Effect of anesthetic strategies on distal stroke thrombectomy in the anterior and posterior cerebral artery

BACKGROUND

Numerous questions regarding procedural details of distal stroke thrombectomy remain unanswered. This study assesses the effect of anesthetic strategies on procedural, clinical and safety outcomes following thrombectomy for distal medium vessel occlusions (DMVOs).

METHODS

Patients with isolated DMVO stroke from the TOPMOST registry were analyzed with regard to anesthetic strategies (ie, conscious sedation (CS), local (LA) or general anesthesia (GA)). Occlusions were in the P2/P3 or A2-A4 segments of the posterior and anterior cerebral arteries (PCA and ACA), respectively. The primary endpoint was the rate of complete reperfusion (modified Thrombolysis in Cerebral Infarction score 3) and the secondary endpoint was the rate of modified Rankin Scale score 0-1. Safety endpoints were the occurrence of symptomatic intracranial hemorrhage and mortality.

RESULTS

Overall, 233 patients were included. The median age was 75 years (range 64-82), 50.6% (n=118) were female, and the baseline National Institutes of Health Stroke Scale score was 8 (IQR 4-12). DMVOs were in the PCA in 59.7% (n=139) and in the ACA in 40.3% (n=94). Thrombectomy was performed under LA±CS (51.1%, n=119) and GA (48.9%, n=114). Complete reperfusion was reached in 73.9% (n=88) and 71.9% (n=82) in the LA±CS and GA groups, respectively (P=0.729). In subgroup analysis, thrombectomy for ACA DMVO favored GA over LA±CS (aOR 3.07, 95% CI 1.24 to 7.57, P=0.015). Rates of secondary and safety outcomes were similar in the LA±CS and GA groups.

CONCLUSION

LA±CS compared with GA resulted in similar reperfusion rates after thrombectomy for DMVO stroke of the ACA and PCA. GA may facilitate achieving complete reperfusion in DMVO stroke of the ACA. Safety and functional long-term outcomes were comparable in both groups.

Breaking with a dogma: persisting diffusion restrictions (pDWI) in follow-up after endovascular treatment for stroke

BACKGROUND

Post-stroke diffusion weighted imaging (DWI) signal transformation of the infarct core, which results in high apparent diffusion coefficient (ADC) values and variable DWI signal intensity, is completed no later than 1 month after onset of ischemia. We observed frequent exceptions to this timeline of change in DWI signal, which led to uncertainties in further clinical patient management.

METHODS

A prospective single-center study of patients treated with mechanical thrombectomy of a large vessel occlusion in the anterior circulation was conducted. Patients received high-resolution MRI at 3T, including DWI, in the acute post-stroke phase and in the follow-up after 3-12 months.

RESULTS

Overall, 78 patients (45 men) of mean age 63.6 years were evaluated. We identified persisting or new diffusion restriction in 29 of the 78 patients (37.2%) on follow-up imaging. Diffusion restrictions in a different location from the infarct core, representing new (sub-)acute ischemia, were observed in four patients (5.1%). Smaller areas of persisting diffusion restriction (pDWI lesions with high DWI signal and reduced ADC values) within the former infarct core were observed in 25 patients (32.1%) without clinical evidence of recurrent stroke, but with worse outcome scores at follow-up compared with patients without pDWI lesions. The presence of pDWI lesions is associated with a large primary infarct core (multivariate regression OR 1.03 (95% CI 1.01 to 1.05); p<0.01), mediating the relationship between pDWI lesions and clinical outcome.

CONCLUSION

Smaller foci of persisting diffusion restriction (pDWI lesions) in the follow-up after endovascular treatment for stroke are frequent and likely represent a slowed ADC signal progression within a formerly large infarct core.

