WHAT THIS PAPER ADDSThe Rotarex and Angiojet thrombectomy devices have been evaluated for the first time in a physiological circulation model to gain a better understanding of device performance and complications. Both devices showed comparable device performance but with slight advantages for the Rotarex system. Significantly more thromboemboli and vascular injuries were observed in the Rotarex group in contrast to the Angiojet being the more tissue preserving procedure. In future, the improved knowledge of device characteristics should support individualised indications for and performance of thrombectomy.Objective: To compare the percutaneous Rotarex and Angiojet thrombectomy devices with regard to effectiveness and in vitro safety. Methods: The Rotarex and Angiojet devices were evaluated in an established in vitro pulsatile flow model with a human femoropopliteal vessel phantom. First pass recanalisation and thrombus weight were assessed after thrombectomy, as well as micro-and macro-emboli. Further, histological evaluation of the vascular phantom was performed to analyse vascular injuries. Results: Thrombus weight did not differ significantly prior to the thrombectomy between the groups, but the Rotarex showed slight advantages in thrombus removal vs. the Angiojet regarding first pass recanalisation. Micro-and macro-emboli occurred in most of the endovascular manoeuvres performed; however, significantly more macro-emboli (2.37 AE 1.51 vs. 0.87 AE 0.83; p ¼ .048) were observed using the Rotarex than the Angiojet. Macroscopic dissections were detected in the Rotarex group (n ¼ 3) but not in the Angiojet group. Microscopic vascular injuries were detected significantly more often in the Rotarex group (Rotarex: 531.61 mm AE 102.81 mm; Angiojet: 705.42 mm AE 61.68 mm [p ¼ .001]). Conclusion:Both devices showed a comparable performance, with a slight advantage for the Rotarex regarding first pass recanalisation. Significantly more thrombo-emboli, and vascular injuries were observed in the Rotarex group with the latter being obviously the more tissue preserving procedure but potentially with a lower rate of recanalisation. Based on the present results, clinical randomised trials, including long term follow up, are needed to optimise and improve the use of catheter based procedures, taking into account the thrombus entity, localisation, and clinical history.
Background Diagnosis of Parkinson’s disease and atypical parkinsonism is based on clinical evaluation of the patient’s symptoms and on magnetic resonance imaging (MRI) of the brain, which can be supplemented by nuclear medicine techniques. MRI plays a leading role in the differentiation between Parkinson’s disease and atypical parkinsonism. While atypical parkinsonism is characterized by relatively specific MRI signs, imaging of Parkinson’s disease previously lacked such signs. However, high-field MRI and new optimized MRI sequences now make it possible to define specific MRI signs of Parkinson’s disease and have significant potential regarding differentiated imaging, early diagnosis, and imaging of disease progression. Methods PubMed was selectively searched for literature regarding the definition and discussion of specific MRI signs of Parkinson’s disease, as well as the most common types of atypical parkinsonism with a leading motor component. No time frame was set, but the search was particularly focused on current literature. Results This review article discusses the different MRI signs of Parkinson’s disease, multiple system atrophy, and progressive supranuclear palsy. The pathogenesis of the MRI signs is described, and imaging examples are given. The technical aspects of image acquisition are briefly defined, and the different signs are discussed and compared with regard to their diagnostic significance according to current literature. Conclusion The MRI signs of Parkinson’s disease, which can be defined with high-field MRI and new optimized MRI sequences, enable differentiated structural image interpretation and consecutive diagnostic workup. Despite the fact that the signs are in need of further validation by bigger studies, they have the potential to achieve significant diagnostic relevance regarding the imaging of Parkinson’s disease and atypical parkinsonism. Key Points: Citation Format
Aim of this study was to establish a simple and highly reproducible physiological circulation model to investigate endovascular device performance. The developed circulation model included a pneumatically driven pulsatile pump to generate a flow rate of 2.7 L/min at 70 beats per minute. Sections from the superficial femoral arteries were used in order to simulate device/tissue interaction and a filter was integrated to analyze periinterventional thromboembolism of white, red and mixed thrombi. The working fluid (3 L) was a crystalloid solution constantly tempered at 36.5 °C. To evaluate the model, aspiration thrombectomy, stent-implantation and thrombectomy with the Fogarty catheter were performed. Usability of the model was measured by the System Usability Scale (SUS) – Score. Histological specimens were prepared and analyzed postinterventional to quantify tissue/device interaction. Moreover, micro- and macroembolism were evaluated for each thrombus entity and each device. Results were tested for normality using the D’Agostino-Pearson test. Statistical comparisons of two groups were performed using the Student’s t-test. All devices were able to remove the occlusions after a maximum of 2 attempts. First-pass-recanalization was not fully achieved for aspiration thrombectomy of mixed thrombi (90.6%), aspiration thrombectomy of red thrombi (84.4%) and stent-implantation in occlusions of red thrombi (92.2%). Most micro- and macroembolism were observed using the Fogarty catheter and after stent-implantation in occlusions of white thrombi. Histological examinations revealed a significant reduction of the vascular layers suggesting vascular damage after use of the Fogarty catheter (327.3 ± 3.5 μm vs. 440.6 ± 3.9 μm; p = 0.026). Analysis of SUS rendered a mean SUS-Score of 80.4 which corresponds to an excellent user acceptability of the model. In conclusion, we describe a stable, easy to handle and reproducible physiological circulation model for the simulation of endovascular thrombectomy including device performance and thromboembolism.
