11:35 am
P020:
Subdural versus subgaleal drainage for chronic subdural hematomas – a post hoc analysis of the TOSCAN trial
Sonja Vulcu (Bern | CH)
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Authors:
Sonja Vulcu (Bern | CH)
Levin Häni (Bern | CH)
Mattia Branca (Bern | CH)
Christian Fung (Freiburg | DE)
Werner J. Z'Graggen (Bern | CH)
Michael Murek (Bern | CH)
Andreas Raabe (Bern | CH)
Jürgen Beck (Freiburg | GL)
Philippe Schucht (Bern | CH)
OBJECT
The use of subdural drains after surgical evacuation of chronic subdural hematoma decreases the risk of recurrence and has become the standard of care. Halfway through the highly controlled, randomized TOSCAN trial, our institutional guidelines changed to recommend subgaleal instead of subdural drainage. We report a post hoc analysis on the influence of drain location in patients participating in the TOSCAN trial.
METHODS
We studied 361 patients enrolled in the TOSCAN trial. The patients were stratified according to whether they received surgery before (cohort A) or after (cohort B) the change in institutional protocol. We performed an intention-to-treat analysis with surgery for recurrence as the primary endpoint. Secondary endpoints were: outcome based on modified Rankin scale, seizures, infections, parenchymal brain injuries, and hematoma diameter.
RESULTS
Of the 361 patients included in the analysis, 214 were stratified into cohort A (subdural drainage recommended), while 147 were stratified into cohort B (subgaleal drainage recommended). There was a 31.78% rate of cross-over from the subdural to the subgaleal drainage insertion site due to technical or anatomical difficulties. No differences in the rates of re-operation (21.5 vs 25.17%, p=0.415), infections (0.47 vs. 2.04%), seizures (3.27 vs 2.72%) or the rate of favorable outcomes at 1 and 6 months (91.26 vs 96.43%; 89.90 vs 91.55%) were noted between the two cohorts. Postoperatively, patients in cohort A had more frequent parenchymal brain tissue injuries (2.8 vs 0%). Postoperative absolute and relative hematoma reduction was similar irrespective of the location of the drain.
CONCLUSION
Subgaleal rather than subdural placement of the drain did not increase the risk for re-operation for recurrence of chronic subdural hematomas, nor did it have a negative impact on clinical or radiological outcome. The intention to place a subdural drain was associated with a higher rate of parenchymal injuries.
11:40 am
P021:
Pituitary function and endocrinological outcome of transsphenoidal surgery with respect to Shape-grade - a SwissPit study
Sven Berkmann (Aarau | CH)
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Authors:
Chris Grebhardt (Aarau | CH)
Philipp Schütz (Aarau | CH)
Javier Fandino (Aarau | CH)
Sven Berkmann (Aarau | CH)
AIM. Transsphenoidal surgery may lead to restoration but also to new deficiencies of pituitary function. The Shape-classification has been introduced to systematically describe different growth patterns of pituitary tumors. In nonfunctioning adenoma (NFA) it was shown, that the higher the Shape-grade, the less likely a total resection and decompression of the optic chiasm and pituitary stalk was possible. The aim of this retrospective study is to describe the correlation between Sahpe-grades and the endocrinological outcome in NFA.
METHODS.
Patients suffering from NFA treated by transsphenoidal surgery at the authors’ institution 2005-2017 were eligible for inclusion. Gross total resection (GTR), preoperative tumor and remnant volume, Knosp grades, decompression of the pituitary stalk, pre- and postoperative pituitary function were assessed with respect to the individual Shape-grade. Based on the maximum coronar and sagittal tumor diameters and the relation to surrounding structures the following grades are distinguished: I) round appearance; IIA) oval shape without CS invasion; IIB) oval with CS invasion; III) dumbbell-shaped with narrowing at sphenoidal plane; IV) mushroom-shaped; V) polylobulated.
RESULTS.
