Is Age a Risk Factor for Poor Outcome of Surgical Treatment of Unruptured Intracranial Aneurysms?

Gender Differences in Procedural Clinical Complications and Outcomes of Intracranial Aneurysms: Analysis of the Stroke Thrombectomy and Aneurysm Registry

BACKGROUND AND OBJECTIVES

Some studies have shown that female patients had a poorer prognosis after endovascular treatment for ruptured intracranial aneurysm than male patients. However, data have been sparse regarding differences in the periprocedural and perioperative complication rate with ruptured and unruptured intracranial aneurysms.

METHODS

This retrospective cohort study used data from the Stroke Thrombectomy and Aneurysm Registry, a database of 9 institutions in the United States, Europe, and Asia. The study presented intracranial aneurysms after microsurgical and/or endovascular treatment from January 1, 2013, to December 31, 2022. The primary outcome was incidence of periprocedural cerebral infarction. Secondary outcomes were periprocedural intracranial hemorrhage, periprocedural mortality, perioperative vasospasm, and functional outcome at 90 days after procedure.

RESULTS

Among 3342 patients with aneurysm, 2447 were female and 857 were male, and the mean age of female and male patients was 59.6 and 57.1 years, respectively. Current smoker, family history of aneurysm, and ruptured aneurysm were observed in 23.5% vs 35.7 %, 10.8 % vs 5.7%, and 28.2% vs 40.5% of female and male patients, respectively. In female patients, internal carotid artery aneurysms were more commonly observed (31.1% vs 17.3%); however, anterior cerebral artery aneurysms were less commonly observed (18.5% vs 33.8%) compared with male patients. Periprocedural cerebral infarction rate was lower in female than male patients (2.4% vs 4.4%; P = .002). The adjusted odds ratio of primary outcome of female to male patients was 0.72 (95% CI, 0.46-1.12). Incidence of periprocedural intracranial hemorrhage and periprocedural mortality and perioperative symptomatic vasospasm and functional outcome was similar in both groups. In subgroup analysis, periprocedural cerebral infarction due to microsurgical treatment occurred frequently in male patients while incidence in endovascular treatment was similar in both groups (interaction P = .005).

CONCLUSION

This large multicenter registry of patients undergoing intracranial aneurysm treatment found that female patients were not at increased risk of perioperative complications.

White Matter Lesions as Brain Frailty and Age are Risk Factors for Surgical Clipping of Unruptured Intracranial Aneurysms in the Elderly

INTRODUCTION

We aimed to identify the risk factors for surgical treatment of unruptured intracranial aneurysms (UIAs) in individuals aged >60 years, particularly focusing on white matter lesions (WMLs).

MATERIAL AND METHODS

We investigated a total of 214 patients with UIAs. The patient group comprised 53 males and 151 females with an average age of 68.2 years. UIA size ranged from 2.7 to 26 (mean: 7.3) mm. The primary endpoint of the study was patient prognosis evaluated at the time of discharge using the modified Rankin Scale. We examined the risk factors for poor outcome and WMLs using magnetic resonance imaging.

RESULTS

Poor outcome was observed in 23 (10.7%) patients. Significant correlations were observed between poor outcome and UIA size (P < 0.0001), UIAs located posteriorly (P = 0.0204), UIA thrombosis (P = 0.0002), and presence of WMLs (P < 0.0001) in univariate regression analysis. However, no significant correlations were noted between poor outcome and age (P = 0.1438). Multivariate logistic regression analyses showed significant correlations between poor outcome and UIA size (P < 0.0001), presence of WMLs (P = 0.001). Severe WMLs based on the Fazekas classification was correlated to age (P < 0.0001) and atherosclerosis (P = 0.0001). Severe WMLs were associated with ischemia (P < 0.001) and epilepsy (P = 0.0502) as well as length of hospitalization (P < 0.0001).

CONCLUSION

Severe WMLs are risk factors for surgical treatment of UIAs in the elderly. Surgical indications must be considered and caution should be taken when managing patients with severe WMLs.

Adverse events after clipping of unruptured intracranial aneurysms: the NSQIP unruptured aneurysm scale

OBJECTIVE

The complex decision analysis of unruptured intracranial aneurysms entails weighing the benefits of aneurysm repair against operative risk. The goal of the present analysis was to build and validate a predictive scale that identifies patients with the greatest odds of a postsurgical adverse event.

