Large-bore catheters allow mechanical thrombectomy in ischemic stroke by engaging and retrieving clots without additional devices (direct aspiration first-pass technique ADAPT). The purpose of this ...study was to establish a model for minimal catheter diameters needed for ADAPT.
We established a theoretic model for the calculation of minimal catheter diameters needed for ADAPT. We then verified its validity in 28 ADAPT maneuvers in a porcine in vivo model. To account for different mechanical thrombectomy techniques, we factored in ADAPT with/without a hypothetic 0.021-inch microcatheter or 0.014-inch microwire inside the lumen of the aspiration catheter and aspiration with a 60-mL syringe versus an aspiration pump.
According to our calculations, catheters with an inner diameter of >0.040 inch and >0.064 inch, respectively, are needed to be effective in the middle cerebral artery (2.5-mm diameter) or in the internal carotid artery (4 mm) in an average patient. There was a significant correlation between predicted and actual thrombectomy results (
= .010). Our theoretic model had a positive and negative predictive value of 78% and 79%, respectively. Sensitivity and specificity were 88% and 64%, respectively.
Our theoretic model allows estimating the minimal catheter diameters needed for successful mechanical thrombectomy with ADAPT, as demonstrated by the good agreement with our animal experiments. Our model will be helpful to interventionalists in avoiding selecting catheters that are likely too small to be effective.
Purpose
Carotid artery anatomy is thought to influence internal carotid artery access time (ICA-AT) in patients requiring mechanical thrombectomy for acute ischemic stroke. This study investigates ...the association between ICA-AT and carotid anatomy.
Material and methods
Computed tomography angiography (CTA) data of 76 consecutive patients presenting with acute ischemic stroke requiring mechanical thrombectomy for middle cerebral artery or carotid T occlusion were evaluated. The supraaortic extracranial vasculature was analyzed regarding take-off angles and curvature of the affected side. Digital subtraction angiography data were primarily analyzed regarding ICA-AT and secondarily regarding recanalization time and radiographic result.
Results
ICA-AT was significantly influenced by vessel tortuosity. Take-off angle of the left common carotid artery (p = 0.001) and the brachiocephalic trunk (p = 0.002) as well as the tortuosity of the common carotid artery (p = 0.002) had highest impact on ICA-AT. For recanalization time, however, we found only the take-off angle of the left common carotid artery to be of significance (p = 0.020). There was a tendency for ICA-AT to correlate with successful (mTICI ≥ 2 b) revascularization (average time of successful results was 24.3 minutes, of unsuccessful was 35.6 minutes; p = 0.065). Every evaluated segment with less carotid tortuosity showed a carotid AT below 25 minutes.
Conclusion
Supraaortic vessel tortuosity significantly influences ICA-AT in mechanical thrombectomy for an acute large vessel. There furthermore was a trend for lower successful recanalization rates with increasing ICA-AT.
