Dual-layered micromesh stent technology for embolic prevention in carotid revascularization: technical experience and clinical outcomes from a high-volume interventional radiology center.

BACKGROUND: Carotid artery stenting (CAS) has become a cornerstone of carotid revascularization for stroke prevention. Despite the advantages of CAS, large-scale randomized trials involving prior (single-layer) generation of carotid stents demonstrated its higher risk of periprocedural cerebrovascular events compared to carotid endarterectomy (CEA). Dual-layer mesh-covered stents (DLSs) showed promising results in terms of 30-day embolic events. This study aims to evaluate 30-day clinical efficacy of DLS against a closed-cell single-layer stent, based on large-volume data. METHODS: The study center is part of the Italian National Outcomes Evaluation Program (PNE). CAS procedures performed between November 2017 and September 2023 were retrospectively analyzed. Our primary endpoint was 30-day survival free of death, stroke, and myocardial infarction (MI). Periprocedural stroke rate, technical success and restenosis rate of CAS procedures performed with DLSs and first-generation stents (FGSs) were also evaluated. RESULTS: Over a total of 1101 CAS procedures (55 men; 745 males; mean age of 79±7.8 years), 80.2% were treated with DLS and 48.6% were symptomatic. The cumulative stroke-, MI- and death-free 30-day survival was 98.9%, Technical success was achieved in 98.9% of cases. The DLS group showed significantly lower 30-day death, stroke and death+stroke and periprocedural minor stroke rates compared to FGS group (P=0.04; P=0.04; P=0.003 and P=0.0002, respectively). CONCLUSIONS: The use of DLS in patients undergoing CAS in our large-volume center showed a high technical success rate and minimal cerebral embolic complications by 30 days. High volumes and an experienced interventional team may contribute to these favorable outcomes.

Baseline clinical and neuroradiological predictors of outcome in patients with large ischemic core undergoing mechanical thrombectomy: A retrospective multicenter study.

BACKGROUND: Recent randomized trials have shown the benefit of mechanical thrombectomy (MT) also in patients with an established large ischemic core. AIMS: The purpose of this study was to define baseline predictors of clinical outcome in patients with large vessel occlusion (LVO) in the anterior circulation and an Alberta Stroke Program Early CT score (ASPECTS) ⩽ 5, undergoing MT. MATERIAL AND METHODS: The databases of 16 comprehensive stroke centers were retrospectively screened for patients with LVO and ASPECTS ⩽5 that received MT. Baseline clinical and neuroradiological features, including the differential contribution of all ASPECTS regions to the composite score, were collected. Primary clinical outcome measure was a 90-day modified Rankin Scale (mRS) score of 0-2. Statistical analysis used a logistic regression model and random forest algorithm. RESULTS: A total of 408 patients were available for analysis. In multivariate model, among baseline features, lower age (odd ratio (OR) = 0.962, 95% confidence interval (CI) = 0.943-0.982) and lower National Institute of Health Stroke Scale (NIHSS) score (OR = 0.911, 95% CI = 0.862-0.963) were associated with the mRS score 0-2. Involvement of the M2 (OR = 0.398, 95% CI = 0.206-0.770) or M4 (OR = 0.496, 95% CI = 0.260-0.945) ASPECTS regions was associated with an unfavorable outcome. Random forest analysis confirmed that age and baseline NIHSS score are the most important variables influencing clinical outcome, whereas involvement of cortical regions M5, M4, M2, and M1 can have a negative impact. CONCLUSION: Our retrospective analysis shows that, along with age and baseline clinical impairment, presence of early ischemic changes involving cortical areas has a role in clinical outcome in patients with large ischemic core undergoing MT. DATA ACCESS STATEMENT: The data that support the findings of this study are available upon reasonable request.

Effect of General Anesthesia Versus Conscious Sedation/Local Anesthesia on the Outcome of Patients with Minor Stroke and Isolated M2 Occlusion Undergoing Immediate Thrombectomy: A Retrospective Multicenter Matched Analysis.

