Association between Left Atrial Appendage Morphology and Clot Histology in Patients with Embolic Ischemic Stroke: An Exploratory Study.

BACKGROUND: Acute embolic ischemic stroke poses a significant healthcare challenge. Histological clot features' variability among patients with acute ischemic stroke treated by mechanical thrombectomy has potential implications for determining treatment and etiology. This study investigated the clot histological feature differences among patients who experienced cardioembolic stroke and embolic stroke of undetermined source with different left atrial appendage (LAA) morphologies. METHODS: We conducted a prospective observational study involving 79 patients with acute embolic ischemic stroke undergoing mechanical thrombectomy. Computed tomography angiography images were used to classify LAA morphologies. An artificial intelligence algorithm assessed the clot fibrin and red blood cell contents. RESULTS: Patients with chicken-wing LAA morphology exhibited lower mean clot fibrin proportions than did those with non-chicken-wing morphology (p < 0.001). Linear regression analysis showed that chicken-wing LAA was significantly associated with a lower clot fibrin proportion (estimate, -0.177; 95% CI [-0.259, -0.096]; p < 0.001). The successful recanalization rate and first-pass effect between the groups did not differ significantly. CONCLUSIONS: The chicken-wing LAA morphological type is associated with lower clot fibrin contents, suggesting potentially different embolism mechanisms or diverse embolic sources, compared with the non-chicken-wing LAA types. Further studies are required to investigate this association.

Intravenous r-tPA Dose Influence on Outcome after Middle Cerebral Artery Ischemic Stroke Treatment by Mechanical Thrombectomy.

Background and Objectives: Pretreatment with intravenous thrombolysis (IVT) is still recommended in all eligible acute ischemic stroke patients with large-vessel occlusion before mechanical thrombectomy (MTE). However, the added value and safety of bridging therapy versus direct MTE remains controversial. We aimed at evaluating the influence of r-tPA dose level in patients with middle cerebral artery (MCA) occlusion treated with MTE. Materials and Methods: We prospectively compared clinical and radiological outcomes in 38 bridging patients, with 65 receiving direct MTE for MCA stroke admitted to Vilnius University Hospital Santaros Clinics. Following our protocol, r-tPA infusion was stopped just before MTE in the operating room. Therefore, we divided all bridging patients into three groups according to the amount of r-tPA they received: bolus, partial dose or full dose. Functional independence at 90 days was assessed by a modified Rankin Scale score, i.e., from 0-2. The safety outcomes included 90-day mortality and any intracerebral hemorrhage (ICH). Results: Baseline characteristics and functional outcome at 90 days did not differ between the bridging and direct MTE groups. Shorter MTE procedure and hospitalization time (p = 0.025 and p = 0.036, respectively) were observed in the direct MTE group. An IVT treatment subgroup analysis showed higher rates of symptomatic ICH (p < 0.001) and longer intervals between imaging to MTE (p = 0.005) in the full r-tPA dose group. Conclusions: In patients with an MCA stroke, direct MTE seems to be a safe and equally effective as bridging therapy. The optimal r-tPA dose remains unclear. Randomized trials are needed to accurately evaluate the added value of r-tPA in patients treated with MTE.

Diagnostic methods, treatment modalities, and follow-up of extracranial arteriovenous malformations.

OBJECTIVE: Arteriovenous malformations (AVMs) are an uncommon vascular pathology that remains challenging to accurately diagnose and successfully treat. This study introduces a novel way to evaluate AVM treatment outcomes using transarterial lung perfusion scintigraphy (TLPS) and reports our treatment results. MATERIAL AND METHODS: The patients treated for extracranial AVMs were studied retrospectively. Diagnosis and outcomes were based on clinical data, ultrasonography, magnetic resonance imaging, computed tomography, angiography, and TLPS studies. The influence of gender; location, form, and stage of AVMs; first attempt at treatment; and treatment modalities was analyzed. Outcomes were defined as positive (cure, improvement, and remission) or negative (no remission and aggravation). RESULTS: Of the 324 patients with congenital vascular malformations, 129 (39.8%) presented with AVMs, and the data of 56 treated patients with AVMs were analyzed. Of the 29 patients in the endovascularly treated group, 15 in the surgically treated group, and 12 in the combined treatment group, 24 (82.8%), 14 (93.3%), and 10 patients (83.3%), respectively, had positive outcomes (P>0.05). All outcomes were positive in surgically treated patients with extratruncular limited AVMs, and these patients were more likely to be cured as compared with those who had other forms of AVMs (OR, 5.8; 95% CI, 1.1-29; P=0.02). The patients with more advanced AVMs (stages III and IV) and with AVMs in the gluteal and pelvic region were more likely to have the worst outcomes than those with stage II AVMs (OR, 8.2; 95% CI, 1-72; P=0.03) and with AVMS in other locations (OR, 5.8; 95% CI, 1.1-29; P=0.02), respectively. Gender and age did not significantly influence treatment results (P>0.05). The TLPS data of 17 patients showed AV shunting ranging from 0% to 92%, which combined with other results helped identify 9 patients who needed further interventions, 6 who were treated successfully, and 2 who had insignificant shunting. CONCLUSIONS: The best outcomes were achieved in surgically treated patients with localized lesions and less advanced AVMs. For the first time in Lithuania, a modified TLPS method has been introduced that enhances a hemodynamic assessment of AV shunting and provides with a more accurate evaluation of AVMs to better serve in planning future treatments.