Anterior Communicating Artery Aneurysm: Incidental Wide-Necked Aneurysm and Stent-Anssisted Coil Occlusion Using a Barrel Stent with Transient In-Stent Stenosis

  • Christian LoehrEmail author
  • Jan Oliver Kuhnt
  • Hans Henkes
Living reference work entry


An 83-year-old woman presented with an ischemic stroke in the supply territory of both anterior cerebral arteries (ACAs). During the diagnostic work-up, a midsized, wide-necked aneurysm of the anterior communicating artery (AcomA) was found. The right A1 segment was missing, and both ACAs were dependent on the left A1 segment. The aneurysm had to be treated while still preserving this solitary left-hand A1 supply channel to both A2 segments. It was decided to treat the patient with stent-assisted coil occlusion. The aneurysm was successfully treated using this method and a Barrel vascular reconstruction device (VRD; AKA “Barrel stent”) (Medtronic). There was a good clinical outcome with no neurological deficits. That the aneurysm had been completely occluded was confirmed by a follow-up DSA after 3 months. This also revealed moderate in-stent stenosis. This stenosis remained asymptomatic and resolved under continued dual platelet function inhibition. Using a Barrel stent as an assist device to treat wide-necked bifurcation aneurysms is the main topic of this chapter.


Anterior communicating artery Wide-necked bifurcation aneurysm Barrel VRD 3D coil Emboli from aneurysm 


An 83-year-old female patient who presented with ischemic stroke. Apart from well-controlled arterial hypertension, the medical history of the patient was unremarkable. Neither atrial fibrillation nor a patent foramen ovale had been found. The ischemic lesions were located in the ACA supply territory on both sides. Diagnostic work-up revealed an incidental midsized, wide-necked AcomA aneurysm.

Diagnostic Imaging

Diagnostic imaging was initiated as a work-up for said ischemic stroke. MRI/MRA showed restricted diffusion in the ACA supply territory on both sides and an incidental midsized, wide-necked aneurysm of the AcomA. Both common carotid arteries (CCA) and internal carotid arteries (ICA) showed only minor atherosclerosis. DSA confirmed an aneurysm with a neck width of 4 mm, a fundus width of 5 mm, and a fundus depth of 6 mm (Fig. 1).
Fig. 1

Diagnostic work-up for an 83-year-old woman who presented with ischemic stroke. DW MRI (a) and T2W MRI (b) showed ischemic lesions in both ACA supply territories. TOF MRA (c) did not reveal significant atherosclerosis of the intracranial carotid arteries. A midsized, wide-necked AcomA aneurysm and that the A1 segment on the right-hand side was missing were shown on 2D (d) and 3D (e) DSA

Treatment Strategy

The goal of the treatment was to prevent the AcomA aneurysm from growing further and rupturing, with the intention of completely occluding the aneurysm. The ischemic lesions were possibly related to the aneurysm and due to repeated emboli from the aneurysm sac into the dependent vasculature. Endovascular therapy was chosen in respect of the age of the patient, her existing medication including ASA, and the patient’s explicit personal preference. Due to the configuration of the aneurysm with its wide neck and aplasia of the right-hand A1 segment, stent-assisted coil occlusion using a bifurcation stent was considered an appropriate strategy.


Procedure, 06.02.2017: Barrel stent-assisted coil occlusion of an unruptured wide-necked AcomA aneurysm

Anesthesia: general anesthesia, 1 × 5000 IU unfractionated heparin (Heparin-Natrium, Rotexmedica) IV

Premedication: 1× 100 mg ASA PO daily; a loading dose of 1× 300 mg clopidogrel (Clopidogrel TAD, TAD Pharma GmbH) PO 5 days before the day of treatment, followed by 1× 75 mg clopidogrel PO daily thereafter. The response test 1 day before the procedure revealed a lack of response to clopidogrel. Therefore, the medication was switched to ticagrelor (Brilique, AstraZeneca) with a loading dose of 1× 180 mg PO followed by 2× 90 mg PO daily every 12 hours. The response test carried out the next day showed that ticagrelor was having a sufficient P2Y12 effect.

Access: left femoral artery, 8F sheath (Cordis); guide catheter: 6F Neuron MAX (Penumbra); microcatheters: Excelsior SL-10 (Stryker) for the coils and Headway 21 (MicroVention) for the Barrel stent; microguidewires: Synchro2 0.014“ 200 cm (Stryker) and Transend 0.014” (Stryker)

Implants: coils, Target 360° standard 6/300 mm, Target 360° soft 4/150 mm, and Target helical ultra 3/100 mm (all Stryker); Barrel stent (Medtronic) 3.5/5/20 mm

