BackgroundFlow diverters have revolutionized the treatment of intracranial aneurysms. However, the delayed complications associated with flow diverter use are unknown.ObjectiveTo evaluate the incidence, severity, clinical outcomes, risk factors, and dynamic changes associated with in-stent stenosis (ISS) after treatment with a Pipeline embolization device (PED).MethodsPatients who underwent PED treatment between 2015 and 2020 were enrolled. The angiographic, clinical, and follow-up data of 459 patients were independently reviewed by four neuroradiologists to identify ISS. Binary logistic regression was conducted to determine ISS risk factors, and an ISS–time curve was established to demonstrate dynamic changes in ISS after PED implantation.ResultsOf the 459 treated patients, 69 (15.0%) developed ISS. At follow-up, nine patients (2.0%) with ISS demonstrated reversal, while 18 (3.9%) developed parental artery occlusion. A total of 380 patients (82.8%) achieved complete aneurysm occlusion (O’Kelly–Marotta grade D). Patients with posterior-circulation aneurysm (OR=2.895, 95% CI (1.732 to 4.838; P<0.001) or balloon angioplasty (OR=1.992, 95% CI 1.162 to 3.414; P=0.037) were more likely to develop ISS. Patients aged >54 years (OR=0.464, 95% CI 0.274 to 0.785; P=0.006) or with a body mass index of >28 kg/m2(OR=0.427, 95% CI 0.184 to 0.991; P=0.026) had a lower ISS risk. Intimal hyperplasia initiated by PED placement peaked within 1 year after the procedure, rarely progressed after 12 months, and tended to reverse within 24 months.ConclusionsISS is a common, benign, and self-limiting complication of PED implantation in the Chinese population.

Although endovascular treatment is a promising approach, blood blister-like aneurysms (BBAs) still present treatment challenges. This study aimed to assess the effectiveness and safety of flow diverter device-assisted coiling (FDDAC) for the treatment of BBAs, which are broad based and friable with a high rebleeding risk. Eight patients (five females and three males) who presented with subarachnoid hemorrhages (SAH) due to BBA ruptures between May 2020 and May 2022 were retrospectively enrolled. All patients were treated by flow diverter device (Tubridge) adjunctive coil embolization using a semi-deploying technique. The demographic information, angiographic data, interval between admission and treatment, materials, therapy, clinical outcomes (including periprocedural and intraprocedural mortality and morbidity), and follow-up results of all patients were reviewed. The mean age of the patients with BBAs was 48.5 years (range 31–62 years); aneurysm sizes ranged from 2.2 × 1.7 mm to 4.6 × 3.2 mm, and the median Hunt–Hess score was 3. All aneurysms were completely closed at follow-up, and all 8 patients had excellent clinical outcomes (modified Rankin scores = 0–2) at discharge. Angiograms showed complete aneurysm occlusion after 6 months to 1 year. In addition, there were no cases of re-rupture, re-treatment, or recurrence of the aneurysms. FDDAC is safe to use in patients with BBAs and provides an alternative treatment option for this disease.