- Email: [email protected]
Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis
Journal of Clinical Neuroscience xxx (xxxx) xxx
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis Rajeev Sivasankar a,⇑, Manish Shrivastava b, Uday S. Limaye c a
Dept of Imaging & Interventional Radiology, INHS Asvini, Colaba, Mumbai, India Consultant Interventional Neuroradiology, Department of Imaging & Interventional Radiology, Kokilaben Dhirubai Ambani Hospital, Mumbai, India c Consultant Interventional Neuroradiology, Department of Imaging & Interventional Radiology, Lilavati Hospital, Mumbai, India b
a r t i c l e
i n f o
Article history: Received 20 January 2019 Accepted 29 July 2019 Available online xxxx Keywords: Flow diverters FRED junior Aneurysms
a b s t r a c t This retrospective study was aimed at assessing our results of endovascular management using the FRED junior flow diverter in cerebral aneurysms at or distal to the circle of Willis. 12 patients with 15 small cerebral vessel aneurysms at or distal to the circle of Willis underwent endovascular treatment using the FRED junior flow diverter at two tertiary care centres in Mumbai, India. 12 of the 15 aneurysms were unruptured, one was treated in an acutely ruptured setting, while two, which had presented with SAH were initially treated with balloon assisted coiling and later treated in a staged manner with a flow diverter. Technical success was 100% in all 15 deployments. Deployments were made across angles ranging from 45° to 180°. There was no stroke/TIA/death in any of the cases, which were unruptured. The O’Kelly-Marotta (OKM) staging was used to analyze angiographic follow up (at least one post procedure angiogram) which was available in 8 patients (10 aneurysms). OKM D & C was seen in 80% of the aneurysms on follow up angiograms. The treatment of small vessel cerebral aneurysms at or distal to the Circle of Willis using a dedicated flow diverter (FRED Jr.) is both technically feasible and highly efficacious. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction
2. Materials and methods
Flow diverters (FDs) are an established modality of endovascular treatment in situations such as giant, wide-necked, dissecting, fusiform aneurysms etc. However their utility in the management of aneurysms which occur at or distal to the circle of Willis is yet being ascertained. Many factors contribute to the differences between use of flow diverters proximal to and at/distal to the Circle of Willis. These include the small size of parent vessels, the presence of important divisions & branches incorporated by the aneurysm and acute bends or tortuosity of vasculature. The FRED Junior flow diverter has been designed for use in the treatment of cerebral aneurysms in smaller vessels. We wish to present experience of usage of this device in the management of cerebral aneurysms at or distal to the circle of Willis.
2.1. Selection of patients
⇑ Corresponding author at: Dept of Imaging & Interventional Radiology, INHS Asvini, Colaba, Mumbai 400005, India. E-mail address: [email protected] (R. Sivasankar).
Retrospective clinical and angiographic data pertaining to patients with cerebral aneurysms at or distal to the circle of Willis from Aug 2015 to July 2018, were collected from two tertiary care centres in Mumbai, India. All patients were chosen for endovascular treatment following ‘in-hospital’ multi-disciplinary discussions at their respective hospitals. 2.2. Antiplatelet regimen Patients with unruptured aneurysms were administered dual antiplatelet therapy (Clopidogrel & Aspirin/Prasugrel & Aspirin/ Ticagrelor & Aspirin) pre-operatively. Dual antiplatelet therapy was continued post – operatively for 6 months in the following dosages: Clopidogrel 75 mg once daily, Aspirin 150 mg once daily, Ticagrelor 90 mg twice a day or Prasugrel 10 mg once a day. Dual anti-platelets were continued for a period of six months after which Aspirin was continued as monotherapy in a dose of 150 mg daily. In the setting of acute subarachnoid hemorrhage, it was preferred to stage the flow diverter treatment and performing
https://doi.org/10.1016/j.jocn.2019.07.079 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
2
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
a balloon assisted coiling in the first stage. In the setting of acute SAH where it was technically impossible to use coils as a first line of management, the patient was loaded with dual antiplatelets via a Ryle’s tube and a bolus dose of Abciximab/Integrillin/Tirofiban was administered during the flow diverter deployment which was followed by a continuous IV infusion for 12 h. Thereafter dual antiplatelets were continued from the next day.
