Mechanical Thrombectomy of M2-Occlusion Dorn, Franziska, MD; Lockau, Hannah, MD; Stetefeld, Henning, MD ...
Journal of stroke and cerebrovascular diseases,
07/2015, Letnik:
24, Številka:
7
Journal Article
Recenzirano
Background There is growing evidence for the efficacy of mechanical thrombectomy in acute stroke patients with large-vessel occlusions in the anterior circulation. Although distal occlusions of the ...middle cerebral artery (MCA) can cause severe clinical symptoms, endovascular therapy is not considered here as the first choice. The aim of our study was to prove the efficacy and safety of mechanical thrombectomy for distal occlusion types in the anterior circulation (M2-segment). Methods Stentretriever-based thrombectomy was performed in 119 patients with acute MCA occlusions between October 2011 and April 2013: 104 (87.4%) were M1- and 15 (12.6%) M2-occlusions. These groups were compared with regard to recanalization success, periprocedural complications, hemorrhage, and modified Rankin Scale (mRS) at 90 days. Results Thrombolysis in cerebral infarction 2b/3 reperfusion was more frequent in M2- than in M1-occlusions (93.3% versus 76.0%; P = .186). There was no significant difference in the mean National Institutes of Health Stroke Scale between the M1- and the M2-group both at admission and at discharge (16.18 ± 7.30 versus 13.73 ± 8.30, P = .235; 9.36 ± 8.60 versus 7.43 ± 9.84, P = .446). A good clinical outcome (mRS 0-2) at 3 months was more frequent in the M2-group (60% versus 43.3%; P = .273) and mortality was higher in the M1-group (21.2% versus 6.7%; P = .297). There were 3 periprocedural complications in the M1- and none in the M2-group. Conclusions Endovascular treatment of M2-occlusions in severely affected patients is not associated with a higher procedural risk or postprocedural hemorrhage. Compared with M1-occlusions, there was a greater chance for a good angiographic and clinical result in our case series. Therefore, stentretriever-based thrombectomy should also be considered for patients with severe symptoms because of an acute M2-occlusion.
Cerebral aneurysms are pathological dilatations of the vessels supplying the brain. They carry a certain risk of rupture, which in turn, results in a high risk of mortality and morbidity. Flow ...diverters (FDs) are high-density meshed stents which are implanted in the vessel segment harboring an intracranial aneurysm to cover the entrance of the aneurysm, thus reducing the blood flow into the aneurysm, promoting thrombosis formation and stable occlusion, which prevents rupture or growth of the aneurysm. In the present study, the blood flow in an idealized aneurysm, treated with an FD stent and a regular stent (RS), were modeled and analyzed considering their design, surface area porosity, and flow reduction to investigate the quantitative and qualitative effect of the stent on intra-aneurysmal hemodynamics. CFD simulations were conducted before and after treatment. Significant reductions were observed for most hemodynamic variables with the use of stents, during both the peak systolic and late diastolic cardiac cycles. FD reduces the intra-aneurysmal wall shear stress (WSS), inflow, and aneurysmal flow velocity, and increases the turnover time when compared to the RS; therefore, the possibility of aneurysm thrombotic occlusion is likely to increase, reducing the risk of rupture in cerebral aneurysms.
