Clinical outcome of paraclinoid internal carotid artery aneurysms after microsurgical neck clipping in comparison with endovascular embolization

Inflow Angle and Height-Width Ratio are Predictors of Incomplete Occlusion at One and Two Years After Flow Diverter Treatment for Small- and Medium-Sized Internal Carotid Artery Aneurysms

OBJECTIVE

We investigated the association between the inflow angle of aneurysms and their occlusion status at 1 and 2 years after flow diverter (FD) treatment.

METHODS

We retrospectively analyzed 42 consecutive patients from a single center with 43 untreated, unruptured internal carotid artery (ICA) proximal to communicating segment, saccular aneurysms sized <12 mm.

RESULTS

At 1 year posttreatment, the complete occlusion (CO) rate was 58.1%. On univariate analyses, the proportion of inflow angle >90° was significantly lower in the CO group than in the incomplete occlusion group (20.0% VS. 83.3%; P < 0.001). The CO incidence decreased with a height-width (H/W) ratio of <1.2 (P = 0.059). On multivariate analysis, an H/W ratio of <1.2 (odds ratio [OR], 0.076; P = 0.027) and an inflow angle of >90° (OR, 0.020; P = 0.0011) significantly influenced CO at 1 year post FD. At 2 years posttreatment, the CO rate was 76.3% (29/38 cases with available follow-up data). On univariate analyses, in the CO group compared to the incomplete occlusion group, the proportion of H/W ratio <1.2 was significantly lower (P = 0.005) and the proportion of inflow angle >90° was significantly lower (P = 0.021); aneurysm dome size tended to be larger (8.5 mm vs. 7.1 mm; P = 0.080). On multivariate analysis, an H/W ratio <1.2 (OR, 0.042; P = 0.015) and an inflow angle >90° (OR: 0.088; P = 0.031) significantly influenced CO at 2 years post FD.

CONCLUSIONS

The inflow angle of >90° and H/W ratio <1.2 may significantly influence the CO rate in small- or medium-sized internal carotid artery aneurysms 1 and 2 years post FD.

Endovascular Treatment and Microsurgical Clipping for the Management of Paraclinoid Intracranial Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVE

We aimed to compare the efficacy and safety of microsurgical clipping versus endovascular treatment (EVT) for paraclinoid aneurysms.

METHODS

A systematic search for studies including patients with paraclinoid aneurysms treated with a microsurgical or endovascular technique was conducted in 6 databases from inception to February 2022. Efficacy outcomes included complete angiographic occlusion at last follow-up, favorable functional outcome, and recurrence of the aneurysm. For safety, we assessed a composite of intraoperative and postoperative complications. Data were pooled using a random-effects model.

RESULTS

A total of 95 studies including 6711 patients, 3029 in the surgical group and 3682 in the EVT group were found. Pooled rates of complete occlusion were 94% (95% CI 91%-96%; I2 = 0%) in the surgical group and 69% (95% CI 63%-74%; I2 = 79%) in the EVT group, respectively. The favorable functional outcome rate was 86% (95% CI 76%-92%; I2 = 72%) with surgical treatment and 95% (95% CI 92%-97%; I2 = 61%) with EVT. The rate of aneurysm recurrence with surgical treatment was 1% (95% CI 0%-4%; I2 = 0%) and 12% (95% CI 9%-16%; I2 = 57%) with EVT. The composite safety outcome rate in the surgical group was 24% (95% CI 18%-30%; I2 = 90%) and 10% (95% CI 8%-13%; I2 = 71%) in the EVT group.

CONCLUSIONS

Our findings suggest that microsurgical clipping seems to have a higher efficacy than EVT in terms of angiographic occlusion and aneurysm recurrence; however, EVT seems to be safer in terms of intraoperative and postoperative complications. Considering the heterogeneity and low-level evidence of the data available, further prospective randomized studies are warranted to confirm our findings.