189 patients (Shape-I, n=28 (15%); Shape-IIA, n=66 (35%); Shape-IIB, n=25 (13%); Shape-III, n=37 (19%); Shape-IV, n=12 (6%); Shape-V, n=21 (11%)) were included. The GTR and pituitary stalk decompression rates varied significantly between the different Shape-grades with higher grades being less likely to be totally resected and the pituitary stalk decompressed. Hypopituitarism was more prevalent in higher shape grades pre- and postoperatively (e.g. Shape I, 53%/21%; Shape V, 81%/56%). The likelihood for endocrinological recovery was higher in lower Shape-grades, whereas the risk for new hormonal deficiencies rose in higher Shape-grades.
CONCLUSION.
The pituitary function as well as the endocrinological outcome of transsphenoidal surgery for NFA is influenced by the shape of a pituitary adenoma. The Shape-classification offers a standardized grading system to assess the different tumor shapes.
11:45 am
P022:
Current patterns of practice in spinal Fusion for chronic Low Back Pain – Results from a Survey at the German Spine Societies' Annual Congress 2018
Domini Baschera (Winterthur | CH)
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Authors:
Domini Baschera (Winterthur | CH)
Leonard Westermann (Cologne | DE)
Sofia Syrianos (Cologne | DE)
Peer Eysel (Cologne | DE)
Alex Alfieri (Winterthur | CH)
Background: The indication for lumbar spine fusion as well as the preoperative selection criteria for patients suffering from chronic lower back pain (CLBP) and corresponding degenerative changes but without nerve root compression or neurogenic claudication are under debate. In such patients, literature suggests minimal improvement after surgical treatment, however for many it remains a last solution after all conservative treatments have failed. The aim of this study was to examine and compare patterns found in current practise.
Method: A total of 143 printed questionnaires containing 51 questions were distributed at the German Spine Societies' annual congress 6-8 December 2018.
Results: 127 (89%) surveys were returned by 64 orthopaedic surgeons and 63 neurosurgeons, 29 working at a university hospital, 57 in a non-university public hospital and 41 in a private hospital or practice. Thirty-one were chairmen of their clinic, 62 consultants and 20 board certified surgeons. The mean experience of respondents was 14.5±8.1 years. The majority of 41 surgeons (32.3%) answered to perform 1-10 lumbar fusion procedures for patients with CLBP per year, 20 perform 11-20, 10 perform 21-30 and 17 answered to performing more than 50. 28 (22%) perform none. The majority of 42.5% of surgeons treats their patients for at least 6-12 months conservatively before considering surgery. Thirty-six (28.3%) respondents would each consider a postoperative pain reduction of 50-60% or 60-70% a treatment success. When asked for an estimate of the percentage of patients with good surgical results after fusion for CLBP 45 (38.4%) respondents think that less than 50% exhibit good results and only 17 (13.4%) think that 70% or more exhibit good results. Orthopaedic surgeons perform more lumbar fusion surgeries than neurosurgeons (p=0.04*), fuse more lumbar segments than neurosurgeons (p= 0.03*), are more likely to order their CLBP patients to cease smoking preoperatively (p=0.02*) and are satisfied with a lesser pain reduction postoperatively (p=0.01*) than neurosurgeons.
Conclusions:
Despite the discouraging evidence in literature, the majority of respondents still perform fusion surgery in CLBP- patients. Orthopaedic surgeons appear to be slightly more optimistic with surgical results but as it appears had a lower threshold on what to consider a surgical success.
11:50 am
P023:
Reduction of external ventricular drain associated infections after introduction of a chlorhexidine containing dressing
Michel Röthlisberger (Basel | CH)
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Authors:
Michel Röthlisberger (Basel | CH)
Simon Stohler (Basel | CH)
Davide Marco Crovi (Lugano | CH)
Stephan Schön (Luzern | CH)
Severina Leu (Basel | CH)
Luigi Mariani (Basel | CH)
Background: Dressings containing chlorhexidine (CHX) lower the incidence of external ventricular drain (EVD)-associated infections (EVDAIs). In a previous prospective randomized trial (RCT) at the University Hospital Basel (NCT02078830), a significant reduction in bacterial cutaneous and catheter colonization was detected. However, the study was underpowered to demonstrate an effect on the incidence of EVDAI.
