Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 59, Num. 2, 2011, pp. 218-223

Neurology India, Vol. 59, No. 2, March-April, 2011, pp. 218-223

Original Article

Outcomes of endovascular coiling of anterior communicating artery aneurysms in the early post-rupture period: A prospective analysis

Mathew P Cherian¹, MB Pranesh², Pankaj Mehta¹, K Vijayan³, P Baskar³, Tejas M Kalyanpur¹, Kaustubh S Narsinghpura¹

¹ Department of Radiology, Kovai Medical Center and Hospital, Avinashi Road, Coimbatore, Tamil Nadu, India
² Department of Neurology, PSG Hospitals, Peelamedu, Coimbatore, Tamil Nadu, India
³ Department of Neurology, Kovai Medical Center and Hospital, Avinashi Road, Coimbatore, Tamil Nadu, India

Correspondence Address: Mathew P Cherian, Department of Radiology, Kovai Medical Center and Hospital,Avinashi Road, Coimbatore, Tamil Nadu - 641 014, India, dr.mathewcherian@gmail.com

Date of Submission: 05-Oct-2010
Date of Decision: 01-Dec-2010
Date of Acceptance: 16-Jan-2011

Code Number: ni11062

PMID: 21483121
DOI: 10.4103/0028-3886.79147

Abstract

Background : There have been significant advances in the technical aspects of endovascular therapy of cerebral aneurysms. Anterior communicating artery (Acom A) aneurysms were traditionally treated by surgical clipping. Endovascular coiling has the distinct advantage of being minimally invasive and can be performed anytime during the course of subarachnoid hemorrhage (SAH).
Aims : To evaluate the results of endovascular coiling of Acom A aneurysms in the early post-rupture period.
Material and Methods : Between June 1999 and December 2009, 103 Acom A aneurysms were treated with endovascular coiling. All the patients underwent digital subtraction angiography (DSA) and a diagnostic 3D rotational angiogram (3D-RA), followed by coiling using dedicated intracranial coils.
Results : Of the 103 patients coiled, 52% presented in Fischer grade 3/4 SAH and 13.5% in Hunt and Hess grade 4/5. Technical success was 98%. Complete obliteration of the aneurysm was achieved in 97 (94%) patients. Only one patient died of direct procedure-related complication due to coil prolapse. None of the patients had rebleeds. Six-month check angiogram performed in 34 patients showed significant recanalization in one patient.
Conclusion : Ruptured Acom A aneurysms are implicated in majority of cases of SAH. Our results support the latest guideline "that endovascular coil occlusion of the aneurysm is appropriate for patients with a ruptured cerebral artery aneurysm that is deemed treatable either by endovascular coiling or by surgical clipping."

Keywords: Anterior communicating artery aneurysm, endovascular coiling, subarachnoid hemorrhage

Introduction

Endovascular therapy has evolved in the last two decades from being restricted to surgically difficult or inaccessible aneurysms to being the procedure of choice. Surgical treatment of anterior communicating artery (Acom A) aneurysms is relatively difficult with a significant risk due to complexity of the anatomy. Cognitive and behavioral disorders may be seen after surgery. ^[1] The International Subarachnoid Aneurysm Trial (ISAT) study, despite being the largest study ever comparing surgical and endovascular coiling, has still had its share of criticism due to a possible selection bias. Only 22% of the 9559 cases were finally included in the study with only 6% representing World Federation of Neurological Surgeons (WFNS) grades 4 and 5. However, with increasing experience and development of appropriate devices endovascular coiling has widened its indications even in the treatment of anterior circulation aneurysms with improved technical success and safety in patients with a poor grade. Anterior circulation intracranial aneurysms are the leading cause of all aneurysmal SAH, many of which arise from the Acom A. We report our series of endovascular treatment in 103 patients with Acom A aneurysms.

Material and Methods

This study includes all consecutive cases of ruptured Acom A aneurysms treated since 1999. Data were collected in all the consecutive cases of ruptured Acom A aneurysms prospectively from September 2007 to December 2009. A total of 103 ruptured Acom A aneurysms were treated with endovascular coiling at our institution. The data collected included age, associated comorbid conditions, clinical Hut and Hess grade, and grade of SAH at the time of presentation. All the patients underwent digital subtraction angiography (DSA) (INNOVA 2100, LCV+, GE Healthcare). Further the patients underwent a diagnostic 3D-RA and images were postprocessed on ADW 4.3 advantage workstation, which allowed for selecting the most appropriate working angulation to visualize the neck and morphology of aneurysm [Figure - 1]. Aneurysm characteristics, such as fundus and neck sizes were taken to be the maximal respective measurements. Aneurysms with a neck to fundus ratio of more than 0.5 were classified as narrow-neck aneurysm and less than 0.5 as wide-neck aneurysm. Those with a ratio of 0.5 were considered moderately wide necked. Regardless of the morphology of aneurysm, vessel tortuosity or patient age, endovascular coiling was performed in all the patients. A neuroguiding catheter was positioned and microcatheter SL-10 with a compatible wire was used to intubate the aneurysm.

