Anterior Communicating Artery Aneurysm: Acute SAH Due to a Small Aneurysm, Coil Occlusion, the Issue of SAH from Small Aneurysms

  • Muhammad AlMatterEmail author
  • Marta Aguilar Pérez
  • Hans Henkes
Living reference work entry

Latest version View entry history



The following presentation describes the clinical and radiological findings of a 75-year-old woman who presented due to spontaneous subarachnoid hemorrhage (SAH), caused by the rupture of a very small aneurysm located at the anterior communicating artery (AcomA). The aneurysm was subsequently treated by endovascular placement of a single 3D coil. Good clinical outcome was achieved despite the advanced age of the patient. The complete occlusion of the treated aneurysm was stable over the follow-up period of 24 months. Although the risk of rupture of small and very small aneurysm is allegedly “exceedingly” low, according to International Study of Unruptured Intracranial Aneurysms (ISUIA), yet most of the ruptured aneurysms encountered in daily practice are in fact small. The presented case is just one of innumerous examples of ruptured (very) small aneurysms.


Small aneurysm SAH Anterior communicating artery Coil Risk of rupture 


A 75-year-old, female patient, spontaneous SAH, Hunt and Hess III, Fisher IV

Diagnostic Imaging

This previously healthy patient experienced a sudden and severe headache accompanied by nausea and vomiting followed by confusion. She was admitted to the emergency department of the nearest hospital with a systolic blood pressure of 210 mmHg. The emergent computer tomography (CT) of the head revealed diffuse subarachnoid hemorrhage (SAH). The patient was then promptly referred to our center for further management. The clinical condition at presentation was graded as Hunt and Hess III.

The cranial CT at admission showed diffuse SAH with no preferential distribution (Fisher IV). Hemorrhagic sedimentations were evident in the lateral ventricles and at the level of the foramen of Magendie (Fig. 1). The CT-angiography was unremarkable. An external ventricular drain (EVD) was inserted due to the dilatation of the lateral ventricles and the patient was transferred to the angiography suite for conventional angiography. The selective injection of the left internal carotid artery (ICA) revealed a small saccular aneurysm of the anterior communicating artery (AcomA), measuring 2 mm in maximal diameter and 1.3 mm at the level of the neck (Fig. 2).
Fig. 1

The initial non-contrast CT showing diffuse subarachnoid hemorrhage in the interhemispheric fissure, the sylvian fissure, and the peri-insular cisterns. The caudal section shows the hemorrhagic subtotal obstruction of the fourth ventricle. The lateral ventricles are mildly dilated

Fig. 2

Digital subtraction angiography (DSA) of the intracranial vessels with injection of the left ICA revealed a small aneurysm at the AcomA measuring 2 mm maximum diameter ((a): 45° left oblique view; (b): posterior-anterior view with caudal angulation)

Treatment Strategy

The goal of the treatment was the prevention of a recurrent SAH. Due to the cranial orientation of the aneurysm and the favorable neck-to-sac ratio, the decision was made for endovascular treatment (EVT) with coils. The patient was extubated the following day and the EVD was removed after six days. The pharmacological management included the routine administration of intravenous (IV) nimodipine. There was no evidence of post-hemorrhagic cerebral vasospasm (CVS) on the daily performed transcranial Doppler sonography (TCD). After an uneventful course, the patient was then discharged into a rehabilitation facility after which she gained complete recovery.


Procedure, 05.11.2014: endovascular coil occlusion of a ruptured AcomA aneurysm

Anesthesia: general anesthesia; 3000 IU unfractionated heparin IV (Heparin-Natrium, B. Braun) after securing the femoral sheath

Premedication: none

Access: right common femoral artery, 1× 6F sheath (Terumo); guide catheter: 1× 6F Heartrail II (Terumo); microcatheter: 1× Prowler14 (Codman); microguidewire: 1× Synchro2 0.014″ 200 cm (Stryker)

Implants: 2 coils: 2/40 mm Nano coil, removed; 1.5/20 mm Nano coil, implanted (Stryker)

Course of treatment: The treatment started with an angiographic examination of all intracranial vessels. An AcomA aneurysm with a fundus diameter of 2 mm and a neck width of 1.5 mm was shown after the injection of the left ICA. A working projection, which showed the aneurysm neck and the entire aneurysm fundus without foreshortening, was selected. The aneurysm was catheterized with the distal tip of the Prowler Select14 catheter at the entrance level of the aneurysm. Given the small size of the aneurysm, the operator tried not to enter the aneurysm fundus with the tip of the microcatheter. From the neck level of the aneurysm a 2/40 mm coil was inserted under fluoroscopic control under road map conditions. The coil was, however, oversized and thus herniated into the A2 segment of the left anterior cerebral artery (ACA) and was therefore removed. After choosing a more appropriately sized 1.5 /20 mm Nano coil (Stryker), the latter was successfully placed into the aneurysmal sack and was detached in a stable position. The final angiographic run showed subtotal occlusion of the ruptured aneurysm. Anti-platelet medication was not required since no implant was inserted into a parent artery.

