A Self-expanding Nitinol Stent (Enterprise) for the Treatment of Wide-necked Intracranial Aneurysms: Angiographic and Clinical Results in 40 Aneurysms

The Enterprise stent…still useful after all these years

BACKGROUND

The Enterprise stent (Codman Neuro, Massachusetts, USA) received Food and Drug Administration (FDA) approval in 2007 for stent-assisted coiling (SAC). Since its introduction, newer stents and devices for aneurysm treatment have been developed resulting in a shift in the utilization of this stent from SAC to other off-label indications.

OBJECTIVE

To describe our experience with the Enterprise stent being used for SAC and other off-label indications.

METHODS

This is a multi-center retrospective review of the use of the Enterprise stent between 2018 and 2023. All patients in which the Enterprise stent was successfully deployed were included in the study.

RESULTS

Our study cohort comprised of 194 patients, mostly females (n = 112, 57.7%), with a mean age of 63.2 years ± 14.3. The Enterprise stent was used for SAC in only 24 (12.4%) patients and was used for rescue stenting in stroke in 101 patients (52.1%), treatment of intracranial stenosis in 53 patients (27.3%), treatment of in-stent stenosis in 1 patient (0.5%), and for treatment of dissections in 15 patients (7.7%). From 2018 to 2023, the use of Enterprise stents for SAC significantly decreased (p < 0.0001) while the use of Enterprise stents for non-SAC purposes was insignificantly variable (p = 0.05).

CONCLUSION

Our study shows that the Enterprise stent remains a reliable tool in neuroendovascular procedures, even if its original intended use has been supplanted by other devices.

Procedural Outcome Following Stent-Assisted Coiling for Wide-Necked Aneurysms Using Three Different Stent Models: A Single-Center Experience

Previous case series have described the safety and efficacy of different stent models for stent-assisted aneurysm coiling (SAC), but comparative analyses of procedural results are limited. This study investigates the procedural outcome and safety of three different stent models (Atlas™, LEO+™ (Baby) and Enterprise™) in the setting of elective SAC treated at a tertiary neuro-endovascular center. We retrospectively reviewed all consecutively treated patients that received endovascular SAC for intracranial aneurysms between 1 July 2013 and 31 March 2020, excluding all emergency angiographies for acute subarachnoid hemorrhage. The primary procedural outcome was the occlusion rate evaluated with the Raymond–Roy occlusion classification (RROC) assessed on digital subtraction angiography (DSA) at 6- and 12-month follow-up. Safety assessment included periprocedural adverse events (i.e., symptomatic ischemic complications, symptomatic intracerebral hemorrhage, iatrogenic perforation, dissection, or aneurysm rupture and in-stent thrombosis) and in-house mortality. Uni- and multivariable logistic regression analyses were performed to identify patient baseline and aneurysm characteristics that were associated with complete aneurysm obliteration at follow-up. A total of 156 patients undergoing endovascular treatment via SAC met the inclusion criteria. The median age was 62 years (IQR, 55–71), and 73.7% (115) of patients were female. At first follow-up (6-month) and last available follow-up (12 and 18 months), complete aneurysm occlusion was observed in 78.3% (90) and 76.9% (102) of patients, respectively. There were no differences regarding the occlusion rates stratified by stent model. Multivariable logistic analysis revealed increasing dome/neck ratio (adjusted odds ratio (aOR), 0.26.; 95% CI, 0.11–0.64; p = 0.003), increasing neck size (aOR, 0.70; 95% CI, 0.51–0.96; p = 0.027), and female sex (aOR, 4.37; 95% CI, 1.68–11.36; p = 0.002) as independently associated with treatment success. This study showed comparable rates of complete long-term aneurysm obliteration and safety following SAC for intracranial aneurysm with three different stent-models highlighting the procedural feasibility of this treatment strategy with currently available stent-models. Increased neck size and a higher dome/neck ratio were independent variables associated with less frequent complete aneurysm obliteration.

[Imaging Parameter Optimization of Non-contrast Three-dimensional Time-of-flight Magnetic Resonance Angiography for Patients with Intracranial Stents Using a 1.5 T Magnetic Resonance Imaging System]

The imaging parameters of non-contrast three-dimensional time-of-flight magnetic resonance angiography (3D TOF-MRA) were optimized to improve the image quality for patients treated using stent-assisted coiling. A simulated blood flow phantom with three types of stents (Enterprise 2, Neuroform Atlas, and LVIS) was imaged by changing echo time (TE), band width (BW), flip angle (FA), and matrix (phase, frequency). The difference between the signal intensity in the simulated vessel and the background was measured at each imaging condition. The ratio of this difference with and without the stent was evaluated as the relative in-stent signal (RIS). In addition, the error ratio of the stent lumen diameter was assessed by comparing the full width at half maximum (FWHM) to that measured by 3D X-ray angiography. The RIS was higher in order of LVIS, Neuroform Atlas, and Enterprise 2 in all conditions. The RIS was higher in imaging conditions with short TE, narrow BW, high FA, and large phase matrix. The highest RIS was seen with a frequency matrix of 320 in the Enterprise 2 and 256 in the others. FWHM error ratio was smaller in the same order as the RIS. FWHM error ratio was smaller in imaging conditions with short TE, large frequency matrix (>384), large phase matrix (>224), and high FA (>20°). Imaging conditions of 3D TOF-MRA that were effective to improve the image quality for stent lumen evaluation were short TE and high spatial resolution.

