Endovascular treatment of challenging aneurysms with FRED Jr flow diverter stents: a single-center experience

Abstract

Purpose: To analyze clinical safety and efficacy of flow re-direction endoluminal device (FRED) Jr flow diverter for treatment of unruptured, ruptured, or recanalyzed aneurysms.

Materials and methods: Between October 2019 and February 2022, 25 patients with 31 aneurysms treated with FRED Jr were included in the study. Clinical and radiological records, procedural details, and follow-up outcomes were retrospectively evaluated. Eighteen (72%) patients were female. Median age was 48.8 (age range 9-85). Mean follow-up was 21 months (6-28 months). Location of the aneurysms were as follows; 13 in middle cerebral artery (MCA), 7 in anterior cerebral artery (ACA), 4 in posterior cerebral artery (PCA), 3 in true posterior communicating artery (PCom), 2 in anterior communicating artery (ACom), 1 in superior cerebellar artery (SCA), 1 in true ophthalmic artery. Five patients (20%) presented with acute subarachnoid hemorrhage (aSAH).

Results: In all procedures, FRED Jr was successfully deployed. Three true Pcom aneurysms and a true ophthalmic aneurysm were treated with FRED Jr. Three patients with two adjacent aneurysms were treated with a single FRED Jr. In two (8%) patients in-stent thrombosis occurred intraoperatively, they were treated with iv tirofiban and thrombectomy without any sequelae. Post-discharge 2 weeks later, intraparenchymal hemorrhage occurred in a patient. He was treated with surgical drainage, the clinical course was modified Rankin score (mRS) 2. Digital subtraction angiography (DSA) was performed on 16 (64%) patients with 21 (67%) aneurysms. Near complete-complete occlusion (O'Kelly-Morata grading scale (OKM C-D) was documented in 15/16 (93.7%) patients, 20/21 (95.2%) aneurysms. In nine (36%) patients, no residual filling was observed in the magnetic resonance angiography (MRA). Good clinical outcome (mRS 0-1) was achieved in 24/25 (96%) of patients.

Conclusion: Endovascular treatment of small cerebral aneurysms with FRED Jr is safe and effective even in complex and challenging morphologies allowing high rates of aneurysm occlusion with low periprocedural complications. Our cohort, consisting of a rate 20% acute ruptured aneurysms, is the major additive data to the published literature.

Keywords: FRED Jr; Low-profile flow diverter; Small cerebral artery aneurysm; Subarachnoid hemorrhage.

Fig. 1

a Preprocedural 3D DSA demonstrated two aneurysms in the right ACA A2-3 segment and an aneurysm in the left ACA A2-3 segment in a 53-year-old-female. b, c First, two adjacent aneurysms in the right A2-3 segment were treated by placing a single Fred Jr on their neck. While FRED Jr covered both aneurysms, stasis was observed in the aneurysms after FD. d No residual filling was observed in both aneurysms located in the right ACA in the 9th-month follow-up AP angiogram. e, f Then in the left A2-3 segment aneurysm was treated with a second FRED Jr deployment in the same session. g In a follow-up lateral angiogram, no residual filling (OKM D) was observed for three aneurysms. h Lateral angiograms showed FRED Jr located bilaterally in A2-3

Fig. 2

a, b, c In the AP, lateral, and 3D angiograms of a 13-year-old female patient, two dissecting giant aneurysms were observed proximal to the PCA. d The procedural lateral angiogram shows both aneurysms treated with a single long dimensional FRED Jr. e Significant stasis was observed in the post-procedural immediate angiogram. f No residual filling(OKM D) was observed in the 6th-month follow-up angiograms

Fig. 3

a A ruptured dissecting giant aneurysm in PCA was detected in a 9-year-old boy in the AP angiogram. b 3D angiogram shows dissecting PCA aneurysm. c, d After crossing the dissecting aneurysm with a microguidewire, a FRED Jr was placed in the aneurysmal segment. d Since there was not enough stasis in the immediate angiogram, sufficient stasis was obtained by placing a second FRED Jr. e Post-operative significant stasis was observed in immediate angiograms. f AP angiogram shows two overlapping FRED Jr in PCA. g, h No residual filling was observed (OKM D) in the 12th-month follow-up angiograms

Fig.4

a, b A true PCom aneurysm was detected on the left PCom artery in the lateral and AP angiograms in a 32-year-old patient presenting with acute SAH. c 3D DSA demonstrated true PCom aneurysm in more detail. d After the PCom artery was selectively catheterized, FRED JR was deployed into PCom artery. e Immediate DSA showed stasis in aneurysm. f No residual filling was observed in the 6th-month MRA (OKM D)

Fig. 5

a, b Ophthalmic artery intracanalicular segment aneurysm was detected in AP and lateral DSA images. c True ophthalmic artery aneurysm was evaluated in detail by taking a procedural 3D angiogram. d Procedural lateral angiogram showed FRED Jr insertion into the neck of the intracanal true ophthalmic artery aneurysm. e Aneurysm occluded immediately after insertion of FRED Jr into the ophthalmic artery. f No residual filling was observed in 6th-month follow up angiogram (OKM D)