BACKGROUND: This study investigates the impact of general anesthesia (GA) versus conscious sedation/local anesthesia (CS/LA) on the outcome of patients with minor stroke and isolated M2 occlusion undergoing immediate mechanical thrombectomy (iMT). METHODS: The databases of 16 comprehensive stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale score ≤5 who received iMT. Propensity score matching was used to estimate the effect of GA versus CS/LA on clinical outcomes and procedure-related adverse events. The primary outcome measure was a 90-day modified Rankin Scale (mRS) score of 0-1. Secondary outcome measures were a 90-day mRS score of 0-2 and all-cause mortality, successful reperfusion, procedural-related symptomatic subarachnoid hemorrhage, intraprocedural dissections, and new territory embolism. RESULTS: Of the 172 patients who were selected, 55 received GA and 117 CS/LA. After propensity score matching, 47 pairs of patients were available for analysis. We found no significant differences in clinical outcome, rates of efficient reperfusion, and procedural-related complications between patients receiving GA or LA/CS (mRS score 0-1, P = 0.815; mRS score 0-2, P = 0.401; all-cause mortality, P = 0.408; modified Treatment in Cerebral Infarction score 2b-3, P = 0.374; symptomatic subarachnoid hemorrhage, P = 0.082; intraprocedural dissection, P = 0.408; new territory embolism, P = 0.462). CONCLUSIONS: In patients with minor stroke and isolated M2 occlusion undergoing iMT, the type of anesthesia does not affect clinical outcome or the rate of procedural-related complications. Our results agree with recent data showing no benefit of one specific anesthesiologic procedure over the other and confirm their generalizability also to patients with minor baseline symptoms.

Predictors of parenchymal hematoma and clinical outcome after mechanical thrombectomy in patients with large ischemic core due to large vessel occlusion: a retrospective multicenter study.

BACKGROUND: The aim of our study was to find predictors of parenchymal hematoma (PH) and clinical outcome after mechanical thrombectomy (MT) in patients with large vessel occlusion (LVO) and baseline large infarct. METHODS: The databases of 16 stroke centers were retrospectively screened for patients with anterior circulation LVO and baseline Alberta Stroke Program Early CT Score (ASPECTS) ≤5 that received MT. Procedural parameters, including the number of passes during first and second technique of MT, were recorded. Outcome measures were occurrence of PH type 2 and any type of PH after MT, and the 90-day modified Rankin Scale (mRS) score of 0-3 and 0-2. RESULTS: In total, 408 patients were available for analysis. A higher number of passes in the second technique was predictive of PH type 2 (odds ratio (OR) - 3.204, 95% confidence interval (CI) 1.140 to 9.005), whereas procedure conducted under general anesthesia was associated with lower risk (OR 0.127, 95% CI 0.002 to 0.808). The modified thrombolysis in cerebral infarction grade 2c-3 was associated with the mRS score 0-3 (OR 3.373, 95% CI 1.891 to 6.017), whereas occurrence of PH type 2 was predictive of unfavorable outcome (OR 0.221, 95% CI 0.063 to 0.773). Similar results were found for the mRS score 0-2 outcome measure. CONCLUSION: In patients with large ischemic core, a higher number of passes during MT and procedure not conducted under general anesthesia are associated with increased rate of PH type 2, that negatively impact the clinical outcome. Our data outline a delicate balance between the need of a complete recanalization and the risk of PH following MT.

Liver-Specific Contrast-Enhanced Magnetic Resonance Cholangio-Pancreatography (Ce-MRCP) in Non-Invasive Diagnosis of Iatrogenic Biliary Leakage.

Current non-invasive diagnostic modalities of iatrogenic bile leak (BL) are not particularly sensitive and often fail to localise the BL origin. Percutaneous transhepatic cholangiography (PTC) and endoscopic retrograde cholangiopancreatography (ERCP) are considered the gold standard, yet are invasive studies with potential complications. Ce-MRCP has been not comprehensively studied in this setting but may prove particularly helpful given its non-invasive nature and the anatomical dynamic detail. This paper reports a monocentric retrospective study of BL patients referred between January 2018 and November 2022 submitted to Ce-MRCP followed by PTC. The primary outcome was the accuracy of Ce-MRCP in detecting and localising BL compared to PTC and ERCP. Blood tests, coexisting cholangitis features and time for leak resolution were also investigated. Thirty-nine patients were included. Liver-specific contrast-enhanced MRCP detected BL in 69% of cases. The BL localisation was 100% accurate. Total bilirubin above 4 mg/dL was significantly associated with false negative results of Ce-MRCP. Ce-MRCP is highly accurate in detecting and localising BL, but sensitivity is significantly reduced by a high bilirubin level. Ce-MRCP may be very useful in early BL diagnosis and in accurate pre-treatment planning, but can only be reliably used in selected patients with TB < 4 mg/dL. Non-surgical techniques, both radiological and endoscopic, are proven to be effective in terms of leak resolution.