Stent-assisted coiling of cerebral aneurysms: a single-center clinical and angiographic analysis

Objective

This study retrospectively compared the clinical and angiographic outcomes of treating cerebral aneurysms with Neuroform (NEU), Enterprise (EP), and Low-profile Visualized Intraluminal Support (LVIS/LVIS Jr) stents.

Materials and methods

We conducted a retrospective analysis of a procedural database. All aneurysm procedures using any of the three types of self-expanding nitinol stents (NEU, EP and LVIS/LVIS Jr) were included. Intra-procedure complications, post-procedure complications, and angiographic results (Raymond–Roy grade scale, RRGS) were analyzed retrospectively. A multivariate logistic regression analysis was conducted to identify predictors of intra-procedure and post-procedure complications.

Results

Two hundred and forty-three aneurysms in 229 patients treated with stent-assisted coiling were included (NEU group: 109 aneurysms; EP group: 61 aneurysms; LVIS/LVIS Jr: 73 aneurysms). The LVIS/LVIS Jr group was associated with the lowest rate of initial complete occlusion (RRGS I: 47.9%; 35/73). Follow-up showed the proportion of RRGS I increased for all stent groups but was greatest in the LVIS/LVIS Jr group. Overall, 17 intra-procedural complications were seen in 229 patients (7.4%) and 15 post-procedural complications were found in 198 patients at follow-up (7.6%), with no differences between stent groups. Thrombotic events were the most common complications and occurred in 13 patients (13/229, 5.7%).

Conclusions

All three types of stents used to treat cerebral aneurysms with unfavorable neck were safe and effective, providing suitable support for the coil mass. LVIS/LVIS Jr promotes better progressive aneurysm complete occlusion than the other two stents but seems to cause more common intra-procedural stent-related thrombotic events and fewer post-procedural complications.

LVIS Stent Versus Enterprise Stent for the Treatment of Unruptured Intracranial Aneurysms

OBJECTIVE

This retrospective study compared clinical and angiographic outcomes between LVIS and Enterprise stents.

MATERIALS AND METHODS

From November 2014 to December 2015, total 190 patients with 208 unruptured intracranial aneurysms were coiled assisted by LVIS and Enterprise stents. Procedure-related complications, clinical outcomes, and angiographic results were analyzed retrospectively.

RESULTS

A total of 92 patients with 96 aneurysms received LVIS stents and 98 patients with 112 aneurysms were treated with Enterprise stents. Procedure-related complications occurred in 10.9% of patients (2 hemorrhagic events and 8 thromboembolic events) in the LVIS stents group whereas 16.3% (1 hemorrhage, 1 mass effect, and 14 thromboembolic events) in the Enterprise stents group. No statistical significant differences in thromboembolic (P = 0.263), hemorrhagic complications (P = 0.611), and favorable clinical outcomes (modified Rankin Scores of 0-2) (P = 0.379) were found between 2 groups. A greater initial complete or near-complete obliteration was found in the LVIS stents group compared with the Enterprise stents group (96.9% vs. 88.4%, P = 0.034). Larger aneurysm size (P = 0.048) was an independent predictor of procedure-related complications in univariate analysis.

CONCLUSIONS

Compared with Enterprise stents, LVIS stents may achieve greater complete or near-complete occlusion rate. There was no significant difference in procedural-related complications and clinical outcomes between LVIS and Enterprise stents.

The Use of Solitaire AB Stents in Coil Embolization of Wide-Necked Cerebral Aneurysms

BACKGROUND

The Solitaire AB stent is one of many assistant stents used for treating wide-necked cerebral aneurysm, and has been used since 2003. However, large sample studies on its safety and effectiveness are lacking. The objective of this study was to evaluate the effectiveness and safety of the Solitaire AB stent in the coil embolization of wide-necked cerebral aneurysms.

METHODS

Retrospective review of the clinical and image data of 116 patients with wide-necked cerebral aneurysms who had been enrolled at six interventional neuroradiology centers from February 2010 to February 2014 and had been treated by coil embolization; in total, 120 Solitaire AB stents were used. The degree of aneurysm occlusion was examined using digital subtraction angiography (DSA) immediately after the procedure and during follow-up, and was graded using the modified Raymond classification. We also observed complications to evaluate the safety and effectiveness of this therapy.

RESULTS

The 120 Solitaire AB stents (4 mm × 15 mm, four stents; 4 mm × 20 mm, 16 stents; 6 mm × 20 mm, 36 stents; 6 mm × 30 mm, 64 stents) were inserted to treat 120 wide-necked cerebral aneurysms. All stents were inserted successfully. DSA immediately post-surgery revealed 55 cases of complete occlusion, 59 cases of neck remnant, and six cases of aneurysm remnant. Perioperatively, there were four cases of hemorrhage and four cases of stent thrombosis. The follow-up spanned 3-37 months; of 92 patients examined by DSA at the 6-month follow up, 12 had disease recurrence.

CONCLUSIONS

The Solitaire AB stent is effective with a good technical success rate and short-term effect for assisting coil embolization of wide-necked cerebral aneurysms.