Endovascular management of fusiform aneurysms in the posterior circulation: the era of flow diversion

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Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

ABBREVIATIONS AICA = anterior inferior cerebellar artery; BA = basilar artery; EC-IC = extracranial-intracranial; IEL = internal elastic lamina; MRA = MR angiography; PCA = posterior cerebral artery; PCFA = posterior circulation fusiform aneurysm; PED = Pipeline embolization device; PICA = posterior inferior cerebellar artery; SAC = stent-assisted coiling; SAH = subarachnoid hemorrhage; SCA = superior cerebellar artery; STA = superficial temporal artery; VA = vertebral artery.

Abstract

Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

Fusiform aneurysms are defined as circumferential dilations of an intracranial artery without an ostium or neck.12 They are commonly located in the posterior circulation, especially the vertebral artery (VA), basilar artery (BA), and posterior cerebral artery (PCA).11 Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat. The first case of a vertebral fusiform aneurysm was described by Wells in 1922,35 and since then several terms have also been used, including dolichoectatic aneurysm, transitional aneurysm, and giant serpentine aneurysm.

Posterior circulation fusiform aneurysms (PCFAs) have a significant male predominance (approximately 70%) and most commonly present as posterior circulation ischemic stroke.12,31 In addition, they may cause cranial nerve palsies, brainstem compression, and subarachnoid hemorrhage (SAH). Contrary to the more common saccular aneurysms, fusiform aneurysms are associated with high rates of rebleeding and morbidity.

In this article, we review PCFAs, including pathogenesis, natural history, cerebrovascular surgical treatment, and endovascular treatment, including the role of flow diversion. In addition, we propose an algorithm for treatment based on our practice.

Pathogenesis and Natural History

Fusiform aneurysms may occur due to a variety of underlying pathologies affecting the wall of the blood vessel. The most common proposed causes are dissection and atherosclerosis.6,7,30 Our understanding of the natural history of PCFAs is very limited and largely depends on the presenting signs and symptoms. Symptomatic patients have a poor natural history if they do not undergo treatment, especially if they present with brainstem ischemia or compression. In patients with ruptured aneurysms, the rebleeding rate is high and ranges between 30% and 85%.1,23 The mortality rate is also high for untreated ruptured aneurysms. In a study that evaluated conservative management in ruptured PCFAs, the mortality rate was 38% after a mean follow-up period of 18 months.10

In a prospective study of vertebrobasilar aneurysms over a 12-year period at the Mayo Clinic, the annual rupture rate of fusiform aneurysms was 2.3%.13,21 The initial diameter of an aneurysm is a significant predictor of lesion rupture. The authors also found that an initial diameter larger than 10 mm in fusiform aneurysms was a significant risk factor for aneurysm enlargement and future rupture. The mortality rate was approximately 6 times higher in patients with aneurysm growth than in those with no enlargement.21

Therefore, based on observations of the natural history, the vast majority of ruptured PCFAs should be treated. Additionally, unruptured PCFAs larger than 10 mm also likely warrant treatment.

Classification

There are 2 widely accepted classification systems for nonsaccular aneurysms, including the fusiform type, that stratify patients into risk groups. Flemming’s classification for nonsaccular vertebrobasilar circulation aneurysms is based on radiographic appearance.12 Lesions are defined as having an arterial dilation greater than 1.5 times the normal diameter without any neck (Huber’s definition), and the types are as follows: A) fusiform (14%), aneurysmal dilation of the vessel without an identifiable neck involving a portion of arterial segment; B) dolichoectasia (45%), uniformed dilation involving the entire artery with any degree of tortuosity; C) transitional (19%), uniform aneurysmal dilation of the artery with superimposed dilation of a portion of the involved arterial segment; and the indeterminate type (20%). Fusiform and transitional types are most likely to be symptomatic, while the dolichoectatic type has a more benign nature. Acute dissecting aneurysms were excluded because of the known distinctive behavior.