2.3. Endovascular technique The technique typically involved use of a 6 French long sheath (Neuron Max, Penumbra Inc/Rabbe, Cook/Destination, Terumo) which was placed in the common carotid artery or V1 segment of the vertebral artery & a guiding catheter (Neuron, Penumbra/ Sofia, Microvention/Envoy, Codman or Catalyst 5, Stryker) which was navigated into the ICA or the V2/V3 segments of the vertebral artery. In the patients treated with FDs and coils, the ‘jailed-micro catheter’ technique was used. Thereafter a Headway 21 microcatheter (Microvention) was navigated over a 0.01400 microwire (Traxcess, Microvention/Synchro-2, Stryker) for purposes of Fred junior deployment across the aneurysm. Flow diverter sizing was performed pre-operatively using CTA and/or rotational DSA images. As far as possible, the device was ‘right-sized’ to the caliber of the proximal vessel diameter.
Fig. 2. A FRED Jr. 2.5 18–13 mm (arrow) was deployed across the aneurysm.
3. Post-operative management & follow-up Patients were extubated post-operatively in all but one case, which had presented with an acute subarachnoid hemorrhage and was electively ventilated for two days. Post-operative CT head was performed in all cases to exclude hemorrhagic complications. Patients were followed up clinically at 1 week, 1, 3 & 6 months after discharge from the hospital. Angiographic follow up was performed at 6 months of the procedure, and in some patients who expressed a logistic inability to get the angiography done in that period, angiography was done within a year post procedure.
Fig. 3. 6-Month control angiogram shows complete resolution of the aneurysm with good caliber of the stented segment. The arrow shows the patency of the branch artery.
Fig. 1. A 55 year old lady presented with history of headaches. She had no comorbidities and was detected to have a wide-necked 8 mm sized distal ACA aneurysm.
Fig. 4. A 62 yr old man was brought with a history of chronic headaches and one episode of transient loss of consciousness, which recovered spontaneously. CT angiography revealed a fusiform aneurysm of the distal M1 segment of the right MCA, which was confirmed on DSA.
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
3
branches from the aneurysm neck after an interval of eight to ten weeks. Only one aneurysm was primarily treated in the acutely ruptured setting. 4.3. Endovascular treatment results & complications
Fig. 5. A FRED Jr. 2.5 18–13 mm was deployed across the aneurysm. Fluoroscopic image shows well -expanded stent with adequate coverage of the abnormal segment of vessel.
The device could be deployed with technical success in all 15 deployments. Deployments were made across angles ranging from 45° to 180°. Figs. 1–3 illustrate the use of a FRED Jr across a DACA aneurysm and the angiographic follow up. There was no stroke/ TIA/death in any of the cases which were unruptured. In one case which was treated in an acutely ruptured setting, an Acute in-stent occlusion occurred which was managed with Gp2b3a inhibitors. No complications occurred in the form of death, stroke or TIAs. 3 out of 15 cases had ‘in-stent’ stenosis without clinical sequelae on their angiographic follow up and were continued on dual antiplatelets Figs. 3–6 illustrate a case where a FRED Jr flow diverter was used to treat an MCA aneurysm. Presence of an ‘in-stent’ stenosis was seen on follow up angiogram. No side-branch occlusions were observed in any of the cases. A summary of the aneurysm location, vessel size, aneurysm size and angles of deployment are detailed vide Table 1. 4.4. Follow-up The O’Kelly-Marotta (OKM) staging was used to analyze angiographic follow up (at least one post procedure angiogram) which was available in 8 patients (10 aneurysms) and are as detailed in Table 2. 5. Discussion
Fig. 6. Control angiogram shows re-modeling of the aneurysm with presence of an ‘in-stent’ stenosis for which he was continued on dual antiplatelets.