Increased Carotid Siphon Tortuosity Is a Risk Factor for Paraclinoid Aneurysms

Background

Geometrical factors associated with the surrounding vasculature can affect the risk of aneurysm formation. The aim of this study was to determine the association between carotid siphon curvature and the formation and development of paraclinoid aneurysms of the internal carotid artery.

Methods

Digital subtraction angiography (DSA) data from 42 patients with paraclinoid aneurysms (31 with non-aneurysmal contralateral sides) and 42 age- and gender-matched healthy controls were analyzed, retrospectively. Morphological characteristics of the carotid siphon [the posterior angle (α), anterior angle (β), and Clinoid@Ophthalmic angle (γ)] were explored via three-dimensional rotational angiography (3D RA) multiplanar reconstruction. The association between carotid siphon morphology and the formation of paraclinoid aneurysms was assessed through univariate analysis. After this, logistic regression analysis was performed to identify independent risk factors for aneurysms.

Results

Significantly smaller α, β, and γ angles were reported in the aneurysmal carotid siphon group when compared with the non-aneurysmal contralateral healthy controls. The β angle was best for discriminating between aneurysmal and non-aneurysmal carotid siphons, with an optimal threshold of 18.25°. By adjusting for hypertension, smoking habit, hyperlipidemia, and diabetes mellitus, logistic regression analysis demonstrated an independent association between the carotid siphons angles α [odds ratio (OR) 0.953; P < 0.05], β (OR 0.690; P < 0.001), and γ (OR 0.958; P < 0.01) with the risk of paraclinoid aneurysms.

Conclusions

The present findings provide evidence for the importance of morphological carotid siphon variations and the likelihood of paraclinoid aneurysms. These practical morphological parameters specific to paraclinoid aneurysms are easy to assess and may aid in risk assessment in these patients.

Lower limb weakness with gyrus rectus hematoma: an unusual presentation of paraclinoid aneurysm; a case report with review of literature

Lower limb weakness is usually a feature of ruptured anterior communicating (ACom) aneurysms due to spasm of the anterior cerebral arteries. Paraclinoid aneurysms, in addition to other cardinal features of subarachnoid haemorrhage (SAH), usually present with headache and visual field defects due to compression of the optic pathway. We report a case of left paraclinoid aneurysm presenting with right lower limb weakness and gyrus rectus hematoma without SAH. The aneurysm was long, passing beneath the optic nerve to emerge in the inter-optic cistern, leading to such atypical presentation. The aneurysm was clipped successfully after drilling the clinoid. As per our knowledge, such a clinical presentation of paraclinoid aneurysm has not been reported in the literature till date.

Contralateral approach for the treatment of a distal supraclinoid aneurysm: a technical case report

Background: When treating intracranial aneurysms with open microsurgery, rare cases arise in which an ipsilateral approach leads to poor visualization, lack of proximal control, or potential damage to nearby vital structures due to the anatomy of the aneurysm. Case Description: We describe a patient with a small, unruptured aneurysm arising from the medial aspect of the distal supraclinoid internal carotid artery (ICA), just below the ICA bifurcation. A contralateral surgical approach was chosen because our view of the aneurysm from an ipsilateral approach would have been obstructed by the ICA. The contralateral approach provided excellent exposure of the aneurysm and allowed for precise clip placement without complications. Conclusions: Contralateral approaches may be a good option for some small medially pointing aneurysm of large proximal cerebral arteries.