Methods: Retrospective (2009-2013) and prospective (2014-2017) review of patients undergoing EVD-insertion at the University Hospital Basel. The control group consisted of patients from January 2009 to October 2013, where the CHX-dressings were not in use. The study group consisted of patients between February 2016 and December 2017, where CHX-dressing was standard of care. Comparisons were made using the Chi-squared test. Primary endpoint was the diagnosis of EVDAI. Statistical significance was set at P ≤ .05.
Results: 224 out of 306 (73.2%) patients were eligible for analysis. 79 out of 224 (35.3%) were assigned to the control group, 55 out of 224 (24.6%) to the RCT-group and 90 out of 224 (40.2%) to the study group. During the whole study period, 118 out of 224 (52.7%) received a CHX-dressing while 106 out of 224 (47.3%) did not. The rate of EVDAI was substantially lower after the introduction of the CHX-dressing as a standard of care with 7 out of 90 (7.8%) when compared to 13 out of 79 (16.4%) patients in the control group. The difference did not reach statistical significance (p=.083). However, the cumulative incidence (4.1 vs. 7.7) and the prevalence (8 vs. 16 per 100 persons) nearly halved respectively. A significant decrease in EVDAI of approximately 8% was observed, when a CHX-dressing was used. In detail, 12 out of 118 (10.2%) in the CHX compared to 19 out of 106 (17.9%) in the Non-CHX-group developed EVDAI (p=.036).
Conclusion: CHX-containing dressings as a standard of care for the exit site of EVD effectively reduce the incidence of EVDAI.
11:55 am
P024:
Angiographic Analyses of natural anastomoses between the posterior and anterior cerebral arteries in Moyamoya disease
Sara Bonasia (Lugano | CH)
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Authors:
Sara Bonasia (Lugano | CH)
Gabriele Ciccio' (Paris | FR)
Alexander Weil (Montreal, Quebec | CA)
Stan Smajda (Paris | FR)
Chiraz Chaalala (Montreal, Quebec | CA)
Raphaël Blanc (Paris | FR)
Michael Reinert (Lugano | CH)
Michel Piotin (Paris | FR)
Michel Bojanowski (Montreal, Quebec | CA)
Thomas Robert (Lugano | CH)
Background and Purpose: Moyamoya disease is a chronic neurovascular steno-occlusive disease of the internal carotid artery and its main branches, associated with the development of compensatory vascular collaterals. A detailed description of collateral circles in literature is lacking. Generally, the posterior circulation is less affected by the pathology and its vascular flow could compensate the hypoperfusion of the ICA territories. The aim of this study is to describe these connections between the posterior cerebral artery and the anterior cerebral artery necessary to compensate the ACA territories hypoperfusion in Moyamoya population.
Materials and Methods: All patients treated for Moyamoya disease from 2004 to 2018 in 4 neurosurgical centers with available cerebral digital subtraction angiography were included. 40 patients (80 hemispheres) with the diagnosis of Moyamoya disease were evaluated. The presence of anastomoses between the PCA and the ACA was found in 31 hemispheres.
Results: 31 hemispheres (38,75 % ) presented a collateral circle between the PCA and the ACA. The most frequently encountered collaterals were branches from the posterior callosal artery (20 % of cases), and from the posterior choroidal arteries (20 % of cases). Other connections found were pio-pial anastomosis between cortical branches of the PCA and the ACA (15 %). We also proposed a four-grade classification based on the competence of these anastomoses to supply retrogradely ACA’s territories.
Conclusion: We found three different types of anastomoses between the anterior and posterior circulation, with different ability to compensate the anterior circulation. Their development depends on the perfusion needs of the anterior cerebral artery territories and can provide to the retrograde refilling of the ACA branches.
12:00 pm
P025:
Chemosensory function in posttraumatic patients: the role of olfactory distortions
Adrien May (Genève | CH)
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Authors:
Adrien May (Genève | CH)
Julien Wen Hsieh (Geneva | CH)
Ramona Guatta (Geneva | CH)
Karl Schaller (Geneva | CH)
Basile N. Landis (Geneva | CH)
Background
The chemical senses comprise smell, taste and intranasal trigeminal function. These systems allow humans to detect their molecular environment. After traumatic head injury chemosensory functions are often impaired. Patients complain not only about quantitative loss (anosmia/hyposmia), but also qualitative impairment, such as parosmia (distorted perception of odors) or phantosmia (odor hallucination). The origin and clinical significance of these olfactory distortions are poorly understood. We aimed to establish the chemosensory characteristics (smell, taste, trigeminal) of posttraumatic patients (PP) and analyzed whether olfactory distortions influence the degree of chemosensory impairment.