4. Results 4.1. Location & aneurysm morphology Based on location, six out of fifteen aneurysms (40%) were at the Distal Anterior cerebral artery (DACA), four aneurysms (27%) were at the Anterior communicating artery (ACoA)/A1-A2-ACoA junction, three (20%) involved the MCA & one each was located at the V4 segment of the Vertebral artery and the Posterior cerebral artery. 12 of the 15 aneurysms (80%) were saccular in nature, 2 were dissecting (13.3%) while one was a blister aneurysm. Sizes of the aneurysms ranged from 1.4 mm to 11 mm. 4.2. Clinical presentation A total of fifteen aneurysms in 12 patients were treated during this period. 12 of these 15 (80%) aneurysms were unruptured and 2 aneurysms of the 15 had presented with SAH due to rupture. These were treated initially with balloon assisted coiling followed by FRED Jr. flow divertor treatment for a residual neck which was intentionally left in these cases due to the origin of important
Flow diverters (FDs) are an established modality of endovascular treatment in situations such as giant, dissecting, blister, partially thrombosed aneurysms etc. [1–4]. However their role in the treatment of aneurysms at or distal to the Circle of Willis in small vessel aneurysms has not yet been clearly established [5– 7]. Flow diverters work on the principle of changing the dynamics of flow within the vessels in which they are implanted, so as to maintain the patency of the parent vessel & their branches whilst propagating thrombosis and remodeling within the aneurysm [8,9]. This study, involving a dedicated flow diverter designed for treatment of cerebral aneurysms in small vessels, had a technical success of 100%. Of the ten aneurysms in which follow up angiograms could be performed (within six months to a year post procedure), 60% had an OKM D occlusion [10]. There was also no death, stroke or TIA in any of the patients. These results are quite similar to those obtained in the EU MultiCentre Trial, where 70% of patients had an OKM D occlusion on follow up angiogram [11]. The results also are akin to an overall final occlusion of 70% as reported by Yan et al in their recent metanalysis of the safety & efficacy of flow divertors in small cerebral vessels which looked at 26 non-comparative studies with 572 aneurysms [12]. The results are also similar to those reported by Pierot et al in the SAFE study wherein an adequate occlusion rate of 81.1% was reported using the FRED device [13]. The high percentage of technical success in deployment is probably directly related to the dual stent construction design of the device [14]. The outer stent, which has 16 wires, helps in anchoring the device, while the inner stent helps in the flow diversion effect. Additionally the presence of only 16 wires in the outer stent may help in smoother deployment compared to other flow diverters, which have a large number of wires that may increase the frictional interplay between surfaces during deployment. The radial force of opening is stronger due to the presence of two nitinol stents, which makes in easier to open at bends
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
4
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
Table 1 Summary of the aneurysm location, vessel size, aneurysm size and angles of deployment. Sl. No
Location
Vessel size (Proximal/Distal) (mm)
Angle (degrees)
Aneurysm size/Neck (mm)
Immediate OKM
Follow up OKM
Ruptured/Unruptured
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
DACA MCA DACA ACoA MCA DACA DACA MCA PCA ACoA DACA V4 DACA ACoA ACoA
2.3/1. 9 2.4/2.1 2.2/1.9 2.3/2.1 3/2.3 2.4/2.0 2.2/2.0 2.6/1.9 2.2/1.9 2.3/1.9 2.3/2.2 3.1/2.6 2.4/2.1 2.9/2.3 2.7/ 2.4
101.4 98.4 103.5 90 88 102 107 45 98 100 104 180 100 95 102
6/2.5 Fusiform 8/3.8 5.2/3.2 5.1/3.0 6.2/4.1 5.5/3 5.4/2.8 1.4 6.9/4.0 11/5 8/4.5 7.2/4.8 5.2/4 4.5/3 (Three aneurysms at the A1-A2 jn)
B1 A B2 B1 B2 C1 B2 A D C1 B3 C1 B2 B1 B1
D B1 D – – D D A D – C2 D – – C1
Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Ruptured Unruptured 2nd stage FRED Jr. Unruptured 2nd stage FRED Jr. Unruptured Unruptured
Table 2 Follow up OKM staging. OKM scale
Number
D C1 C2 A B1
6/10 (60%) 1/10 (10%) 1/10 (10%) 1 (10%) 1 (10%)
