Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil
- Graduate Program in Surgical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
DOI:10.25259/SNI_41_2019Copyright: © 2019 Surgical Neurology International This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-Share Alike 4.0 License, which allows others to remix, tweak, and build upon the work non-commercially, as long as the author is credited and the new creations are licensed under the identical terms.
How to cite this article: Fabiano Pasqualotto Soares, Maira Cristina Velho, Apio Claudio Martins Antunes. Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil. 04-Oct-2019;10:193
How to cite this URL: Fabiano Pasqualotto Soares, Maira Cristina Velho, Apio Claudio Martins Antunes. Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil. 04-Oct-2019;10:193. Available from: http://surgicalneurologyint.com/surgicalint-articles/9684/
Background: The aim of the study was to characterize the clinical profile of patients with anterior communicating artery (ACoA) aneurysms and examine potential correlations between clinical findings, aneurysm morphology, and outcome.
Methods: A review of medical records and diagnostic neuroimaging reports of patients treated at a neurosurgical service in Porto Alegre, Brazil, between August 2008 and January 2015 was performed.
Results: During the period, 100 patients underwent surgery for ACoA aneurysms. Fifteen had unruptured aneurysms and 85 had ruptured aneurysms. Ruptured aneurysms had a higher aspect ratio than unruptured ones (2.37 ± 0.71 vs. 1.93 ± 0.51, P = 0.02). Intraoperative rupture occurred in 3%, and temporary clipping was performed in 15%. Clinical vasospasm occurred in 43 patients with ruptured aneurysms (50.6%). Overall, mortality was 26%; 25 patients in the ruptured group (29.4%) and one in the unruptured group (6%). The Glasgow Outcome Scale (GOS) was favorable (GOS 4 or 5) in 54% of patients, significantly more so in those with unruptured aneurysms (P = 0.01). In patients with ruptured aneurysms, mortality was associated with preoperative Hunt and Hess (HH) score (P P P P P = 0.015), clinical vasospasm (P = 0.012), external ventricular drain (P = 0.015), hydrocephalus (P P = 0.001). In patients with unruptured aneurysms, presence of clinical complications was the only factor associated with mortality (P
Conclusion: Despite advances in the management of subarachnoid hemorrhage and surgical treatment of aneurysms, mortality is still high, especially due to clinical complications.
Keywords: Anterior communicating artery aneurysm, Craniotomy, Intracranial aneurysm, Ruptured aneurysm, Subarachnoid hemorrhage
Intracranial aneurysms (IAs) are present in 2%–5% of the population.[
The ACoA complex often exhibits anatomical variations, such as asymmetry of the A1 segment, lateral rotation of the complex, ACoA aplasia, and hypoplasia. Aneurysms usually arise at the junction of A1 with ACoA. Due to their multiple vascular relationships, deep location, and frequent anatomical variations, they are considered complex aneurysms.[
Surgery of ACoA aneurysms is usually performed through the pterional approach,[
Within this context, the aim of the present study was to characterize the clinical and morphological profile of ACoA aneurysms treated surgically at Hospital Beneficência Portuguesa de Porto Alegre, Brazil, from August 2008 to January 2015. We present the clinical data of this group of patients, the morphological features of the aneurysms; and we try to correlate these data with the clinical outcome, according to the findings of the existing literature.
This was a retrospective chart review study of patients with ACoA aneurysms who underwent microsurgical treatment by physicians of the Department of Neurosurgery, Hospital Beneficência Portuguesa de Porto Alegre (Dr. Mario Coutinho Neurosurgical Service), Brazil, from August 2008 to January 2015. Only those patients in whom aneurysm diagnosis was established or confirmed by digital angiography or computed tomography (CT) angiography before the intervention were considered. Patients who underwent endovascular treatment were not included in the sample. Ethics Committee Approval was obtained before data collection (CAAE 79257717.9.1001.5327).
Demographic data (age and sex) and clinical information (risk factors, craniotomy side, and presence of postoperative complications) were obtained from medical records. In patients with ruptured aneurysms, additional data were obtained: initial symptoms, Hunt and Hess (HH) classification at admission and at the time of the procedure, and Glasgow Coma Score (GCS). Clinical vasospasm was defined as the late onset of neurological deficits, including a GCS decline of two or more points, with no other attributable cause, such as fluid-electrolyte disturbance, hydrocephalus, or ventriculitis. The clinical outcome at discharge was assessed using the Glasgow Outcome Scale (GOS).