Methods
We performed a retrospective study based on 75 patients with olfactory complaints following head trauma. We assessed their chemosensory function with Sniffin' Sticks (olfaction), lateralization test (trigeminal), and taste strips (taste). Demographics, test and CT scan/MRI results were reported in a database. Data were analyzed with unpaired t-test with Welch ́s correction, Mann-Whitney test, and Fischer's exact test. Statistical significance was reached when p< 0.05.
Results
Besides olfaction, taste and trigeminal function were also slightly below normal values in PP. The mean identification test score (+/-SD) was higher in the group with distortions (7.1+/-2.6; n=34) compared to the group without (5.6+/-3.2; n=41; p< 0.05). Regarding the percentage of subjects with cerebral abnormalities, gender and results of other chemosensory tests, there was no significant difference between the two groups.
Conclusion
We found that patients with qualitative dysfunction have better odor identification test scores compared to those without qualitative dysfunction. It may support the hypothesis that parosmia or phantosmia may be a sign of olfactory neuroregeneration. A longitudinal study is needed to further assess whether these symptoms may be a useful prognostic factor for olfactory recovery after head injury.
12:05 pm
P026:
Prehemorrhage antiplatelet use in aneurysmal subarachnoid haemorrhage and its impact on clinical outcome
Martina Sebök (Zürich | CH)
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Authors:
Martina Sebök (Zürich | CH)
Emanuela Keller (Zurich | CH)
Luca Regli (Zurich | CH)
B.A. Coert (Amsterdam | NL)
W.P. Vandertop (Amsterdam | NL)
A. Sardeha (Amsterdam | NL)
D. Verbaan (Amsterdam | NL)
Menno Robbert Germans (Zurich | CH)
Aim: The aim of this study was to investigate whether the rebleed rate and rate of poor outcome were influenced by the use of antiplatelet agents before aneurysmal subarachnoid hemorrhage (aSAH).
Methods: Patients were collected from prospective databases of two tertiary referral centers for aSAH patients. Patients were divided into “antiplatelet user” and “nonuser” according to their use of antiplatelet agents before the initial hemorrhage. With multivariate analyses we assessed the use of antiplatelets regarding rebleed rate and poor outcome, defined as Glasgow outcome Scale 1-3 at 6 months follow-up. In the antiplatelet user group, the impact of thrombocyte transfusion on rebleed rate and poor outcome was calculated.
Results: A total of 1,134 patients were included (15.2% antiplatelet users). Patients in the antiplatelet user group were significantly older with higher incidence of hypertension, diabetes and hypercholesterinemia. Antiplatelet users showed both a significant increase in in-hospital mortality (25.4% vs. 17.0%, p = 0.031) as well as poor outcome (57.4% vs. 43.3%, p=0.003). No difference in rebleed rates was seen. In multivariate analysis, antiplatelet use remained associated with poor outcome (OR 1.83, 95% CI 1.22-2.74; p = 0.04). Thrombocyte transfusion did not lead to a significant change in rebleed rate or poor outcome (transfusion vs. no transfusion: 11,1% vs. 16,0%, p = 0.37 and 59.6% vs. 59.1%, p = 0,96, respectively).
Conclusion: In this multicenter study the use of antiplatelet agents before aSAH was associated with increased risk of poor outcome at 6 months without significant increase in rebleed rate. Thrombocyte transfusion had no impact on rebleed or outcome.