METHODS

Data on patients who underwent surgical clipping of an unruptured aneurysm were extracted from the prospective National Surgical Quality Improvement Program registry (NSQIP; 2007-2014); NSQIP does not systematically collect data on patients undergoing intracranial endovascular intervention. Multivariable logistic regression evaluated predictors of any 30-day adverse event; variables screened included patient demographics, comorbidities, functional status, preoperative laboratory values, aneurysm location/complexity, and operative time. A predictive scale was constructed based on statistically significant independent predictors, which was validated using both NSQIP (2015-2016) and the Nationwide Inpatient Sample (NIS; 2002-2011).

RESULTS

The NSQIP unruptured aneurysm scale was proposed: 1 point was assigned for a bleeding disorder; 2 points for age 51-60 years, cardiac disease, diabetes mellitus, morbid obesity, anemia (hematocrit < 36%), operative time 240-330 minutes; 3 points for leukocytosis (white blood cell count > 12,000/μL) and operative time > 330 minutes; and 4 points for age > 60 years. An increased score was predictive of postoperative stroke or coma (NSQIP: p = 0.002, C-statistic = 0.70; NIS: p < 0.001, C-statistic = 0.61), a medical complication (NSQIP: p = 0.01, C-statistic = 0.71; NIS: p < 0.001, C-statistic = 0.64), and a nonroutine discharge (NSQIP: p < 0.001, C-statistic = 0.75; NIS: p < 0.001, C-statistic = 0.66) in both validation populations. Greater score was also predictive of increased odds of any adverse event, a major complication, and an extended hospitalization in both validation populations (p ≤ 0.03).

CONCLUSIONS

The NSQIP unruptured aneurysm scale may augment the risk stratification of patients undergoing microsurgical clipping of unruptured cerebral aneurysms.

Comprehensive analysis of perforator territory infarction on postoperative diffusion-weighted imaging in patients with surgically treated unruptured intracranial saccular aneurysms

OBJECTIVE

Perforator territory infarction (PTI) is still a major problem needing to be solved to achieve good outcomes in aneurysm surgery. However, details and risk factors of PTI diagnosed on postoperative MRI remain unknown. The authors aimed to investigate the details of PTI on postoperative diffusion-weighted imaging (DWI) in patients with surgically treated unruptured intracranial saccular aneurysms (UISAs).

METHODS

The data of 848 patients with 1047 UISAs were retrospectively evaluated. PTI was diagnosed on DWI, which was performed the day after aneurysm surgery. Clinical and radiological characteristics were compared between UISAs with and without PTI. Poor outcome was defined as an increase in 1 or more modified Rankin Scale scores at 12 months after aneurysm surgery.

RESULTS

Postoperative DWI was performed in all cases, and it revealed PTI in 56 UISA cases (5.3%). Forty-three PTIs occurred without direct injury and occlusion of perforators (43 of 56, 77%). Poor outcome was more frequently observed in the PTI group (17 of 56, 30%) than the non-PTI group (57 of 1047, 5.4%) (p < 0.0001). Thalamotuberal arteries (p < 0.01), lateral striate arteries (p < 0.01), Heubner's artery (p < 0.01), anterior median commissural artery (p < 0.05), terminal internal carotid artery perforators (p < 0 0.01), and basilar artery perforator (p < 0 0.01) infarctions were related to poor outcome by adjusted residual analysis. On multivariate analysis, statin use (OR 10, 95% CI, 3.3-31; p < 0.0001), specific aneurysm locations (posterior communicating artery [OR 4.1, 95% CI 2.1-8.1; p < 0.0001] and basilar artery [OR 3.1, 95% CI 1.1-8.9; p = 0.031]), larger aneurysm size (OR 1.1, 95% CI 1.1-1.2; p = 0.043), and permanent decrease of motor evoked potential (OR 38, 95% CI 3.1-468; p = 0.0045) were related to PTI.

CONCLUSIONS

Despite efforts to avoid PTI, it occurred even without direct injury, occlusion of perforators, or evoked potential abnormality. Therefore, surgical treatment of UISAs, especially with the aforementioned risk factors of PTI, should be more carefully considered. The evaluation of PTI in the territory of the above-mentioned perforators could be useful in helping predict the clinical course in patients after aneurysm surgery.

