The new system represents a significant improvement over earlier-generation stents, one expert says.
A pivotal trial of a self-expanding, retrievable microstent system for the treatment of wide-necked cerebral aneurysms has demonstrated excellent safety and efficacy, with durable, adequate (> 90%) occlusion at 1 year in almost all patients. On the strength of the data, the stents received US Food and Drug Administration premarket approval (PMA) in May 2018.
The US LVIS pivotal trial, led by David Fiorella, MD (State University of New York at Stony Brook), was a prospective, multicenter, single-arm study conducted at 21 US centers. It enrolled 153 adults with 153 wide-necked cerebral aneurysms of the anterior and posterior circulations who were treated using LVIS stent-assisted coil embolization.
The LVIS stent system, which includes the LVIS and LVIS Jr (MicroVention/Terumo), represents an improvement over stents previously used for this indication, including the Neuroform (Stryker Neurovascular) and Enterprise (Codman Neuro) systems, “in that it can be delivered through a smaller microcatheter, be partially deployed and then retrieved, and put into very small vessels,” Bradley Gross, MD (University of Pittsburgh Medical Center, Pittsburgh, PA), told Neurovascular Exchange in a comment on the study.
Results of the pivotal trial were published recently online ahead of print in the Journal of NeuroInterventional Surgery.
The primary effectiveness endpoint was defined as successful aneurysm treatment with the LVIS system as evidenced by complete (100%) aneurysm occlusion at 12 months on conventional angiography, without retreatment or significant (≥ 50%) stenosis of the treated artery at 12 months, as determined by an independent core laboratory. The primary safety endpoint was defined as the rate of stroke or death within 30 days, or ipsilateral stroke or neurologic death within 12 months.
Patients’ mean age was 58.3 ± 10.5 years and, and most (71.9%) were female. Among the aneurysms, 57 (37.3%) arose from the anterior cerebral artery, 43 (28.1%) from the internal carotid artery, 17 (11.1%) from the middle cerebral artery, 27 (17.6%) from the basilar artery, and 6 (3.9 %) from the posterior circulating artery. Two aneurysms arose from the vertebral artery, and one arose from the superior cerebellar artery.
Mean aneurysm dome height was 6.0 ± 2.2 mm, mean width was 5.5 ± 2.3, and mean neck width was 4.2 ± 1.4 mm.
In total of 22 participants presented for retreatment of a previously ruptured (> 30 days prior to treatment) target aneurysm.
Based on an intent-to-treat analysis, the primary effectiveness endpoint was observed in 108 patients (70.6%). Of the 139 patients for whom follow-up data were available at 12 months, 128 (92.1%) had ≥ 95% occlusion and 132 (95%) had ≥ 90% occlusion.
In the overall intent-to-treat population, eight patients (5.2%) experienced at least one primary safety event.
Easier Delivery of Care
“Prior to this study, all other stents designed for stent-assisted coiling were all HDE [humanitarian device exemption] stents, meaning for every stent you put in the patient, you had to specifically get the consent of the patient for that specific type of stent in addition to the consent for the procedure,” explained Gross. “This is the first stent that has a PMA approval, which means you do not need an additional consent. . . . This helps us to deliver care to patients more easily.”
Perhaps more importantly, PMA status is evidence for just how good a stent it is, according to Gross. “This is a safe and effective stent, and it is indeed worthy of PMA approval,” he added. “This is a good leap for the general field of endovascular because we deal with a fairly rare disease process across the general population, and it’s nice for us to be able to get approval to use this device.”
Despite a personal preference for the Neuroform Atlas stent, which is currently the main competitor of the LVIS system in the United States, Gross recognizes the benefits of both the LVIS and the recent approval.
“There is a tremendous cost and effort involved [in getting PMA approval],” he said. “This is going to be a nice benchmark to help show that we can help get PMA approval for future stents.”
Fiorella D, Boulos A, Turk AS, et al. The safety and effectiveness of the LVIS stent system for the treatment of wide-necked cerebral aneurysms: Final results of the pivotal US LVIS trial. J NeuroIntervent Surg. 2018;Epub ahead of print.
- Fiorella reports receiving research and consulting support from MicroVention/Terumo.
- Gross reports consulting for MicroVention/Terumo.