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Year : 2018  |  Volume : 31  |  Issue : 3  |  Page : 1069-1072

Endovascular management of small intracranial aneurysms: a retrospective study of 98 consecutive patients

Department of Neurology, Menoufia University, Menoufia, Egypt

Date of Submission23-Feb-2017
Date of Acceptance30-Apr-2017
Date of Web Publication31-Dec-2018

Correspondence Address:
Mostafa S Melake
Agiad Tower, Eastern Side, Shebin El-Kom, Menoufia 32111
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/mmj.mmj_138_17

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The aim of the study was to assess the feasibility and safety of endovascular treatment of small intracranial aneurysms.
Endovascular coiling of small intracranial aneurysms is still controversial mainly owing to possible technical difficulties in such groups of aneurysms.
Patients and methods
We retrospectively analyzed the angiographic and clinical effects of endovascular therapy of 98 small intracranial aneurysms (≤5 mm), both ruptured and unruptured, between March 2002 and August 2013. The angiographic and clinical outcomes of those patients were studied retrospectively using chart reviews, operative, and angiographic reports. Glasgow Outcome Scale was used as a clinical follow-up tool. The overall outcome and the pretreatment variables predicting outcomes were analyzed thoroughly.
Aneurysm occlusion was complete in 64.3%, a neck remnant in 19.4%, and aneurysm body filling in 16.3% of the small aneurysms embolized. According to Glasgow Outcome Scale, clinical outcome showed good recovery in 76.5%, moderate disability in 6.1%, severe disability in 8.2%, vegetative state in 5.1%, and death in 4.1%. The complication rate was 9.2% (9/98). Five of nine complications occurred in patients with ruptured aneurysms. Four patients died, three were harboring ruptured aneurysms, and one had an unruptured aneurysm.
Endovascular embolization may be an effective and feasible treatment for small intracranial aneurysms.

Keywords: angiography, endovascular procedures, intracranial aneurysm, retrospective studies

How to cite this article:
Melake MS. Endovascular management of small intracranial aneurysms: a retrospective study of 98 consecutive patients. Menoufia Med J 2018;31:1069-72

How to cite this URL:
Melake MS. Endovascular management of small intracranial aneurysms: a retrospective study of 98 consecutive patients. Menoufia Med J [serial online] 2018 [cited 2020 Feb 28];31:1069-72. Available from: http://www.mmj.eg.net/text.asp?2018/31/3/1069/248720

  Introduction Top

Coiling of intracranial aneurysms is increasingly accepted owing to technical advances and enhanced practical skills[1]. Management of small-sized asymptomatic unruptured aneurysms is still debatable, even with respect to the relative rupture risk occurring in these aneurysms[2],[3].

Although accumulating evidence points to the impact of aneurysm size on rupture risk in patients with unruptured aneurysms, the hazardous critical size remains uncertain[2],[4]. Recent evidence in the literature does not precisely support a standard treatment strategy regarding those aneurysms, specifically in patients without a previous history of subarachnoid hemorrhage (SAH)[5]. Moreover, it has been noticed that ruptured small aneurysms may cause even much SAH than larger aneurysms[6]. On the other hand, small-sized aneurysm has a possible risk for procedure-related ruptures during coiling[7],[8]. Surgical clipping is as well limited because these aneurysms have often a thin wall and carry the risks of narrowing or injuring the parent artery during clipping[9].

For that, we retrospectively recruited our endovascular coiling of small aneurysms (≤5 mm), both ruptured and unruptured, to report their incidence, clinical findings, complications, and outcome with assessment of its feasibility, safety, and efficacy.

  Patients and Methods Top


From March 2002 to August 2013, 98 saccular bifurcation aneurysms measured to be less than or equal to 5 mm in size were treated by endovascular coiling. Of these aneurysms, 42 (43%) were ruptured aneurysms and 56 (57%) were unruptured. The mean age of patients with ruptured aneurysms was 65.2 years (range, 42–85 years), and of those with unruptured aneurysms was 58.3 years (range, 32–77 years). We had 70 (71%) women (ruptured aneurysms, 34; unruptured, 36) and 28 (29%) men (ruptured aneurysms, 8; unruptured, 20).

