More than five stentriever passes: real benefit or futile recanalization?

BACKGROUND AND AIMS: Clot extraction is associated with favorable outcome in patients with large vessel occlusions (LVO) undergoing endovascular thrombectomy (EVT). However, whether revascularization becomes futile or harmful with an increasing number of passes remains unknown. METHODS: We performed a retrospective analysis of 271 consecutive patients with LVO who underwent stentriever-based EVT as the primary recanalization strategy. Primary outcomes including favorable recanalization, survival, and favorable functional outcomes were compared according to a dichotomized number of stentriever passes utilized with a cutoff of 4. RESULTS: In the entire cohort, 234 (86%) patients reached favorable recanalization and 46 (17%) patients had ≥ 5 passes (range 5-40). Patients that had ≤ 4 passes had significantly higher rates of favorable recanalization and favorable outcomes and a trend towards lower mortality rates compared with those that had ≥ 5 stentriever passes (92% vs. 61%; p < 0.001, 52% vs. 30%; p = 0.009 and 12% vs. 22%, p = 0.098). Among patients that received ≥ 5 stentriever passes, 30% reached favorable outcomes. Patients who achieved recanalization after ≥ 5 passes had higher rates of favorable outcome in comparison with those who did not (p = 0.009). Among patients that had ≥ 5 stentriever passes favorable recanalization (OR 97.3, 95%CI 2.8-3399.3) and admission NIHSS (OR 0.77, 95%CI 0.60-0.99) remained independent predictors of favorable outcome, whereas the number of passes did not. CONCLUSIONS: A substantial proportion of patients reach favorable outcomes even when ≥ 5 stentriever passes are performed. Treatment choices should be individualized based on personal preferences and expertise as well as on patient and clot-specific characteristics.

Predictors and Prognostic Implications of Hemorrhagic Transformation Following Cerebral Endovascular Thrombectomy in Acute Ischemic Stroke: A Multicenter Analysis.

PURPOSE: Hemorrhagic transformation (HT) following cerebral endovascular thrombectomy (EVT) for large vessel occlusion (LVO) in acute ischemic stroke is associated with poor outcome. Recent studies have shown that EVT can be efficacious in imaging-selected patients as late as 6-24 h from onset (late time window; LTW). We sought to determine predictors and prognostic implications of HT following EVT in LTW. METHODS: Consecutive patients undergoing EVT for LVO were recruited into a prospective multicenter database. HT was divided into petechial hemorrhagic-infarction and parenchymal hematoma (PH) type 1 or 2 defined as confluent hemorrhage covering < or > than 1/3 of the infarct volume, respectively. Multivariate analyses were performed to determine variables associated with HT subtypes. RESULTS: Among 611 patients included (mean age 70.5 ± 12.5 years; median NIHSS 16), 115 (18.8%) had HT and 33 of them (5.4%) had PH2. Independent PH2 predictors included failed recanalization (OR 7.0, 95% CI 2.3-21.6), longer time from symptom onset to admission (OR 1.002 per minute 95% CI 1.001-1.003) and hyperlipidemia (OR 3.12; 95%CI 1.12-8.7). HT was not associated with outcome. In contrast, PH2 patients had lower favorable outcome rates (14.3 vs 41.6%, p = 0.004) and higher mortality rates (39 vs 17%, p = 0.001). Patients who underwent EVT in the late versus early window had similar PH2 rates (4.5 vs 6.7%, p = 0.27). In multivariate models, PH2 tripled the odds of both 90-day poor outcome (OR 3.1, 95% CI 1.01-9.5) and 90-day mortality (OR 3.2, 95% CI 1.4-7.3). CONCLUSIONS: PH2 following EVT is associated with increased mortality and unfavorable outcome rates. Rates of PH2 are not different between LTW patients and those treated < 6 h from symptom onset.

Outcomes after reperfusion therapies in patients with ACA stroke: A multicenter cohort study from the EVATRISP collaboration.

