Placement of a Stent within a Flow Diverter Improves Aneurysm Occlusion Rates

BACKGROUND AND PURPOSE: Placement of a stent within a flow diverter has been described previously but its consequences have not been analyzed. We evaluated the clinical and angiographic results of stent placement within a flow diverter during the same treatment session.

MATERIALS AND METHODS: All patients treated with a Surpass flow diverter were retrospectively evaluated. Patients with previously deployed stents and procedures in which scaffolding stents, a second flow diverter, or intrasaccular devices were used were excluded. Patient and aneurysm characteristics and clinical and imaging follow-up results were compared between stented and nonstented Surpass flow-diverter groups and stent assisted coiling.

RESULTS: Thirty-five patients (41 aneurysms) were treated with a Surpass flow diverter only (monotherapy group), and in 33 patients (35 aneurysms), a stent was placed within the Surpass flow diverter (stented group). Stents were placed inside the Surpass flow diverter for a variety of reasons at the operator's discretion. No statistical difference was noted between the 2 groups in age, body weight, sex, history of thromboembolic events, smoking, platelet inhibition levels, hypertension, hyperlipidemia, diabetes mellitus, malignancy, and aneurysm location. Aneurysms in the stented group were larger than those in the monotherapy group (14.8 versus 9.1 mm, P < .001). The rate of clinically significant adverse events and complete aneurysm occlusion rates at 0–3 and 3–6 months (73.3% versus 61.3%, P = .31, and 84.8% versus 70.2%, P = .14) were similar. At 9–12 months, a significantly higher proportion of aneurysms in the stented group achieved complete occlusion (93.9% versus 73.2%, P = .019). There was a trend toward a higher obliteration rate on final follow-up in the stented group (93.9% versus 82.9%, P = .14).

CONCLUSIONS: Placement of a stent within a flow diverter increases the rate of aneurysm occlusion. We propose that these results are from improved flow-diverter apposition due to the higher radial force of intracranial stents.