The other classification system is that of Mizutani et al. and consists of 4 types based on histopathology.24 Type I, classic dissecting aneurysm characterized by widespread disruption of the internal elastic lamina (IEL) without intimal thickening. This type typically presents with SAH and high rates of rebleeding. Type II, segmental ectasia, with a more benign clinical course than Type I. This type is characterized by extended and/or fragmented IEL with intimal thickening. In addition, the luminal surface is smooth without thrombus formation. Type III, dolichoectatic dissecting aneurysm. This type is distinguished pathologically from Type II by dissections in the thickened intima and organized luminal thrombus. Most Type III aneurysms are symptomatic, grow over time, and are frequently associated with hemorrhage and a mortality rate of 50%. Lastly, Type IV is saccular aneurysm characterized by minimally disrupted IEL without intimal thickening and is associated with a high risk of rupture.

Treatment

Choice of Treatment

All fusiform aneurysms have been historically treated with different open surgical treatment modalities, including Hunterian ligation, trapping, surgical bypass, and clip reconstruction techniques.31 However, endovascular therapy has emerged as the primary treatment modality for PCFAs over the past decade. Recently, endovascular treatments have been successfully used in treating PCFAs with good outcomes. In fact, microsurgical treatment is generally reserved for cases that cannot be treated with endovascular therapy. The endovascular options include parent vessel coil occlusion, stenting alone, stent-assisted coiling (SAC), and flow-diverting stents (Fig. 1).

Fig. 1.
Fig. 1.

Suggested treatment algorithm for fusiform aneurysms in the posterior circulation based on presentation. FD = flow diverter; PVO = parent vessel occlusion.

Microsurgical Management

Open surgical treatment of PCFAs is becoming a less popular option given the recent advancements in endovascular therapy. Microsurgical treatment modalities often involve flow reduction or bypass/trapping in cases of poor collateral supply, flow reversal in cases of adequate collateral supply, or trapping with aneurysm decompression for lesions with mass effect. Since fusiform aneurysms do not have a true neck, they are usually not amenable to clip reconstruction techniques. Additionally, it is not uncommon for PCFAs to be partially calcified and/or thrombosed, further complicating the open surgical approach. Hence, trapping with or without bypass is considered the main microvascular modality.

Drake and colleagues published extensively on their operative experience with fusiform aneurysms in the posterior circulation.8,9,33 The authors used different modalities based on patient presentation, clinical status, and collateral supply. Outcomes were almost comparable between the different modalities, with approximately 70% of treated patients achieving good to excellent outcomes.

Kalani et al.16 reported the most recent experience at the Barrow Neurological Institute with giant aneurysms in the posterior circulation. The 12-aneurysm cohort included 8 fusiform aneurysms. The primary treatment modality was extracranial-intracranial (EC-IC) bypass. Superficial temporal artery–superior cerebellar artery (STA-SCA) bypasses were performed in 7 cases and STA-PCA was performed in 1 case. Flow was reserved or reduced by complete (n = 6) or partial (n = 1) occlusion of the BA, or by occlusion of the VA distal to the posterior inferior cerebellar artery (PICA) (n = 1). Recurrence and complications were high and the mortality rate among fusiform aneurysms was approximately 40%. The authors did admit that despite their aggressive surgical approach, the long-term outcome was poor for most patients.

More recently, Lawton et al. published an evolved technique of surgical bypass for treating fusiform aneurysms in the basilar trunk.19 The study included 37 patients, and the bypass evolved in 3 distinct phases, each with different hemodynamic alternations. Surgical bypasses consisted of EC-IC (STA-SCA and STA-PCA) bypasses in Phase 1 for flow reversal, IC-IC (VA-SCA) bypasses in Phase 2 for flow reduction, and Phase 3 (middle cerebral artery–PCA) for distal occlusion. Phase 1 led to extensive flow reduction that prompted BA thrombosis and was associated with 100% mortality. On the other hand, Phase 2 was safer (67% mortality rate) but did not prevent aneurysm growth or progression of symptoms. As a result, the authors revised their technique to distal occlusion, achieving an improved surgical outcome and aneurysm stabilization with a better mortality rate (62%). However, this technique reduced the flow to brainstem perforators causing ischemic damage, despite treatment with antiplatelet agents.

