Kadirvel, Ramanathan

Background The modified Rankin Scale (mRS) score of ≤2 (functional independence) has been the most common primary endpoint of modern mechanical thrombectomy (MT) trials. However, unlike mRS 0-1, mRS score of 2 indicates disability. An important proportion of the mRS 2 patients are home dependent and report a significant decrease in their quality of life. Purpose To investigate excellent outcome (mRS 0-1) rates after MT. Methods We systematically searched Ovid MEDLINE, Ovid EMBASE, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science databases. Randomized controlled trials (RCTs) investigating the role of modern MT in acute ischemic stroke were screened. Posterior circulation and large-core infarct trials were excluded from the study. The data regarding excellent outcomes (mRS: 0-1), functional independence (mRS: 0-2), and reperfusion were collected. Results Twenty-two RCTs comprising 5692 patients were included in the meta-analysis. The overall mRS 0-1 rate was 31.24% (95% CI = 26.95–36.2). The rate of successful reperfusion was 81.8% (95% CI = 77.93–85.86). MT achieved significantly higher rates of mRS 0-1 compared to standard care alone (OR = 2.04; 95% CI = 1.64–2.55; P-value < 0.001), with no heterogeneity detected among studies (I 2 = 0%; P-value = 0.52). The direct MT and MT plus intravenous thrombolytic treatment groups’ excellent outcome rates were comparable (OR = 0.98; 95% CI = 0.82–1.18; P-value = 0.863). Also, aspiration and stent retriever thrombectomy techniques provided similar excellent outcome rates (OR = 0.76; 95% CI = 0.55–1.05; P-value = 0.141). Conclusions Our results prove the additional benefit of MT over standard care, using a stricter definition for favorable functional outcome. Nearly one-third of patients presenting with large artery occlusion and treated with MT had no disability at 90 days. While this is remarkable, our results also indicate that reperfusion alone is often not enough to prevent disability and underline the need for better neuroprotection strategies.

Background Although direct contact aspiration has emerged as one of the leading techniques for mechanical thrombectomy (MT), there is still ongoing debate about the aspiration/suction pump devices that can optimize recanalization rates. To address this gap, we conducted a meta-analysis comparing the aspiration efficacy of 60 ml syringe and pump devices in benchtop MT models. Methods Systematic literature review was conducted using Medline, Embase, Web of Science, and Scopus in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Outcomes of interest included flow rate and vacuum pressure delivered by a 60 ml syringe and several aspiration pumps. We used a random effects model to calculate the mean difference (MD) with 95% confidence intervals (CIs) and a statistically significant difference was considered as a two-sided p -value of less than 0.05. Results We included six benchtop studies comparing 60 ml syringes and vacuum pumps. Our meta-analysis showed that there were no significant differences in vacuum pressure (MD:0.71inHg, 95% CI: [−0.81;2.23], p = 0.359) and flow rate (MD:0.27 mL/s, 95% CI: [−3,07; 3.61], p = 0.873) between 60 ml syringes and vacuum pumps groups. Conclusions Our study demonstrated comparable performance in terms of vacuum pressure and flow rates between a 60 ml syringe and a heterogeneous combination of commercially available aspiration pumps.

Background The presence of an outer shell has been recently described as a common feature of acute ischemic stroke (AIS) thrombi. We performed a systematic review of the current literature on shell genesis, structure, and clinical significance. Methods Following PRISMA guidelines, we searched Ovid Cochrane Central Register of Controlled Trials, Embase, Medline, Scopus, and Web of Science for studies reporting the composition and structure of AIS thrombi and clot analogs. Identified studies were added to Covidence software for primary screening. Two reviewers independently screened titles and abstracts followed by full-text screening. Results From 1290 identified studies, 10 were included in this review. Studies using histology/immunohistochemistry/immunofluorescence described fibrin, platelets, von Willebrand factor, and neutrophil extracellular traps as the main components of the shell. Scanning electron microscopy demonstrated a dense, compact fibrin/platelet-rich shell, and a core rich in polyhedrocytes. Microfluidics studies identified highly activated P-selectin-positive platelets and fibrin forming the core while secondary agonists adenosine diphosphate and thromboxane, along with loosely packed P-selectin-negative platelets constituted the shell. Conclusions The composition, compaction, and integrity of the shell may impact thrombolysis and revascularization outcomes. The preponderance of studies supported this conclusion.