Course of treatment: The left common carotid artery was catheterized with a 6F Simmons2 catheter to reach the left ICA via a 0.035″ 260 cm guidewire (Terumo) to be switched to a 6F Neuron MAX guide catheter. After performing DSA runs in standard projections and a rotational angiography with a 3D reconstruction, a working projection was selected. Two microcatheters were inserted simultaneously. A Headway 21 microcatheter was inserted from the left A1 into the right A2 segment and used to deploy the Barrel stent with its center section covering the neck of the aneurysm. Using the deployed stent, the aneurysm was gently catheterized at the neck level with a Transend 0.014″ microguidewire and an Excelsior SL-10 microcatheter. A large standard 3D coil was used to form a cage. The coil loops were well retained inside the aneurysm by the Barrel stent. Two more coils were inserted and detached. After completely occluding the aneurysm, the Excelsior SL-10 microcatheter was withdrawn, and the stent was electrolytically detached. The final DSA run showed an occlusion of the aneurysm and a normal opacification of both A2 segments (Fig. 2).
Fig. 2

Endovascular coil occlusion of a midsized, wide-necked unruptured AcomA aneurysm assisted by a Barrel stent. Based on the 3D DSA, a working projection was chosen (a). The Barrel stent was deployed from the right A2 into the left A1 segment (b). The center section of the Barrel stent is covering the aneurysm neck. Note the center markers of the stent in front of the neck of the aneurysm (c). The entrance level of the aneurysm was catheterized with an Excelsior SL-10 catheter using a road map (d). A magnified view after the insertion of the first 3D coil shows how well the Barrel stent keeps the coil loops inside the aneurysm (e). Gradual occlusion of the aneurysm was achieved by adding more coils (f). The final DSA run (g, h) in standard posterior-anterior projection confirmed the complete occlusion of the aneurysm and the uncompromised perfusion of both A2 segments

Duration: 1st–27th DSA run: 82 min; fluoroscopy time: 82 min

Complications: none

Postmedication: 1× 100 mg ASA PO daily for life and 2× 90 mg ticagrelor (1-0-1) PO daily for 3 months

Clinical Outcome

The patient continued not to display any signs of neurological deficits (mRS 0) during the 9-month follow-up period after the endovascular treatment.

Follow-Up Examinations

The first follow-up after 3 months showed a complete occlusion of the aneurysm and a moderate in-stent stenosis without clinical sequelae. ASA and ticagrelor were prescribed for a further 6 months to continue dual platelet inhibition. The next follow-up DSA after those 6 months (i.e., 9 months after the treatment) confirmed the complete occlusion of the aneurysm. Meanwhile the in-stent stenosis had resolved (Fig. 3).
Fig. 3

Follow-up DSA examinations after a Barrel stent-assisted coil occlusion of an unruptured wide-necked AcomA aneurysm. The DSA examination after 3 months shows a low-grade in-stent stenosis inside the Barrel stent, affecting the right proximal A2 segment (arrow) (a). Under continued treatment for dual platelet function inhibition, this in-stent stenosis resolved during the following 6 months (arrow), as shown by the follow-up DSA 9 months after the treatment (b)

The ticagrelor medication was brought to an end, and a medication of 1× 100 mg ASA PO daily for life was prescribed. An MRI/MRA examination including TOF angiography as a baseline examination was carried out, and the next routine MRI/MRA examination is scheduled in 1 year’s time.


Treating an unruptured wide-necked AcomA aneurysm with a fundus diameter of 7 mm in an 83-year-old patient is certainly a matter of controversy. An abstract, statistic-oriented approach would be based on risk estimates. Only sparse data is available concerning the risk of recurrent distal emboli from such an aneurysm (Guest et al. 2017). The clinical course of this event is frequently benign (Cohen et al. 2010). The annual rupture risk of intracranial aneurysms was the subject of several research papers, with contradictory results. The risk rupture of AcomA aneurysms with a fundus diameter < 7 mm is higher than that of aneurysms in other locations of the anterior circulation (Bijlenga et al. 2013). In a large-scale study in elderly Japanese patients, being 80 years old plus and having an aneurysm with a fundus diameter of at least 7 mm were factors both associated with an increased rupture risk. The rupture rate was 1.6% for 1 year, 3.8% for 2 years, and 6.3% for 5 years of observation (Hishikawa et al. 2015). If an aneurysm rupture occurs, the risk of death in an octogenarian is >50% (Koffijberg et al. 2008). The likelihood of a poor outcome after a ruptured aneurysm increases with age (AlMatter et al. 2018). The average remaining life expectancy for a woman in 2013–2015 in the German federal state in question was 9.3 years for an 80-year-old and 6.3 years for an 85-year-old (Statistisches Bundesamt, Statistik der natürlichen Bevölkerungsbewegung). The risks associated with the microsurgical clipping or endovascular coiling of a midsized AcomA aneurysm depend on a variety of factors related to both the patient and the neurosurgeon. A rough guess would be a morbidity and mortality risk of about 4–8% for either treatment modality (O’Neill et al. 2017; Schmalz et al. 2018). Apart from these general considerations, which were explained to the patient, the individual risk assessment of the interventionist may deviate in either direction. Eventually, the well-informed patient has to decide if he or she prefers conservative, observational management or active treatment of the aneurysm. The patient whose case history can be found in this chapter clearly opted for an endovascular treatment after the numbers quoted above had been explained to her.