The following neuroimaging data were obtained through direct analysis of patient scans: aneurysm dome direction in the coronal plane, aneurysm size, aneurysm neck size, presence of A1 dominance, presence of multiple aneurysms, and presence of preferential angiographic filling. The aspect ratio (AR) (i.e., the ratio of aneurysm size to neck size) was calculated on the basis of the aforementioned data.
CT angiography images were obtained in a GE Brightspeed CT scanner, using a specific thin-slice protocol (0.625 mm). Digital angiography images were obtained with GE OEC 9800 Series and Novomédica Radius S/R C-arms, using a bilateral three-view protocol (anteroposterior, lateral, and oblique) for the anterior circulation.
Quantitative variables were described as mean and standard deviation or median and interquartile range as appropriate. Categorical variables were expressed as absolute and relative frequencies.
Student’s t-test or the Mann–Whitney U test (in case of asymmetrically distributed data) was used to compare means. Pearson’s Chi-square test or Fisher’s exact test was used to compare proportions. For polytomous variables, a supplemental analysis using adjusted residuals was performed as well.
To control for confounding factors, Poisson regression analysis was carried out to evaluate factors independently associated with mortality and unfavorable outcomes. The level of significance was set at 5% (P ≤ 0.05), and all analyses were performed using SPSS, version 23.0.
From August 2008 to January 2015, 100 patients with ACoA aneurysms underwent surgery at the study facility. The mean age was 53.1 ± 12.1 years. On average, patients with unruptured aneurysms were older (ruptured = 51.4 years and unruptured = 62.3 years). There was a slight female predominance (43 men and 57 women). Among the 100 patients, 85 had ruptured aneurysms and 15 had unruptured aneurysms. Of those with ruptured aneurysms, most had a HH score of 1 or 2 (HH1/2 = 44, HH3 = 32, HH4 = 10, and HH5 = 0). Detailed demographic data are described in
During the study period, only three patients with ACoA aneurysms underwent endovascular treatment: two unruptured and one ruptured aneurysm (HH4). There were no deaths. GOS of the patients was five for the patients with unruptured aneurysms and three for the ruptured aneurysm patient.
The morphological features of the aneurysms are described in
Regarding A1 segment morphology, preferential filling of the left side predominated in the sample (left = 52, right = 33, and bilateral = 15). Multiple aneurysms were present in 21% of patients (n = 21). Hypoplasia of the A1 segment was present in 45% of cases (left = 15, right = 30, and no hypoplasia = 55).
On average, ruptured aneurysms were larger than unruptured ones (5.32 ± 1.96 mm vs. 4.79 ± 0.97 mm), but the difference was not statistically significant (P = 0.49). There was also no significant difference in neck size between ruptured and unruptured aneurysms (2.31 ± 0.79 vs. 2.69 ± 0.97, P = 0.11).
Conversely, the AR differed significantly between ruptured and unruptured aneurysms (2.37 ± 0.71 vs. 1.93 ± 0.51, P = 0.02).
Surgical intervention was performed most often 4 days after the hemorrhagic stroke (range, 2–6 days). In all cases, access was obtained through pterional craniotomy (left-sided in 54 cases and right-sided in the remaining 46). The laterality of the approach was defined by preferential angiographic filling. In cases with no evidence of preferential filling, craniotomy was performed contralateral to the projection of the aneurysm dome. In patients with multiple aneurysms, craniotomy was performed on the side that would allow access to the largest number of lesions. Symmetrically filling single aneurysms with no lateral projection were approached from the right. Hydrocephalus was present in 43 patients (43%).
Intraoperative aneurysm rupture occurred in 3% of cases, and temporary clipping was performed in 15%. The mean duration of temporary clipping was 115 s. An external ventricular drain was placed at some point during hospitalization (either at admission or intraoperatively) in 37% of patients. Patients with mild ventricular enlargement and a normal level of consciousness (HH score 1 or 2) were treated with daily therapeutic lumbar puncture and cerebrospinal fluid (CSF) manometry per routine hospital protocol, obviating the need for ventriculostomy.
Clinical vasospasm occurred in 43 patients (43%). Clinical complications occurred in 41% of patients and are listed in
In this case series, 26 patients died (26%). Among patients with ruptured aneurysms, 25 died (29.4%), whereas only one patient in the unruptured group died (6.6%).