Endovascular Management

The lack of a true aneurysm neck usually makes simple coil embolization impossible and more advanced techniques are required, including SAC and, more recently, flow diversion (Figs. 2 and 3). Parent vessel occlusion is a reasonable option for nondominant VA aneurysms as well as distal aneurysms of the nondominant PICA, anterior inferior cerebellar artery (AICA), or SCA.

Fig. 2.
Fig. 2.

Angiograms obtained in a 46-year-old woman with a good-grade SAH. A and B: Initial digital subtraction (DS) angiograms (right VA injection [A] and left VA injection [B]) demonstrating bilateral fusiform VA aneurysms, of which the right-sided aneurysm appeared irregular and the likely source of SAH. C and D: The patient was treated acutely with coil occlusion of the right VA (right vertebral injection, unsubtracted [C] and subtracted [D] views). Given that the right VA aneurysm was the likely source of SAH, the patient was acutely allowed to recover from her SAH. E–G: The fusiform left VA aneurysm (left VA DS angiogram lateral view [E]) was treated with flow diversion a few weeks later (left VA injection, unsubtracted [F] and subtracted [G] views). The patient will undergo delayed angiography to evaluate for aneurysm occlusion and vessel remodeling.

Fig. 3.
Fig. 3.

Angiograms obtained in a 57-year-old man who presented with poor-grade SAH. A: Initial DS angiogram (left VA injection) demonstrated a single fusiform aneurysm involving the left VA and encompassing the origin of the PICA. B: Given the nature of the aneurysm, flow diversion was thought to be the only treatment option that could exclude the aneurysm. Therefore, the patient received dual antiplatelet therapy (aspirin and Plavix), and a flow diverter was placed in the left VA (left VA injection, unsubtracted view). The patient required ventriculoperitoneal shunting, for which Plavix was discontinued. C: Delayed DS angiogram demonstrated complete aneurysm occlusion and arterial remodeling (left VA injection).

Higashida et al.15 reported the first case of SAC in PCFAs. They used an intravascular stent in conjunction with Guglielmi detachable coils in a ruptured fusiform aneurysm in the BA. Since then, several case series have been published regarding the use of SAC in the treatment of PCFAs.6,29,34 Interestingly, it appears that certain locations of fusiform aneurysms in the PCA have distinct entities with different outcomes. In the 14-year Stanford experience of treating PCFAs,6 Steinberg et al.33 reported that PCA aneurysms had the best outcome (90%), followed by VA and PICA aneurysms (60%); aneurysms located in the BA and vertebrobasilar junction had the worst outcome (39%).

Initial experience with flow diversion in PCFAs was mixed with poor outcomes.32 However, when used in carefully selected patients, PCFAs have been recently reported to have a good to excellent outcome in the majority of those patients. Table 1 summarizes large series (> 5 cases) on the use of flow diverters for PCFAs.

TABLE 1.

Summary of large series (> 5 patients) on the use of flow diverters for PCFAs

Authors & YearNo. of PCFAsFlow Diverter DeviceNo. of Device-Related ComplicationsNo. of DeathsNo. w/ Complete Obliteration on Angiography
Byrne et al., 201011Silk22NA
Siddiqui et al., 20127PED (6), Silk (1)642
Monteith et al., 20147PED212
Munich et al., 201412PED319 (75%)*
Natarajan et al., 201612PED1012 (100%)
Bhogal et al., 201724PED, p64NA118 (75%)

NA = not available.

Data were not available for 2 patients. Of the 10 patients who underwent angiography, 9 patients (90%) had complete occlusion.

Byrne and colleagues published their initial experience with Silk (Balt Extrusion) flow diverters in the treatment of intracranial aneurysms in a multicenter prospective study.4 Of 70 patients, there were 11 cases of PCFAs. Of these patients, 2 patients died, and there were 2 device-related complications. There were no available data on postoperative angiographic obliteration.