Mechanical thrombectomy of distal cerebral vessel occlusions of the anterior circulation

Mechanical thrombectomy (MT) is frequently performed for distal medium vessel occlusions (DMVO) of the anterior circulation in acute stroke patients. However, evidence for its clinical benefit remains scarce. In this study, we aim to investigate clinical course and safety outcomes of MT in comparison to standard medical therapy (SMT) in DMVO. This single-center retrospective observational study included 138 consecutive patients treated for DMVO of the anterior circulation between 2015 and 2021. To reduce the risk of selection bias, propensity score matching (PSM) of patients with MT versus SMT was performed for the covariates NIHSS and mRS at admission. Out of all 138 patients, 48 (34.8%) received MT and 90 (65.2%) received SMT only. Overall, patients treated with MT showed significantly higher NIHSS and mRS scores at admission. Post 1:1 PSM, there was a trend toward a better NIHSS improvement in patients with MT (median 4 vs. 1, P = 0.1). No significant differences were observed in the occurrence of symptomatic intracranial hemorrhage or mortality between the groups before and after PSM. A subgroup analysis showed significantly higher NIHSS improvement (median 5 versus 1, P = 0.01) for patients with successful MT (≥ mTICI 2b). Mechanical thrombectomy for distal medium vessel occlusions (DMVO) in the anterior circulation appeared safe and feasible. Successful recanalization was associated with clinical improvement. Larger, multi-center, randomized-controlled trials are required to corroborate these findings.

Thrombectomy versus Medical Management for Isolated Anterior Cerebral Artery Stroke: An International Multicenter Registry Study

Background Evidence supporting a potential benefit of thrombectomy for distal medium vessel occlusions (DMVOs) of the anterior cerebral artery (ACA) is, to the knowledge of the authors, unknown. Purpose To compare the clinical and safety outcomes between mechanical thrombectomy (MT) and best medical treatment (BMT) with or without intravenous thrombolysis for primary isolated ACA DMVOs. Materials and Methods Treatment for Primary Medium Vessel Occlusion Stroke, or TOPMOST, is an international, retrospective, multicenter, observational registry of patients treated for DMVO in daily practice. Patients treated with thrombectomy or BMT alone for primary ACA DMVO distal to the A1 segment between January 2013 and October 2021 were analyzed and compared by one-to-one propensity score matching (PSM). Early outcome was measured by the median improvement of National Institutes of Health Stroke Scale (NIHSS) scores at 24 hours. Favorable functional outcome was defined as modified Rankin scale scores of 0-2 at 90 days. Safety was assessed by the occurrence of symptomatic intracerebral hemorrhage and mortality. Results Of 154 patients (median age, 77 years; quartile 1 [Q1] to quartile 3 [Q3], 66-84 years; 80 men; 94 patients with MT; 60 patients with BMT) who met the inclusion criteria, 110 patients (median age, 76 years; Q1-Q3, 67-83 years; 50 men; 55 patients with MT; 55 patients with BMT) were matched. DMVOs were in A2 (82 patients; 53%), A3 (69 patients; 45%), and A3 (three patients; 2%). After PSM, the median 24-hour NIHSS point decrease was -2 (Q1-Q3, -4 to 0) in the thrombectomy and -1 (Q1-Q3, -4 to 1.25) in the BMT cohort (P = .52). Favorable functional outcome (MT vs BMT, 18 of 37 [49%] vs 19 of 39 [49%], respectively; P = .99) and mortality (MT vs BMT, eight of 37 [22%] vs 12 of 39 [31%], respectively; P = .36) were similar in both groups. Symptomatic intracranial hemorrhage occurred in three (2%) of 154 patients. Conclusion Thrombectomy appears to be a safe and technically feasible treatment option for primary isolated anterior cerebral artery occlusions in the A2 and A3 segment with clinical outcomes similar to best medical treatment with and without intravenous thrombolysis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Zhu and Wang in this issue.

Aspiration Versus Stent Retriever Thrombectomy for Distal, Medium Vessel Occlusion Stroke in the Posterior Circulation: A Subanalysis of the TOPMOST Study

BACKGROUND

The optimal endovascular strategy for reperfusing distal medium-vessel occlusions (DMVO) remains unknown. This study evaluates angiographic and clinical outcomes of thrombectomy strategies in DMVO stroke of the posterior circulation.