Patients in the ruptured aneurysm group were assessed by Hunt and Hess (HH) scale, which showed six (14%) patients with grade I; 16 (38%) patients with grade II; seven (17%) patients with grade III; 11 (26%) patients with grade IV; and two (5%) patients with grade V. In patients with unruptured aneurysms, lesions were mostly discovered incidentally.

Location of aneurysms varied between internal carotid artery (33%, n = 32); anterior communicating artery (10%, n = 10); anterior cerebral artery (12%, n = 12); middle cerebral artery (3%, n = 3); and posterior circulation (42%, n = 41) [Figure 1].
Figure 1: Location of aneurysms. ICA, internal carotid artery; Acom, anterior communicating artery; ACA, anterior cerebral artery; MCA, middle cerebral artery.

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Management strategy and procedure

We chose aneurysm coiling if it appeared to be the best option after assessment by the neuroendovascular team, or if the patient refused surgical clipping. All coiling procedures were performed in a neuroangiography suite having digital subtraction angiography, road-mapping, and three-dimensional rotational angiography capabilities. A baseline activated clotting time was assessed and then repeatedly done during the operation to be maintained 2–2.5 times of the control, to adjust the dose of heparin (excluding cases with parenchymal cerebral hematoma). We used Matrix coils and Guglielmi detachable coils (Boston Scientific, Fremont, California, USA). Hyperform and hyperglide balloon microcatheters (ev3, Irvine, California, USA) were used when necessary. Patients were transferred to the neurointensive care unit after the procedure until they become stable, and then they were transferred to the ward.

Clinical and angiographic assessment

We used Glasgow Outcome Scale (GOS) as a clinical tool to divide patients into five categories: good recovery (GR), regain of normal activities, although there may be minor neurological or psychological deficits; moderately disabled (MD), independent as far as daily life is concerned; severely disabled (SD), patient depends on others for daily support because of mental or physical disability or both; persistent vegetative state (VS), patient exhibits no obvious cortical function; death (D). It was performed during outpatient follow-up visits (3 months post coiling). Angiographic results were recorded after coiling (immediately), and classified as follows: class 1, complete occlusion (CO); class 2, residual neck (RN); or class 3, residual aneurysm sac [body filling (BF)] according to Raymond et al.[10].

Statistical analysis

Data were tabulated and analyzed by SPSS, version 16.0, statistical package (SPSS Inc. Chicago, Illinois, USA). Quantitative data were expressed as mean and SD. Qualitative data were expressed as number and percentage and analyzed by χ2-test with or without Yate's Continuity Correction when appropriate.

  Results Top

Aneurysm embolization

Ninety-one patients harbored one aneurysm, six patients had two aneurysms, and one patient had multiple aneurysms. We used ‘conventional coiling technique’ in 89 (90.8%) cases, ‘balloon-assisting technique’ in eight (8.2%) cases, all having wide neck, and ‘double catheter technique’ in one (1%) case. Ventriculoperitoneal shunt was used in five (5.1%) cases.

Clinical and angiographic outcome

For unruptured aneurysms, GOS showed 35 (85.7%) patients as GR, three (5.4%) as MD, three (5.4%) as SD, one (1.8%) as VS, and one patient (1.8%) died. Postprocedure angiographic assessment showed 35 (62.5%) aneurysms as CO, 12 (21.4%) as RN, and nine (16.1%) as BF. Correlation was found to be significant with different aneurysm locations [Table 1].
Table 1: Unruptured aneurysms, clinical and angiographic outcome as a function of different variables

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For ruptured aneurysms, GOS showed 27 (64.3%) patients as GR, three (7.1%) as MD, five (11.9%) as SD, four (9.5%) as VS, and three (7.1%) patients died. Postprocedure angiographic assessment showed 28 (66.7%) aneurysms as CO, seven (16.7%) as RN, and seven (16.7%) as BF. Correlation was found to be significant with patients' age, HH grade, and different techniques used [Table 2].
Table 2: Ruptured aneurysms, clinical and angiographic outcome as a function of different variables

