclerosis: association with myocardial fibrosis.

PURPOSE: To evaluate the relationship between pulmonary and myocardial fibrosis in patients with systemic sclerosis (SS). MATERIALS AND METHODS: Eighteen patients with SS prospectively underwent cardiac magnetic resonance imaging (CMR) and high-resolution computed tomography (HRCT) of the chest. Cardiac biomarkers (N-terminal pro B-type natriuretic peptide) and quality-of-life measures (SF-36 and SS health assessment questionnaires) were assessed. Two readers blinded to other test results evaluated the CMRs in consensus for functional left and right ventricular parameters and for myocardial late enhancement. HRCT images were reviewed at 5 levels and scored for total disease extent, extent of reticulation, proportion of ground-glass opacities (GGO), and coarseness of reticulation. RESULTS: Right ventricular ejection fraction correlated significantly with the percentage of late enhancement of the myocardium (R=0.63, P<0.01), extent of pulmonary fibrosis (R=0.57, P<0.01), and extent of GGO (R=0.53, P<0.05). Significant correlations were also found between the percentage of late enhancement of the myocardium and the extent of overall pulmonary fibrosis (R=0.59, P<0.05) and the extent of the ground-glass subcomponent (R=0.58, P<0.05). N-terminal pro B-type natriuretic peptide correlated significantly with the number of myocardial segments with late enhancement (R=0.64, P<0.05). Stepwise multiple linear regression revealed the extent of pulmonary GGO to be the only independent predictor of the percentage of myocardial enhancement (R2=0.61, P<0.0001). CONCLUSION: In patients with SS with pulmonary fibrosis on HRCT images, CMR may be a useful test to detect early-stage myocardial fibrosis.