Early neurological deterioration in patients with minor stroke due to isolated M2 occlusion undergoing medical management: a retrospective multicenter study.

BACKGROUND: Patients with minor stroke and M2 occlusion undergoing best medical management (BMM) may face early neurological deterioration (END) that can lead to poor long-term outcome. In case of END, rescue mechanical thrombectomy (rMT) seems beneficial. Our study aimed to define factors relevant to clinical outcome in patients undergoing BMM with the possibility of rMT on END, and find predictors of END. METHODS: Patients with M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score≤5 that received either BMM only or rMT on END after BMM were extracted from the databases of 16 comprehensive stroke centers. Clinical outcome measures were a 90-day modified Rankin Scale (mRS) score of 0-1 or 0-2, and occurrence of END. RESULTS: Among 10 169 consecutive patients with large vessel occlusion admitted between 2016 and 2021, 208 patients were available for analysis. END was reported in 87 patients that were therefore all subjected to rMT. In a logistic regression model, END (OR 3.386, 95% CI 1.428 to 8.032), baseline NIHSS score (OR 1.362, 95% CI 1.004 to 1.848) and a pre-event mRS score=1 (OR 3.226, 95% CI 1.229 to 8.465) were associated with unfavorable outcome. In patients with END, successful rMT was associated with favorable outcome (OR 4.549, 95% CI 1.098 to 18.851). Among baseline clinical and neuroradiological features, presence of atrial fibrillation was a predictor of END (OR 3.547, 95% CI 1.014 to 12.406). CONCLUSION: Patients with minor stroke due to M2 occlusion and atrial fibrillation should be closely monitored for possible worsening during BMM and, in this case, promptly considered for rMT.

Can machine learning of post-procedural cone-beam CT images in acute ischemic stroke improve the detection of 24-h hemorrhagic transformation? A preliminary study.

PURPOSE: Hemorrhagic transformation (HT) is an independent predictor of unfavorable outcome in acute ischemic stroke (AIS) patients undergoing endovascular thrombectomy (EVT). Its early identification could help tailor AIS management. We hypothesize that machine learning (ML) applied to cone-beam computed tomography (CB-CT), immediately after EVT, improves performance in 24-h HT prediction. METHODS: We prospectively enrolled AIS patients undergoing EVT, post-procedural CB-CT, and 24-h non-contrast CT (NCCT). Three raters independently analyzed imaging at four anatomic levels qualitatively and quantitatively selecting a region of interest (ROI) < 5 mm2. Each ROI was labeled as "hemorrhagic" or "non-hemorrhagic" depending on 24-h NCCT. For each level of CB-CT, Mean Hounsfield Unit (HU), minimum HU, maximum HU, and signal- and contrast-to-noise ratios were calculated, and the differential HU-ROI value was compared between both hemispheres. The number of anatomic levels affected was computed for lesion volume estimation. ML with the best validation performance for 24-h HT prediction was selected. RESULTS: One hundred seventy-two ROIs from affected hemispheres of 43 patients were extracted. Ninety-two ROIs were classified as unremarkable, whereas 5 as parenchymal contrast staining, 29 as ischemia, 7 as subarachnoid hemorrhages, and 39 as HT. The Bernoulli Naïve Bayes was the best ML classifier with a good performance for 24-h HT prediction (sensitivity = 1.00; specificity = 0.75; accuracy = 0.82), though precision was 0.60. CONCLUSION: ML demonstrates high-sensitivity but low-accuracy 24-h HT prediction in AIS. The automated CB-CT imaging evaluation resizes sensitivity, specificity, and accuracy rates of visual interpretation reported in the literature so far. A standardized quantitative interpretation of CB-CT may be warranted to overcome the inter-operator variability.