Difficult access

When the internal carotid artery (ICA) was tortuous, a triaxal system was used. A 70 cm long sheath was placed in the proximal common carotid artery (CCA) and the supporting neuroguiding catheter was positioned in the petrous segment of the ICA. Through this system a microcatheter and a guidewire was used to intubate the aneurysm. In 2 patients a direct carotid puncture was performed due to excessive tortuosity of the vessels [Figure - 2]. In this technique, a 6F sheath was placed under fluoroscopic guidance in the CCA in such a way that the tip of the sheath was at the mouth of the internal carotid artery. A 6F neuroguiding catheter was placed within or just below the petrous segment of ICA . The sheath and the guiding catheter were secured in place using 3 M Tegaderm HP transparent films dressing to ensure no movement took place, and the procedure was carried out as usual. The aneurysm was then coiled using dedicated intracranial coils. The first coil diameter is usually a mean between the length and breadth of the aneurysm and progressively smaller coils are used to pack the aneurysm. Complex coils were used initially followed by hydrocoils as the last coil to achieve complete obliteration of the sac.

Difficult morphology

Wide-neck aneurysms were treated using balloon remodeling technique. In the balloon remodeling technique, a 6F guiding catheter was used along with a Double Hemostasis Valve Y Connector, which allowed for passage of both microcatheter and the balloon through the same system. The various balloons used were the Hyperglide balloon for the internal carotid artery, and Hyperfoam and Eclipse balloons for the middle and anterior cerebral artery (ACA). The diameter of the balloon was 7 mm in the ICA and 6 mm in the middle and anterior cerebral arteries. In narrow neck small aneurysms, where we anticipated higher risk of on-table rupture, a balloon was positioned proximal to the neck in the parent artery so as to arrest the bleeding. The patients underwent a follow-up angiogram at 6 months and 1 year.

Results

One hundred and three patients with Acom A aneurysms were included in the study. All the aneurysms were treated with endovascular coiling. Of these patients, 102 (99%) patients underwent coiling of the aneurysm alone, and 1 (1%) patient was treated by coiling with parent vessel occlusion. More than one aneurysm was seen in 10.7% of the patients: 2 aneurysms in 7 patients and 3 aneurysms in 2 patients. The patients' age ranged between 17 and 76 years (mean 51 years) and 55 patients (53%) were male. The comorbid conditions were hypertensives in 39% and diabetes in 14%, and 60% of male patients were smokers [Table - 1].

Of the 6 aneurysms with ≤3 mm size, the smallest size measured was 2 Χ 2 mm. The positioning of coils is more difficult in smaller aneurysms, however, newer softer and complex-shaped coils have made the procedure easier. The largest diameter of the aneurysm treated was 21 Χ 15 mm. Of the 103 aneurysms treated 76 were narrow necked [Figure - 3], 12 were wide necked and 15 had moderately wide neck. Among the wide-necked aneurysms, all were treated with the assistance of balloon [Figure - 4] and were analyzed separately and their angiographic outcome was recorded.

Outcome based on the morphology

Of the total 103 aneurysms, complete obliteration was achieved in 97 patients (94%). Minimal residual filling of the neck was seen in 6 patients (5.8%), 3 of which were moderately wide necked and 3 were narrow-necked aneurysms. Coil prolapse into parent artery leading to occlusion was seen in 2 patients, one of which was narrow and other wide neck [Figure - 5]. On-table rupture of aneurysm occurred in 3 patients (2.9%), which were arrested by inflation of the balloon or coiling of the parent artery and there were no untoward events [Figure - 6]. Of these 1 patient died on day 7 probably secondary to vasospasm, another showed progressive deterioration in neurologic status and died on day 4, and the third patient was discharged without any deficit. Deaths following on-table rupture could not be directly attributed to the rupture as they occurred more than 4 days after the procedure. Coiling was abandoned in one of the patients where the aneurysm was small and the first coil had a tendency to restrict flow within the parent artery. This patient re-bled after 12 h and died 4 days later. A case of a moderately wide-necked aneurysm developed minimal thrombus at the mouth of the aneurysm, where coils were exposed to ICA. The patient was asymptomatic but was empirically started on heparin, and eventually had a good outcome. None of our patients developed any thromboembolic complications resulting in death [Table - 2].

Outcome based on neurologic status

The neurologic grades of patients who were treated for ruptured aneurysms, at the time of admission into the hospital were analyzed and classified into 5 groups based on the Hunt and Hess grading system. Fourteen patients died, of whom 1 patient died due to infarcts following coil prolapse into the anterior cerebral artery (ACA). Another patient could not be coiled as the ACA showed flow restriction and the coil was removed before detachment, and he died 4 h later as a result of rebleed. Rest of the patients died due to nonintervention related causes, 8 of which were attributed to vasospasm [Figure - 7], 2 each due to cardiac arrest and sepsis [Table - 3].

Clinical outcome based on Fischer's grade

All the patients who underwent treatment for ruptured aneurysms were classified based on the Fischer's grading system into grades 1-4 and their clinical outcomes analyzed. The best outcomes were seen in grades 2 and 3 [Table - 4].