Twenty patients with deep lumbosacral spinal dural arteriovenous fistulas were included in this series. Cord T2 hyperintensity and contrast enhancement were present in most cases. The filum vein ...and/or lumbar veins were dilated in 95% of patients. Time-resolved contrast-enhanced dynamic MRA indicated a spinal DAVF at or below the L5 vertebral level in 7/8 (88%) patients who received time-resolved contrast-enhanced dynamic MRA before DSA. A bilateral arterial supply of the fistula was detected via DSA in 5 (25%) patients. The authors conclude that time-resolved contrast-enhanced dynamic MRA facilitates the detection of the drainage vein and helps to localize deep lumbosacral-located fistulas with a high sensitivity before DSA. Definite detection remains challenging and requires conventional spinal angiography.BACKGROUND AND PURPOSE:Spinal dural arteriovenous fistulas located in the deep lumbosacral region are rare and the most difficult to diagnose among spinal dural arteriovenous fistulas located elsewhere in the spinal dura. Specific clinical and radiologic features of these fistulas are still inadequately reported and are the subject of this study.MATERIALS AND METHODS:We retrospectively evaluated all data of patients with spinal dural arteriovenous fistulas treated and/or diagnosed in our institution between 1990 and 2017. Twenty patients with deep lumbosacral spinal dural arteriovenous fistulas were included in this study.RESULTS:The most common neurologic findings at the time of admission were paraparesis (85%), sphincter dysfunction (70%), and sensory disturbances (20%). Medullary T2 hyperintensity and contrast enhancement were present in most cases. The filum vein and/or lumbar veins were dilated in 19/20 (95%) patients. Time-resolved contrast-enhanced dynamic MRA indicated a spinal dural arteriovenous fistula at or below the L5 vertebral level in 7/8 (88%) patients who received time-resolved contrast-enhanced dynamic MRA before DSA. A bilateral arterial supply of the fistula was detected via DSA in 5 (25%) patients.CONCLUSIONS:Clinical symptoms caused by deep lumbosacral spinal dural arteriovenous fistulas are comparable with those of spinal dural arteriovenous fistulas at other locations. Medullary congestion in association with an enlargement of the filum vein or other lumbar radicular veins is a characteristic finding in these patients. Spinal time-resolved contrast-enhanced dynamic MRA facilitates the detection of the drainage vein and helps to localize deep lumbosacral-located fistulas with a high sensitivity before DSA. Definite detection of these fistulas remains challenging and requires sufficient visualization of the fistula-supplying arteries and draining veins by conventional spinal angiography.
Because stroke therapy has changed with the introduction of endovascular stroke treatment as a standard approach, studies on intrahospital causes of death from stroke are no longer up-to-date. The ...purpose of this observational study was to present the causes of death during hospitalization of patients with ischemic stroke who received endovascular stroke treatment, with the focus on a differentiation of curative and secondary palliative treatment.
We studied a total cohort of 1342 patients who received endovascular stroke treatment in a tertiary stroke center (Aachen, Germany) between 2010 and 2020 and analyzed the causes of death in all 326 consecutive deceased patients. We distinguished between curative treatment and a secondary palliative approach and analyzed causes of death and treatment numbers across the years.
In the entire cohort of 326 deceased patients, the most common cause of death was of a cerebrovascular nature (51.5%), followed by pneumonia and sepsis (25.8%) and cardiovascular causes (8.3%). Neurovascular causes constituted 75.8% of reasons for palliation. In the group with a secondary palliative approach, causes of death were neurovascular in 54.0% of patients and pneumonia and sepsis in 26.0% of patients.
Cerebrovascular causes in patients with stroke play a major role in the intrahospital causes of death and reasons for palliation. Considering the large proportion of secondarily palliative-treated patients, reasons for palliation should be considered instead of causes of death to avoid concealment by, for example, life-terminating measures.
Transient cortical blindness (TCB) has been reported as a complication after diagnostic cerebral angiography in 0.3–1% of cases. Our aim was to observe the frequency of TCB after diagnostic cerebral ...angiography over a period of 11 years using only hypo-osmolar, nonionic contrast agents and following a protocol to reduce both the total volume of injected contrast agent and the number of angiography series obtained.
We retrospectively included all 2431 patients who received diagnostic cerebral angiographies at our institution. Primary outcome measure was the occurrence of TCB after diagnostic cerebral angiography, hypothesizing that the occurrence of TBC depends on the volume of contrast agent and angiography of the vertebrobasilary arteries.
Over the analyzed time period of 11 years, we did not observe a single case of TCB following diagnostic cerebral angiography. The median contrast volume used was 100 ml (IQR, 100–200), ranging from 15 ml to 500 ml. In our cohort, 61.5% of patients received a selective catheterization of the vertebrobasilary territory. In 99.8% of angiographies iopamidol was used a contrast agent.
Our results indicate that following to certain aspects of the angiography protocol (using the hypoosmolar, non-ionic contrast agent iopamidol and reducing the number of catheterized vessels and angiography series to a diagnostic minimum) the frequency of transient cortical blindness as a complication of diagnostic cerebral angiography considerably can be very low.
Blood flow should be interrupted during mechanical thrombectomy to prevent embolization of clot fragments. The purpose of our study was to provide a handy overview of the most common aspiration ...devices and to quantify their flow characteristics.