Regarding the patients with ruptured aneurysm, the ones who died had a preoperative HH score of 3 or 4 (HH1/2 = 8, HH3 = 11, HH4 = 6, and HH5 = 0); clinical vasospasm occurred in 13 of them. Clinical complications occurred on 22 patients (pneumonia = 14, urinary tract infection = 3, sepsis = 14, and other = 8).
In the unruptured group, the only death occurred due to pulmonary thromboembolism on the third postoperative day, which occurred despite routine prophylactic measures.
Regarding clinical outcome, information on the GOS was available for 98 of the 100 patients. The clinical outcome was favorable (GOS 4 or 5) in 53 patients (54%) and unfavorable (GOS 1, 2, or 3) in 45 (46%). Outcomes were significantly better among patients with unruptured aneurysms than in those with ruptured aneurysms (P = 0.01).
Among the factors of interest, the following were associated with mortality in patients with ruptured aneurysms: HH score in the immediate preoperative period (P < 0.001), hydrocephalus (P < 0.001), and presence of clinical complications (P < 0.001). Detailed data are provided in
Comparison of patients with favorable versus unfavorable outcomes in the group of ruptured aneurysms revealed that the following factors were associated with an unfavorable outcome: HH score (P < 0.001), Fisher grade (P = 0.015), clinical vasospasm (P = 0.012), external ventricular drainage (P = 0.015), hydrocephalus (P < 0.001), and presence of clinical complications (P = 0.001) [
There have been a few recent case series of patients undergoing surgical treatment for ACoA aneurysms. With the advent of endovascular techniques, these approaches have become increasingly popular, although they are not necessarily superior to conventional surgical treatment.[
Petraglia et al. analyzed a series of 28 patients with ACoA aneurysms treated operatively and found two deaths (7%). The authors note that this mortality may be attributable to the low proportion of patients with poor neurological status (HH score 3 or higher) in the series.[
We observed a high rate of infectious clinical complications, which explains the high mortality. It should be noted that, in our series, most patients (85%) had ruptured aneurysms and among these cases, 48.8% were in severe neurological condition (HH score 3 or higher) preoperatively. The postoperative course of this patient population tends to be worse due to the higher incidence of clinical complications and clinical vasospasm.[
Ventriculitis was present in 7 patients (18.9% of those who received an external ventricular drain), which is equivalent to 19.1 cases/1000 catheter days. Ramanan, in a meta-analysis of 35 observational studies, found an overall incidence of 11.4/1000 catheter days. When analyzing only smaller studies (<1000 catheter-days), the observed incidence was higher (18.3/1000 catheter-days).[
Clinical vasospasm occurred in 50% of patients. Although the occurrence of clinical vasospasm had no direct correlation with mortality, it did correlate with unfavorable outcomes (GOS 1, 2, or 3). However, this statistical association was not maintained on multivariate analysis. Rosengart and Orakdogen, among other authors, have reported an association between clinical vasospasm and mortality.[
In our series, there was no significant difference in overall aneurysm size or aneurysm neck size between ruptured and unruptured aneurysms. Aneurysm size has been studied by several authors as a potential predictor of rupture.[
In our series, the criterion used to define the laterality of craniotomy was preferential filling, as described by Chemale.[
Intraoperative rupture occurred in 3% of the cases, a lower rate than those reported in the literature. Leipzig et al., in a series of 1694 aneurysms,[
We found no association between temporary clippings and worse outcomes in our patients, a finding consistent with the literature. Araújo Jr., in a series of 32 patients with ACoA aneurysm, of whom 21 required temporary clipping, did not find a significant association between duration of temporary clipping and outcome.[
The limitations of this case series are those inherent to retrospective study designs. Our data were collected from medical records completed by different individuals in a heterogeneous manner over time. Sometimes, specific data were unavailable for a specific patient.
Regarding morbidity and mortality, due to the paucity of data available in outpatient medical records at our facility, it was impossible to evaluate late outcomes in the cohort.
The present study reports a series of 100 cases of ACoA aneurysms treated surgically over 7 years at a tertiary care center in Southern Brazil. The overall mortality rate was 26%, demonstrating that, despite advances in the management of subarachnoid hemorrhage, it is still an event that carries high morbidity and mortality rates, especially in patients who present with severe neurological deficit (as did a substantial portion of our sample). The development of clinical complications, especially infectious ones, was the key determinant of mortality, highlighting the importance of adequate neurointensive care in these patients.
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