MEDISCHE BEELDVORMING

CENTRUM MEDISCHE BEELDVORMING

ARTIKELS

ABSTRACT 1

Clinical added value of MRI to CT in patients scheduled for local therapy of colorectal liver metastases (CAMINO): study protocol for an international multicentre prospective diagnostic accuracy study

Görgec B, Hansen I, Kemmerich G, Lutin B, et al. BMC Cancer, 2021, 21(1), 1116

ABSTRACT Abstract is na te lezen op p. 9

ABSTRACT 2

Detailed histological analysis of a thrombectomyresistant ischemic stroke thrombus: a case report

Staessens S, François O, Desender L, Andersson T, et al. Thrombosis Journal, 2021, 19 (1), 11

ABSTRACT Mechanical removal of a thrombus by thrombectomy can be quite challenging. For reasons that are not fully understood, some thrombi require multiple passes to achieve successful recanalization, whereas other thrombi are efficiently removed in a single pass. Since first pass success is associated with better clinical outcome, it is important to better understand the nature of thrombectomy resistant thrombi. The aim of this study was therefore to characterize the cellular and molecular composition of a thrombus that was very hard to retrieve via mechanical thrombectomy.

In a patient that was admitted with a right middle cerebral artery M1-occlusion, 11 attempts using various thrombectomy devices and techniques were required for removal of the thrombus. This peculiar case provided a rare opportunity to perform an in-depth histopathological study of a difficult to retrieve thrombus. Thrombus material was histologically analyzed using hematoxylin and eosin, Martius Scarlet Blue stain (red blood cells and fibrin), Feulgen stain (DNA), von Kossa stain (calcifications) and immunohistochemical analysis of von Willebrand factor, platelets, leukocytes and neutrophil extracellular traps. Histological analysis revealed abnormally high amounts of extracellular DNA, leukocytes, von Willebrand factor and calcifications. Extracellular DNA stained positive for markers of leukocytes and NETs, suggesting that a significant portion of DNA is derived from neutrophil extracellular traps. In this unique case of a nearly thrombectomy-resistant stroke thrombus, our study showed an atypical composition compared to the common structural features found in ischemic stroke thrombi. The core of the retrieved thrombus consisted of extracellular DNA that colocalized with von Willebrand factor and microcalcifications.

These results support the hypothesis that von Willebrand factor, neutrophil extracellular traps and microcalcifications contribute to mechanical thrombectomy resistance. Such information is important to identify novel targets in order to optimize technical treatment protocols and techniques to increase first pass success rates.

ABSTRACT 3

Thrombectomy for primary distal posterior cerebral artery occlusion stroke: the topmost study

Meyer L, Stracke CP, Jungi N, Andersson T, et al. JAMA Neurology, 2021, 78 (4), 434-444

ABSTRACT Clinical evidence of the potential treatment benefit of mechanical thrombectomy for posterior circulation distal, medium vessel occlusion (DMVO) is sparse. To investigate the frequency as well as the clinical and safety outcomes of mechanical thrombectomy for isolated posterior circulation DMVO stroke and to compare them with the outcomes of standard medical treatment with or without intravenous thrombolysis (IVT) in daily clinical practice. Clinical end point was the improvement of National Institutes of Health Stroke Scale (NIHSS) scores at discharge from baseline. Safety end point was the occurrence of symptomatic intracranial hemorrhage and hemorrhagic complications were classified based on the Second European-Australasian Acute Stroke Study (ECASSII). Functional outcome was evaluated with the modified Rankin Scale (mRS) score at 90-day follow-up. Of 243 patients from all participating centers who met the inclusion criteria, 184 patients were matched. Among these patients, the median (interquartile range [IQR]) age was 74 (62-81) years and 95 (51.6%) were female individuals. Posterior circulation DMVOs were located in the P2 segment of the PCA in 149 patients (81.0%) and in the P3 segment in 35 patients (19.0%). At discharge, the mean NIHSS score decrease was -2.4 points (95% CI, -3.2 to -1.6) in the standard medical treatment cohort and -3.9 points (95% CI, -5.4 to -2.5) in the mechanical thrombectomy cohort, with a mean difference of -1.5 points (95% CI, 3.2 to -0.8; P = .06). Significant treatment effects of mechanical

thrombectomy were observed in the subgroup of patients who had higher NIHSS scores on admission of 10 points or higher (mean difference, -5.6; 95% CI, -10.9 to -0.2; P = .04) and in the subgroup of patients without IVT (mean difference, -3.0; 95% CI, -5.0 to -0.9; P = .005). Symptomatic intracranial hemorrhage occurred in 4 of 92 patients (4.3%) in each treatment cohort. This study suggested that, although rarely performed at comprehensive stroke centers, mechanical thrombectomy for posterior circulation DMVO is a safe, and technically feasible treatment option for occlusions of the P2 or P3 segment of the PCA compared with standard medical treatment with or without IVT.

