Enterprise Stent Has Low Inaccurate Deployment , Morbidity , Mortality Rates Treatment of Intracranial Aneurysms With the Enterprise Stent : A Multicenter Registry

Background: The development of self-expanding stents has led to great improvements in the endovascular management of intracranial aneurysms with wide necks. These devices are thought to help by way of several mechanisms, including: (1) acting as a mechanical buttress that minimizes intraluminal coil protrusion; (2) increasing packing density; (3) flow diversion; and (4) providing a scaffold for endothelialization. One such device, the Neuroform (Boston Scientific), was the only self-expanding stent for treating intracranial aneurysms in the U.S. until the recent FDA approval of the Enterprise stent. However, data regarding the safety and efficacy of Enterprise are lacking. Objective: To present the authors' initial experience with Enterprise from a large multicenter registry. Methods: The initial 3 to 6 months' experience with Enterprise from 10 U.S. institutions is presented herein. Consecutive data on all patients with intracranial aneurysms treated or with intent-to-treat with Enterprise were gathered. Information regarding demographics, procedures, and complications was recorded. Procedural outcome was classified as: 100% occlusion; 95% to <100%; 90% to <95%; 80% to 90%; partial (<80%); planned staged stenting when coiling was planned for a later session; unplanned staged when intended coiling couldn't be performed thus was deferred; aborted coiling; and aborted stent. Results: 141 patients harboring 142 aneurysms underwent 143 attempted stenting procedures. Overall, 39% of patients had <7 mm aneurysms, 34% had 7 to 12 mm, 17% had 12 to 24 mm, and 3%had ≥25 mm. The 2 most common locations were paraclinoid in 50% and basilar tip in 13%. In 4 cases, no stenting could be performed due to challenging vascular anatomy. In total, 107 cases had attempted coiling. Of these, 33% were 100% occluded, 63% were ≥95% occluded, and 76% were ≥90% occluded. There were 3 unplanned staged procedures due to stent migration in 2 cases and unstable micro-catheter position in 1. There were 3 aborted coiling procedures due to coil protrusion with stent migration in 2 cases and coil protrusion only in 1. Morbidity was temporary in 6.0% of cases and permanent in 2.8%, among which were 1 intra-procedural stroke, 1 postprocedural intracerebral hemorrhage, 1 cerebellar stroke, and 1 aneurysm perforation. Mortality rate was 2.0% overall, 0.8% for unruptured aneurysms, and 12% for ruptured ones. Causes of death included aneurysm perforation and hemorrhagic complications that occurred post-procedure. Conclusions: The Enterprise stent had a high rate of successful navigation and was associated with low rates of inaccurate deployment. Furthermore, low morbidity and mortality rates were noted. Nonetheless, the authors recommended prudence when using Enterprise in patients with subarachnoid hemorrhage, as they seem to be associated with a high rate of fatal hemorrhagic complications. Reviewer's Comments: The early results of this large series demonstrate that the Enterprise stent is safe and can be successfully navigated in the intricate intracranial vasculature with high reliability. Nonetheless, a longterm follow-up study is warranted in order to evaluate its durability and long-term complication rates. (Reviewer-Ziad A. Hage, MD).