The TRAIL multicentre study has found that the LVIS (Low Profile Visualized Intraluminal Support) and LVIS Jr devices (MicroVention) are safe and effective for stent-assisted coil embolisation of wide-necked intracranial aneurysms.
Christina Iosif (Department of Interventional Neuroradiology, CHU-Limoges Dupuytren University Hospital, Limoges, France) and others report their experience with LVIS and LVIS Jr in the Journal of NeuroInterventional Surgery.
The TRAIL study was a prospective, multicentre, observational study of unruptured and ruptured intracranial aneurysms treated with the LVIS devices. Imaging and clinical data were independently analysed respectively by CoreLab and Clinical Event Committee. Primary endpoints were clinical safety, effectiveness, and angiographic stability of the results at six and 18 months.
Patients’ clinical status was assessed with the modified Rankin Scale (mRS). The permanent morbidity rate was calculated as the percentage of patients with an adverse event which resulted in a mRS >2 at the time of clinical evaluation (six and 18 months). Mortality, permanent morbidity, and events with sequelae rates were statistically analysed by the modified Wald method. Comparisons between the two types of stents (LVIS and LVIS Jr) were performed using the χ2 or Fisher exact tests.
Ten centres participated in the study; 102 patients were included and 90 patients (42.2% men, 57.8% women) were eventually analysed, among which 27 (30%) had multiple aneurysms. Twenty-three (25.6%) were ruptured aneurysms, four of which (4.4%) were treated in the acute phase. One aneurysm was treated per patient; 92 LVIS and LVIS Jr devices were placed overall.
The total aneurysm occlusion rate was 91% on immediate post-procedure angiograms, which remained unchanged at six-month follow-up and was 92.4% at 18-month follow-up. One patient (1.1%) underwent retreatment between six and 18 months of follow-up.
Comparison of aneurysm occlusion rates at six months with the two stent types (LVIS and LVIS Jr) showed no statistically significant difference (p=1.00, Fisher exact test). Aneurysm size (small or large) did not seem to affect the six-month occlusion rate (p=0.07, Fisher exact test).
A modified Rankin score of 0 was documented for most cases immediately after the procedure (86.7%) and at six-month (86.8%) and 18-month (83.3%) follow-up. The overall permanent morbidity rate at 18 months was 5.6% and the overall rate of events with sequelae related to the stent was 2.2%. The 18-month procedure-related mortality rate was 3.3%. No patient was deemed to require retreatment at 18-month follow-up.
Commenting on the features of the devices specifically, the authors explain that “The LVIS design provided easier navigability of the devices, which allowed for their use with double-lumen balloons (Scepter XC; MicroVention). The technique of balloon remodelling with subsequent immediate deployment of the stent through the balloon lumen provides support for the deployed coils without the need for exchange manoeuvres. This resulted in fewer manoeuvres, and thus probably fewer technical complications. Additionally, the LVIS devices seem to be adapted to complex stenting treatments such as Y-stenting and coiling for bifurcation aneurysms.”
Iosif et al conclude: “In the TRAIL study, the LVIS and LVIS Jr devices have been proved to be safe and effective in the treatment of complex ruptured and unruptured intracranial aneurysms, with very high immediate, mid-term, and long-term total exclusion rates and acceptable morbidity and mortality rates.”