Characteristic pattern of pleural effusion in electrical impedance tomography images of critically ill patients.

BACKGROUND: Electrical impedance tomography (EIT) is increasingly used for continuous monitoring of ventilation in intensive care patients. Clinical observations in patients with pleural effusion show an increase in out-of-phase impedance changes. We hypothesised that out-of-phase impedance changes are a typical EIT finding in patients with pleural effusion and could be useful in its detection. METHODS: We conducted a prospective observational study in intensive care unit patients with and without pleural effusion. In patients with pleural effusion, EIT data were recorded before, during, and after unilateral drainage of pleural effusion. In patients with no pleural effusion, EIT data were recorded without any intervention. EIT images were separated into four quadrants of equal size. We analysed the sum of out-of-phase impedance changes in the affected quadrant in patients with pleural effusion before, during, and after drainage and compared it with the sum of out-of-phase impedance changes in the dorsal quadrants of patients without pleural effusion. RESULTS: We included 20 patients with pleural effusion and 10 patients without pleural effusion. The median sum of out-of-phase impedance changes was 70 (interquartile range 49-119) arbitrary units (a.u.) in patients with pleural effusion before drainage, 25 (12-46) a.u. after drainage (P<0.0001) and 11 (6-17) a.u. in patients without pleural effusion (P<0.0001 vs pleural effusion before drainage). The area under the receiver operating characteristics curve was 0.96 (95% limits of agreement 0.91-1.01) between patients with pleural effusion before drainage and those without pleural effusion. CONCLUSIONS: In patients monitored with EIT, the presence of out-of-phase impedance changes is highly suspicious of pleural effusion and should trigger further examination.

Mechanical thrombectomy with the penumbra 3D separator and lesional aspiration: technical feasibility and clinical outcome.

BACKGROUND AND PURPOSE: Intravenous recombinant human tissue plasminogen activator (IV rtPA) therapy has limited revascularization rates in large artery occlusions. We describe the safety and effectiveness of the self-expanding, fully retrievable Separator 3D device as a component of the Penumbra System in revascularization of large artery occlusion in acute ischemic stroke. The 3D secures thrombus with lesional aspiration and functions by retrieving or debulking the clot. MATERIALS AND METHODS: Prospective, single-center pilot study of 20 patients with an acute ischemic stroke secondary to a large artery occlusion within 9 h from symptom onset. The occlusion sites were middle cerebral artery in nine patients, internal carotid artery terminus in eight patients, and basilar artery in three patients. Thrombectomy was performed in 18 patients who had previously received IV rtPA, and of these, two patients had prior failed treatment with the Solitaire stent. One patient had prior failed treatment with the Revive stent. RESULTS: Successful revascularization defined by Thrombolysis in Cerebral Infarction grade 2b-3 was achieved in 17 of 20 (85%) treated vessels. The median time from symptom onset to recanalization was 4.4 h (interquartile range 3.8-5.6 h). No procedural complications occurred, and no symptomatic intracranial hemorrhage was observed. Three (15%) patients died. At 90 days, 50% of patients showed good functional outcome (modified Rankin Scale score ≤ 2). CONCLUSION: Early results suggest that the Separator 3D, which combines a retriever with lesional aspiration, enables safe and effective revascularization.

Clinical outcome of neurointerventional emergency treatment of extra- or intracranial tandem occlusions in acute major stroke: antegrade approach with wallstent and solitaire stent retriever.

BACKGROUND: Acute large cerebral artery occlusions respond poorly to systemic thrombolysis with recombinant tissue plasminogen activator (rTPA) alone. The value of stent retriever-based mechanical thrombectomy in patients with additional extracranial occlusion of the internal carotid artery (ICA), who require acute a priori extracranial stenting in order to reach the intracranial obstruction site, is not well known. We determined the outcome after emergency revascularization in acute stroke with tandem occlusions of the anterior circulation. METHODS: According to specific inclusion/exclusion criteria, eligible stroke patients with large artery occlusions underwent mechanical recanalization with the Solitaire stent retriever. In case of a tandem occlusion, we performed an acute stenting with the Wallstent before thrombectomy. From October 2009 to March 2011, 50 patients were treated according to this protocol; time frames, clinical data, recanalization rates, and midterm outcome were recorded. RESULTS: Forty-one patients had a large artery occlusion in the anterior circulation and nine in the posterior circulation. Mechanical recanalization was successful in 35/41 cases (85 %). Six of 41 patients (15 %) died in the acute phase. In 17/41 patients (42 %), thrombectomy was preceded by an emergency stenting in the extracranial portion of the internal carotid artery (ICA). National Institutes of Health Stroke Scale (NIHSS)/modified Rankin Scale (mRS) scores showed significant improvement in both the stenting group and the nonstenting group; there were no significant differences between the groups. At 90 days, 54 % of patients with emergency stenting had a good outcome. CONCLUSIONS: Acute extracranial stenting with the Wallstent combined with intracranial Solitaire-based thrombectomy is safe and may lead to an improvement in neurological outcome in patients with an otherwise poor prognosis under i.v. thrombolysis alone.