METHODS

TOPMOST (Treatment for Primary Medium Vessel Occlusion Stroke) is an international, retrospective, multicenter, observational registry of patients treated for DMVO between January 2014 and June 2020. This study analyzed endovascularly treated isolated primary DMVO of the posterior cerebral artery in the P2 and P3 segment. Technical feasibility was evaluated with the first-pass effect defined as a modified Thrombolysis in Cerebral Infarction Scale score of 3. Rates of early neurological improvement and functional modified Rankin Scale scores at 90 days were compared. Safety was assessed by the occurrence of symptomatic intracranial hemorrhage and intervention-related serious adverse events.

RESULTS

A total of 141 patients met the inclusion criteria and were treated endovascularly for primary isolated DMVO in the P2 (84.4%, 119) or P3 segment (15.6%, 22) of the posterior cerebral artery. The median age was 75 (IQR, 62-81), and 45.4% (64) were female. The initial reperfusion strategy was aspiration only in 29% (41) and stent retriever in 71% (100), both achieving similar first-pass effect rates of 53.7% (22) and 44% (44; P=0.297), respectively. There were no significant differences in early neurological improvement (aspiration: 64.7% versus stent retriever: 52.2%; P=0.933) and modified Rankin Scale rates (modified Rankin Scale score 0-1, aspiration: 60.5% versus stent retriever 68.6%; P=0.4). In multivariable logistic regression analysis, the time from groin puncture to recanalization was associated with the first-pass effect (adjusted odds ratio, 0.97 [95% CI, 0.95-0.99]; P<0.001) that in turn was associated with early neurological improvement (aOR, 3.27 [95% CI, 1.16-9.21]; P<0.025). Symptomatic intracranial hemorrhage occurred in 2.8% (4) of all cases.

CONCLUSIONS

Both first-pass aspiration and stent retriever thrombectomy for primary isolated posterior circulation DMVO seem to be safe and technically feasible leading to similar favorable rates of angiographic and clinical outcome.

Only Hyperuricemia with Crystalluria, but not Asymptomatic Hyperuricemia, Drives Progression of Chronic Kidney Disease

BACKGROUND

The roles of asymptomatic hyperuricemia or uric acid (UA) crystals in CKD progression are unknown. Hypotheses to explain links between UA deposition and progression of CKD include that (1) asymptomatic hyperuricemia does not promote CKD progression unless UA crystallizes in the kidney; (2) UA crystal granulomas may form due to pre-existing CKD; and (3) proinflammatory granuloma-related M1-like macrophages may drive UA crystal-induced CKD progression.

METHODS

MALDI-FTICR mass spectrometry, immunohistochemistry, 3D confocal microscopy, and flow cytometry were used to characterize a novel mouse model of hyperuricemia and chronic UA crystal nephropathy with granulomatous nephritis. Interventional studies probed the role of crystal-induced inflammation and macrophages in the pathology of progressive CKD.

RESULTS

Asymptomatic hyperuricemia alone did not cause CKD or drive the progression of aristolochic acid I-induced CKD. Only hyperuricemia with UA crystalluria due to urinary acidification caused tubular obstruction, inflammation, and interstitial fibrosis. UA crystal granulomas surrounded by proinflammatory M1-like macrophages developed late in this process of chronic UA crystal nephropathy and contributed to the progression of pre-existing CKD. Suppressing M1-like macrophages with adenosine attenuated granulomatous nephritis and the progressive decline in GFR. In contrast, inhibiting the JAK/STAT inflammatory pathway with tofacitinib was not renoprotective.

CONCLUSIONS

Asymptomatic hyperuricemia does not affect CKD progression unless UA crystallizes in the kidney. UA crystal granulomas develop late in chronic UA crystal nephropathy and contribute to CKD progression because UA crystals trigger M1-like macrophage-related interstitial inflammation and fibrosis. Targeting proinflammatory macrophages, but not JAK/STAT signaling, can attenuate granulomatous interstitial nephritis.