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Treatment-related complications

Procedural complications leading to morbidity occurred in seven patients (7.1%; two procedural ruptures, six thromboembolic complications) and complications leading to mortality in two patients (2%; one procedural rupture, one brainstem infarction). Complication rate was 9.2% (9/98). Five of nine complications occurred in patients with ruptured aneurysms. Four patients died, three were harboring ruptured aneurysms, and one had an unruptured aneurysm. One patient developed monoparesis after the procedure and then fully improved after a few days. Arterial dissection took place in one patient with internal carotid–paraclinoid aneurysm, with GR of the patient.

  Discussion Top

In this study, we retrospectively analyzed our data of endovascular coiling in cases of unruptured and ruptured small aneurysms (≤5 mm).

Some neurointerventionists prefer conservative management as the treatment of choice in the group of unruptured aneurysms, especially in elderly patients without history of SAH. Probably, they depend on some previous estimates of annual bleeding rates of such aneurysms. However, these estimates vary considerably and appear to depend on study population, study design, and aneurysm features[2],[5].

Wiebers et al.[2] found that 5-year cumulative rupture rates for unruptured aneurysms present in the internal carotid artery, anterior communicating artery, anterior cerebral artery, or middle cerebral artery were 0, 2.6, 14.5, and 40% for aneurysms less than 7, 7–12, 13–24, and greater than or equal to 25 mm, respectively, compared with rates of 2.5, 14.5, 18.4, and 50%, respectively, for the same-sized categories involving posterior circulation and posterior communicating artery aneurysms. Other studies showed that the annual rupture rates among asymptomatic unruptured aneurysms patients varied from 0.05 to 2.3% per year[11],[12],[13].

In spite of the low rupture risk of such aneurysms, no sure evidence validates conservative management for the treatment of small asymptomatic unruptured aneurysms[5]. Moreover, it has been reported that small aneurysms if ruptured may cause much more excessive SAH than bigger aneurysms[6].

In addition, our results showed immediate CO of 64.3%, a neck remnant in 19.4%, and aneurysm BF in 16.3% of the aneurysms coiled, in comparison with 55% total occlusion, 35.5% RN, and 3.5% incomplete occlusion in Guglielmi detachable coils coiling of aneurysms done by Murayama et al.[14].

Regarding ruptured small aneurysms, we found significant correlation between age (P = 0.045), HH grade (P = 0.009), and coiling technique (P = 0.012) and clinical outcome. Initial HH-grade score seems to be the most effective parameter as patients with grades I, II, and III did better than those with grades IV and V; also, patients aged less than 60 years have better results. However, in case of unruptured aneurysms, aneurysm location was found to be the only significant parameter influencing the clinical outcome (P < 0.001).

Complications related to the procedure including rupture aneurysm, thromboembolization, migration of coil, and parent artery injury have been reported during endovascular coiling of intracranial aneurysms[15]. In this current study, we had complications in nine (9.2%) patients; some were transient in the form of monoparesis followed by recovery in few days and some were severe enough and nonresponding to treatment to end in death, as occurred in four cases: three of them were harboring ruptured aneurysms where the main causes of death were aneurysmal rupture and extensive cerebral infarction. In addition, the high morbidity and mortality incidence reported for endovascular management of ruptured cerebral aneurysms is probably related to high-grade SAH[15].

In addition, we found more complications in cases with ruptured aneurysms (5/42, 12%) than in cases of unruptured aneurysms (4/56, 7%); these data coincide with those of Nguyen et al.[7], who described strong association of small ruptured aneurysms coiling with increased rates of procedure-related complications.

In this case series, we selected balloon-assisting technique for coiling for aneurysms with unfavorable dome/neck ratio to ensure complete aneurysm occlusion; however, it was correlated with higher rate of complications, especially in cases with ruptured aneurysms (P = 0.012) in the form of brainstem infarction, arterial occlusion, and aneurysm rupture in three cases out of eight cases treated by this technique. These results agree with reports showing increased morbidity and procedural-related complications with this technique when used in treating small aneurysms[16].