Duration: 1st–21st DSA run: 140 min; fluoroscopy time: 44 min

Complication: none

Postmedication: The patient received 2 mg nimodipine IV (Nimotop S, Bayer Vital) per h from day one, then throughout the 10th day after the SAH, which was then switched to an oral dose of 60 mg nimodipine (Nimotop, Bayer Vital) every 4 h (Fig. 3).
Fig. 3

Endovascular coil occlusion of the ruptured AcomA aneurysm. The working projection shows the entire aneurysm without foreshortening (a). After placement of one 1.5/2 mm 3D coil, the aneurysm was excluded from the blood circulation (b). The final DSA run confirms an almost complete occlusion of the aneurysm (c)

Clinical Outcome

The patient regained full functionality shortly after discharge. The most recent routine clinical follow-up two years after the treatment showed no residual neurological or functional deficits (modified Rankin Scale: 0, Glasgow outcome score: 5).

Follow-up Examinations

The first angiographic and cross-sectional follow-up was performed three months after the EVT. The catheter angiography showed complete occlusion of the previously ruptured aneurysm (Fig. 4). The cranial magnetic resonance imaging (MRI) revealed only minor gliosis at the site of the previously inserted EVD, with the ventricular system now within normal limits. The latest angiographic follow-up was performed two years after the EVT with persistent complete occlusion of the AcomA aneurysm.
Fig. 4

The catheter angiography two years after the endovascular occlusion of the ruptured AcomA-aneurysm showing persistent complete aneurysm occlusion with no evidence of regrowth or compaction of the coil ((a): Towne’s view; (b): 45°right oblique view)


This case represents a typical scenario of a ruptured cerebral aneurysm with favorable anatomy for endovascular management. With the appropriate sizing of the coil, the latter of the two remained stable after detachment and was sufficient for complete and stable occlusion of the aneurysm over the two-year follow-up.

Interestingly, despite the small size and the relative smooth contour of the aneurysmal sac, the presentation was due to acute rupture and diffuse SAH, which questions the applicability of the results from the International Study of Unruptured Intracranial Aneurysms (ISUIA Investigators 1998) in daily practice. Smaller prospective studies do indeed suggest that the risk of rupture in incidentally detected aneurysms is higher than what was observed in the ISUIA (Yasui et al. 1997; Tsutsumi et al. 2000; Korja et al. 2014).

The fact that large aneurysms have a high tendency for rupture does not mean that small aneurysms are always benign; therefore other factors should be considered in the decision-making for treatment of unruptured aneurysms (Wermer et al. 2007). The presented case is an example to demonstrate that there is no absolute lower limit, beyond which the risk of rupture is negligible. This applies not only to aneurysms of the AcomA but extends to almost all other anatomic locations. In fact, the vast majority of the ruptured aneurysms treated in our center over the last decade were (very) small (AlMatter et al. 2017) in size. Figures 5, 6, 7, 8, and 9 show some examples of similarly (very) small ruptured aneurysms at different anatomic locations.
Fig. 5

This 31-year-old man was admitted due to acute deterioration of consciousness. The admission CT (a) showed acute hydrocephalus due to basal SAH with intraventricular hemorrhage. The cerebral angiography revealed a 3 mm small aneurysm at the tip of the basilar artery as the source of hemorrhage (b). The aneurysm was treated successfully with stent-assisted coiling (c). The patient had nonetheless a poor clinical outcome and was lost to follow-up

Fig. 6

CT (a), 3D angiography (b), pretreatment (c), and posttreatment DSA images (d) of a 44-year-old male with a ruptured 2.5 mm MCA aneurysm leading to thick SAH in the left Sylvian fissure. The ruptured aneurysm was occluded with coils. A peri-procedural occlusion of the inferior trunk of the MCA was treated by placement of an Enterprise stent (Codman). The patient recovered completely with no residual deficit