in the distal vessels or at bifurcations. Additionally, the use of a coil braided 0.02100 microcatheter with an outer diameter of 2.0F, makes it easy to navigate distally. The lack of a distal wire increases the safety of the procedure by reducing risk of perforation of small vessels during device deployment. Three patients in this series had ‘in-stent’ stenosis (ranging from 20% to 50%), without clinical sequelae, which required them to be continued on dual antiplatelets. One of these three had good remodeling of the stenosis on further follow up angiogram at 18 months. The other two patients are due for follow up angiograms. This observational study has several limitations owing to the small study population and a short follow up period. However this being a challenging subset of cerebral aneurysms for both endovascular and microsurgical techniques, this case series will contribute significantly to the data on the use of flow diverters in small cerebral vessels. Larger studies will throw more light on the long-term benefits and efficacy of flow diverters, which are dedicatedly designed to be used for the treatment of small cerebral vessel aneurysms. 6. Sources of financial & material support Nil. References
[2] Brinjikji W, Murad MH, Lanzino G, Cloft HJ, Kallmes DF. Endovascular treatment of intracranial aneurysms with flow diverters: a meta-analysis. Stroke 2013;44:442–7. [3] Fischer S, Vajda Z, Aguilar Perez M, Schmid E, Hopf N, Bazner H, et al. Pipeline embolization device (PED) for neurovascular reconstruction: initial experience in the treatment of 101 intracranial aneurysms and dissections. Neuroradiology 2012;54:369–82. [4] Briganti F, Leone G, Ugga L, Marseglia M, Solari D, Caranci F, et al. Safety and efficacy of flow re-direction endoluminal device (FRED) in the treatment of cerebral aneurysms: a single centre experience. Acta Neurochir (Wien) 2016;158:1745–55. [5] Pistocchi S, Blanc R, Bartolini B, Piotin M. Flow diverters at and beyond the level of the circle of Willis for the treatment of intracranial aneurysms. Stroke 2012;43:1032–8. [6] Martinez-Galdamez M, Romance A, Vega P, Vega A, Caniego JL, Paul L, et al. Pipeline endovascular device for the treatment of intracranial aneurysms at the level of the circle of Willis & beyond: multicenter experience. J Neurointerv Surg 2015;7:816–23. [7] Lin N, Lanzino G, Lopez DK, Arthur AS, Ogilvy CS, Ecker RD, et al. Treatment of distal anterior circulation aneurysms with the Pipeline embolization device: a US multicenter experience. Neurosurgery 2016;79:14–22. [8] Cebral JR, Mut F, Raschi M, Hodis S, Ding YH, Erickson BJ, et al. Analysis of hemodynamics and aneurysm occlusion after flow-diverting treatment in rabbit models. AJNR Am J Neuroradiol 2014;35:1567–73. [9] Suzuki T, Takao H, Fujimura S, Dahmani C, Ishibashi T, Mamori H, et al. Selection of helical braided flow diverter stents based on hemodynamic performance and mechanical properties. J NeuroInterv Surg 2017;9:999–1005. [10] O’Kelly CJ, Krings T, Fiorella D, Marotta TR. A novel grading scale for the angiographic assessment of intracranial aneurysms treated using flow diverting stents. Interv Neuroradiol 2010;16:133–7. [11] Möhlenbruch MA, Kizilkilic O, Killer-Oberpfalzer M, Baltacioglu F, Islak C, Multicenter Bendsuz M, et al. Experience with FRED Jr. flow re-direction endoluminal device for intracranial aneurysms in small arteries. AJNR 2017;38 (10):1959–65. [12] Xin Wen-qiang, Xin Qi-qiang, Yuan Yan, Chen Shi, Gao Xiang-liang, Zhao Yan, Zhang Hao, Li Wen-kui, Yang Xin-yu. Comparison of flow diversion and coiling for the treatment of unruptured intracranial aneurysms. World Neurosurg 2019. ISSN 1878-8750. [13] Pierot L, Spelle L, Berge J, Januel A-C, Herbreteau D, Aqqour M, et al. SAFE study (Safety and efficacy analysis of FRED embolic device in aneurysm treatment): 1-year clinical and anatomical results. J Neurointerv Surg 2019;11(2):184–9. [14] Luecking H, Engelhorn T, Lang S, Goelitz P, Kloska S, Roessler K, et al. FRED flow diverter: a study on safety and efficacy in a consecutive group of 50 patients. AJNR 2017;38:596–602.
[1] Briganti F, Leone G, Marseglia M, Mariniello G, Caranci F, Brunetti A. Endovascular treatment of cerebral aneurysms using flow diverter devices: a systematic review. Neuroradiol J 2015;28(4):365–75.