Immediate complications

Of the 103 patients treated, 5 patients developed communicating hydrocephalus, 2 of whom required an extraventricular drainage (EVD), while others were managed conservatively. At the time of discharge ventricles were normal in size in all the 5 patients. Nineteen patients developed symptomatic vasospasm and were managed conservatively by triple-H therapy.

Outcomes at discharge

Outcomes at discharge were assessed on the basis of modified Rankin Score (mRS). Of the 103 patients, 75 patients had a score of 0 (no symptoms at all), 12 patients had a score of 1 (no significant disability despite symptoms; able to carry out all usual duties and activities), 2 had a score of 3 (moderate disability; requiring some help, but able to walk without assistance) and there were14 deaths.

Angiographic follow-up

Follow-up angiogram at 6 months was done in 34 patients. One patient with a narrow-necked 7 mm aneurysm showed a regrowth of neck at 6 months follow-up. The patient did not undergo any further treatment. In the cases that were followed-up, 5 patients showed minimal filling of the neck, which remained stable at 1-year follow-up, and did not undergo any further treatment. There were no cases of coil compaction seen.

Discussion

Several of the studies in the last decade have established the efficacy and safety of endovascular coiling in the treatment of cerebral aneurysms. However, there have not been many studies that exclusively analyzed Acom A aneurysms in detail. Acom A aneurysm accounts for approximately 40% of subarachnoid hemorrhage. ^[2] In the present study, all the patients were treated within 4 days of the ictus with an overall good outcome of 94.6%. The good technical success rate in this series could be attributed to intense preprocedural planning using 3D-RA and the fact that all procedures were performed by a single experienced interventional radiologist. Long-term follow-up of patients in the ISAT study has shown increase in the risk of rebleeding and retreatment in the coiling group than the clipping group. ^[3] In our study there had been no rebleeds, with complete obliteration in 86% of the cases. Patients with minimal residual filling of the aneurysms at the end of the procedure showed no regrowth of the neck on follow-up angiogram. This observation is in agreement with other studies, a small residual aneurysm neck of 2 mm does not pose a risk for future SAH. ^[4]

Procedure-related morbidity ranges between 3.7% and 10% and mortality between 0% and 2.1%. ^[5] Location of the aneurysm to some extent determines the rate of endovascular treatment-related complications. Treating an aneurysm at the site of the Acom A is associated with a much lower complication rate than treating an aneurysm at MCA bifurcation (3% vs 7%). ^[6] The complications we encountered in relation to the morphology of aneurysms were too few to make any statistically significant conclusion. We had 2 patients with coil prolapse and 3 patients with on-table rupture. Gonsalez et al[7] identified 6 factors of outcome for coil embolization of Acom A aneurysm: dome direction, neck location, and presence of associated anomalies, neck size, dome size, and sac-to-neck ratio. In their study anteriorly directed aneurysms were better candidates for surgery. ^[7] However, we did not find any difficulty in coiling the anteriorly oriented aneurysms. In this study the overall mortality was 1.4%, however, only one death was procedure-related. In other patients, death occurred 4 days after the procedure and the deaths were related to the bleed. Of the 19 patients with symptomatic vasospasm, 8 (7.7%) died. A systemic review and meta-analysis showed no significant difference between clipping or coiling on the risk of development of cerebral vasospasm and its consequences. ^[8] However, Noritaka et al, ^[8] in their study, found a lower incidence of symptomatic vasospasm in patients who had endovascular coiling than in patients who had clipping with the exception of poor-grade SAH. ^[9] Shunt-dependent hydrocephalus occurs in a significant proportion of patients with SAH. ^[10] In our series of the 4.8% of patients who developed hydrocephalus, only 2 patients required an EVD. Gruber et al[11] found similar incidence of shunt-dependent hydrocephalus between the endovascular treatment group and the surgical treatment group. The reported incidence of hyperacute thromboembolic complications vary between 3% and 11%. ^{[12],[13],[14]} Asymptomatic thrombus formation was seen in only 1 patient at the mouth of the aneurysm where the coils were exposed to parent vessel.

Recanalization rates are of great concern after successful endovascular coiling. In our series only 34 (33%) of the patients had follow-up angiogram and only 1 patient required treatment for recanalization. The study by Ortiz et al showed a recanalization rate of 6%, ^[15] whereas in a large multicenter study comprising 705 ruptured aneurysms, only 4.7% of aneurysms required retreatment. ^[16] These data suggest that recanalization rates in patients treated with endovascular coiling can be significantly lowered by use of newer coils.

The major limitation of our study is poor follow-up. However, it compares well with the available data. ^[15],[16] Excellent technical success, low procedure-related complications with low mortality rates, absence of rebleeds even in the presence of minimal residual neck filling along with no significant recanalization make endovascular coiling as the procedure of choice in patients with Acom A aneurysms. Our results support the guideline of offering all patients with ruptured Acom A aneurysms with the option of endovascular coiling whenever feasible. ^[17]

References

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