Background Acute ischaemic stroke due to distal medium vessel occlusion (AIS-DMVO) causes significant morbidity. Endovascular thrombectomy advancement has made treating AIS-DMVO with stent retrievers (SR) and aspiration catheters (AC) possible, however the optimal technique remains unknown. We performed a systematic review and meta-analysis to investigate the efficacy and safety of SR use compared to purely AC use in patients with AIS-DMVO. Methods We systematically searched PubMed, Cochrane Library and EMBASE, from inception to 2nd September 2022, for studies comparing SR or primary combined (SR/PC) against AC in AIS-DMVO. We adopted the Distal Thrombectomy Summit Group’s definition of DMVO. Efficacy outcomes were functional independence (modified Rankin Scale (mRS) 0–2 at 90 days), first pass effect (modified Thrombolysis in Cerebral Infarction scale (mTICI) 2c-3 or expanded Thrombolysis in Cerebral Infarction scale (eTICI) 2c-3 at first pass), successful final recanalisation (mTICI or eTICI 2b-3), and excellent final recanalisation (mTICI or eTICI 2c-3). Safety outcomes were symptomatic intracranial haemorrhage (sICH) and 90-day mortality. Results 12 cohort studies and 1 randomised-controlled trial were included, involving 1881 patients with 1274 receiving SR/PC and 607 receiving AC only. SR/PC achieved higher odds of functional independence (odds ratio (OR) 1.33, 95% confidence interval (CI) 1.06–1.67) and lower odds of mortality (OR 0.69, 95% CI 0.50–0.94) than AC. Odds of successful/excellent recanalisation and sICH were similar between both groups. Stratified to compare only SR and only AC, the use of only SR, achieved significantly higher odds of successful recanalisation as compared to only AC (OR 1.80, 95% CI 1.17–2.78). Conclusion There is potential for efficacy and safety benefits in SR/PC use as compared to AC only in AIS-DMVO. Further trials are necessary to validate the efficacy and safety of SR use in AIS-DMVO.

BackgroundThe optimal mechanical thrombectomy technique for acute ischaemic stroke (AIS) caused by distal, medium vessel occlusion (DMVO) is uncertain. We performed a systematic review and meta-analysis evaluating the efficacy and safety of first-line thrombectomy with combined techniques, which entail simultaneous use of a stent retriever and aspiration catheter, vs. single-device techniques, whether stent retriever or direct aspiration alone, for DMVO-AIS patients.MethodsWe systematically searched the PubMed, Embase and Cochrane CENTRAL databases from inception until 2 September 2022 for studies comparing combined and single-device techniques in DMVO-AIS patients. We adopted the Distal Thrombectomy Summit Group's definition of DMVO. Our outcomes were the modified first-pass effect [mFPE; modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3 at first-pass], first-pass effect (FPE; mTICI 2c-3 at first-pass), successful and complete final reperfusion (mTICI 2b-3 and 2c-3 at end of all procedures, respectively), 90-day functional independence (modified Rankin scale 0-2), 90-day mortality, and symptomatic intracranial hemorrhage (sICH).ResultsNine studies were included, with 477 patients receiving combined techniques, and 670 patients receiving single-device thrombectomy. Combined techniques achieved significantly higher odds of mFPE [odds ratio (OR), 2.12; 95% confidence interval (CI), 1.12–4.02; p = 0.021] and FPE (OR, 3.55; 95% CI, 1.97–6.38; p < 0.001), with lower odds of sICH (OR, 0.23; 95% CI 0.06–0.93; p = 0.040). There were no significant differences in final reperfusion, functional independence (OR, 1.19; 95% CI 0.87–1.63; p = 0.658), or mortality (OR, 0.94; 95% CI, 0.50–1.76; p = 0.850).ConclusionsIn DMVO-AIS patients, mechanical thrombectomy combining stent retrievers and aspiration catheters achieved higher odds of FPE and lower odds of sICH over single-device techniques. There were no differences in functional independence and mortality. Further trials are warranted to establish these findings.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/display_recor d.php?ID=CRD42022370160, identifier: CRD42022370160.