In 2014, both Thomas Jefferson University and Rush University groups published their experience with the Pipeline embolization device (PED; Medtronic) for fusiform aneurysms in the posterior circulation.25,26 These reports included 7 and 12 cases of PCFAs, respectively. The device-related complication rate was approximately 25%, and 70%–90% of patients had good to excellent neurological outcome. During angiographic follow-up, complete occlusion varied significantly between the 2 studies, ranging between 30%25 and 75%.26

Contrary to their initial experience with poor outcomes,32 a team from the University at Buffalo reported excellent results in their latest experience with PED for PCFAs.27 Eleven (90%) of 12 patients recovered to a modified Rankin Scale score of 0 or 1 after a clinical follow-up duration of 22 months, with only 1 patient experiencing a perforator territory infarction with poor clinical outcome (modified Rankin Scale Score 4). At last follow-up, the complete occlusion rate was 100%, and the PEDs were patent. The authors attributed the dramatic improvement in outcomes to careful patient selection. All patients presented early, and none had evidence of stroke on MRI before treatment. The second factor was the strict dual antiplatelet regimen with confirmation of the therapeutic effect of antiplatelet therapy by using response testing before flow diversion. Technically, the authors used fewer but longer (35 mm) PEDs compared with more and shorter (20 mm) devices in their initial report. In addition, the new experience included adjunctive coiling, which might reduce stent prolapse by acting as a scaffold.

More recently, Bhogal and his colleagues from Germany published the largest series of flow diversion in PCFAs.2 Of the 56 patients with nonsaccular aneurysms, there were 24 fusiform aneurysms. The study used 2 types of flow-deverter devices: PED and p64 flow modulation device (Phenox). The mortality rate was low, with only 1 death (4%). The complete aneurysm occlusion rate was 75% with minor residual filling seen in 12.5% of cases and an unchanged appearance in 1 patient (4%). In the 4 patients without angiographic occlusion, the aneurysm decreased in maximum diameter, with increased intraaneurysmal thrombus in 3 cases (75%) on MRI follow-up.

The Fate of Covered Branch Vessels With Flow Diverters

The location of aneurysms in the distal VA (V4) and vertebrobasilar junction in relation to the branch vessels, especially PICA and AICA, often requires covering the arterial ostium, theoretically increasing the risk of branch vessel occlusion and infarction. A meta-analysis published in 2013 showed that the rate of perforator infarction is 3% with significantly higher odds in posterior circulation aneurysms.3

Initial experiences with flow diverters have shown mixed results regarding the fate of covered branch vessels, ranging between complete patency on all follow-up studies to immediate occlusion after flow-diverter deployment or shortly after.5,17,18,28,36 However, recent experiences reported a 0% rate of branch occlusion in the posterior circulation on immediate or follow-up angiography.14,20,22 Mazur and colleagues’ series specifically reported the patency of PICA and aneurysm occlusion on angiography.22 This series of 11 aneurysms located predominantly in the VA included fusiform aneurysms (80%). The flow diverter spanned the PICA ostium in all cases, with 1 patient experiencing an occluded PICA and in-stent stenosis on immediate angiography. The in-stent stenosis was resolved after abciximab administration, and the covered PICA was noted to have recanalized on follow-up imaging 6 months later. Follow-up angiography was reported in 8 patients (the remaining 3 cases are awaiting follow-up) and demonstrated thrombosis of the aneurysm with patency of the PICA in all of them.