Purpose: To assess accuracy, the frequency of hemorrhagic complications and computed tomography (CT) radiation dose parameters in pediatric patients undergoing landmark-guided external ventricular ...drain (EVD) placement in an emergency setting. Methods: Retrospective analysis comprised 36 EVD placements with subsequent CT control scans in 29 patients (aged 0 to 17 years) in our university hospital from 2008 to 2022. The position of the EVD as well as the presence and extension of bleeding were classified according to previously established grading schemes. Dose length product (DLP), volume-weighted CT dose index (CTDIvol) and scan length were extracted from the radiation dose reports and compared to the diagnostic reference values (DRLs) issued by the German Federal Office for Radiation Protection. Results: After the initial EVD placement, optimal positioning of the catheter tip into the ipsilateral frontal horn or third ventricle (Grade I), or a functional positioning in the contralateral lateral ventricle or the non-eloquent cortex (Grade II), was achieved in 28 and 8 cases, respectively. In 32 of 36 procedures, no evidence of hemorrhage was present in the control CT scan. Grade 1 (<1 mL) and Grade 2 (≥1 to 15 mL) bleedings were detected after 3 and 1 placement(s), respectively. For control scans after EVD placements, CTDIvol (median 25%; 75% quartile) was 39.92 30.80; 45.55 mGy, DLP yielded 475.50 375.00; 624.75 mGy*cm and the scan length result was 136 120; 166 mm. Exceedances of the DRL values were observed in 14.5% for CTDIvol, 12.7% for DLP and 65.6% for the scan length. None of these values was in the range requiring a report to the national authorities. Conclusion: Landmark-based emergency EVD placement in pediatric patients yielded an optimal position in most cases already after the initial insertion. Complications in terms of secondary hemorrhages are rare. CT dose levels associated with the intervention are below the reportable threshold of the national DRLs in Germany.
From aqueous solutions containing Λ-Co(en)3I3 (1, 2), Δ-Co(en)3I3 (5), or racemic Co(en)3I3 (3, 4) AgI and PbI2 respectively were precipitated by addition of Ag2EDC, Ag(en)Ag(BDC), PbADC or ...(NH4)Ag5(BTC)2(NH3)(H2O)2 and filtered off (en = ethylenediamine, H2EDC = fumaric acid, H2BDC = terephthalic acid, H2ADC = acetylenedicarboxylic acid, H3BTC = trimesic acid). After slow evaporation of the remaining solutions single crystals of ∞ 1{Λ-Co(en)3EDC3/2}·5.625H2O (P21, Z = 4, 1), ∞ 1{Λ-Co(en)3BDC3/2}·10H2O (P1, Z = 2, 2), ∞ 2{Co(en)3ADC3/2}·4H2O (P1̅, Z = 2, 3), ∞ 2{Co(en)3BTC}·5.55H2O (P21/c, Z = 8, 4), and ∞ 2{Δ-Co(en)3EDC(NO3)}·2H2O (C2, Z = 4, 5) were obtained. In all compounds the Co(en)33+ cores are connected in a T-shaped mode via N–H···O hydrogen bonds to the carboxylates to form complex networks. Water molecules are bound via O–H···O hydrogen bonds to the networks, further increasing their complexity. It is noteworthy that the chirality of the starting material (Λ- or Δ-Co(en)3I3) is maintained during the reaction thus leading to non-centrosymmetric polymers, whereas with racemic Co(en)3I3 centrosymmetric polymers are obtained.
Carotid cavernous fistulas (CCFs) are abnormal connections between the cavernous sinus and the internal and/or external carotid artery. Endovascular therapy is the gold standard treatment. In the ...current retrospective single-center study we report detailed dosimetrics of all patients with CCFs treated by endovascular coil embolization between January 2012 and August 2021. Procedural and dosimetric data were compared between direct and indirect fistulas according to Barrow et al., and different DSA protocol groups. The local diagnostic reference level (DRL) was defined as the 3rd quartile of the dose distribution. In total, thirty patients met the study criteria. The local DRL was 376.2 Gy cm
. The procedural dose area product (DAP) (
= 0.03) and the number of implanted coils (
= 0.02) were significantly lower in direct fistulas. The median values for fluoroscopy time (FT) (
= 0.08) and number of DSA acquisitions (
= 0.84) were not significantly different between groups. There was a significantly positive correlation between DAP and FT (
= 0.003). The application of a dedicated low-dose protocol yielded a 32.6% DAP reduction. In conclusion, this study provides novel DRLs for endovascular CCF treatment using detachable coils. The data presented in this work might be used to establish new specific DRLs.