<b><i>Introduction:</i></b> A patent foramen ovale (PFO) may coexist with other potential embolic sources (PESs) in patients with embolic stroke of undetermined source (ESUS), leading to difficulty in attributing the stroke to either the PFO or other PESs. We aimed to investigate the prevalence and predictors of concomitant PESs in ESUS patients with PFOs. <b><i>Methods:</i></b> A retrospective cohort study was conducted in a tertiary stroke centre. Consecutive patients with ESUS and a concomitant PFO admitted between 2012 and 2021 were included in the study. Baseline characteristics and investigations as a part of stroke workup including echocardiographic and neuroimaging data were collected. PESs were adjudicated by 2 independent neurologists after reviewing the relevant workup. <b><i>Results:</i></b> Out of 1,487 ESUS patients, a total of 309 patients who had a concomitant PFO with mean age of 48.8 ± 13.2 years were identified during the study period. The median Risk of Paradoxical Embolism (RoPE) score for the study cohort was 6 (IQR 5–7.5). Of the 309 patients, 154 (49.8%) only had PFO, 105 (34.0%) patients had 1 other PES, 34 (11.0%) had 2 PES, and 16 (5.2%) had 3 or more PES. The most common PESs were atrial cardiopathy (23.9%), left ventricular dysfunction (22.0%), and cardiac valve disease (12.9%). The presence of additional PESs was associated with age ≥60 years (<i>p</i> &#x3c; 0.001), RoPE score ≤6 (<i>p</i> <i>≤</i>0.001), and the presence of comorbidities including diabetes mellitus (<i>p</i> = 0.004), hypertension (<i>p</i>≤ 0.001), and ischaemic heart disease (<i>p</i> = 0.011). <b><i>Conclusion:</i></b> A large proportion of ESUS patients with PFOs had concomitant PESs. The presence of concomitant PESs was associated with older age and a lower RoPE score. Further, large cohort studies are warranted to investigate the significance of the PES and their overlap with PFOs in ESUS.

Photorealistic 3D models (PR3DM) have great potential to supplement anatomy education; however, there is evidence that realism can increase cognitive load and negatively impact anatomy learning, particularly in students with decreased spatial ability. These differing viewpoints have resulted in difficulty in incorporating PR3DM when designing anatomy courses. To determine the effects of spatial ability on anatomy learning and reported intrinsic cognitive load using a drawing assessment, and of PR3DM versus an Artistic colour-coded 3D model (A3DM) on extraneous cognitive load and learning performance. First-year medical students participated in a cross-sectional (Study 1) and a double-blind randomised control trial (Study 2). Pre-tests analysed participants' knowledge of anatomy of the heart (Study 1, N = 50) and liver (Study 2, N = 46). In Study 1, subjects were first divided equally using a mental rotations test (MRT) into low and high spatial ability groups. Participants memorised a 2D-labeled heart valve diagram and sketched it rotated 180°, before self-reporting their intrinsic cognitive load (ICL). For Study 2, participants studied a liver PR3DM or its corresponding A3DM with texture-homogenisation, followed by a liver anatomy post-test, and reported extraneous cognitive load (ECL). All participants reported no prior anatomy experience. Participants with low spatial ability (N = 25) had significantly lower heart drawing scores (p = 0.001) than those with high spatial ability (N = 25), despite no significant differences in reported ICL (p = 0.110). Males had significantly higher MRT scores than females (p = 0.011). Participants who studied the liver A3DM (N = 22) had significantly higher post-test scores than those who studied the liver PR3DM (N = 24) (p = 0.042), despite no significant differences in reported ECL (p = 0.720). This investigation demonstrated that increased spatial ability and colour-coding of 3D models are associated with improved anatomy performance without significant increase in cognitive load. The findings are important and provide useful insight into the influence of spatial ability and photorealistic and artistic 3D models on anatomy education, and their applicability to instructional and assessment design in anatomy.