Mechanical thrombectomy in minor stroke due to isolated M2 occlusion: a multicenter retrospective matched analysis.

BACKGROUND: The purpose of this study was to evaluate the effectiveness of mechanical thrombectomy (MT) in patients with isolated M2 occlusion and minor symptoms and identify possible baseline predictors of clinical outcome. METHODS: The databases of 16 high-volume stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score ≤5 who received either early MT (eMT) or best medical management (BMM) with the possibility of rescue MT (rMT) on early neurological worsening. Because our patients were not randomized, we used propensity score matching (PSM) to estimate the treatment effect of eMT compared with the BMM/rMT. The primary clinical outcome measure was a 90-day modified Rankin Scale score of 0-1. RESULTS: 388 patients were initially selected and, after PSM, 100 pairs of patients receiving eMT or BMM/rMT were available for analysis. We found no significant differences in clinical outcome and in safety measures between patients receiving eMT or BMM/rMT. Similar results were also observed after comparison between eMT and rMT. Concerning baseline predicting factors of outcome, the involvement of the M2 inferior branch was associated with a favorable outcome. CONCLUSION: Our multicenter retrospective analysis has shown no benefit of eMT in minor stroke patients with isolated M2 occlusion over a more conservative therapeutic approach. Although our results must be viewed with caution, in these patients it appears reasonable to consider BMM as the first option and rMT in the presence of early neurological deterioration.

Mechanical thrombectomy in acute ischemic stroke due to large vessel occlusion in the anterior circulation and low baseline National Institute of Health Stroke Scale score: a multicenter retrospective matched analysis.

BACKGROUND AND PURPOSE: The benefit of mechanical thrombectomy (MT) in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO) and baseline mild neurological symptoms remains unclear. The purpose of this study was to evaluate the effectiveness of MT in this subgroup of patients. METHODS: The databases of 9 high-volume Italian stroke centers were retrospectively screened for patients with LVO in the anterior circulation and a baseline National Institute of Health Stroke Scale (NIHSS) score ≤ 5 that received either immediate MT or best medical management (BMM) with the possibility of rescue MT upon neurological worsening. Primary outcome measure was a modified Rankin Scale score of 0-1 at 90 days. Propensity score matching (PSM) analysis was used to estimate the treatment effect of immediate MT compared to BMM/rescue MT. RESULTS: Two hundred and seventy-two patients received immediate MT (MT group). The BMM/rescue MT group included 41 patients. The primary outcome was achieved in 78.6% (n = 246) of overall patients, with a higher proportion in the MT group (80.5% vs. 65.9%, p = 0.03) in unadjusted analysis. After PSM, patients in the MT group had a 19.5% higher chance of excellent outcome at 90 days compared to the BMM/Rescue MT group with a similar risk of death from any cause. CONCLUSIONS: Our experience is in favor of a potential benefit of MT also in patients with LVO and a NIHSS score ≤ 5 at the time of groin puncture. Nonetheless, this issue waits for a clear-cut recommendation in a dedicated clinical trial.

Anemia and erythropoietin in space flights.

Since the very early manned missions in space, a state of anemia associated with reduced erythropoietin levels and reduced plasma volume was disclosed. The reduction in red blood cell mass is driven by a process of selective hemolysis, which has been named neocytolysis. This phenomenon also occurs in people living at a high altitude who descend rapidly to sea level. The origin of the signal leading to destruction of newly produced red blood cells probably is located in central circulation, but the operating mechanism is unknown. The importance of plasma cell volume reduction in the genesis of a lower red cell mass also is supported by the inverse correlation seen at moderate altitude. People arriving at moderate altitude have increased erythropoietin concentration that decreases after a few days and is in inverse correlation with central venous pressure. Studies under simulated microgravity conditions in human beings (bed rest, head-down tilt at -6 degrees , water immersion) and in rats provide further insight in unraveling the mechanism of astronauts' anemia, a problem difficult to study in space because of the limited availability of spaceflights.

Low urinary albumin excretion in astronauts during space missions.