We assessed volumetric flow rates generated by a 60-mL VacLok vacuum pressure syringe, a Pump MAX aspiration pump, and a Dominant Flex suction pump connected to the following: 1) an 8F long sheath, 2) an 8F balloon-guide catheter, 3) an ACE 64 distal aspiration catheter, and 4) an AXS Catalyst 6 Distal Access Catheter. We used a water/glycerol solution, which was kept at a constant temperature of 20°C (viscosity, 3.7 mPa · s).
Aspiration with the syringe and the Dominant Flex suction pump achieved the highest flows, whereas aspiration with the Pump MAX was significantly lower (
< .001). Resistors in the aspiration system (tubing, connectors, and so forth) restricted flows, especially when the resistance of the catheter was small (due to its large diameter) and the connected resistors became the predominant resistance (
< .001). The syringe achieved an average vacuum pressure of -90 kPa, and the resulting flow was constant during almost the entire procedure of filling the syringe.
Sixty-milliliter VacLok vacuum pressure syringes and the Dominant Flex suction pump achieved high and constant flows likely sufficient to reverse blood flow during thrombectomy with an 8F sheath or balloon-guide catheter in the ICA and modern distal aspiration catheters in the MCA. The Pump MAX aspiration pump is dedicated for use with distal aspiration catheters and is unlikely to reverse blood flow in the ICA and MCA without balloon protection.
Current classifications of cerebral cavernous malformations focus solely on morphologic aspects. Our aim was to provide a morphologic classification that reflects hemorrhage rates.
We retrospectively ...categorized 355 cavernous malformations of 70 children and adolescents according to their morphologic appearance on MR imaging and calculated prospective hemorrhage rates on the basis of survival functions for 255 lesions in 25 patients with a radiologic observation period of >180 days.
Overall, there were 199 MR imaging examinations with 1558 distinct cavernous malformation observations during a cumulative observation period of 1094.2 lesion-years. The mean hemorrhage rate of all 355 cavernous malformations was 4.5% per lesion-year. According to Kaplan-Meier survival models, Zabramski type I and II cavernous malformations had a significantly higher hemorrhage rate than type III and IV lesions. The presence of acute or subacute blood-degradation products was the strongest indicator for an increased hemorrhage risk (P = .036, Cox regression): The mean annual hemorrhage rate and mean hemorrhage-free interval for cavernous malformations with and without signs of acute or subacute blood degradation products were 23.4% and 22.6 months and 3.4% and 27.9 months, respectively. Dot-sized cavernous malformations, visible in T2* and not or barely visible in T1WI and T2WI sequences, had a mean annual hemorrhage rate of 1.3% and a mean hemorrhage-free interval of 37.8 months.
It is possible to predict hemorrhage rates based on the Zabramski classification. Our findings imply a tripartite classification distinguishing lesions with and without acute or subacute blood degradation products and dot-sized cavernous malformations.
Blood flow management in the carotid artery during mechanical thrombectomy is crucial for safety and effectiveness. There is an ongoing discussion about whether balloon-guide catheters or large-bore ...sheaths are needed for effective flow management. We compared general flow characteristics of proximal aspiration through a large-bore sheath and a balloon-guide catheter in a porcine in vivo model.
We investigated blood flow in a porcine common carotid artery with and without aspiration (VacLok syringe and Penumbra pump, Pump MAX) through an 8F-long sheath and an 8F balloon-guide catheter. Blood hemodynamics were assessed via continuous duplex sonography.
Average vessel diameter and baseline blood flow were 4.4 ± 0.2 mm and 244 ± 20 mL/min, respectively. For the 8F sheath, pump aspiration resulted in a significant flow reduction (225 ± 25 mL/min,
< .001), but with a persisting antegrade stream. Manual aspiration resulted in collapse of the vessel in 2 of 7 measurements and oscillatory flow with antegrade systolic and retrograde diastolic components in the remaining 5 measurements. Net flow was antegrade (52 ± 44 mL/min) in 3 and retrograde (-95 ± 52 mL/min) in the remaining 2 measurements. For balloon-guide catheters, balloon inflation always resulted in flow arrest. Additional pump or manual aspiration resulted in significant flow reversal of -1100 ± 230 and -468 ± 46 mL/min, respectively (both,
< .001).