Korean Clinical Practice Guidelines for Aneurysmal Subarachnoid Hemorrhage

Despite advancements in treating ruptured cerebral aneurysms, an aneurysmal subarachnoid hemorrhage (aSAH) is still a grave cerebrovascular disease associated with a high rate of morbidity and mortality. Based on the literature published to date, worldwide academic and governmental committees have developed clinical practice guidelines (CPGs) to propose standards for disease management in order to achieve the best treatment outcomes for aSAHs. In 2013, the Korean Society of Cerebrovascular Surgeons issued a Korean version of the CPGs for aSAHs. The group researched all articles and major foreign CPGs published in English until December 2015 using several search engines. Based on these articles, levels of evidence and grades of recommendations were determined by our society as well as by other related Quality Control Committees from neurointervention, neurology and rehabilitation medicine. The Korean version of the CPGs for aSAHs includes risk factors, diagnosis, initial management, medical and surgical management to prevent rebleeding, management of delayed cerebral ischemia and vasospasm, treatment of hydrocephalus, treatment of medical complications and early rehabilitation. The CPGs are not the absolute standard but are the present reference as the evidence is still incomplete, each environment of clinical practice is different, and there is a high probability of variation in the current recommendations. The CPGs will be useful in the fields of clinical practice and research.

Risk Factors to Predict Neurologic Complications After Endovascular Treatment of Unruptured Paraclinoid Aneurysms

OBJECTIVE

Unruptured paraclinoid aneurysms are often asymptomatic, and endovascular coiling is the main treatment. However, endovascular treatment of these lesions still leads to neurologic complications. We aimed to identify predictors of neurologic complications in these lesions.

METHODS

We retrospectively analyzed patients with unruptured paraclinoid aneurysms who were treated with endovascular coiling between January 2014 and December 2015. A neurologic complication was defined as any transient or permanent increase in the modified Rankin Scale score after aneurysm embolization. Univariate and mulitivariate logistic regression analyses were performed to assess the risk factors of neurologic complications.

RESULTS

Of the 443 unruptured paraclinoid aneurysms that were included in this study, the incidence of neurologic complications was 5.2%. Neurologic complications were highly correlated with hypertension (odds ratio [OR], 3.147; 95% confidence interval [CI], 1.217-8.138; P = 0.018), cerebral ischemic comorbidities (OR, 3.396; 95% CI, 1.378-8.374; P = 0.008), and aneurysm size (OR, 7.714; 95% CI, 1.784-31.635; P < 0.001), and irregular shape (OR, 3.157; 95% CI, 1.239-8.043; P = 0.016) in the univariate analysis. Cerebral ischemic comorbidities (OR, 2.837, 95% CI, 1.070-7.523; P = 0.036) and aneurysm size as dichotomous variables (OR, 7.557; 95% CI, 2.975-19.198; P < 0.001) were strongly correlated with neurologic complications in the final adjusted multivariate logistic analysis.

CONCLUSIONS

Unruptured paraclinoid aneurysms after endovascular treatments had 5.2% of neurologic complications. Cerebral ischemic comorbidities and aneurysm size were predictors of neurologic complications.

Clipping in Awake Surgery as End-Stage in a Complex Internal Carotid Artery Aneurysm After Failure of Multimodal Endovascular and Extracranial-Intracranial Bypass Treatment

BACKGROUND

Intracranial carotid artery aneurysm can be treated via microsurgical or endovascular techniques. The optimal planning is the result of the careful patient selection through clinical, anatomic, and angiographic analysis.

CLINICAL PRESENTATION

We present a case of ruptured internal carotid artery (ICA) aneurysm that became a complex aneurysm after failure of multi-endovascular and surgery treatment. We describe complete trapping in awake craniotomy after failure of coiling, stenting, and bypassing.

CONCLUSIONS

ICA aneurysms could become complex aneurysms following multi-treatment failure. Endovascular approaches to treat ICA aneurysms include coiling, stenting, flow diverter stenting, and stenting-assisted coiling technique. The role of surgery remains relevant. To avoid severe neurologic deficits, recurrence, and the need of retreatment, a multidisciplinary discussion with experienced endovascular and vascular neurosurgeons is mandatory in such complex cases.

Larger inflow angle and incomplete occlusion predict recanalization of unruptured paraclinoid aneurysms after endovascular treatment

BACKGROUND

Unruptured paraclinoid aneurysms have a high incidence of aneurysm recanalization (AR) after endovascular treatment. We aimed to identify the incidence and predictors of AR in these lesions.

