Aneurysm treatment with WEB in the cumulative population of two prospective, multicenter series: 3-year follow-up

Abstract

Background: WEB treatment is an endovascular approach for wide-neck bifurcation aneurysms that has demonstrated high safety and good efficacy in mid-term follow-up. While evaluating safety in the long term is important to determine if delayed adverse events occur affecting late morbidity and mortality, the most important point to evaluate is the long-term stability of aneurysm occlusion. The current analysis reports the 3-year clinical and anatomical results of WEB treatment in the combined population of two European trials (WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm Therapy) and WEBCAST-2).

Methods: Aneurysm occlusion was evaluated using a 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant.

Results: The safety population comprised 79 patients. The efficacy population comprised 61 aneurysms. Aneurysm locations were middle cerebral artery in 32/61 aneurysms (52.5%), anterior communicating artery in 13/61 (21.3%), basilar artery in 9/61 (14.8%), and internal carotid artery terminus in 7/61 (11.5%). No adverse events related to the device or procedure occurred between 2 and 3 years. At 3 years, complete occlusion was observed in 31/61 (50.8%) aneurysms, neck remnant in 20/61 (32.8%), and aneurysm remnant in 10/61 (16.4%). Between 1 year and 3 years, aneurysm occlusion was improved or stable in 53/61 (86.9%) aneurysms and worsened in 8/61 (13.1%). Worsening was mostly from complete occlusion to neck remnant in 6/61 (9.8%) aneurysms. The retreatment rate at 3 years was 11.4%.

Conclusions: This analysis confirms the high safety profile of WEB. Moreover, evidence demonstrates the great stability of aneurysm occlusion with adequate occlusion (complete occlusion or neck remnant) in 83.6% of aneurysms.

Clinical trial registration: URL: http://www.clinicaltrials.gov. WEBCAST and WEBCAST-2: Unique identifier: NCT01778322.

Keywords: aneurysm.

Figure 1

Population flow chart for two studies for safety and efficacy at 3 years. * This patient had no vascular follow-up imaging at 1 year, but had it at 3 years. "lost to follow-up" means that the centers were unable to contact the patients using different techniques (phone call, email, letter, etc) so the patient exited the study. "missed visits" means that the patient did not attend the 3-year follow-up, but attended a later visit.

Figure 2

Unruptured basilar tip aneurysm. a: DSA (frontal view) before web treatment shows the aneurysm. b: post-operative DSA (frontal view) shows residual flow in the aneurysm and the device. c: 1-year DSA shows complete aneurysm occlusion. d: 3-year MRA shows stable complete aneurysm occlusion.

Figure 3

Unruptured middle cerebral artery aneurysm. a: DSA (frontal view) shows the aneurysm. b: 1-year DSA (unsubstracted, non injected) shows web retraction. c:1-year DSA shows an aneurysm remnant. d: retreatment by stent-assisted coiling. e: final control DSA after retreatment shows complete aneurysm occlusion.