Background Distal transradial artery access (dTRA) has received increasing consideration for performing diagnostic cerebral angiography and neurointerventional procedures. In this meta-analysis, we aim to evaluate the safety and efficacy of dTRA compared to conventional transradial access (cTRA) for cerebral angiography and neurointerventions. Method A systematic review and meta-analysis were conducted on studies investigating outcomes of dTRA and cTRA in neurointerventions. The primary outcome was technical success rates. Secondary outcomes included access site complication rates, crossover rates to alternative vessels, fluoroscopy time, and contrast volume. The random effects model was used to calculate the mean difference (MD) and odds ratios (OR) with 95% confidence intervals (Cl). Results Eight retrospective observational studies with a total of 1477 patients who underwent 1175 diagnostic cerebral angiography and 516 neurointerventional procedures using 546 dTRA and 1164 cTRA approaches were included in our meta-analysis. The technical success rate was similar between dTRA and cTRA groups (95.8% vs 91.4%; OR:1.65; 95% Cl: 0.52 to 5.22; P = 0.40). Similarly, no difference was seen in dTRA and cTRA regarding access site complications (2% vs 1.4%; OR: 1.31; 95% CI: 0.47 to 3.61; P = 0.61) and access site crossover (2.1% vs 5.3%; OR: 0.55; 95% Cl: 0.28 to 1.05; P = 0.07). After resolving heterogeneity among included studies, dTRA was associated with a shorter fluoroscopy time (MD: −0.91 min; 95% CI: −1.74 to −0.09; P = 0.03) and lower contrast volume (MD: −8.32 mL; 95% CI = −14.7 to −1.94; P = 0.011). Conclusion Our findings suggest that the dTRA approach is a safe and effective alternative to the cTRA approach in patients undergoing cerebral angiography and neurointerventions.

Background The Woven EndoBridge (WEB) device is used to treat wide-neck bifurcation aneurysms (WNBAs). We conducted a systematic review and meta-analysis to determine the retreatment rate strategies following aneurysmal recurrence of WEB device treated WNBAs. Methods This study is reported following the PRISMA 2020 guidelines. We conducted a systematic review of the literature using PubMed, Scopus, Embase, and Web of Science. Data were pooled using a random-effects model. We calculated pooled prevalence and corresponding 95% confidence intervals (CI). Results We included 11 studies. The overall retreatment rate was 171/1875 aneurysms (10.3%; 95% CI = 8.3–12.9). Stent-assisted coiling was used to treat 59 aneurysms (36.7%; 95% CI = 26.4–48.5), and flow diverters were used to treat 44 aneurysms (18.7%; 95% CI = 9.9–32.5). Following retreatment, the complete occlusion rate was 57/91 aneurysms (62.8%; 95% CI = 48.2–75.3) and the adequate occlusion rate was 24/91 aneurysms (26.4%; 18.4%–36.4%). The most common aneurysmal recurrence site was the anterior communicating artery (44/136 aneurysms, 32.4%; 95% CI = 25.0–40.7). Conclusions Roughly 10% of WNBAs initially treated with the WEB device will undergo retreatment. Retreatment is an effective strategy for WEB-treated aneurysms, with high rates of adequate and complete occlusion. Future studies should work to identify risk factors for aneurysmal recurrence.

