Does Small Aneurysm Size (<10 mm) Predict Complete Occlusion After Flow Diversion? A Surpass Evolve Single-Center Study

Background: Long-term safety and efficacy outcomes of Surpass Evolve flow diverter (SEFD) in treatment of intracranial aneurysms are lacking. Factors predicting complete aneurysm occlusion are elusive in literature. Methods: A retrospective review of all consecutive aneurysms treated with SEFD from February 2020 to July 2022, at a single comprehensive stroke center. Results: Fifty-one patients with 80 aneurysms were included. Mean target aneurysm size was 5.6 mm and mean neck-width 3.42 mm. Small aneurysms (<10 mm) were 75% (n=60), while 25% were >10 mm. Unruptured were 71 (88.7%), previously ruptured were 8 (10%), and partially thrombosed 2.3% (n=1). Mean SEFDs used per patient were 1.07 and 40% (n=22) procedures were performed transradially. Mean procedure time was 59.1 minutes. The technical success rate for device deployment was 100%. Raymond Roy (RR) class I occlusion at 6 month (n=73) was seen among 56.2% (n=41), at 1 year (n=35) among 85.7% (n=30) and at 2 year (n=18) among 88.8% (n=16) aneurysms. Aneurysm size <10 mm significantly predicted RR-I occlusion outcome (odds ratio [OR]: 2.16; confidence interval [CI]: 0.02-4.29) at 6 months. Age, gender, smoking status, hypertension, location of aneurysm, and rupture status did not predict RR-I occlusion outcome. No mortality or permanent neurological morbidity was observed in the cohort. Major complications seen in 7.2% (n=4) patients were stent thrombosis (n=1, 1.8%), carotid-cavernous fistula (n=1, 1.8%) and transient ischemia in 2 (3.6%). Non-flow limiting stenosis was observed in 3 (5.4%) patients. Conclusion: SEFD gives good aneurysm occlusion rates with favorable long-term safety profile and low rate of thromboembolic complications. Small aneurysm size (<10 mm) was associated with complete aneurysm occlusion at 6-month angiographic follow-up. Clinical Impact As Surpass Evolve is a newer generation Flow diverter of the Stryker Surpass FDs, with its improved design and applicability in intracranial aneurysms, we believe that more physicians will be encouraged to use this device worldwide.