Purpose In this in vitro study, the effectiveness and safety of four aspiration-based techniques for thrombectomy are evaluated for three types of thrombi in a flow model simulating the femoropopliteal segment. Material and Methods Red, white, and mixed thrombi were produced in a standardized manner and used to simulate occlusion of a superficial femoral artery using a pulsatile flow model. Four techniques were compared: aspiration alone, aspiration + stent retriever, exposing thrombus to laser by an excimer laser system and a laser catheter + aspiration, and aspiration + mechanical fragmentation by a separator. Rate of first-pass recanalization, embolic events, and number of embolized fragments > 1 mm were compared. Results Aspiration alone, stent retriever, laser, and separator differed in rates of first-pass recanalization (53.3%; 86.6%; 20%; and 100%) and embolic events (40%; 93.3%; 73.3%; and 60%). Number of embolized fragments was lowest with aspiration and higher with separator, laser, and stent retriever. Rates of first-pass-recanalization (75%; 75%; and 45%) and embolic events (65%; 60%; and 75%) differed for red, white, and mixed thrombi. The mixed thrombus caused the highest number of embolized fragments, which was particularly high using the stent retriever. Conclusion Additional use of mechanical techniques significantly enhances the effectiveness of thrombectomy but simultaneously provokes more embolism. Laser seems to negatively alter the structure of a thrombus and thus diminishes the effectiveness, while provoking embolism. All techniques had lowest effectiveness, but highest embolism with the mixed thrombus. This was particularly striking when a stent retriever was used with the mixed thrombus.
Objective Thrombectomy of the aortoiliac segment remains a challenge for surgical and endovascular revision. This study aimed to evaluate the concept of percutaneous thrombectomy in patients with aortoiliac segment occlusions. Materials & Methods Eighteen patients with aortoiliac occlusion who underwent percutaneous thrombectomy were retrospectively identified using the local picture archive and divided into the stent-graft (N = 10) and native vessels (N = 8) groups. The procedure was performed by placing a 12–24 French sheath adjacent to the distal end of the occluded vessel segment. The occlusion was passed with a balloon catheter which was retracted after inflation, to deliver the thrombus into the sheath. Technical success (reperfusion of the vessel and no residual thrombus/stenosis < 30%), complications and primary arterial patency were assessed. Follow-up included computed tomography angiography and evaluation of the clinical situation via telephone. Results Technical success was achieved in 38% (7/18) of patients after percutaneous thrombectomy alone and in 100% after additional procedures. The most common complication was peripheral embolism (44%, 8/18), which was treated successfully in all cases and was linked to a mismatch between the sheath and target vessel of ≥ 1 mm (P < .01). There were no significant differences in the incidence of complications between the two groups. Primary patency was 72% (13/18) with no significant difference between groups (P = .94). Follow-up CT scans were available for 13/18 patients (72%), with a mean follow-up time of 270 ± 146 days. All patients were contacted via phone (follow-up time, 653 ± 264 days). Conclusion Percutaneous thrombectomy appears to be effective for revascularization of the aortoiliac segment, both in stent-grafts and in native vessels. The most common complication is peripheral embolism; however, the risk may be reduced by choosing an adequate sheath size.
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