Background Smoking represents a leading risk factor for acute ischemic stroke (AIS). Previous literature has described a “smoking paradox”, wherein smokers experience better outcomes following intravenous thrombolysis for AIS. It is unclear whether such a phenomenon exists in smokers undergoing endovascular therapy (EVT) for AIS. To assess outcomes in smokers following EVT for AIS, we conducted a systematic review and meta-analysis. Methods Following the PRISMA guidelines, a systematic literature review of the English language literature was conducted using PubMed, Embase Web of Science, and Scopus. Outcomes of interest included 90-day modified Rankin Scale (mRS) 0–2, thrombolysis in cerebral infarction (TICI) score 2b-3, symptomatic intracranial hemorrhage (sICH), and mortality. We calculated mean difference (MD), pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CI). Results Eight studies with 2633 patients comprised our analysis. On average, smokers were 10.14 years (MD = 10.14, [95% CI = −14.49 to −5.79], P-value < 0.001) younger than non-smokers. Smokers achieved mRS 0–2 (OR = 1.82, [95% CI, 1.34–2.48], P-value < 0.001) and TICI 2b-3 (OR = 1.61, [95% CI, 1.19–2.19], P-value = 0.002) at a higher rate than non-smokers. sICH rates were comparable between smokers and non-smokers (OR = 1.07, [95% CI, 0.62–1.85], P-value = 0.81). Smokers had a lower rate of 90-day mortality than non-smokers (OR = 0.54, [95% CI, 0.41–0.71], P-value < 0.001). Conclusions In this meta-analysis of eight studies, we found that smokers with AIS undergoing EVT experienced better 90-day outcomes and higher rates of TICI 2b-3. This may be due to baseline differences between smokers and non-smokers, but future studies should explore alternative reasons that could explain this relationship between smoking and AIS treated with EVT.

Acute ischemic stroke (AIS) due to distal, medium vessel occlusion (DMVO) is increasingly recognized as the next frontier for mechanical thrombectomy. Distal, medium vessel occlusions are typically defined as an occlusion in the following arteries: anterior cerebral artery, M2–M4 segments of the middle cerebral artery, posterior cerebral artery, posterior inferior cerebellar artery, anterior inferior cerebellar artery, and superior cerebellar artery. It is estimated that 25–40% of all AIS is due to DMVO. Because of the large burden of DMVO, the frequency of literature published regarding these occlusions has greatly increased in recent years. Furthermore, treatment modalities have been created specifically for DMVOs. Due to the rapidly evolving literature on this topic, remaining up to date on DMVO definitions, anatomy, management, imaging, and clinical course is difficult. In this review article, we synthesized existing literature regarding the aforementioned topics and discussed future directions.

Background Vertebrobasilar junction (VBJ) aneurysms represent a relatively rare and often anatomically complex subgroup of saccular aneurysms. This systematic review and meta-analysis aimed to assess the safety and efficacy of endovascular treatment (EVT) of VBJ aneurysms. Methods PubMed, Web of Science, Ovid Medline, Ovid Embase, and Scopus were searched from inception to 20 December 2022. We included primary studies assessing the long-term clinical and angiographic outcomes for VBJ aneurysms treated with endovascular techniques. We excluded surgically managed studies. All data were analyzed using R software version 4.2.1. We calculated pooled prevalence rates and their corresponding 95% confidence intervals (CI). Results In this meta-analysis, a total of 76 VBJ aneurysms from seven studies were included for quantitative analysis. The results showed that the rate of adequate occlusion (complete + near complete occlusion) was 94.1% (95% CI = 76.71–98.71), and the rate of complete occlusion was 77.7% (95% CI = 63.07–87.65). A modified Rankin Scale (mRS) score of 0–2 was achieved in 93.9% of patients (95% CI = 67.65–99.14). The mortality rate was found to be 5.9% (95% CI = 0.97–28.55), and the retreatment rate was 4.6% (95% CI = 1.50–13.36). The overall ischemic complication rate was 4.7% (95% CI = 0.73–25.4), while the overall hemorrhagic complication rate was 4.6% (95% CI = 1.5–13.36). Conclusions The treatment of VBJ aneurysms with EVT is effective in achieving curative treatment and is associated with good clinical outcomes and low mortality rates. These findings provide important insights into the clinical and angiographic outcomes and the complication rates of EVT for VBJ aneurysms.