ABSTRACT 4

Health economic impact of first pass success: an asia-pacific cost analysis of the ARISE II study

Yeo L, Zaidat OO, Saver JL, Andersson T, et al Journal of Stroke, 2021, 23 (1), 139-143

ABSTRACT Er is geen abstract beschikbaar.

ABSTRACT 5

How are manual skills to reach excellence in microsurgery and endovascular technique best acquired, maintained, and developed with relation to unruptured aneurysm treatment: hybrid neurosurgeons or team approach?

Andersson T

Acta Neurochirurgica, 2021, 136(5), 1525-1526

ABSTRACT Er is geen abstract beschikbaar.

ABSTRACT 6

Suction force rather than aspiration flow correlates with recanalization in hard clots: an in vitro study model

Fernandez-Sanchez D, Garcia-Sabido D, Jovin TG, Andersson T, et al. Journal of Neurointerventional Surgery, 2021, 13(12), 1157-1161

ABSTRACT ANA Advanced Neurovascular Access provides a novel funnel component designed to reduce clot fragmentation and facilitate retrieval in combination with stent-retrievers (SRs) in stroke patients by restricting flow and limiting clot shaving. In previous publications ANA presented excellent in vitro/in vivo efficacy data, especially with fibrin-rich hard clots. We aimed to determine the main physical property responsible for these results, namely suction force versus aspiration flow.

We evaluated in a bench model the suction force and flow generated by ANA and compared them to other neurovascular catheters combined with a SR (Solitaire). Aspiration flow was evaluated with a flow rate sensor while applying vacuum pressure with a pump. Suction force was determined using a tensile strength testing machine and a purposely designed tool that completely seals the device tip simulating complete occlusion by a hard clot. Suction force was defined as the force needed to separate the device from the clot under aspiration. All experiments were repeated five times, and mean values used for comparisons.

Aspiration flow increased with the inner diameter of the device: ANA 1.85±0.04 mL/s, ACE68 3.74±0.05 mL/s, and 8F-Flowgate2 5.96±0.30 mL/s (P<0.001). After introducing the SR, the flow was reduced by an average of 0.57±0.12 mL/s. Due to its larger distal surface, ANA suction force (1.69±0.40 N) was significantly higher than ACE68 (0.26±0.04 N) and 8F-Flowgate2 (0.42±0.06 N) (P<0.001). After introducing the SR, suction force variation was not relevant except for ANA that increased to 2.64±0.41 N. Despite lower in vitro aspiration flow, the ANA design showed a substantially higher suction force than other thrombectomy devices.

ABSTRACT 7

High-resolution cone-beam computed tomography is a fast and promising technique to quantify bone microstructure and mechanics of the distal radius

Mys K, Varga P, Stockmans F, Vanovermeire O Calcified Tissue International, 2021, 108 (3), 314-323

ABSTRACT Obtaining high-resolution scans of bones and joints for clinical applications is challenging. HR-pQCT is considered the best technology to acquire high-resolution images of the peripheral skeleton in vivo, but a breakthrough for widespread clinical applications is still lacking.

Recently, we showed on trapezia that CBCT is a promising alternative providing a larger FOV at a shorter scanning time. The goals of this study were to evaluate the accuracy of CBCT in quantifying trabecular bone microstructural and predicted mechanical parameters of the distal radius, the most often investigated skeletal site with HR-pQCT, and to compare it with HR-pQCT. Nineteen radii were scanned with four scanners: (1) HR-pQCT (XtremeCT, Scanco Medical AG, @ (voxel size) 82 μm), (2) HR-pQCT (XtremeCT-II, Scanco, @60.7 μm), (3) CBCT (NewTom 5G, Cefla, @75 2021, 2021, µm) reconstructed and segmented using in-house developed software and (4) microCT (VivaCT40, Scanco, @19 μm-gold standard).

The following parameters were evaluated: predicted stiffness, strength, bone volume fraction (BV/TV) and trabecular thickness (Tb.Th), separation (Tb.Sp) and number (Tb.N). The overall accuracy of CBCT with in-house optimized algorithms in quantifying bone microstructural parameters was comparable (R2 = 0.79) to XtremeCT (R2 = 0.76) and slightly worse than XtremeCT-II (R2 = 0.86) which were both processed with the standard manufacturer's technique. CBCT had higher accuracy for BV/TV and Tb.Th but lower for Tb.Sp and Tb.N compared to XtremeCT. Regarding the mechanical parameters, all scanners had high accuracy (R2 [Formula: see text] 0.96).

While HR-pQCT is optimized for research, the fast scanning time and good accuracy renders CBCT a promising technique for high-resolution clinical scanning.