Outcome of retreatment for recurrent saccular cerebral aneurysms: a propensity score-matched analysis

Although endovascular or surgical treatment has been performed for preventing the rupture of saccular cerebral aneurysms (sCA), in some patients, the aneurysms may recur and require retreatment. We aimed to investigate the clinical and radiological outcomes of treating recurrent sCA. We retrospectively evaluated the data of 52 patients with 60 recurrent sCAs who were retreated and 1534 patients with 1817 sCAs who received initial treatment. The primary outcome was a recurrence of the aneurysm. Secondary outcomes were an additional treatment, rupture after treatment, and a neurological worsening, which was defined as an increase of 1 or more scores using the modified Rankin Scale at 12-month. Safety outcomes included postoperative ischemic and hemorrhagic complications. We compiled the 120 (60 each) propensity score-matched cohort based on a propensity score for the treatment of recurrent sCA. In the propensity score-matched cohort, recurrence after treatment was observed in 25% and 6.7% of cases in the retreatment and initial treatment groups, respectively. The odds ratio of recurrence after treatment was 4.7 (95% CI, 1.4-15; P = 0.011). The secondary and safety outcomes were not significantly different between the two groups. This study showed that the treatment of recurrent sCA was a risk factor for recurrence after treatment but not for additional treatment, rupture after treatment, or neurological worsening. Although decision-making regarding the treatment varies depending on the institutional protocols and personal experience of the physicians, endovascular or surgical retreatment could be performed without hesitation.

Morphological parameters as factors of 12-month neurological worsening in surgical treatment of patients with unruptured saccular intracranial aneurysms: importance of size ratio

OBJECTIVE

It is well known that larger aneurysm size is a risk factor for poor outcome after surgical treatment of unruptured saccular intracranial aneurysms (USIAs). However, the authors have occasionally observed poor outcome in the surgical treatment of small USIAs and hypothesized that size ratio has a negative impact on outcome. The aim of this paper was to investigate the influence of size ratio on outcome in the surgical treatment of USIAs.

METHODS

Prospectively collected clinical and radiological data of 683 consecutive patients harboring 683 surgically treated USIAs were evaluated. Dome-to-neck ratio was defined as the ratio of the maximum width of the aneurysm to the average neck diameter. The aspect ratio was defined as the ratio of the maximum perpendicular height of the aneurysm to the average neck diameter of the aneurysm. The size ratio was calculated by dividing the maximum aneurysm diameter (height or width, mm) by the average parent artery diameter (mm). Neurological worsening was defined as an increase in modified Rankin Scale score of 1 or more points at 12 months. Clinical and radiological variables were compared between patients with and without neurological worsening.

RESULTS

The median patient age was 64 years (IQR 56-71 years), and 528 (77%) patients were female. The median maximum size, dome-to-neck ratio, aspect ratio, and size ratio were 4.7 mm (IQR 3.6-6.7 mm), 1.2 (IQR 1.0-1.4), 1.0 (IQR 0.76-1.3), and 1.9 (IQR 1.4-2.8), respectively. The size ratio was significantly correlated with maximum size (r = 0.83, p < 0.0001), dome-to-neck ratio (r = 0.69, p < 0.0001), and aspect ratio (r = 0.74, p < 0.0001). Multivariate logistic regression analysis showed that the specific USIA location (paraclinoid segment of the internal carotid artery: OR 6.2, 95% CI 2.6-15, p < 0.0001; and basilar artery: OR 8.4, 95% CI 2.8-25, p < 0.0001), size ratio (OR 1.3, 95% CI 1.1-1.6, p = 0.021), and postoperative ischemic lesion (OR 9.4, 95% CI 4.4-19, p < 0.0001) were associated with neurological worsening (n = 52, 7.6%), and other characteristics showed no significant differences.

CONCLUSIONS

The present study showed that size ratio, and not other morphological parameters, was a risk factor for 12-month neurological worsening in surgically treated patients with USIAs. The size ratio should be further studied in a large, prospective observational cohort to predict neurological worsening in the surgical treatment of USIAs.

Influence of comorbidities on treatment of unruptured intracranial aneurysms in the elderly

Current evidence does not conclusively justify conservative management of unruptured intracranial aneurysms (UIA) in the elderly (age ≥ 65 years). To rationalise intervention, the authors investigated the role of age and comorbidity burden on treatment outcomes. A retrospective chart review for consecutive cases of UIAs treated in the elderly between 2007 and 2018 was performed. Preoperative Charlson Comorbidity Index (CCI) and Neurovascular Comorbidities Index (NCI) were calculated. Standard statistical methods with univariate and multiple logistic regression were used. A total of 123 patients (46 surgery, 77 endovascular) with 131 UIAs were treated. The mean age was 70.6 ± 4.1 years, and 90 patients were female (73.1%). The mean aneurysm size was 8.6 ± 5.0 mm, and the mean follow up period was 22.9 ± 21.3 months. The rates of poor outcome (mRS > 1) at discharge, 6 weeks and 6 months were 9.8%, 5.8% and 3.6%, respectively. There was no difference in outcomes between surgical and endovascular treatment. Correlation and regression analyses revealed that aneurysm size, higher preoperative comorbidity index (CCI > 4), and endovascular treatment with a stent or flow diverter (p = 0.009, 0.02, and 0.005, respectively) were associated with a poor outcome. When adjusted in a multivariate analysis, only high comorbidity burden (CCI > 4) predicted unfavourable outcome (p = 0.01). Elderly patients who undergo treatment for UIAs are at high risk of postoperative deterioration. Careful preoperative case selection based on comorbidity burden, rather than chronological age, would be useful for improved risk stratification.

