RESUMEN
The effective treatment of wide necked cerebral aneurysms located at vessel bifurcations (WNBAs) remains a significant challenge. Such aneurysm geometries have typically been approached with Y or T stenting configurations of stents and/or flow diverters, often with the addition of endovascular coils. In this study, two WNBAs were virtually treated by a novel T-stenting technique (Flow-T) with a number of braided stents and flow-diverter devices. Multiple possible device deployment configurations with varying device compression levels were tested, using fast-deployment algorithms, before a steady state computational hemodynamic simulation was conducted to examine the efficacy and performance of each scenario. The virtual fast deployment algorithm based on a linear and torsional spring analogy is used to accurately deploy nine stents in two WNBAs geometries. The devices expand from the distal to proximal side of the devices with respect to aneurysm sac. In the WNBAs modelled, all configurations of Flow-T device placement were shown to reduce factors linked with increased aneurysm rupture risk including aneurysm inflow jets and high aneurysm velocity, along with areas of flow impingement and elevated wall shear stress (WSS). The relative position of the flow-diverting device in the secondary daughter vessel in the Flow-T approach was found to have a negligible effect on overall effectiveness of the procedure in the two geometries considered. The level of interventionalist-applied compression in the braised stent that forms the other arm of the Flow-T approach was shown to impact the aneurysm inflow reduction and aneurysm flow pattern more substantially. In the Flow-T approach the relative position of the secondary daughter vessel flow-diverter device (the SVB) was found to have a negligible effect on inflow reduction, aneurysm flow pattern, or WSS distribution in both aneurysm geometries. This suggests that the device placement in this vessel may be of secondary importance. By contrast, substantially more variation in inflow reduction and aneurysm flow pattern was seen due to variations in braided stent (LVIS EVO or Baby Leo) compression at the aneurysm neck. As such we conclude that the success of a Flow-T procedure is primarily dictated by the level of compression that the interventionalist applies to the braided stent. Similar computationally predicted outcomes for both aneurysm geometries studied suggest that adjunct coiling approach taken in the clinical intervention of the second geometry may have been unnecessary for successful aneurysm isolation. Finally, the computational modelling framework proposed offers an effective planning platform for complex endovascular techniques, such as Flow-T, where the scope of device choice and combination is large and selecting the best strategy and device combination from several candidates is vital.
RESUMEN
OBJECTIVES: To investigate the long-term clinical outcomes of second-generation drug-eluting stent (2G-DES) implantation for the treatment of complex unprotected left main coronary artery (ULMCA) bifurcation lesions with different two-stent techniques. BACKGROUND: Several two-stent techniques for ULMCA bifurcation lesions have been described. However, a paucity of data exists regarding the optimal strategy, especially in the 2G-DES era. METHODS: The FAILS-2 registry enrolled 1270 consecutive patients treated for ULMCA stenosis with 2G-DES. We compared long-term outcomes of different two-stent strategies in patients who underwent PCI for complex ULMCA bifurcation disease. The primary endpoints were the incidence of death and major adverse cardiac events (MACE, defined as a composite of all-cause death, myocardial infarction [MI], target-lesion revascularization [TLR], and stent thrombosis [ST]) at long-term follow-up. RESULTS: A total of 238 patients were included in the present analysis. T-stenting strategy was used in 66 patients, mini-crush in 104 patients, and culotte in 68 patients. After a median follow-up of 2.27 years, death rates were comparable for the three techniques (9.3% T-stenting vs 9.0% mini-crush vs 4.5% culotte [P=.48]). MACE rates were also similar between the three groups (22% T-stenting vs 26% mini-crush vs 31% culotte [P=.50]). Finally, we showed no differences in MI, ST, and TLR rates between groups. At multivariate analysis, no significant advantage of one technique over the others was observed. CONCLUSION: T-stenting, mini-crush, and culotte techniques using 2G-DES for ULMCA bifurcation disease showed similar clinical outcomes at long-term follow-up. MACE rates were mainly driven by in-stent restenosis at the circumflex ostium.