Large vessel occlusion (LVO) stroke patients routinely undergo interhospital transfer to endovascular thrombectomy capable centers. Imaging is often repeated with residual intravenous (IV) iodine ...contrast at post-transfer assessment. We determined imaging findings and the impact of residual contrast on secondary imaging. Anterior circulation LVO stroke patients were selected out of a consecutive cohort. Directly admitted patients were contrast naïve, and transferred patients had previously received IV iodine contrast for stroke assessment at the referring hospital. Two independent readers rated the visibility of residual contrast on non-contrast computed tomography (CT) after transfer and assessed the hyperdense vessel sign. Multivariate linear regression analysis was used to investigate the association of the Alberta Stroke Program Early CT score (ASPECTS) with prior contrast administration, time from symptom onset (TFSO), and CTP ischemic core volume in both directly admitted and transferred patients.
We included 161 patients, with 62 (39%) transferred and 99 (62%) directly admitted patients. Compared between these groups, transferred patients had a longer TFSO-to-imaging at our institution (median: 212 vs. 75 min,
< 0.001) and lower ASPECTS (median: 8 vs. 9,
< 0.001). Regression analysis presented an independent association of ASPECTS with prior contrast administration (β = -0.25,
= 0.004) but not with TFSO (β = -0.03,
= 0.65). Intergroup comparison between transferred and directly admitted patients pointed toward a stronger association between ASPECTS and CTP ischemic core volume in transferred patients (β = -0.39 vs. β = -0.58,
= 0.06). Detectability of the hyperdense vessel sign was substantially lower after transfer (66 vs. 10%,
< 0.001).
Imaging alterations due to residual IV contrast are frequent in clinical practice and render the hyperdense vessel sign largely indetectable. Larger studies are needed to clarify the influence on the association between ASPECTS and ischemic core.
Purpose
To evaluate the diagnostic value of CT-like images based on a 3D T1-weighted spoiled gradient echo-based sequence (T1SGRE) for the visualization of the pediatric skull and the identification ...of pathologies, such as craniosynostosis or fractures.
Methods
In this prospective study, 20 patients with suspected craniosynostosis (mean age 1.26 ± 1.38 years, 10 females) underwent MR imaging including the T1SGRE sequence and 2 more patients were included who presented with skull fractures (0.5 and 6.3 years, both male). Additionally, the skull of all patients was assessed using radiography or CT in combination with ultrasound. Two radiologists, blinded to the clinical information, evaluated the CT-like images. The results were compared to the diagnosis derived from the other imaging modalities and intraoperative findings. Intrarater and interrater agreement was calculated using Cohen’s κ.
Results
Of the 22 patients 8 had a metopic, 4 a coronal and 2 a sagittal craniosynostosis and 2 patients showed a complex combination of craniosynostoses. The agreement between the diagnosis based on the T1SGRE and the final diagnosis was substantial (Cohen’s κ = 0.92, 95% confidence interval (CI) 0.77–1.00 for radiologist 1 and κ = 0.76, CI 0.51–1.00 for radiologist 2). Of the patients with fractures, one presented with a ping pong fracture and one with a fracture of the temporal bone. Both radiologists could identify the fractures using the T1SGRE.
Conclusion
The visualization of the pediatric skull and the assessment of sutures using a CT-like T1SGRE MR-sequence is feasible and comparable to other imaging modalities, and thus may help to reduce radiation exposure in pediatric patients. The technique may also be a promising imaging tool for other pathologies, such as fractures.
