Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms: A Randomized Clinical Trial

Abstract

BACKGROUND AND PURPOSE: Stent-assisted coiling may improve angiographic results of endovascular treatment of unruptured intracranial aneurysms compared with coiling alone, but this has never been shown in a randomized trial. MATERIALS AND METHODS:The Stenting in the Treatment of Aneurysm Trial was an investigator-led, parallel, randomized (1:1) trial conducted in 4 university hospitals. Patients with intracranial aneurysms at risk of recurrence, defined as large aneurysms ($10 mm), postcoiling recurrent aneurysms, or small aneurysms with a wide neck ($4 mm), were randomly allocated to stent-assisted coiling or coiling alone. The composite primary efficacy outcome was "treatment failure," defined as initial failure to treat the aneurysm; aneurysm rupture or retreatment during follow-up; death or dependency (mRS . 2); or an angiographic residual aneurysm adjudicated by an independent core laboratory at 12 months. The primary hypothesis (revised for slow accrual) was that stent-assisted coiling would decrease treatment failures from 33% to 15%, requiring 200 patients. Primary analyses were intent to treat. RESULTS:Of 205 patients recruited between 2011 and 2021, ninety-four were allocated to stent-assisted coiling and 111 to coiling alone. The primary outcome, ascertainable in 203 patients, was reached in 28/93 patients allocated to stent-assisted coiling (30.1%; 95% CI, 21.2%-40.6%) compared with 30/110 (27.3%; 95% CI, 19.4%-36.7%) allocated to coiling alone (relative risk ¼ 1.10; 95% CI, 0.7-1.7; P ¼ .66). Poor clinical outcomes (mRS .2) occurred in 8/94 patients allocated to stent-assisted coiling (8.5%; 95% CI, 4.0%-16.6%) compared with 6/111 (5.4%; 95% CI, 2.2%-11.9%) allocated to coiling alone (relative risk ¼ 1.6; 95% CI, 0.6%-4.4%; P ¼ .38).

ARISE I Consensus Review on the Management of Intracranial Aneurysms

“…35–37 However, according to the STAT trial (Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms), stent-assisted coiling was not superior to coiling alone in terms of functional and angiographic outcomes when used in the treatment of large, wide-neck, or recurrent unruptured aneurysms. 38 Balloon-assisted coiling has similar results with complete occlusion rates at the end of the treatment comparable to stent-assisted coiling in a large systematic review and meta-analysis by Wang et al 39–42 Stented patients had higher progressive aneurysm occlusion at 6-month follow-up (odds ratio, 1.82 [95% CI, 1.21–2.74]) compared with balloon patients.…”

History of Neurointervention

“…65 Although SAC was thought to help remodel the parent artery and serve as a scaffold for adjunctive coiling of wide necked aneurysms, a randomized trial did not demonstrate superiority of SAC compared with conventional coiling among patients with wide neck, or recurrent cerebral aneurysms. 66 Bifurcation aneurysms remained a challenge for which double stent-assisted coil embolization was first reported in 2004 for a basilar apex aneurysm. 67 Many variations in this technique have been reported such as an X or Y configurations, in which stents can be crossed, placed in parallel, or be non-overlapping.…”

Endovascular and Medical Management of Unruptured Intracranial Aneurysms

“…71 More recently, the Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms (STAT) randomized controlled trial reported interim data which showed no significant benefit of stent-assisted coiling over primary coiling for large, wideneck, or recurrent aneurysms. 72 "Y-stenting" is a technique sometimes employed to treat wide-neck bifurcation aneurysms, where two stents are placed at the bifurcation to provide support. 73 ►Fig.…”

“…71 More recently, the Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms (STAT) randomized controlled trial reported interim data which showed no significant benefit of stent-assisted coiling over primary coiling for large, wide-neck, or recurrent aneurysms. 72…”