12:10 pm
P027:
Intravenous Thrombolysis versus Endovascular Therapy in Acute Middle Cerebral Artery M2-Segment Occlusion: A Monocenter Cohort Study
Philipp Gruber (Aarau | CH)
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Authors:
Philipp Gruber (Aarau | CH)
Enrique Barvulsky (Aarau | CH)
Jatta Berberat (Aarau | CH)
Timo Kahles (Aarau | CH)
Javier Anon (Aarau | CH)
Michael Diepers (Aarau | CH)
Krassen Nedeltchev (Aarau | CH)
Luca Remonda (Aarau | CH)
Introduction: Since the endovascular milestone stroke trials there is striking evidence for endovascular treatment in acute stroke patients with proximal vessel occlusion of the anterior cerebral circulation. However, there is limited evidence available for endovascular treatment in acute stroke patients with M2-segment occlusion of the middle cerebral artery. Recent data shows that endovascular treatment (EVT) might be also beneficial in selected patients with acute M2 occlusions (1). Thus, we aimed to compare the safety and effectiveness of EVT versus intravenous thrombolysis with recombinant tissue plasminogen activator (iv-rtPA) in M2- occlusions.
Method: Retrospective, monocenter, cohort-study of 120 stroke patients with acute M2-occlusion and complete follow-up from a comprehensive stroke center between 2014 and 2018, of whom 24 (20%) patients received iv-rtPA and 61 patients (51%) were treated with EVT. Epidemiological, clinical and radiological data were statistically analyzed.
Results: The median NIHSS on admission was similar for both groups (EVT group = 10; iv-rtPA= 8; p=0.83). The rate of good clinical outcome (modified Rankin Scale (mRS) ≤2) was significantly higher in the EVT group (75%) compared to the iv-rtPA group (46%) (p=0.009), whereas the mortality rate was significantly higher in the iv-rtPA group (29%) compared to the EVT group (10%) (p=0.026). The intracranial hemorrhage rate was similar for both groups (13% vs. 5%, p=0.2).
Conclusion: This retrospective cohort-study suggests that endovascular treatment of acute stroke patients with M2 occlusion might be beneficial compared to iv-thrombolysis only.
12:15 pm
P028:
Build-Up Effect of Motor Evoked Potentials
Nicole Frank (Luzern | CH)
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Authors:
Nicole Frank (Luzern | CH)
Kathleen Seidel (Bern | CH)
Karl F. Kothbauer (Luzern | CH)
Background and Objective
Interpretation of MEPs during intraoperative neurophysiological monitoring is a debated issue. Warning criteria vary among centers: Presence and absence of myogenic responses, increase in stimulus threshold and decrease in response amplitudes, which may carry different meanings for monitoring of brain, brainstem, or spinal cord surgery. The phenomenon of increase of MEP ampli-tudes during rapid sequences of stimuli has been described usually when stimulations are done at frequencies of 1 or 2 Hz. So far it is unknown, whether or not the presence or magnitude of this build-up effect correlates to clinical findings, or if it can be used intraoperatively to assess reversible damage to the motor system.
Methods
Muscle MEPs from upper and or lower extremity muscles were recorded during surgeries for spinal or intracranial pathologies in 50 patients with and without neurological dysfunction. All MEP ampli-tudes of ten subsequent responses were recorded at baseline and closing at stimulus intensities 10% above motor threshold using stimulus rates of 1 Hz and 2 Hz. MEP-amplitudes were plotted against the number of stimulations. Presence of build-up was noted with subsequent increase of amplitudes by at least 30% from the first response of ten. The clinical status was recorded before and after surgery using the NIHSS and the MRC muscle strength (0-5). Presence and absence of a build-up effect was correlated to the presence or absence of motor deficits.
Results
MEP amplitude build-up was noted to be present in 46%, and absent in 54%. Patients without build-up had a higher likelihood of having motor deficits. The majority of those patients with motor deficits and without build-up at baseline showed appearance of a build-up after tumor removal or neural decompression.
Conclusion
Presence of MEP amplitude build-up effect seemed to be associated with intact motor function and loss of the effect with motor impairment . Further studies are needed to elucidate this relation.
12:20 pm
P029:
Combating Glioblastoma: Activation of microglia by targeting CD47 and Siglecs
Philip Schmassmann (Basel | CH)
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Authors:
Philip Schmassmann (Basel | CH)
Tala Shekarian (Basel | CH)
Marie-Francoise Ritz (Basel | CH)
Anna Wachnowicz (Basel | CH)
Tomas Martins (Basel | CH)
Heinz Läubli (Basel | CH)
Gregor Hutter (Basel | CH)
Aims: Instead of targeting the tumor cells directly, modulation of the tumor microenvironment (TME) has gained more attention. Microglia (MG), the most prevalent cell type of the GBM-TME, represents a promising cell population for modulation. Here we aim at defining the role of inhibitory CD33-related Siglecs on MG, in particular Siglec-9, in GBM progression, and as an additional target to CD47-Sirpa disruption for MG specific immunotherapy in GBM patients.
