Assessment of the intrasinusidal volume before and after maxillary sinus augmentation using mri - a pilot study of eight patients.

PURPOSE: The purpose of this study was to evaluate the suitability, accuracy, and reliability of a non-invasive 3-Tesla magnetic resonance imaging technique (3 T-MRI) for the visualization of maxillary sinus grafts in comparison to conventional, X-ray-based, established standard imaging techniques. METHODS: A total of eight patients with alveolar bone atrophy who required surgical sinus floor augmentation in the course of dental implantation were included in this pilot study. Alongside pre-operative cone-beam computed tomography (CBCT), 3 T-MRI was performed before and 6 months after sinus floor augmentation. Two investigators measured the maxillary sinus volume preoperatively and after bone augmentation. RESULTS: In all cases, MRI demonstrated accurately the volumes of the maxillary sinus grafts. Following surgery, the bony structures suitable for an implant placement increased at an average of 4.89 cm3, corresponding with the decrease of the intrasinusidal volumes. In general, interexaminer discrepancies were low and without statistical significance. CONCLUSION: In this preliminary study, we could demonstrate the feasibility of MRI bone volume measurement as a radiation-free alternative with comparable accuracy to CT/CBCT before procedures like sinus floor augmentation. Nevertheless, costs and artifacts, also present in MRI, have to be taken into account. Larger studies will be necessary to justify the practicability of MRI bone volume evaluation.

Effect of intravenous alteplase on ischaemic lesion water homeostasis.

BACKGROUND AND PURPOSE: Intravenous (IV) lysis with alteplase is known to increase biomarkers of blood-brain barrier breakdown and has therefore been associated with secondary injuries such as hemorrhagic transformation. The impact of alteplase on brain edema formation, however, has not been investigated yet. The purpose was to examine the effects of IV alteplase on ischaemic lesion water homeostasis differentiated from final tissue infarct in patients with and without successful endovascular therapy (sET). METHODS: In all, 232 middle cerebral artery stroke patients were analyzed. 147 patients received IV alteplase, of whom 106 patients received subsequent sET. Out of 85 patients without IV alteplase, 50 received sET. Ischaemic brain edema was quantified at admission and follow-up computed tomography using quantitative lesion net water uptake (NWU) and its difference was calculated (ΔNWU). The relationship of alteplase on ΔNWU and edema-corrected final infarct volume was analyzed using univariate and multivariate linear regression models. RESULTS: The mean ΔNWU was 11.8% (SD 7.9) in patients with alteplase and 11.5% (SD 8.3) in patients without alteplase (P = 0.8). Alteplase was not associated with lowered ΔNWU whilst being associated with reduced edema-corrected tissue infarct volume [-27.4 ml, 95% confidence interval (CI) -49.4 to -5.4 ml; P = 0.02], adjusted for the Alberta Stroke Program Early Computed Tomography Score and recanalization status. In patients with sET, ΔNWU was 10.5% (95% CI 6.3%-10.5%) for patients with IV alteplase and 8.4% (95% CI 9.1%-12.0%) for patients without IV alteplase. CONCLUSION: The application of IV alteplase did not significantly alter ischaemic lesion water homeostasis but was associated with reduced edema-corrected tissue infarct volume, which might be directly linked to improved functional outcome.

Incomplete or failed thrombectomy in acute stroke patients with Alberta Stroke Program Early Computed Tomography Score 0-5 - how harmful is trying?

BACKGROUND AND PURPOSE: It is currently unknown whether mechanical thrombectomy (MT) for ischaemic stroke patients with low initial Alberta Stroke Program Early Computed Tomography Score (ASPECTS) is clinically beneficial or even harmful. The purpose of this study was to investigate whether failed or incomplete MT in acute large vessel occlusion stroke with an initial ASPECTS ≤ 5 is associated with worse clinical outcome compared to patients not undergoing MT. METHODS: This observational cohort study included a consecutive sample of patients with anterior circulation stroke and initial ASPECTS ≤ 5 admitted between March 2015 and August 2019. Failed recanalization was defined as Thrombolysis in Cerebral Infarction (TICI) score 0-2a, and incomplete recanalization as TICI 2b. Clinical outcome was assessed using the modified Rankin Scale (mRS) at 90 days defining very poor clinical outcome as mRS > 4. RESULTS: One hundred and seventy patients were included. Ninety-nine patients underwent MT and 71 patients received best medical treatment only. Clinical outcome after failed or incomplete MT (TICI 0-2b) was significantly better compared to patients with medical treatment only (median mRS 5, interquartile range 4-6 vs 5-6, P = 0.03). In multivariable logistic regression analysis, failed or incomplete MT (TICI 0-2b) showed a significantly reduced likelihood for very poor outcome (odds ratio 0.39, 95% confidence interval 0.19-0.83, P = 0.01). Failed MT (TICI 0-2a) was not associated with a worse outcome compared to best medical treatment. CONCLUSIONS: Patients with failed or incomplete recanalization results (TICI 0-2b) showed a reduced likelihood for very poor outcome compared with those who did not receive MT. Evidence from randomized trials is needed to confirm that even failed or incomplete MT is not harmful in these patients.

Early TICI 2b or Late TICI 3-Is Perfect the Enemy of Good?