Analysis for risk factors of 12-month neurological worsening in patients with surgically treated small-to-moderate size unruptured intracranial aneurysms

The risk associated with surgical treatment for small-to-moderate size unruptured intracranial aneurysms (SMUIAs, defined as <15 mm) has not been well characterized. Authors aimed to investigate risk factors for poor outcome in surgical treatment of SMUIAs. The data of prospectively collected 801 consecutive patients harboring 971 surgically treated SMUIAs was evaluated. Neurological worsening (NW) was defined as an increase in 1 or more modified Rankin Scale at 12-month. Clinical and radiological characteristics were compared. Neurological worsening was observed in 45 (4.6%). In multivariate analysis, only perforator territory infarction (PTI) on postoperative diffusion-weighted imaging (odds ratio (OR), 13; 95% confidence interval (CI), 4.9-32, p < 0.0001), and aneurysm locations (paraclinoid (OR, 6.9; 95% CI, 3.1-15, p < 0.0001), basilar artery (OR, 4.5; 95% CI, 1.5-14, p = 0.008), vertebral artery (OR, 11; 95% CI, 3.3-34, p < 0.0001)) were related to neurological worsening. Multivariate analysis showed that statin use (OR, 12; 95% CI, 3.8-39, p < 0.0001) and aneurysm locations (internal carotid artery-posterior communicating artery (OR, 3.9; 95% CI, 1.8-8.2, p < 0.0001) and basilar artery (OR, 6.3; 95% CI, 2.3-17, p = 0.008)), and aneurysm size >10 mm (OR, 5.3; 95% CI, 1.8-15, p = 0.003) were related to PTI. Although all SMUIAs should be carefully considered whether to be treated, those with statins, specific locations, and larger sizes should perhaps be more meticulously contemplated, and neurosurgeons should continue to avoid PTI.

Surgical Treatment of Middle Cerebral Artery Aneurysms: Aneurysm Location and Size Ratio as Risk Factors for Neurologic Worsening and Ischemic Complications

BACKGROUND

Regardless of acceptable surgical results of middle cerebral artery aneurysms (MCAs), MCA territory infarction (MCATI) remains a major obstacle to achieving a good outcome. We investigated the MCATI in patients with surgically treated MCA aneurysms.

METHODS

The data of 286 consecutive patients with 322 MCA aneurysms were evaluated retrospectively. The aneurysm location was classified as early frontal cortical branch (EFCB), early temporal cortical branch (ETCB), bifurcation or trifurcation (M1-2), and distal aneurysms on the insular, opercular, or cortical segments of the MCA (distal MCA). Neurologic worsening was defined as an increase in 1 or more modified Rankin Scale (mRS) scores.

RESULTS

Multivariate analysis identified EFCB location as the sole risk factor for MCATI (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.2-12; P = 0.021) and MCATI (OR, 18; 95% CI, 2.8-117; P = 0.002) and a larger size ratio (OR, 1.4; 95% CI, 1.1-1.8; P = 0.019) were related to 12-month neurologic worsening (n = 6; 1.9%). During follow-up (median, 885 days; interquartile range, 485-1229 days), posttreatment rupture and aneurysm recurrence were not observed.

CONCLUSIONS

In the present study, compared with M1-2 aneurysms, MCATIs were observed more frequently in EFCB aneurysms, and the presence of MCATI and a larger size ratio were related to 12-month neurologic worsening in patients with surgically treated MCA aneurysms.

Subarachnoid hemorrhage after surgical treatment of unruptured intracranial aneurysms

