What is the hemodynamic effect of the Woven EndoBridge? An in vivo quantification using time-density curve analysis

Abstract

Purpose Using the Woven EndoBridge (WEB) for aneurysm treatment has emerged as endovascular approach aiming for flow disruption in aneurysm sac. Since quantifiable data confirming the hemodynamic effect are lacking, we investigated in vivo aneurysmal flow alterations using time-density curve (TDC) analysis. Additionally, we evaluated whether flow parameters could be identified as independent factor to predict aneurysm occlusion. Methods Forty cerebral aneurysm patients treated with WEB were enrolled. Pre-and postinterventional digital subtraction angiography series were postprocessed and TDCs generated. TDCs were quantified calculating the parameters aneurysmal inflow velocity, outflow velocity, mean flow velocity, and relative time-to-peak (rTTP) of aneurysm filling. Pre-and postinterventional values were compared and related to occlusion rate. Results WEB implanting induced highly significant rTTP prolongation by 52% (p = 0.001) and highly significant decrease of aneurysmal inflow, outflow, and mean flow velocity (p < 0.001). While outflow velocity was reduced by 49%, inflow velocity was reduced by 33% only. No statistically significant difference between the occluded and the non-occluded group was observed. No flow parameter reached significance level concerning predicting aneurysm occlusion. Conclusion Flow quantification confirms a significant flow-disrupting effect of WEB reducing more the outflow than the inflow velocity. In our small cohort, no flow parameter reached statistical significance to show predictive value regarding complete aneurysm occlusion. The hemodynamic effect of WEB is on comparable level to flow-diverting stents meaning that aneurysm closure can be delayed. In case of only slight inflow changes and high aneurysmal hemodynamic stress, some aneurysms might not be adequately protected in the short term.

Treatment of Wide-Necked Cerebral Aneurysms Using the WEB Device Including Flow Alteration Assessment With Color-Coded Imaging: A Single Center Experience

“…also describe a significant flow-disrupting effect of the WEB device that reduces the outflow more than the inflow in their TDC analysis. 15 Despite the fact that the TDC analysis using iFlow by Gölitz et al. recorded different parameters compared with our study, we believe that the results are comparable.…”

“…Aneurysm occlusion was assessed using the Beaujon Occlusion Scale Score (BOSS) previously described in the literature 15 as follows: grade 0, no residual flow inside the aneurysm or WEB; grade ó, opacification of the proximal recess of the WEB; grade 1, residual flow inside the WEB; grade 2, neck remnant; grade 3, aneurysm remnant; grade 1+3, contrast agent is depicted inside and around the device. Aneurysms showing grade 0 and ó were classified as adequately occluded.…”

Prediction of the trans-stenotic pressure gradient with arteriography-derived hemodynamic features in patients with idiopathic intracranial hypertension

“…Perfusion features, including the time to peak, MTT, cerebral blood flow, and CBV, can be derived from MRI perfusion images and DSA images. 23,24 The application of these features has expanded to clinical settings, such as the prediction of aneurysm occlusion, 25 AVM rupture 26 and AVM embolization outcome. 27 Most of the studies focused on flow estimation on arteries, but not until very recently, this method was translated into the venous sinus.…”

Endovascular Treatment of a Direct Carotid Cavernous Sinus Fistula with the Woven EndoBridge Aneurysm Embolization System

“…The WEB, as self-expanding intrasaccular device with dense microwoven mesh structure, leads to a disruption of the intra-aneurysmal flow and following to intra-aneurysmal and intra-device thrombus formation [ 8 ]. This effect could be explained by the changes in intra-aneurysmal blood flow, probably mainly by decreasing of outflow velocity than inflow velocity [ 9 ]. The safety and technical efficacy of the WEB in the treatment of ruptured and unruptured aneurysms have been described in many studies and it is nowadays a well-established treatment option [ 7 ].…”