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis Rajeev Sivasankar a,⇑, Manish Shrivastava b, Uday S. Limaye c a
Dept of Imaging & Interventional Radiology, INHS Asvini, Colaba, Mumbai, India Consultant Interventional Neuroradiology, Department of Imaging & Interventional Radiology, Kokilaben Dhirubai Ambani Hospital, Mumbai, India c Consultant Interventional Neuroradiology, Department of Imaging & Interventional Radiology, Lilavati Hospital, Mumbai, India b
a r t i c l e
i n f o
Article history: Received 20 January 2019 Accepted 29 July 2019 Available online xxxx Keywords: Flow diverters FRED junior Aneurysms
a b s t r a c t This retrospective study was aimed at assessing our results of endovascular management using the FRED junior flow diverter in cerebral aneurysms at or distal to the circle of Willis. 12 patients with 15 small cerebral vessel aneurysms at or distal to the circle of Willis underwent endovascular treatment using the FRED junior flow diverter at two tertiary care centres in Mumbai, India. 12 of the 15 aneurysms were unruptured, one was treated in an acutely ruptured setting, while two, which had presented with SAH were initially treated with balloon assisted coiling and later treated in a staged manner with a flow diverter. Technical success was 100% in all 15 deployments. Deployments were made across angles ranging from 45° to 180°. There was no stroke/TIA/death in any of the cases, which were unruptured. The O’Kelly-Marotta (OKM) staging was used to analyze angiographic follow up (at least one post procedure angiogram) which was available in 8 patients (10 aneurysms). OKM D & C was seen in 80% of the aneurysms on follow up angiograms. The treatment of small vessel cerebral aneurysms at or distal to the Circle of Willis using a dedicated flow diverter (FRED Jr.) is both technically feasible and highly efficacious. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction
2. Materials and methods
Flow diverters (FDs) are an established modality of endovascular treatment in situations such as giant, wide-necked, dissecting, fusiform aneurysms etc. However their utility in the management of aneurysms which occur at or distal to the circle of Willis is yet being ascertained. Many factors contribute to the differences between use of flow diverters proximal to and at/distal to the Circle of Willis. These include the small size of parent vessels, the presence of important divisions & branches incorporated by the aneurysm and acute bends or tortuosity of vasculature. The FRED Junior flow diverter has been designed for use in the treatment of cerebral aneurysms in smaller vessels. We wish to present experience of usage of this device in the management of cerebral aneurysms at or distal to the circle of Willis.
2.1. Selection of patients
⇑ Corresponding author at: Dept of Imaging & Interventional Radiology, INHS Asvini, Colaba, Mumbai 400005, India. E-mail address: [email protected] (R. Sivasankar).
Retrospective clinical and angiographic data pertaining to patients with cerebral aneurysms at or distal to the circle of Willis from Aug 2015 to July 2018, were collected from two tertiary care centres in Mumbai, India. All patients were chosen for endovascular treatment following ‘in-hospital’ multi-disciplinary discussions at their respective hospitals. 2.2. Antiplatelet regimen Patients with unruptured aneurysms were administered dual antiplatelet therapy (Clopidogrel & Aspirin/Prasugrel & Aspirin/ Ticagrelor & Aspirin) pre-operatively. Dual antiplatelet therapy was continued post – operatively for 6 months in the following dosages: Clopidogrel 75 mg once daily, Aspirin 150 mg once daily, Ticagrelor 90 mg twice a day or Prasugrel 10 mg once a day. Dual anti-platelets were continued for a period of six months after which Aspirin was continued as monotherapy in a dose of 150 mg daily. In the setting of acute subarachnoid hemorrhage, it was preferred to stage the flow diverter treatment and performing
https://doi.org/10.1016/j.jocn.2019.07.079 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
2
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
a balloon assisted coiling in the first stage. In the setting of acute SAH where it was technically impossible to use coils as a first line of management, the patient was loaded with dual antiplatelets via a Ryle’s tube and a bolus dose of Abciximab/Integrillin/Tirofiban was administered during the flow diverter deployment which was followed by a continuous IV infusion for 12 h. Thereafter dual antiplatelets were continued from the next day.
2.3. Endovascular technique The technique typically involved use of a 6 French long sheath (Neuron Max, Penumbra Inc/Rabbe, Cook/Destination, Terumo) which was placed in the common carotid artery or V1 segment of the vertebral artery & a guiding catheter (Neuron, Penumbra/ Sofia, Microvention/Envoy, Codman or Catalyst 5, Stryker) which was navigated into the ICA or the V2/V3 segments of the vertebral artery. In the patients treated with FDs and coils, the ‘jailed-micro catheter’ technique was used. Thereafter a Headway 21 microcatheter (Microvention) was navigated over a 0.01400 microwire (Traxcess, Microvention/Synchro-2, Stryker) for purposes of Fred junior deployment across the aneurysm. Flow diverter sizing was performed pre-operatively using CTA and/or rotational DSA images. As far as possible, the device was ‘right-sized’ to the caliber of the proximal vessel diameter.