Background Procedural success following mechanical thrombectomy for acute ischemic stroke is assessed using the thrombolysis in cerebral infarction scale. We conducted a systematic review and meta-analysis to determine whether outcomes differed between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. Methods We conducted a systematic review of the literature using PubMed, Embase, Scopus, and Web of Science. We included original studies in which outcomes were stratified based on first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. The primary outcome of interest was the rate of modified Rankin Scale 0-2. Secondary outcomes of interest were rates of modified Rankin Scale 0-1, symptomatic intracranial hemorrhage, and mortality. We calculated odds ratios and corresponding 95% confidence intervals. Results Four studies with 1554 patients were included in the quantitative analysis. Rate of modified Rankin Scale 0–2 (odds ratio = 0.91, 95% confidence interval = 0.70–1.18; P -value = 0.49), modified Rankin Scale 0–1 (odds ratio = 1.21, 95% confidence interval = 0.86–1.71; P -value = 0.27), symptomatic intracranial hemorrhage (odds ratio = 1.36, 95% confidence interval = 0.47–3.98; P -value = 0.57), and mortality (odds ratio = 0.91, 95% confidence interval = 0.67–1.25; P -value = 0.56) did not differ between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. There was no heterogeneity among included studies for modified Rankin Scale 0–2, modified Rankin Scale 0–1, or mortality; however, there was moderate heterogeneity among studies for symptomatic intracranial hemorrhage ( I 2 = 53%, P -value = 0.12). Conclusions Clinical and safety outcomes did not differ between first pass thrombolysis in cerebral infarction 2b and multiple pass thrombolysis in cerebral infarction 2c-3. Future prospective studies and clinical trials should determine whether first pass thrombolysis in cerebral infarction 2b is a viable endpoint to thrombolysis in cerebral infarction 2c-3.

Background Flow diverter treatment may inevitably require jailing of the branch vessels. While the patency of covered branch arteries and associated safety risks have been a topic of substantial interest, the question of whether the characteristics of branch vessels affect flow diversion's efficacy remains unanswered. In this study, we aimed to assess the impact of branch arteries on the efficacy of endoluminal flow diverters, specifically focusing on posterior communicating artery (Pcomm) aneurysms. Methods Following PRISMA guidelines, we systematically searched the MEDLINE, EMBASE, Scopus, Web of Science, and Cochrane databases with predefined keywords. Studies providing data for flow diversion outcomes in Pcomm aneurysms were included. Outcomes of interest included complete and adequate aneurysm obliteration, ischemic and hemorrhagic complications, and Pcomm occlusion in the follow-up period. A random or fixed effects model was used to calculate the odds ratios (ORs) and pooled event rates with their corresponding confidence intervals (CI). Results The overall complete and adequate aneurysm occlusion rates were 72.25% (95% CI: 64.46–78.88%) and 88.37% (95% CI: 84.33–92.6), respectively. Fetal-type Pcomm aneurysms had significantly lower complete aneurysm occlusion rates than the nonfetal-type Pcomm aneurysms (OR: 0.12, 95% CI: 0.05–0.29). Overall ischemic and hemorrhagic complication rates were 2.62% (95% CI = 0.71–5.32) and 0.71% (95% CI: 0–2.24), respectively. There were no significant associations between Pcomm morphology and complications (OR: 3.61, 95% CI = 0.42–31.06 for ischemic complications and OR: 2.31, 95% CI = 0.36–14.6 for hemorrhage). Overall Pcomm occlusion rate was 32.04% (95% CI = 19.96–47.13), and the Pcomm patency was significantly lower in nonfetal-type Pcomm aneurysms (OR: 0.10, 95% CI = 0.02–0.44). Conclusion Our meta-analysis suggests that flow diversion is a safe treatment option for Pcomm aneurysms, regardless of fetal-type Pcomm morphology. However, on the other hand, our findings indicate that Pcomm anatomy or the presence of jailed large branches can affect the efficacy of flow diverter treatment.