Fig. 7

CT (a), 3D angiography (b), pretreatment (c), and follow-up DSA images (d) of a 73-year-old woman who presented with SAH in grade Hunt and Hess IV and diffuse SAH in the basal cisterns with blood sedimentation in the third and lateral ventricles (Fisher IV). Angiography revealed a blister-like aneurysm of the superior hypophyseal artery of the right ICA measuring 1.2 mm. After stabilization of the clinical condition and appropriate preparation, the aneurysm was treated by flow diversion eight days later. The patient showed complete recovery over the later course and the aneurysm was occluded at the one year DSA follow-up (d)

Fig. 8

CT and DSA of a 46-year-old female patient with spontaneous SAH. Blood in the subarachnoid space is found in the interhemispheric fissure (a) as well as in the left lateral ventricle (b). DSA showed a ruptured 2.5 mm aneurysm of the left anterior cerebral artery at the origin of the pericallosal artery (c). The aneurysm was treated successfully with coils (d) and the patient recovered completely

Fig. 9

CT (a), 3D angiography (b), pretreatment (c), and posttreatment DSA (d) images of a 73-year-old female patient who presented with massive SAH (Hunt and Hess V) due to a ruptured 2 mm aneurysm at the origin of the left posterior inferior cerebellar artery (PICA); the aneurysm was treated successfully with coils but despite active management the patient had a poor clinical outcome (mRS 5)

The presented case also demonstrates that with the appropriate management in a specialized center, good clinical outcome can be achieved in a subset of elderly patients. Although, it is beyond question that older age is independently associated with unfavorable clinical outcome after aneurysmal SAH (Mocco et al. 2006; Nieuwkamp et al. 2006). Nevertheless, treatment should not be withheld based only on age, especially in case of a good initial clinical condition (Schöller et al. 2013).



  1. AlMatter M, Bhogal P, Aguilar Pérez M, Schob S, Hellstern V, Bäzner H, Ganslandt O, Henkes H. The size of ruptured intracranial aneurysms: a 10-year series from a single center. Clin Neuroradiol. 2017. [Epub ahead of print]. Scholar
  2. International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured intracranial aneurysms – risk of rupture and risks of surgical intervention. N Engl J Med. 1998;339(24):1725–33.
  3. Korja M, Lehto H, Juvela S. Lifelong rupture risk of intracranial aneurysms depends on risk factors: a prospective Finnish cohort study. Stroke. 2014;45(7):1958–63. Scholar
  4. Mocco J, Ransom ER, Komotar RJ, Schmidt JM, Sciacca RR, Mayer SA, Connolly ES Jr. Preoperative prediction of long-term outcome in poor-grade aneurysmal subarachnoid hemorrhage. Neurosurgery. 2006;59(3):529–38. Scholar
  5. Nieuwkamp DJ, Rinkel GJ, Silva R, Greebe P, Schokking DA, Ferro JM. Subarachnoid haemorrhage in patients > or = 75 years: clinical course, treatment and outcome. J Neurol Neurosurg Psychiatry. 2006;77(8):933–7. Scholar
  6. Schöller K, Massmann M, Markl G, Kunz M, Fesl G, Brückmann H, Pfefferkorn T, Tonn JC, Schichor C. Aneurysmal subarachnoid hemorrhage in elderly patients: long-term outcome and prognostic factors in an interdisciplinary treatment approach. J Neurol. 2013;260(4):1052–60. Scholar
  7. Tsutsumi K, Ueki K, Morita A, Kirino T. Risk of rupture from incidental cerebral aneurysms. J Neurosurg. 2000;93(4):550–3. Scholar
  8. Wermer MJ, van der Schaaf IC, Algra A, Rinkel GJ. Risk of rupture of unruptured intracranial aneurysms in relation to patient and aneurysm characteristics: an updated meta-analysis. Stroke. 2007;38(4):1404–10. Scholar
  9. Yasui N, Suzuki A, Nishimura H, Suzuki K, Abe T. Long-term follow-up study of unruptured intracranial aneurysms. Neurosurgery. 1997;40(6):1155–9.

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • Muhammad AlMatter
    • 1
    Email author
  • Marta Aguilar Pérez
    • 1
  • Hans Henkes
    • 1
  1. 1.Neuroradiologische Klinik, NeurozentrumKlinikum StuttgartStuttgartGermany

Personalised recommendations