BACKGROUND: Physiological changes occur in man during space missions also at the renal level. Proteinuria was hypothesized for space missions but research data are missing. METHODS: Urinary albumin, as an index of proteinuria, and other variables were analyzed in 4 astronauts during space missions onboard the MIR station and on the ground (control). Mission duration before first urine collection in the four astronauts was 4, 26, 26, and 106 days, respectively. On the ground, data were collected 2 months before mission in two astronauts, 6 months after in the other astronauts. A total of twenty-two 24-hour urine collections were obtained in space (n per astronaut = 1-14) and on the ground (n per astronaut = 2-12). Urinary albumin was measured by radioimmunoassay. For each astronaut, mean of data in space and on the ground was defined as individual average. RESULTS: The individual averages of 24 h urinary albumin were lower in space than on the ground in all astronauts; the difference was significant (mean +/- SD, space and on the ground = 3.41 +/- 0.56 and 4.70 +/- 1.20 mg/24 h, p = 0.017). Dietary protein intake and 24-hour urinary urea were not significantly different between space and on the ground. CONCLUSIONS: Urinary albumin excretion is low during space mission compared to data on the ground before or after mission. Low urinary albumin excretion could be another effect of exposure to weightlessness (microgravity).

Effects of the aromatase inhibitor fadrozole on plasma sex steroid secretion, spermatogenesis and epididymis morphology in the lizard, Podarcis sicula.

Recently, increasing importance has been attached to the role of estrogens and their receptors in male reproduction, since they have been found to be abundant in the male reproductive tract. In the lizard, Podarcis sicula, a seasonal breeder, estrogens seem to be involved in the regulation of testicular activity. Particularly, it has been hypothesized that the block of spermatogenesis and the complete regression of the epididymis and other secondary sexual characters (SSCs) in autumn might be due to high estrogen levels. To investigate the role of estrogens in the reproductive process of male lizards, we utilized Fadrozole ((AI) [4-(5,6,7,8-tetrahydroimidazole [1,5-a] pyridin-5-yl)-benzonitrile monohydrochloride] (CGS 16949A)), a nonsteroidal inhibitor of aromatase, the enzyme involved in the aromatization of androgens to estrogens, evaluating its effects on plasma sex-hormone release, spermatogenesis and epididymis morphology. For this purpose, adult male lizards, captured during the autumnal recrudescence, were intraperitoneally injected with 0.5 microg and 5 microg/g/body weight of AI for 15 and 30 days. In the animals treated with the higher AI dose, estrogen levels decreased if compared to the control groups, whereas androgen levels increased. Furthermore, histologic sections of testes and epididymes showed that the 30-day treatment with AI-induced spermatogenesis resumption with release of sperms into the large lumen of the seminiferous tubules, and the epididymes appeared more developed with moderately secreting columnar canal cells. Therefore, it is proposed that failure of spermatogenesis in autumn might be due to high estrogen levels.

Urinary albumin in space missions.

Proteinuria was hypothesized for space mission but research data are missing. Urinary albumin, as index of proteinuria, was analyzed in frozen urine samples collected by astronauts during space missions onboard MIR station and on ground (control). Urinary albumin was measured by a double antibody radioimmunoassay. On average, 24h urinary albumin was 27.4% lower in space than on ground; the difference was statistically significant. Low urinary albumin excretion could be another effect of exposure to weightlessness (microgravity).

Urinary albumin in head-down bed rest.

Previous studies reported low urinary albumin excretion in astronauts during space missions, suggesting an effect of microgravity on renal albumin handling. To test this hypothesis, urinary albumin excretion was investigated with use of head-down bed rest at -6 degrees (HDBR), an experimental model of microgravity. Eight healthy young men underwent two phases. Each phase included 2 days of dietary adaptation (run-in), 4 days of baseline (light activities and bed rest), and 6 days of experiment: HDBR 24h every day for intervention light activities and bed rest for control. The study was done in metabolic ward (DLR, Cologne, Germany). Urine were collected in days 3-4 of baseline and days 4-6 of experiment. Urinary albumin was measured by a double antibody radioimmunoassay, creatininuria by automated colourimetry. Data are expressed as albumin/creatinine ratio to control for timing and completeness of urine collection. Compared to baseline, albumin/creatinine ratio decreased by 9.3% during HDBR and increased by 14.9% during control. The difference in changes over baseline was significant between HDBR and control (p < 0.01 by paired comparison). The data support the hypothesis that low gravity reduces renal albumin excretion.