[Recommendations for the management of unruptured intracranial aneurysms]

Microsurgical and endovascular treatment of un-ruptured cerebral aneurysms by European hybrid neurosurgeons to balance surgical skills and medical staff management

Background

In Europe, aneurysm treatment performed by dually trained neurosurgeons is extremely scarce. We provide outcome data for un-ruptured aneurysm patients treated at a European hybrid center to prove that hybrid neurosurgeons achieve clinical and angiographical results allowing to integrate hybrid neurosurgery into routine aneurysm treatment. This will not only help to maintain neurovascular microsurgical skills but will influence staff costs in related hospitals.

Methods

We retrospectively analyzed all consecutively treated un-ruptured aneurysm patients between 2000 and 2016. The decision-making took into account the pros and cons of both modalities and considered patient and aneurysm characteristics. Clinical outcome was assessed by the modified Rankin scale (mRS). Occlusion rates were stratified into grade I for 100%, grade II for 99–90%, and grade III for <90% occlusion. To account for the introduction of stents, two treatment periods (p1, 2000 to 2008; p2, 2009 to 2016) were defined.

Results

The study population consisted of 274 patients (median age 55 years) harboring 338 un-ruptured aneurysms. Microsurgery (MS) was performed in 51.8% and endovascular therapy (EVT) in 43.1%; 5.1% required combined treatment. Overall, 93% showed a favorable clinical outcome (mRS 0–2), 94.3% after MS and 91.5% after EVT. Grade I aneurysm occlusion was achieved in 82.6% patients, 91.9% after MS and 72.9% after EVT. Procedure-related complications occurred after MS in 5.6% and after EVT in 4.4% patients. Mortality was recorded for five (1.8%) patients, one patient after MS and four after EVT. For the EVT cohort, significant improvement from p1 to p2 was seen with clinical outcomes (P=0.030, RR = 0.905, CI: 0.8351–0.9802) and occlusion rates (P=0.039, RR = 0.6790, CI: 0.499–0.923).

Conclusion

Hybrid neurosurgeons achieve qualified clinical and angiographic results. Dual training will allow to maintain neurovascular caseloads and preserve future aneurysm treatment within neurosurgery. Furthermore economic benefits could be observed in hospital management.

Small Aneurysms Should Be Clipped?

Background:

Cerebral aneurysm prevalence may vary from 0.4% to 10%. The decision to treat or not incidental aneurysms remains controversial, especially when the lesions are small (<5 mm). Many recent publications are demonstrating that these lesions often bleed.

Methods:

We reviewed admitted patients with angiographic studies submitted to intracranial aneurysm surgical treatment from April 2012 to July 2013 in the Neurosurgery Department of São Paulo Medical School University (15 months), to define the rate and risk of bleeding. In addition, we proceeded literature review with collected 357 papers (past 5 years) which were selected 50 that were focused on our research. Clinical patients’ status at the time of discharge was evaluated with the modified Rankin scale.

Results:

A series of 118 cases of surgically clipped aneurysms was analyzed: 73.7% woman; Ruptured (61 cases, 51%); middle cerebral artery (51 cases, 43%) was the more common aneurysm. Small size (<5 mm) was 25 cases (21%); that 2 died (16%), 3 (25%) with severe disability,restricted to bed and dependent on nursing care; blood pressure was the main risk factors (56%); and an aneurysm <2 mm (100%) was ruptured.

Conclusion:

The number of small aneurysms in our series was significant (25 cases, 21%), and its rate of bleeding was high (25 cases, 48%), resulting in death and disability in a significant number of cases. Our tendency is for surgical treatment when it is associated with risk factors.

Comparison of Clinical Outcomes of Intracranial Aneurysms: Procedural Rupture versus Spontaneous Rupture

BACKGROUND AND PURPOSE

Procedural rupture of an intracranial aneurysm is a devastating complication in endovascular treatment. The purpose of this study was to evaluate the clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms compared with those with spontaneously ruptured aneurysms.

MATERIALS AND METHODS

A retrospective review was performed for 1340 patients with 1595 unruptured saccular intracranial aneurysms that underwent endovascular coil embolization between February 2010 and December 2014. The clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms were compared with those of 198 patients presenting with spontaneously ruptured aneurysms.

RESULTS

In this series, procedural rupture developed in 19 patients (1.4% per patient and 1.2% per aneurysm), and the morbidity related to procedural rupture was 26.3% (95% confidence interval, 8.5%-61.4%) with no mortality. Hunt and Hess scale grades and hospitalization days of patients with procedural rupture were equivalent to those of patients presenting with spontaneous aneurysm rupture. Subsequent treatment procedures after hemorrhage (including lumbar drainage, extraventricular drainage, decompressive craniectomy, and permanent shunt) showed no difference between the 2 groups. The hemorrhage volumes were smaller in the procedural-rupture group (P = .03), and the endovascular vasospasm therapies tended to be more frequently required in the spontaneous aneurysm-rupture group (P = .08). At postictus 6 months, the proportion of modified Rankin Scale scores of ≥2 were lower in the procedural-rupture group (5.3% versus 26.8%, P = .049). In multivariate analysis, spontaneous aneurysm rupture was a significant risk factor for worse clinical outcome (OR = 14.9; 95% CI, 1.2-193.1; P = .039).