Only balloon-guide catheters allow reliable blood flow arrest and flow reversal in combination with aspiration via syringes or high-flow pump systems. Aspiration through an 8F sheath results in either collapse of the vessel or oscillatory flow, which can result in a net antegrade or retrograde stream.
Purpose
In intracranial wide-neck aneurysms, simple coil embolization is often not a feasible treatment option. Balloon-assisted coiling comes with the drawback of blood flow impairment, whereas ...permanent stent placement requires long-term antiplatelet therapy. Temporary stent-assisted coiling (coiling assisted by temporary stenting, CATS) is an alternative that eliminates both disadvantages. Because prior studies included only small numbers of patients, it was our aim to analyze the safety and effectiveness of this technique in a larger cohort of patients.
Methods
We retrospectively evaluated all endovascular aneurysm treatments at our institution from 2011 to 2020. Out of a total of 688 aneurysm treatments, we intended to perform 95 (14%) with temporary stent-assisted coiling and included them in our study.
Results
Sixty-four (64)% of aneurysms were acutely ruptured, 3% were symptomatic but unruptured, and 33% were incidental. Successful stent recovery was possible in 93% of treatments. Initial complete and adequate occlusion rate were 53% and 82%, respectively. Long-term follow-up at 6 and 12 months was available for 71% and 44% of cases. Aneurysm recurrence was observed in 10% of cases after 6 months, and in 17% after 1 year or later. Periprocedural complications were noted in 12 cases (13%), of which only 1 complication was definitely associated with temporary stent-assisted coiling (1%). One of the periprocedural complications resulted in neurological damage, the other complications were asymptomatic.
Conclusion
Temporary stent-assisted coiling appears to be a safe and effective treatment method in intracranial wide-neck aneurysms. Procedural safety appears to be comparable with balloon remodeling or permanent stent-assisted coiling, but it comes with the further benefit of diminished need for posttreatment antiplatelet therapy, which may improve the outcome of patients. However, to define the true value and potential benefit of this technique, further prospective studies are required.
Background and purpose
In 1995 intravenous recombinant tissue plasminogen activator (IVRTPA) was the first reperfusion therapy to be approved in patients with acute ischaemic stroke (AIS). The ...significance and impact of IVRTPA in times of modern endovascular stroke treatment (EST) were analysed in a German academic stroke centre.
Methods
A retrospective observational cohort analysis of 1034 patients with suspected AIS presenting at the emergency department in 2014 was performed. Patients were evaluated for baseline characteristics, reperfusion procedures, IVRTPA eligibility, clinical outcome, symptomatic intracranial haemorrhage (sICH) and mortality. Data acquisition was part of an investigator‐initiated, prospective and blinded end‐point registry.
Results
In 718 (69%) patients the diagnosis of symptomatic AIS was confirmed. 419 (58%) patients presented within 4.5 h of symptom onset and of those 260 (62%) received reperfusion therapy (IVRTPA alone, n = 183; combination or bridging therapy, n = 60; EST alone, n = 17). Subtracting cases with absolute contraindications for IVRTPA resulted in an effective thrombolysis rate of 82%. sICH occurred in two patients treated with IVRTPA alone (1.1%). The median door‐to‐needle interval was 30 min. Fifty (17%) non‐EST eligible AIS patients presenting within 4.5 h without absolute contraindications did not receive IVRTPA mainly due to mild or regressive symptoms. Most of these untreated IVRTPA eligible patients (82%) were discharged with a good clinical outcome (modified Rankin Scale ≤ 2).
Conclusions
Intravenous recombinant tissue plasminogen activator remains the most frequently applied reperfusion therapy in AIS patients presenting within 4.5 h of onset in a tertiary stroke centre. An effective thrombolysis rate of over 80% can be achieved without increased rates of sICH.
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