Background The diagnosis of ischemic cerebellar stroke is challenging because of nonspecific symptoms and very limited accuracy of commonly applied computed tomography (CT) imaging. Advances in CT ...perfusion imaging provide increasing value in the detection of posterior circulation stroke, but the prognostic value remains unclear. We aimed to identify imaging parameters that predict morphologic outcome in cerebellar stroke patients using advanced CT including whole-brain CT perfusion (WB-CTP). Methods and Results We selected all subjects with cerebellar WB-CTP perfusion deficits and follow-up-confirmed cerebellar infarction from a consecutive cohort with suspected stroke who underwent WB-CTP. Posterior-circulation-Acute-Stroke-Prognosis-Early-CT-Score (pc-ASPECTS) was determined on noncontrast CT, CT angiography source images, and on parametric WB-CTP maps. Cerebellar perfusion deficit volumes on all maps and the final infarction volume on follow-up imaging were quantified. Uni- and multivariate regression analyses were performed. Sixty patients fulfilled the inclusion criteria. pc-ASPECTS on CT angiography source images (ß, -9.239; 95% CI, -14.220 to -4.259;
<0.001) and cerebral blood flow deficit volume (ß, 0.886; 95% CI, 0.684 to 1.089;
<0.001) were significantly associated with final infarction volume in univariate linear regression analysis. The association of cerebral blood flow deficit volume (ß, 0.830; 95% CI, 0.605-1.055;
<0.001) was confirmed in a multivariate linear regression model adjusted for age, sex, pc-ASPECTS on noncontrast CT, and CT angiography source images and the National Institutes of Health Stroke Scale score on admission. No other clinical or imaging parameters were associated with cerebellar stroke final infarction volume (
>0.05). Conclusions In contrast to noncontrast CT and CT angiography, WB-CTP imaging contains prognostic information for morphologic outcome in patients with acute cerebellar stroke.
MR perfusion imaging is important in the clinical evaluation of primary brain tumors, particularly in differentiating between true progression and treatment-induced change. The utility of ...velocity-selective ASL (VSASL) compared to the more commonly utilized DSC perfusion technique was assessed in routine clinical surveillance MR exams of 28 patients with high-grade gliomas at 1.5T. Using RANO criteria, patients were assigned to two groups, one with detectable residual/recurrent tumor ("RT", n = 9), and the other with no detectable residual/recurrent tumor ("NRT", n = 19). An ROI was drawn to encompass the largest dimension of the lesion with measures normalized against normal gray matter to yield rCBF and tSNR from VSASL, as well as rCBF and leakage-corrected relative CBV (lc-rCBV) from DSC. VSASL (rCBF and tSNR) and DSC (rCBF and lc-rCBV) metrics were significantly higher in the RT group than the NRT group allowing adequate discrimination (
< 0.05, Mann-Whitney test). Lin's concordance analyses showed moderate to excellent concordance between the two methods, with a stronger, moderate correlation between VSASL rCBF and DSC lc-rCBV (r = 0.57,
= 0.002; Pearson's correlation). These results suggest that VSASL is clinically feasible at 1.5T and has the potential to offer a noninvasive alternative to DSC perfusion in monitoring high-grade gliomas following therapy.
Opportunistic osteoporosis screening using multidetector CT-scans (MDCT) and convolutional neural network (CNN)-derived segmentations of the spine to generate volumetric bone mineral density (vBMD) ...bears the potential to improve incidental osteoporotic vertebral fracture (VF) prediction. However, the performance compared to the established manual opportunistic vBMD measures remains unclear. Hence, we investigated patients with a routine MDCT of the spine who had developed a new osteoporotic incidental VF and frequency matched to patients without incidental VFs as assessed on follow-up MDCT images after 1.5 years. Automated vBMD was generated using CNN-generated segmentation masks and asynchronous calibration. Additionally, manual vBMD was sampled by two radiologists. Automated vBMD measurements in patients with incidental VFs at 1.5-years follow-up (
= 53) were significantly lower compared to patients without incidental VFs (
= 104) (83.6 ± 29.4 mg/cm
vs. 102.1 ± 27.7 mg/cm
,
< 0.001). This comparison was not significant for manually assessed vBMD (99.2 ± 37.6 mg/cm
vs. 107.9 ± 33.9 mg/cm
,
= 0.30). When adjusting for age and sex, both automated and manual vBMD measurements were significantly associated with incidental VFs at 1.5-year follow-up, however, the associations were stronger for automated measurements (β = -0.32; 95% confidence interval (CI): -20.10, 4.35;
< 0.001) compared to manual measurements (β = -0.15; 95% CI: -11.16, 5.16;
< 0.03). In conclusion, automated opportunistic measurements are feasible and can be useful for bone mineral density assessment in clinical routine.
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