BACKGROUND AND PURPOSE: A Thrombolysis in Cerebral Infarction (TICI) score of 3 has been established as therapeutic goal in endovascular therapy (EVT) for acute ischemic stroke; however, in the case of early TICI2b reperfusion, the question remains whether to stop the procedure or to continue in the pursuit of perfection (i.e., TICI 2c/3). METHODS: A total of 6635 patients were screened from the German Stroke Registry. Patients who underwent EVT for occlusion of the middle cerebral artery (M1 segment), with final TICI score of 2b/3 were included. Multivariable logistic regression was performed with functional independence (modified Rankin Scale, mRS at day 90 of 0-2) as the dependent variable. RESULTS: Of 1497 patients, 586 (39.1%) met inclusion criteria with a final TICI score of 2b and 911 (60.9%) with a TICI score of 3. Patients who achieved first-pass TICI3 showed highest odds of functional independence (Odds ratio [OR] 1.71, 95% confidence interval [95% CI] 1.18-2.47). Patients who achieved TICI2b with the second pass (OR 0.53, 95% CI 0.31-0.89) or with three or more passes (OR 0.44, 95% CI 0.27-0.70) had significantly worse clinical outcomes compared to first-pass TICI2b. TICI3 at the second pass was by trend better than first-pass TICI2b (OR 1.55, 95% CI 0.98-2.45), but TICI3 after 3 or more passes (OR 0.93, 95% CI 0.57-1.50) was not significantly different from first-pass TICI2b. CONCLUSION: First-pass TICI2b was superior to TICI2b after ≥ 2 retrievals and comparable to TICI3 at ≥ 3 retrievals. The potential benefit in outcome after achieving TICI3 following further retrieval attempts after first-pass TICI2b need to be weighed against the risks.

Impact of the Implementation of Thrombectomy with Stent Retrievers on the Frequency of Hemicraniectomy in Patients with Acute Ischemic Stroke.

BACKGROUND: The increasing use of endovascular treatments has led to higher recanalization rates and better clinical outcomes compared with intravenous thrombolysis alone. Stent retrievers represent the latest development for recanalization of large vessel occlusions. Decompressive hemicraniectomy has proved beneficial in patients suffering from rising intracranial pressure after malignant stroke. AIMS AND/OR HYPOTHESIS: We investigated the effect of the implementation of stent retriever treatment on the frequency of hemicraniectomy as a surrogate marker for infarct size and thus for poor neurological outcome. METHODS: Patients with acute ischemic stroke were retrospectively studied. We compared the frequency of hemicraniectomy following proximal artery occlusion of the internal carotid artery and middle cerebral artery main stem in the years before (2009 and 2010) and after (2012 and 2013) introducing stent retrievers. RESULTS: Overall, 497 patients with proximal arterial occlusion were included in the study. Of 253 patients admitted in the years 2009 and 2010 44 (17.4 %) and of 244 patients admitted in 2012 and 2013, 20 (8.2 %) received a hemicraniectomy. This decrease in the proportion of hemicraniectomies was statistically significant (p < 0.01). CONCLUSIONS: The findings in this study illustrate a significantly reduced rate of hemicraniectomies in patients with proximal artery occlusions after implementation of thrombectomy with stent retriever. Hereby, we could show a significant reduction of malignant infarctions after thrombectomy with stent retriever.

Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits.

PURPOSE: Intracranial hypotension has been reported as a complication of accidental drainage after surgical treatment in several cases. Application of negative pressure systems (wound drains, VAC(®)-therapy, chest tube drainage) had typically led to severe intracranial hypotension including intracranial hemorrhage and tonsillar herniation. In the last year the authors observed 2 cases of accidental spinal drainage of CSF in patients with neurological deficits, regressing after reduction of the device suction. MATERIAL AND METHODS: We conducted a systematic PubMed-based research of the literature to study the variety and frequency of the reported symptoms from 1st of January 1980 until 1st of October 2015. RESULTS: Reviewing the literature 24 relevant citations including 27 reported cases of posttraumatic or postoperative loss of CSF leading to neurological symptoms were identified. All 15 reported cases in which a negative pressure suction device had been applied showed severe neurological and radiological symptoms such as coma or brain herniation and intracranial hemorrhage. In all cases patients recovered rapidly after removal of the suction device. Milder symptoms were observed in the patients without negative pressure suction, mainly only presenting with headaches or cranial nerve involvement.Additionally, we give an overview about current recommendations regarding cranial and spinal imaging to rule out dural laceration and cranial hypotension. CONCLUSION: Patients with dural laceration complicated by accidental drainage of CSF can present with life-threatening conditions. Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis. A precise radiological examination can help to rule out dural laceration and intracranial hypotension. KEY POINTS: • Undetected dural laceration complicated by negative pressure suction drains can induce life-threatening symptoms.• Increasing use of negative pressure suction devices makes the reported condition an important differential diagnosis for radiologists Citation Format: • Sporns PB, Schwindt W, Cnyrim CD et al. Undetected Dural Leaks Complicated by Accidental Drainage of Cerebrospinal Fluid (CSF) can Lead to Severe Neurological Deficits. Fortschr Röntgenstr 2016; 188: 451 - 458.