Clinical and Radiographic Follow-Up

Our practice protocol involves a clinical follow-up at 1 month, 3–6 months, and 12–18 months. We find that, in general, these time periods end up synching well with the stages of a patient’s recovery and clinical progress. Additionally, they coincide with our imaging follow-up. Depending on the case and symptoms, later follow-up can be scheduled at 1- to 3-year intervals. Our imaging follow-up protocol consists of immediate postoperative control conventional angiography, then at 3–6 months and another session at 12–18 months. We also recommend MR angiography (MRA) at 12–18 months after treatment, and every 1–3 years subsequently, depending on the degree of aneurysm obliteration. We have settled on this follow-up paradigm based on both of the most common practices reported in current literature and from discussion with colleagues around the globe. We feel that, in a stable aneurysm, MRA is an adequate surrogate for conventional angiography, hence our switching to MRA after the 12- to 18-month follow-up angiography. However, the limitations of resolution of MRA make us feel that gold-standard angiography with maximal detail and resolution is still worthwhile for most patients during the first 12–18 months, although this is certainly debatable and, in high-risk patients, we switch to MRA follow-up sooner. Patients undergoing SAC and flow-diverter placement are kept on a strict regimen of pre- and postoperative antiplatelet therapy, and dual therapy is maintained at least until the 3- to 6-month angiogram, after which aspirin is continued for life.

Conclusions

Given the evolving endovascular technologies over the last 2 decades in addition to high rates of complications and mortality associated with open surgery, endovascular therapy should be considered as the primary treatment modality for PCFAs. For aneurysms that are not treatable by endovascular methods, microsurgical treatment should be considered. Flow diversion is a new endovascular method and can achieve excellent outcomes in carefully selected patients with PCFAs.

Disclosures

Dr. Mocco reports that he is a consultant for Rebound Medical, EndoStream, Synchron, and Cerebrotech; has ownership in Apama, The Stroke Project, EndoStream, Synchron, Cerebrotech, Neurvana, and NeuroTechnology Investors; and receives non–study-related support from Stryker Neurovascular, Penumbra, Medtronic, and MicroVention.

Author Contributions

Conception and design: Mocco, Awad, Mascitelli. Acquisition of data: Awad. Drafting the article: Awad, Mascitelli, Haroun. Critically revising the article: all authors.

References

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Article Information

Correspondence J Mocco, Department of Neurological Surgery, Icahn School of Medicine at Mount Sinai, Mount Sinai Health System, 1468 Madison Ave., New York, NY 10029. email: j.mocco@mountsinai.org.

INCLUDE WHEN CITING DOI: 10.3171/2017.3.FOCUS1748.

Disclosures Dr. Mocco reports that he is a consultant for Rebound Medical, EndoStream, Synchron, and Cerebrotech; has ownership in Apama, The Stroke Project, EndoStream, Synchron, Cerebrotech, Neurvana, and NeuroTechnology Investors; and receives non–study-related support from Stryker Neurovascular, Penumbra, Medtronic, and MicroVention.

© AANS, except where prohibited by US copyright law.

Headings

Figures

  • View in gallery

    Suggested treatment algorithm for fusiform aneurysms in the posterior circulation based on presentation. FD = flow diverter; PVO = parent vessel occlusion.

  • View in gallery

    Angiograms obtained in a 46-year-old woman with a good-grade SAH. A and B: Initial digital subtraction (DS) angiograms (right VA injection [A] and left VA injection [B]) demonstrating bilateral fusiform VA aneurysms, of which the right-sided aneurysm appeared irregular and the likely source of SAH. C and D: The patient was treated acutely with coil occlusion of the right VA (right vertebral injection, unsubtracted [C] and subtracted [D] views). Given that the right VA aneurysm was the likely source of SAH, the patient was acutely allowed to recover from her SAH. E–G: The fusiform left VA aneurysm (left VA DS angiogram lateral view [E]) was treated with flow diversion a few weeks later (left VA injection, unsubtracted [F] and subtracted [G] views). The patient will undergo delayed angiography to evaluate for aneurysm occlusion and vessel remodeling.

  • View in gallery

    Angiograms obtained in a 57-year-old man who presented with poor-grade SAH. A: Initial DS angiogram (left VA injection) demonstrated a single fusiform aneurysm involving the left VA and encompassing the origin of the PICA. B: Given the nature of the aneurysm, flow diversion was thought to be the only treatment option that could exclude the aneurysm. Therefore, the patient received dual antiplatelet therapy (aspirin and Plavix), and a flow diverter was placed in the left VA (left VA injection, unsubtracted view). The patient required ventriculoperitoneal shunting, for which Plavix was discontinued. C: Delayed DS angiogram demonstrated complete aneurysm occlusion and arterial remodeling (left VA injection).