METHODS

We retrospectively analyzed consecutive patients with unruptured paraclinoid aneurysms who underwent endovascular treatment between January 2013 and December 2014. Patients with fusiform aneurysms, dissection aneurysms, traumatic aneurysms, or without digital subtraction angiography (DSA) at follow-up, were excluded. AR was defined as any aneurysm remnant that had increased in size or contrast filling that was observed via DSA at the follow-up. Univariate and multivariate logistic regression analyses were performed to assess the predictors of AR.

RESULTS

We included 145 patients with 150 unruptured paraclinoid aneurysms in the analysis. The incidence of AR was 8.7% (95% confidence interval (CI): 4.7-13.3%) at a mean follow-up of 7.4 months. In the univariate analysis, AR was associated with aneurysm size (odd ratio (OR): 6.098; 95% CI: 1.870-19.886; p = 0.003), location (OR: 3.88; 95% CI: 1.196-12.583; p = 0.024), inflow angle (OR: 6.852; 95% CI: 1.463-32.087; p = 0.015), and Raymond scale (OR: 12.473; 95% CI: 2.7496-56.59; p < 0.001). In the adjusted multivariate analysis, AR was independently predicted by Raymond scale (OR: 9.136; 95% CI: 1.683-49.587; p = 0.001) and inflow angle (OR: 16.159; 95% CI: 3.211-81.308; p = 0.01).

CONCLUSIONS

Unruptured paraclinoid aneurysms had a high incidence of AR after endovascular treatment. An inflow angle of ≥90 degrees and incomplete occlusion were significant predictors of AR.

Clinical and Radiological Outcomes After Treatment of Unruptured Paraophthalmic Internal Carotid Artery Aneurysms: a Comparative and Pooled Analysis of Single-Center Experiences

OBJECTIVE

Unruptured paraophthalmic aneurysms present unique challenges, and the ideal management remains unknown.

METHODS

We performed a pooled analysis of single-center experiences to compare the risks and effectiveness involving patients with unruptured paraophthalmic aneurysms treated with clipping, coiling alone, stent-assisted coiling, and flow-diversion. The MEDLINE database was searched and thirty-three series (including our institutional experience) were included.

RESULTS

Clipping caused more intracranial hemorrhage (ICH) and neurologic complications (NCs) than coiling alone (ICH: odds ratio [OR] = 3.058, P = 0.013; NC: OR = 5.809, P < 0.001), stent-assisted coiling (ICH: P = 0.018; NC: OR = 7.367, P < 0.001), and flow-diversion (ICH: P = 0.006; NC: OR = 16.954, P < 0.001). Clipping also caused more unfavorable visual outcomes than both coiling alone (OR = 3.037, P = 0.001) and stent-assisted coiling (OR = 6.055, P = 0.005). Clipping resulted in a lower reoperation rate than coiling alone in large/giant aneurysm group, which approached statistical significance (OR = 0.133, P = 0.057). Clipping, stent-assisted coiling, and flow-diversion all showed higher occlusion rates compared with coiling alone (OR [clipping vs. coiling alone] = 2.852, P ≤ 0.001; OR [coiling alone vs. stent-assisted coiling] = 0.302, P = 0.003; OR [coiling alone vs. flow-diversion] = 0.400, P = 0.013). Flow-diversion showed comparative complication rate, clinical outcomes, and angiographic result compared with stent-assisted coiling. No significant differences were found among all 4 treatment modalities on mortality and poor outcome.

CONCLUSIONS

Endovascular therapies have benefits over surgical clipping in terms of fewer intracranial hemorrhage complications, fewer NCs, and lower unfavorable visual outcome rate. Flow diversion showed comparative safety and effectiveness to stent-assisted coiling, and they both achieved better radiologic results than coiling alone. Further validation by randomized cohort studies is still needed to provide robust evidence.