In endovascular treatment, several technical options have to be considered. These include:
  • Straight coiling, maybe using a dual catheter technique or balloon remodeling

  • Stent-assisted coiling, possibly with “crossing” or “kissing” Y-stent technique

  • pCONus-assisted coiling

  • PulseRider-assisted coiling

  • WEB occlusion

The use of a Barrel stent was chosen by the operator (CL).

The Barrel vascular reconstruction device (VRD) is a stent derivate with unique features (Fig. 4).
Fig. 4

The Barrel vascular reconstruction device (VRD). Key feature is the central “belly” or “herniation section,” which is supposed to offer improved coil retention inside the aneurysm

The Barrel stent is inserted via any 0.021” ID microcatheter. After complete deployment, this can either then be retrieved or electrolytically detached from the insertion wire. The device comes with 12 radiopaque markers: one proximal tip marker, one proximal center herniation section marker, six center herniation section markers, one distal center herniation section marker, and three distal tip markers (Fig. 5).
Fig. 5

Radiograph of a Barrel stent with the 12 markers: one proximal tip marker (1), one proximal center herniation section marker (2), six center herniation section markers (in this case, only four markers are visible due to coil superimposition) (3), one distal center herniation section marker (4), and three distal tip markers (5)

The following device sizes with their respective target vessel diameters are available:


Recommended vessel diameter (mm)

Proximal end diameter (mm)

Distal end diameter (mm)

Center herniation section diameter (mm)

Center herniation section span length (mm)

Usable length (mm)




































The BV-3.5-5.0×20 and BV-3.5-6.0×20 are the most frequently used Barrel stent sizes.

The operator has to determine which of the efferent vessels allows more coverage of the aneurysm neck and better herniation of the central segment of the Barrel stent inside the aneurysm. Microcatheter access to this artery is usually more difficult. Choosing the appropriate size to use involves considering the diameters of the afferent and efferent arteries as well as the span at the aneurysm neck.

The manufacturer recommends a formal measurement procedure (Fig. 6).
Fig. 6

Measurement procedure for the size selection of the Barrel stent: Step #1: Start by measuring diagonally from the distal shoulder of the aneurysm neck to the opposite wall of the parent artery. Step #2: If necessary, also measure the second diagonal line from the opposite distal shoulder of the aneurysm at the branch vessel back to the opposite wall of the parent artery. Step 3: After both measurements have been taken, select which vessel would best cover and center herniation into. This is the bifurcation “span length.” Step 4: Measure the diameter of the afferent and the selected efferent arteries

The usage of a Barrel stent requires dual platelet function inhibition, as it is currently the case with any other neurovascular stent. Under fluoroscopy, the center section can be identified by a distal and a proximal marker and six markers in the middle of the center section (Kabbasch et al. 2018). This center section has to be positioned over the aneurysm neck and herniates to the aneurysmal ostium upon deployment. The coil retention exerted by the Barrel stent is usually quite stable, and coil herniation into the parent artery is very uncommon (Gory et al. 2018; Mühl-Benninghaus et al. 2017). The usage of 3D coils together with the Barrel stent is recommended.

The advantage of the Barrel stent over any other self-expanding aneurysm stent is a matter of speculation. A potential alternative, among others, would have been a Neuroform Atlas stent (Stryker), which is accepted by a 0.017″ inner diameter (ID) microcatheter, while the Barrel stent requires a 0.021” ID (Ulfert et al. 2018). Y-stenting would have also been possible, but given the bifurcation geometry, it was assumed that a single stent would provide sufficient protection of the parent artery.

If the catheterization of one or both efferent arteries is an issue, pCONus (phenox) and PulseRider (Cerenovus) are potential alternative implants (Aguilar Pérez et al. 2014). The distal petals of the pCONus are deployed inside the aneurysm sac adjacent to the neck region. The two petals of the PulseRider are supposed to be deployed inside the efferent arteries, but deployment inside the aneurysm sac similar to a pCONus has been reported as well (Aguilar-Salinas et al. 2018). The in-stent stenosis of the Barrel stent, as described in this chapter, is an infrequent phenomenon (Gory et al. 2018). In the vast majority of patients, the in-stent stenosis has continued to be without hemodynamic relevance or clinical sequelae and usually resolves spontaneously under continued dual platelet function inhibition (Cohen et al. 2014).




The authors are most grateful to Sabine Wolff (Medtronic), who supported us with knowledge and material.


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Copyright information

© Springer International Publishing AG, part of Springer Nature 2018

Authors and Affiliations

  • Christian Loehr
    • 1
    Email author
  • Jan Oliver Kuhnt
    • 1
  • Hans Henkes
    • 2
  1. 1.Klinik für Radiologie, Neuroradiologie und NuklearmedizinKnappschaftskrankenhaus Recklinghausen, Klinikum VestRecklinghausenGermany
  2. 2.Neuroradiologische Klinik, Neurozentrum, Klinikum StuttgartStuttgartGermany

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