BACKGROUND: Patients with stroke secondary to occlusions of the anterior cerebral artery (ACA) often have poor outcomes. The optimal acute therapeutic intervention for these patients remains unknown. METHODS: Patients with isolated ACA-stroke were identified from 10 centers participating in the EndoVascular treatment And ThRombolysis in Ischemic Stroke Patients (EVATRISP) prospective registry. Patients treated with endovascular thrombectomy (EVT) were compared to those treated with intravenous thrombolysis (IVT). Odds ratios with 95% confidence intervals (OR; 95%CI) were calculated using multivariate regression analysis. RESULTS: Included were 92 patients with ACA-stroke. Of the 92 ACA patients, 55 (60%) were treated with IVT only and 37 (40%) with EVT (±bridging IVT). ACA patients treated with EVT had more often wake-up stroke (24% vs. 6%, p = 0.044) and proximal ACA occlusions (43% vs. 24%, p = 0.047) and tended to have higher stroke severity on admission [NIHSS: 10.0 vs 7.0, p = 0.054). However, odds for favorable outcome, mortality or symptomatic intracranial hemorrhage did not differ significantly between both groups. Exploration of the effect of clot location inside the ACA showed that in patients with A1 or A2/A3 ACA occlusions the chances of favorable outcome were not influenced by treatment allocation to IVT or EVT. DISCUSSION: Treatment with either IVT or EVT could be safe with similar effect in patients with ACA-strokes and these effects may be independent of clot location within the occluded ACA.

Clopidogrel underactivity is a common in patients with acute symptomatic severe carotid stenosis.

BACKGROUND: Clopidogrel is commonly used for secondary stroke prevention in patients with large vessel stenosis. Reduced Clopidogrel high on treatment platelet reactivity (CR) can lead to Clopidogrel underactivity (CU) causing acute thrombosis. However, the prevalence of CU among patients with acute symptomatic carotid disease remains unknown. Therefore, we aimed to find the prevalence and identify the predictors for CU among patients with acutely symptomatic carotid stenosis. PATIENTS AND METHODS: Over the span of 14 months, CR was measured at the time of endovascular procedure in all patients undergoing angiography and stenting because of acute symptomatic carotid stenosis. Only patients treated per institutional protocol with a combination of Clopidogrel and Aspirin were included. CR was measured with VerifyNowP2Y12 reaction units (PRU) and CU was defined as PRU > 208. Patients with CU were compared to those without CU. RESULTS: Thirty-five patients were included (mean age 71.3 ± 10, 76% men) and twelve (34.3%, mean age 71.8 ± 8.4, 58% men) had CU at the time of endovascular intervention. On univariate analysis more severe carotid stenosis was seen in CU patients (92.6 ± 6.5% vs 81.6 ± 13.6%, p = 0.013) and percent stenosis was independently associated with CU on multivariate analysis (p = 0.023). CONCLUSIONS: CU is present in 1 of every 3 patients with acutely symptomatic carotid disease. The current results suggest that CR testing should become part of routine care in patients with acutely symptomatic carotid disease.

THE DECADE OF THE RABiT (2005-15).

The RABiT (Rapid Automated Biodosimetry Tool) is a dedicated Robotic platform for the automation of cytogenetics-based biodosimetry assays. The RABiT was developed to fulfill the critical requirement for triage following a mass radiological or nuclear event. Starting from well-characterized and accepted assays we developed a custom robotic platform to automate them. We present here a brief historical overview of the RABiT program at Columbia University from its inception in 2005 until the RABiT was dismantled at the end of 2015. The main focus of this paper is to demonstrate how the biological assays drove development of the custom robotic systems and in turn new advances in commercial robotic platforms inspired small modifications in the assays to allow replacing customized robotics with 'off the shelf' systems. Currently, a second-generation, RABiT II, system at Columbia University, consisting of a PerkinElmer cell::explorer, was programmed to perform the RABiT assays and is undergoing testing and optimization studies.