Fig. 2. A FRED Jr. 2.5 18–13 mm (arrow) was deployed across the aneurysm.
3. Post-operative management & follow-up Patients were extubated post-operatively in all but one case, which had presented with an acute subarachnoid hemorrhage and was electively ventilated for two days. Post-operative CT head was performed in all cases to exclude hemorrhagic complications. Patients were followed up clinically at 1 week, 1, 3 & 6 months after discharge from the hospital. Angiographic follow up was performed at 6 months of the procedure, and in some patients who expressed a logistic inability to get the angiography done in that period, angiography was done within a year post procedure.
Fig. 3. 6-Month control angiogram shows complete resolution of the aneurysm with good caliber of the stented segment. The arrow shows the patency of the branch artery.
Fig. 1. A 55 year old lady presented with history of headaches. She had no comorbidities and was detected to have a wide-necked 8 mm sized distal ACA aneurysm.
Fig. 4. A 62 yr old man was brought with a history of chronic headaches and one episode of transient loss of consciousness, which recovered spontaneously. CT angiography revealed a fusiform aneurysm of the distal M1 segment of the right MCA, which was confirmed on DSA.
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
3
branches from the aneurysm neck after an interval of eight to ten weeks. Only one aneurysm was primarily treated in the acutely ruptured setting. 4.3. Endovascular treatment results & complications
Fig. 5. A FRED Jr. 2.5 18–13 mm was deployed across the aneurysm. Fluoroscopic image shows well -expanded stent with adequate coverage of the abnormal segment of vessel.
The device could be deployed with technical success in all 15 deployments. Deployments were made across angles ranging from 45° to 180°. Figs. 1–3 illustrate the use of a FRED Jr across a DACA aneurysm and the angiographic follow up. There was no stroke/ TIA/death in any of the cases which were unruptured. In one case which was treated in an acutely ruptured setting, an Acute in-stent occlusion occurred which was managed with Gp2b3a inhibitors. No complications occurred in the form of death, stroke or TIAs. 3 out of 15 cases had ‘in-stent’ stenosis without clinical sequelae on their angiographic follow up and were continued on dual antiplatelets Figs. 3–6 illustrate a case where a FRED Jr flow diverter was used to treat an MCA aneurysm. Presence of an ‘in-stent’ stenosis was seen on follow up angiogram. No side-branch occlusions were observed in any of the cases. A summary of the aneurysm location, vessel size, aneurysm size and angles of deployment are detailed vide Table 1. 4.4. Follow-up The O’Kelly-Marotta (OKM) staging was used to analyze angiographic follow up (at least one post procedure angiogram) which was available in 8 patients (10 aneurysms) and are as detailed in Table 2. 5. Discussion
Fig. 6. Control angiogram shows re-modeling of the aneurysm with presence of an ‘in-stent’ stenosis for which he was continued on dual antiplatelets.
