Three-year outcomes of the Surpass intracranial aneurysm embolisation system pivotal trial to treat large or giant wide neck aneurysm (SCENT trial) confirm the safety and efficacy of the device. Referring to the significant progression of aneurysm occlusion, Ricardo Hanel (Baptist Stroke & Cerebrovascular Center, Jacksonville, USA) said “the efficacy improves over time”, while the 12-month to three-year adverse event-rate with the Surpass device (Stryker) was found to be very low.
During his presentation of the data at the Society of NeuroInterventional Surgery’s (SNIS) annual meeting (22–25 July, Miami, USA), Hanel acknowledged that the trial’s 12 month results— presented at SNIS two years ago—led to the Surpass device becoming the first flow diverter to be indicated by the US Food and Drug Administration (FDA) to treat large and giant posterior communicating artery aneurysms.
“Its premarket approval enables its use for unruptured or giant saccular or fusiform aneurysms (≥10mm diameter), as well as wide neck, or those within the petrous segment to the terminus arising from a parent vessel—for artery diameters of 2.5–5.3mm,” said Hanel, adding that patients above the age of 18 with a single internal carotid artery aneurysm were eligible for enrolment in the SCENT trial.
Moreover, he reported, “If you compare this SCENT trial with previously published prospective trials, it was mostly an intradural aneurysm trial, as 69% of the aneurysms were intradural, and 31% extradural—mostly cavernous aneurysms.”
Alluding to the decrease in the patient population over the past two years, he acknowledged that, “over time, we lose patients to follow-up”. Though the investigators began with a modified intention-to-treat number of 180, 42 were lost due to withdrawal or death, leaving the three-year outcomes representative of 138 patients. Hanel surmised, “In total, 94.9% [131/138] patients completed clinical follow-up at 36-months, while 81.2% [112/138] completed clinical and angiogram follow-up at 36 months.”
In terms of the safety results, he said, “When the 12-month data ware presented here before at SNIS, new or worsening ipsilateral stroke occurred in 8.3% [15/180] of the patient population, while 2.2% incurred an aneurysm rupture, and 0.6% had to undergo retreatment at 12 months.”
Furthermore, Hanel pointed to data indicating that only two new ischaemic events occurred beyond 12 months. One involved an ischaemic stroke in a patient with sickle cell disease who had stopped taking antiplatelet agents, specifically aspirin, and the other was a posterior circulation ischaemic stroke that, according to Hanel, “was not related to the device and not in the territory of the index procedure”.
In relation to the efficacy of the Surpass device, Hanel said there was an improvement from baseline occlusion rates. Clinically speaking, the percentage of modified Rankin Scale (mRS) scores that had improved from the last visit was 24.7% at 12 months, and 11.2% at 36 months, while the percentage of those that had remained stable was 64.5% and 75% at 12 and 36 months, respectively.
Pointing to the effectiveness outcomes, Hanel reported, “There is not much difference between parent stenosis or implant stenosis at one year compared to three years.” Further, in terms of the complete aneurysm occlusion rates, which increased from 68.3% at 12 months to 78.3% at 36 months, he noted that they represent “a progression of the occlusion of the aneurysm as expected from one-year follow-up results to 36 months”, telling the SNIS audience: “You can see this represented in a different way, between Raymond Class Grade 1, 2, or 3. At 12-month follow-up, Raymond 1 was 66.1% and increased to 78.3% at 36 months, so a dramatic