Functional interplay between gelatinases and hyperalgesia in endotoxin-induced localized inflammatory pain.

The role of ECM-degrading proteinases in normal developmental processes and in pathological conditions is extensively studied. However, few reports describe the role ECM-degrading proteinases play in modulating hyperalgesia. The goal of this study is to describe the regulation of gelatinases during endotoxin mediated local inflammation, induced by intra plantar endotoxin (ET; 1.25 microg/50 microl) injection in Balb/c mice, and to correlate that with hyperalgesia. ET injections induced hyperalgesia, as determined by hot plate and paw pressure tests, which peaked by 24 h and recovered by 48 h post-injection. Contralateral paw of ET injected mice and saline injected paws in control mice elicited no hyperalgesia. Zymography showed that ET and saline injected paws elicited increased gelatinase activity by 9 h after injection. However, only the former maintained high levels of expression of a 90 kD gelatinase up to at least 96 h post ET injection, while in the latter gelatinase expression was down regulated by 24 h. Interestingly, the 90-kD gelatinase was upregulated in the contralateral paw of the ET-injected mice beyond 48 h post injection. Saline injection in that paw, during a time when gelatinases are upregulated, induced hyperalgesia. Intraperitoneal injection of either ZnCl(2) (100 microM), thymulin (5 microg/100 microl), or morphine (2 mg/kg/100 microl) reversed the ET-induced hyperalgesia and suppressed gelatinase activity. Furthermore, intraperitoneal injection of MPI, an ECM-degrading proteinase inhibitor, reversed ET induced hyperalgesia. Taken together, the above suggests that a functional interplay exists between gelatinase upregulation triggered by ET injections and hyperalgesia. The exact mechanism underlying such correlation remains to be determined.

Partial purification and characterization of proteins with growth promoting activities from ovine mammary gland secretions.

Developmental regulation of growth promoting activities in mammary secretions of pregnant Awassi ewes was defined, and growth factors contained in these secretions were partially purified and characterised. Mammary secretions from pregnant ewes enhanced fibroblast cell (AKR-2B) and mammary cell (CID-9 cell strain) proliferation to levels comparable to that induced by 10% Foetal calf serum. Major milk proteins in mammary secretions collected from pregnant ewes one month prior to lambing up to one week after lambing, were resolved by SDS-PAGE, while gelatinases were resolved by zymography. Gelatinase activity was noted prior to P134 and decreased thereafter to reach a minimum during lactation. This decrease was concomitant with the onset of casein production. It is during this critical developmental period that highest growth promoting activity in mammary secretions was detected. Secretions with highest growth promoting activity were fractionated by ion exchange and gel filtration chromatography. Two heat-resistant, trypsin/chymotrypsin sensitive, growth-promoting activities were characterised. The first, designated ovine mammary derived growth factor-1 (oMDGF-1), had around a 30 kDa molecular weight and eluted at 0.65 M NaCl gradient on cation ion exchange chromatography. The second, oMDGF-2, eluted under gel filtration conditions at a molecular weight of 50 kDa and 150 kDa. oMDGF-1 induced changes in Connexin 43, but not in beta-casein mRNA expression by CID-9 mammary cells. In conclusion, growth factor activities in ewe mammary secretions peak during gestation at a period that overlaps maximal gelatinase expression and precedes milk protein synthesis. The factors modulate mammary cell function and may play a role in mammary gland development.

Lessons learned using the insertable robotic effector platform (IREP) for single port access surgery.

This paper presents the preliminary evaluation of a robotic system for single port access surgery. This system may be deployed through a 15-mm incision. It deploys two surgical arms and a third arm manipulating a stereo-vision module that tracks instrument location. The paper presents the design of the robot along with experiments demonstrating the capabilities of this robot. The evaluation includes use of tasks from fundamentals of laparoscopic surgery, evaluation of telemanipulation accuracy, knot tying, and vision tracking of tools.