Methods: To gather information about the expression and prognostic implication of Siglecs in GBM- associated MG, human MG are directly sorted from resected tumors by flow cytometry using a MG specific marker panel and subjected to RNAseq analysis. Mouse MG are sorted from MG reporter mice. Sorted human/mouse MG are co-cultured in vitro with respective tumor cells, and anti-Siglec-9 and/or anti-CD47 antibodies are administered to assess tumor cell phagocytosis by flow cytometry and time-lapse imaging.
Results: Flow-cytometric characterization revealed high expression of Siglec-9 on human GBM-associated MG and a gradient from the tumor center to periphery (51.2% center vs. 29.2% periphery). Phagocytosis assays with human PBMC-derived macrophages (M0) co-cultured with GBM-cell lines showed a significant increase in tumor-phagocytizing M0 in the combination treatment compared to control or anti-CD47 alone (1.46% control vs 8.46% combination, p = 0.001; 5.87% anti-CD47 vs 8.46% combination, p = 0.007). We did not see a significant increase with anti-Siglec-9 alone. However, after enzymatic removal of sialic acid on the tumor cells by treatment with sialidase and therefore targeting not only Siglec-9 but all the Siglec receptors, we observed a significant increase in phagocytosis (1.08% control vs 14.85% desialylation, p < 0.001) which could be even boosted by adding anti-CD47 (14.85% desialylation vs 21.8% desialylation + anti-CD47, p < 0.05). Phagocytosis assays performed with mouse MG showed as well a significant increase in GBM-cell phagocytosis in the combination treatment compared to control (1.36% control vs 6.62% combination, p < 0.05).
Conclusion: Taken together our findings implicate the sialic acid-Siglec pathway as a potential ‘don’t eat me signal’ in M0 and MG. But to fully restore the phagocytic capacity, combination with other ‘don’t eat me signals’ like CD47 and/or inhibition of several Siglecs by targeting their ligand seems to be a promising approach, which we will confirm in-vivo.
12:25 pm
P030:
Radiomics-based thrombus features predict the number of passes for arterial recanalization in patients with acute ischemic stroke
Jeremy Hofmeister (Genève | CH)
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Authors:
Jeremy Hofmeister (Genève | CH)
Paolo Machi (Geneva | CH)
Gianmarco Bernava (Geneva | CH)
Andrea Rosi (Geneva | CH)
Simon Burgermeister (Geneva | CH)
Maria Isabel Vargas (Geneva | CH)
Xavier Montet (Geneva | CH)
Karl-Olof Lövblad (Geneva | CH)
Aims: Stentretriever-based mechanical thrombectomy (MTB) is a reference treatment for acute ischemic stroke (AIS) due to large artery occlusion, but the more attempts to retrieve the occluding thrombus, the worse the clinical outcome. Thrombus radiomics features (RF) are predictive of recanalization with IV alteplase and may help predict the number of passes needed for successful recanalization with MTB.
Methods: Intracranial thrombi of 47 patients with AIS due to anterior circulation large-vessel occlusion were segmented. 1477 RF were extracted from non-contrast CT scan (NCCT). A linear regression analysis was applied to select RF most strongly associated with the number of passes for complete recanalization. These RF were then used to train a support-vector regression machine-learning classifier. The machine-learning classifier was finally tested on an independent consecutive cohort of 15 patient.
Results: Selected thrombus radiomics features computed from NCCT are predictive of the number of passes with MTB for successful arterial recanalization (R-squared: 0.663, p < 0.05; on the independent testing cohort). Notably, our machine-learning model performed better than thrombus length, volume, mean or maximal attenuation coefficient (all p < 0.05).
Conclusions: Radiomics-based intracranial thrombus features accurately predict the number of attempts to retrieve the occluding thrombus in acute ischemic stroke.