4. Results 4.1. Location & aneurysm morphology Based on location, six out of fifteen aneurysms (40%) were at the Distal Anterior cerebral artery (DACA), four aneurysms (27%) were at the Anterior communicating artery (ACoA)/A1-A2-ACoA junction, three (20%) involved the MCA & one each was located at the V4 segment of the Vertebral artery and the Posterior cerebral artery. 12 of the 15 aneurysms (80%) were saccular in nature, 2 were dissecting (13.3%) while one was a blister aneurysm. Sizes of the aneurysms ranged from 1.4 mm to 11 mm. 4.2. Clinical presentation A total of fifteen aneurysms in 12 patients were treated during this period. 12 of these 15 (80%) aneurysms were unruptured and 2 aneurysms of the 15 had presented with SAH due to rupture. These were treated initially with balloon assisted coiling followed by FRED Jr. flow divertor treatment for a residual neck which was intentionally left in these cases due to the origin of important
Flow diverters (FDs) are an established modality of endovascular treatment in situations such as giant, dissecting, blister, partially thrombosed aneurysms etc. [1–4]. However their role in the treatment of aneurysms at or distal to the Circle of Willis in small vessel aneurysms has not yet been clearly established [5– 7]. Flow diverters work on the principle of changing the dynamics of flow within the vessels in which they are implanted, so as to maintain the patency of the parent vessel & their branches whilst propagating thrombosis and remodeling within the aneurysm [8,9]. This study, involving a dedicated flow diverter designed for treatment of cerebral aneurysms in small vessels, had a technical success of 100%. Of the ten aneurysms in which follow up angiograms could be performed (within six months to a year post procedure), 60% had an OKM D occlusion [10]. There was also no death, stroke or TIA in any of the patients. These results are quite similar to those obtained in the EU MultiCentre Trial, where 70% of patients had an OKM D occlusion on follow up angiogram [11]. The results also are akin to an overall final occlusion of 70% as reported by Yan et al in their recent metanalysis of the safety & efficacy of flow divertors in small cerebral vessels which looked at 26 non-comparative studies with 572 aneurysms [12]. The results are also similar to those reported by Pierot et al in the SAFE study wherein an adequate occlusion rate of 81.1% was reported using the FRED device [13]. The high percentage of technical success in deployment is probably directly related to the dual stent construction design of the device [14]. The outer stent, which has 16 wires, helps in anchoring the device, while the inner stent helps in the flow diversion effect. Additionally the presence of only 16 wires in the outer stent may help in smoother deployment compared to other flow diverters, which have a large number of wires that may increase the frictional interplay between surfaces during deployment. The radial force of opening is stronger due to the presence of two nitinol stents, which makes in easier to open at bends
Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079
4
R. Sivasankar et al. / Journal of Clinical Neuroscience xxx (xxxx) xxx
Table 1 Summary of the aneurysm location, vessel size, aneurysm size and angles of deployment. Sl. No
Location
Vessel size (Proximal/Distal) (mm)
Angle (degrees)
Aneurysm size/Neck (mm)
Immediate OKM
Follow up OKM
Ruptured/Unruptured
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
DACA MCA DACA ACoA MCA DACA DACA MCA PCA ACoA DACA V4 DACA ACoA ACoA
2.3/1. 9 2.4/2.1 2.2/1.9 2.3/2.1 3/2.3 2.4/2.0 2.2/2.0 2.6/1.9 2.2/1.9 2.3/1.9 2.3/2.2 3.1/2.6 2.4/2.1 2.9/2.3 2.7/ 2.4
101.4 98.4 103.5 90 88 102 107 45 98 100 104 180 100 95 102
6/2.5 Fusiform 8/3.8 5.2/3.2 5.1/3.0 6.2/4.1 5.5/3 5.4/2.8 1.4 6.9/4.0 11/5 8/4.5 7.2/4.8 5.2/4 4.5/3 (Three aneurysms at the A1-A2 jn)
B1 A B2 B1 B2 C1 B2 A D C1 B3 C1 B2 B1 B1
D B1 D – – D D A D – C2 D – – C1
Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Unruptured Ruptured Unruptured 2nd stage FRED Jr. Unruptured 2nd stage FRED Jr. Unruptured Unruptured
Table 2 Follow up OKM staging. OKM scale
Number
D C1 C2 A B1
6/10 (60%) 1/10 (10%) 1/10 (10%) 1 (10%) 1 (10%)
in the distal vessels or at bifurcations. Additionally, the use of a coil braided 0.02100 microcatheter with an outer diameter of 2.0F, makes it easy to navigate distally. The lack of a distal wire increases the safety of the procedure by reducing risk of perforation of small vessels during device deployment. Three patients in this series had ‘in-stent’ stenosis (ranging from 20% to 50%), without clinical sequelae, which required them to be continued on dual antiplatelets. One of these three had good remodeling of the stenosis on further follow up angiogram at 18 months. The other two patients are due for follow up angiograms. This observational study has several limitations owing to the small study population and a short follow up period. However this being a challenging subset of cerebral aneurysms for both endovascular and microsurgical techniques, this case series will contribute significantly to the data on the use of flow diverters in small cerebral vessels. Larger studies will throw more light on the long-term benefits and efficacy of flow diverters, which are dedicatedly designed to be used for the treatment of small cerebral vessel aneurysms. 6. Sources of financial & material support Nil. References
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Please cite this article as: R. Sivasankar, M. Shrivastava and U. S. Limaye, Experience with FRED junior flow diverter in treatment of cerebral aneurysms at or distal to the circle of Willis, Journal of Clinical Neuroscience, https://doi.org/10.1016/j.jocn.2019.07.079