References

1

Aoki NSakai T: Rebleeding from intracranial dissecting aneurysm in the vertebral artery. Stroke 21:162816311990

2

Bhogal PPérez MAGanslandt OBäzner HHenkes HFischer S: Treatment of posterior circulation non-saccular aneurysms with flow diverters: a single-center experience and review of 56 patients. J Neurointerv Surg 9:4714812017

3

Brinjikji WMurad MHLanzino GCloft HJKallmes DF: Endovascular treatment of intracranial aneurysms with flow diverters: a meta-analysis. Stroke 44:4424472013

4

Byrne JVBeltechi RYarnold JABirks JKamran M: Early experience in the treatment of intra-cranial aneurysms by endovascular flow diversion: a multicentre prospective study. PLoS One 5:52010

5

Chalouhi NTjoumakaris SDumont ASGonzalez LFRandazzo CStarke RM: Treatment of posterior circulation aneurysms with the Pipeline Embolization Device. Neurosurgery 72:8838892013

6

Coert BAChang SDDo HMMarks MPSteinberg GK: Surgical and endovascular management of symptomatic posterior circulation fusiform aneurysms. J Neurosurg 106:8558652007

7

Day ALGaposchkin CGYu CJRivet DJDacey RG Jr: Spontaneous fusiform middle cerebral artery aneurysms: characteristics and a proposed mechanism of formation. J Neurosurg 99:2282402003

8

Drake CG: Giant intracranial aneurysms: experience with surgical treatment in 174 patients. Clin Neurosurg 26:12951979

9

Drake CGPeerless SJ: Giant fusiform intracranial aneurysms: review of 120 patients treated surgically from 1965 to 1992. J Neurosurg 87:1411621997

10

Echiverri HCRubino FAGupta SRGujrati M: Fusiform aneurysm of the vertebrobasilar arterial system. Stroke 20:174117471989

11

Fischer SPerez MAKurre WAlbes GBäzner HHenkes H: Pipeline Embolization Device for the treatment of intra- and extracranial fusiform and dissecting aneurysms: initial experience and long-term follow-up. Neurosurgery 75:3643742014

12

Flemming KDWiebers DOBrown RD JrLink MJHuston J IIIMcClelland RL: The natural history of radiographically defined vertebrobasilar nonsaccular intracranial aneurysms. Cerebrovasc Dis 20:2702792005

13

Flemming KDWiebers DOBrown RD JrLink MJNakatomi HHuston J III: Prospective risk of hemorrhage in patients with vertebrobasilar nonsaccular intracranial aneurysm. J Neurosurg 101:82872004

14

Gascou GLobotesis KBrunel HMachi PRiquelme CEker O: Extra-aneurysmal flow modification following Pipeline Embolization Device implantation: focus on regional branches, perforators, and the parent vessel. AJNR Am J Neuroradiol 36:7257312015

15

Higashida RTSmith WGress DUrwin RDowd CFBalousek PA: Intravascular stent and endovascular coil placement for a ruptured fusiform aneurysm of the basilar artery. Case report and review of the literature. J Neurosurg 87:9449491997

16

Kalani MYZabramski JMNakaji PSpetzler RF: Bypass and flow reduction for complex basilar and vertebrobasilar junction aneurysms. Neurosurgery 72:7637762013

17

Kulcsár ZErnemann UWetzel SGBock AGoericke SPanagiotopoulos V: High-profile flow diverter (Silk) implantation in the basilar artery: efficacy in the treatment of aneurysms and the role of the perforators. Stroke 41:169016962010

18

Lall RRCrobeddu ELanzino GCloft HJKallmes DF: Acute branch occlusion after Pipeline embolization of intracranial aneurysms. J Clin Neurosci 21:6686722014