This study has the limitation of being a retrospective analysis, selection bias, and not having a long-term follow-up. Preventive therapy of unruptured aneurysms should be done by well-experienced neurointerventionists in order to get the best possible results. In addition, technological innovations and meticulous treatment, such as antiplatelet therapy and anticoagulation, have significantly minimized morbidity rates in past years[17].

  Conclusion Top

Endovascular embolization may be an effective and feasible therapy for small intracranial aneurysms. Long-term efficacy and safety of endovascular coiling for these lesions remains in need for large series to be confirmed.


This work was done at Tokyo Women Medical University, Tokyo, Japan, while on a scholarship program in Japan.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Niimi Y, Song J, Madrid M, Berenstein A. Endosaccular treatment of intracranial aneurysms using matrix coils: early experience and midterm follow-up. Stroke 2006; 37:1028–1032.  Back to cited text no. 1
Wiebers DO, Whisnant JP, Huston J III, Meissner I, Brown RD Jr, Piepgras DG. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet 2003; 362:103–110.  Back to cited text no. 2
Weir B. Unruptured intracranial aneurysms: a review. J Neurosurg 2002; 96:3–42.  Back to cited text no. 3
International Study of Unruptured Intracranial Aneurysms Investigators. Unruptured intracranial aneurysms: risk of rupture and risks of surgical intervention. N Engl J Med 1998; 339:1725–1733; Erratum in: N Engl J Med 1999; 340:744.  Back to cited text no. 4
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Nguyen TN, Raymond J, Guilbert F, Roy D, Bérubé MD, Mahmoud M, et al. Association of endovascular therapy of very small ruptured aneurysms with higher rates of procedure related rupture. J Neurosurg 2008; 108:1088–1092.  Back to cited text no. 7
Proust F, Debono B, Hannequin D, Gerardin E, Clavier E, Langlois O, et al. Treatment of anterior communicating artery aneurysms: complementary aspects of microsurgical and endovascular procedures. J Neurosurg 2003; 99:3–14.  Back to cited text no. 8
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Raymond J, Guilbert F, Weill A, Georganos SA, Juravsky L, Lambert A et al. Long-term angiographic recurrences after selective endovascular treatment of aneurysms with detachable coils. Stroke 2003; 34:1398–1403.  Back to cited text no. 10
Zuccarello M. Treatment strategy for patients with unruptured intracranial aneurysms. Neurol Med Chir (Tokyo) 2001; 41:571–575.  Back to cited text no. 11
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Juvela S, Porras M, Poussa K. Natural history of unruptured intracranial aneurysms: probability of and risk factors for aneurysm rupture. J Neurosurg 2000; 93:379–387.  Back to cited text no. 13
Murayama Y, Nien YL, Duckwiler G, Gobin YP, Jahan R, Frazee J, et al. Guglielmi detachable coil embolization of cerebral aneurysms: 11 years' experience. J Neurosurg 2003; 98:959–966.  Back to cited text no. 14
Taha MM, Nakahara I, Higashi T, Iwamuro Y, Iwaasa M, Watanabe Y, et al. Endovascular embolization vs surgical clipping in treatment of cerebral aneurysms: morbidity and mortality with short-term outcome. Surg Neurol 2006; 66:277–284.  Back to cited text no. 15
Sluzewski M, Bosch JA, van Rooij WJ, Nijssen PC, Wijnalda D. Rupture of intracranial aneurysms during treatment with Guglielmi detachable coils: incidence, outcome, and risk factors. J Neurosurg 2001; 94:238–240.  Back to cited text no. 16
Lanterna LA, Tredici G, Dimitrov BD, Biroli F. Treatment of unruptured cerebral aneurysms by embolization with Guglielmi detachable coils: case-fatality, morbidity, and effectiveness in preventing bleeding – A systematic review of the literature. Neurosurgery 2004; 55:767–775.  Back to cited text no. 17


  [Figure 1]

  [Table 1], [Table 2]


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