OBJECTIVE Only a few previous studies have investigated subarachnoid hemorrhage (SAH) after surgical treatment in patients with unruptured intracranial aneurysms (UIAs). Given the improvement in long-term outcomes of embolization, more extensive data are needed concerning the true rupture rates after microsurgery in order to provide reliable information for treatment decisions. The purpose of this study was to investigate the incidence of and risk factors for postoperative SAH in patients with surgically treated UIAs. METHODS Data from 702 consecutive patients harboring 852 surgically treated UIAs were evaluated. Surgical treatments included neck clipping (complete or incomplete), coating/wrapping, trapping, proximal occlusion, and bypass surgery. Clippable UIAs were defined as UIAs treated by complete neck clipping. The annual incidence of postoperative SAH and risk factors for SAH were studied using Kaplan-Meier survival analysis and Cox proportional hazards regression models. RESULTS The patients' median age was 64 years (interquartile range [IQR] 56-71 years). Of 852 UIAs, 767 were clippable and 85 were not. The mean duration of follow-up was 731 days (SD 380 days). During 1708 aneurysm years, there were 4 episodes of SAH, giving an overall average annual incidence rate of 0.23% (95% CI 0.12%-0.59%) and an average annual incidence rate of 0.065% (95% CI 0.0017%-0.37%) for clippable UIAs (1 episode of SAH, 1552 aneurysm-years). Basilar artery location (adjusted hazard ratio [HR] 23, 95% CI 2.0-255, p = 0.0012) and unclippable UIA status (adjusted HR 15, 95% CI 1.1-215, p = 0.046) were significantly related to postoperative SAH. An excellent outcome (modified Rankin Scale score of 0 or 1) was achieved in 816 (95.7%) of 852 cases overall and in 748 (98%) of 767 clippable UIAs at 12 months. CONCLUSIONS In this large case series, microsurgical treatment of UIAs was found to be safe and effective. Aneurysm location and unclippable morphologies were related to postoperative SAH in patients with surgically treated UIAs.

Giant Intracranial Aneurysms: Surgical Treatment and Analysis of Risk Factors

OBJECTIVE

To study clinical outcome of giant intracranial aneurysms (diameter ≥25 mm) treated with different surgical modalities and to analyze factors affecting prognosis.

METHODS

A retrospective analysis was performed of 204 consecutive patients with giant intracranial aneurysms who underwent surgical treatment in our department from 1995 to 2008. Clinical outcome was evaluated with the Glasgow Outcome Scale.

RESULTS

Surgical modalities included direct aneurysm neck clipping in 102 patients (50.0%), parent artery reconstruction in 51 patients (25.0%), proximal artery ligation in 23 patients (11.3%; 4 patients combined with revascularization), trapping in 26 patients (12.7%), and wrapping in 2 patients (1.0%). Follow-up data were available for 181 patients (88.7%), with a mean follow-up period of 62 months (range, 12-164 months). A good outcome (Glasgow Outcome Scale score 5) was observed in 114 patients (63.0%), and a poor outcome (Glasgow Outcome Scale score 1-4) was observed in 67 patients (37.0%). Independent factors that affected prognosis were age and location of aneurysm. Older age (≥50 years) and location of aneurysm in posterior circulation were associated with poor outcome. In 85 patients with preoperative subarachnoid hemorrhage, patients with a higher Hunt and Hess grade (≥3) had a worse outcome compared with patients with a low Hunt and Hess grade (1 or 2). Surgical modalities and other factors were not significantly associated with clinical outcome.

CONCLUSIONS

Giant intracranial aneurysms are effectively treated with craniotomy and surgical treatment. Older age, aneurysm location in posterior circulation, and higher Hunt and Hess grade are risk factors affecting prognosis.

Microsurgical Clipping of Unruptured Intracranial Aneurysms: A Single Surgeon's Experience over 16 Years

BACKGROUND

Unruptured intracranial aneurysms (UIAs) have become an issue of greater significance as their detection rates have increased over the years. We present the overall experience of microsurgical clipping of unruptured aneurysms by a single surgeon over a period of more than 16 years.

METHODS

The clinical and radiologic data were reviewed retrospectively. Clinical outcome at follow-up was assessed with Glasgow Outcome Scale, and angiograms were reviewed for the degree of occlusion.

RESULTS

One hundred ninety-six patients with 221 UIAs were included in the analysis. The median age of patients was 54 years, with a female preponderance. Eighty-two percent of the patients had chronic headache on presentation. Middle cerebral artery aneurysms (32.2%) and posterior-inferior-cerebellar-artery aneurysms (46.1%) were most common in the anterior and posterior circulation, respectively. The perioperative complication rate was 17.3%. The overall surgical morbidity and mortality were 2.1% and 1.5%, respectively. With median follow-up of 11.3 months, 82% of patients were almost asymptomatic with a complete occlusion rate of 94%. The proportion of UIAs being coiled has significantly increased in the last decade, with a concomitant increase in the risk of poor clinical outcome after surgery.

CONCLUSION

Surgical clipping is effective and can provide a good long-term outcome. The most commendable consequence that it provides is a better long-term occlusion rate. The experience of the individual surgeon is important for a superior and enduring overall outcome. An increase in the rate of coiling in recent years has affected the outcome rate after surgery that calls for further evaluation.