19

Lawton MTAbla AARutledge WCBenet AZador ZRayz VL: Bypass surgery for the treatment of dolichoectatic basilar trunk aneurysms: a work in progress. Neurosurgery 79:83992016

20

Levitt MRPark MSAlbuquerque FCMoon KKalani MYMcDougall CG: Posterior inferior cerebellar artery patency after flow-diverting stent treatment. AJNR Am J Neuroradiol 37:4874892016

21

Mangrum WIHuston J IIILink MJWiebers DOMcClelland RLChristianson TJ: Enlarging vertebrobasilar nonsaccular intracranial aneurysms: frequency, predictors, and clinical outcome of growth. J Neurosurg 102:72792005

22

Mazur MDKilburg CWang VTaussky P: Pipeline Embolization Device for the treatment of vertebral artery aneurysms: the fate of covered branch vessels. J Neurointerv Surg 8:104110472016

23

Mizutani TAruga TKirino TMiki YSaito ITsuchida T: Recurrent subarachnoid hemorrhage from untreated ruptured vertebrobasilar dissecting aneurysms. Neurosurgery 36:9059131995

24

Mizutani TMiki YKojima HSuzuki H: Proposed classification of nonatherosclerotic cerebral fusiform and dissecting aneurysms. Neurosurgery 45:2532601999

25

Monteith SJTsimpas ADumont ASTjoumakaris SGonzalez LFRosenwasser RH: Endovascular treatment of fusiform cerebral aneurysms with the Pipeline Embolization Device. J Neurosurg 120:9459542014

26

Munich SATan LAKeigher KMChen MMoftakhar RLopes DK: The Pipeline Embolization Device for the treatment of posterior circulation fusiform aneurysms: lessons learned at a single institution. J Neurosurg 121:107710842014

27

Natarajan SKLin NSonig ARai ATCarpenter JSLevy EI: The safety of Pipeline flow diversion in fusiform vertebrobasilar aneurysms: a consecutive case series with longer-term follow-up from a single US center. J Neurosurg 125:1111192016

28

Phillips TJWenderoth JDPhatouros CCRice HSingh TPDevilliers L: Safety of the Pipeline Embolization Device in treatment of posterior circulation aneurysms. AJNR Am J Neuroradiol 33:122512312012

29

Raphaeli GCollignon LDe Witte OLubicz B: Endovascular treatment of posterior circulation fusiform aneurysms: single-center experience in 31 patients. Neurosurgery 69:2742832011

30

Sacho RHSaliou GKostynskyy AMenezes RTymianski MKrings T: Natural history and outcome after treatment of unruptured intradural fusiform aneurysms. Stroke 45:325132562014

31

Serrone JCGozal YMGrossman AWAndaluz NAbruzzo TZuccarello M: Vertebrobasilar fusiform aneurysms. Neurosurg Clin N Am 25:4714842014

32

Siddiqui AHAbla AAKan PDumont TMJahshan SBritz GW: Panacea or problem: flow diverters in the treatment of symptomatic large or giant fusiform vertebrobasilar aneurysms. J Neurosurg 116:125812662012

33

Steinberg GKDrake CGPeerless SJ: Deliberate basilar or vertebral artery occlusion in the treatment of intracranial aneurysms. Immediate results and long-term outcome in 201 patients. J Neurosurg 79:1611731993

34

Uda KMurayama YGobin YPDuckwiler GRViñuela F: Endovascular treatment of basilar artery trunk aneurysms with Guglielmi detachable coils: clinical experience with 41 aneurysms in 39 patients. J Neurosurg 95:6246322001

35

Wells HG: Intracranial aneurysm of the vertebral artery. Arch Neurol Psychiatry 7:3113201922

36

Yeung TWLai VLau HYPoon WLTan CBWong YC: Long-term outcome of endovascular reconstruction with the Pipeline Embolization Device in the management of unruptured dissecting aneurysms of the intracranial vertebral artery. J Neurosurg 116:8828872012

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