CONCLUSIONS

This study showed better clinical outcomes in the procedural-rupture group. Even though there is a potential chance of aneurysm rupture during treatment, the clinical outcomes after procedural bleeds seem to be more favorable than those of spontaneous rupture.

Long-Term Functional Outcome of Symptomatic Unruptured Intracranial Aneurysms in an Interdisciplinary Treatment Concept

OBJECTIVE

In symptomatic unruptured intracranial aneurysms (UIAs), data on long-term functional outcome are sparse in the literature, even in the light of modern interdisciplinary treatment decisions. We therefore analyzed our in-house database for prognostic factors and long-term outcome of neurologic symptoms after microsurgical/endovascular treatment.

METHODS

Patients treated between 2000 and 2016 after interdisciplinary vascular board decision were included. UIAs were categorized as symptomatic in cases of cranial nerve or brainstem compression. Symptoms were categorized as mild/severe. Long-term development of symptoms after treatment was assessed in a standardized and independent fashion.

RESULTS

Of 98 symptomatic UIAs (microsurgery/endovascular 43/55), 84 patients presented with cranial nerve (NII-VI) compression and 14 patients with brainstem compression symptoms. Permanent morbidity occurred in 9% of patients. Of 119 symptoms (mild/severe 71/48), 60.4% recovered (full/partial 22%/39%) and 29% stabilized by the time of last follow-up; median follow-up was 19.5 months. Symptom recovery was higher in the long-term compared with that at discharge (P = 0.002). Optic nerve compression symptoms were less likely to improve compared with abducens nerve palsies and brainstem compression. Prognostic factors for recovery were duration and severity of symptoms, treatment modality (microsurgery) and absence of ischemia in the multivariate analysis.

CONCLUSIONS

This recent study presents for the first time a detailed analysis of relevant prognostic factors for long-term recovery of cranial nerve/brainstem compression symptoms in an interdisciplinary treatment concept, which was excellent in most patients, with lowest recovery rates in optic nerve compression. Symptom recovery was remarkably higher in the long-term compared with recovery at discharge.

Estimated low risk of rupture of small-sized unruptured intracranial aneurysms (UIAs) in relation to intracranial aneurysms in patients with subarachnoid haemorrhage

OBJECTIVE

International guidelines for the management of unruptured intracranial aneurysms (UIAs) recommend observation in aneurysms <10 mm due to the estimated low risk of rupture. The aim of our study was analyse the data of recently treated patients with ruptured cerebral aneurysms with the special focus on size and configuration in view of the frequency scale in a daily routine setting.

METHODS

We reviewed the data of all patients with aneurysmal subarachnoid haemorrhage (SAH) during the last 24 months at our institution. Configuration and size of the aneurysms were measured. Clinical data were collected using the following classifications for analysis: Hunt and Hess (H&H), modified Rankin Scale (mRS) and Fisher classification.

RESULTS

Data of 135 patients with aneurysmal SAH (98 women, 37 men; ratio 2.6:1) were analysed. Analysis showed that 19 aneurysms (14 %) were >10 mm (mean size, 19.2 mm) and 116 aneurysms (85.9 %) <10 mm (mean size, 6.2 mm). In total, 112 were categorised as berry-like configured aneurysms (n = 113 <10 mm, n = 3 >10 mm), 18 as multi-lobar (n = 16 <10 mm, n = 2 >10 mm) and 5 as fusiform (n = 4 <10 mm, n = 1, >10 mm).

CONCLUSION

Since the results of our study showed that the majority of the aneurysms are <10 mm (mean, 6.2 mm), it is justified to challenge the recommendations of the international guidelines in a daily routine setting. We believe that the published data are not convincing enough to play a guidance role in daily routine. Due to improving surgical and endovascular techniques with satisfying results and the high number of ruptured small aneurysms, we believe a change in attitude in management of small-sized aneurysms is needed. Further diagnostic models are needed to determine the risk of rupture of intracranial aneurysms properly to obtain adequate treatment for UIAs.

[Intracerebral aneurysm--treatment options, informed consent, and legal aspects]

All medical subspecialties and, in particular, high-tech field neurosurgery are subject to continuous change in therapeutic concepts due to novel treatment options emerging through research and evolution in the field. Hence, the question arises if the patient's informed consent needs to be adjusted in the face of multiple therapeutic options with different configurations of risk/benefit relationships. In this paper we discuss different therapeutic scenarios with regard to ruptured intracerebral aneurysms (RIA) and unruptured intracerebral aneurysms (UIA), and we advise the medical doctor involved in the process. Indeed, experienced neurosurgeons and endovascular interventionalists are very familiar with the management of these scenarios; likewise, interns, residents, and otherwise affiliated physicians may be faced with these situations. In general, asymptomatic and mentally capacitated patients as well as legal guardians of minor patients and of mentally incapacitated patients with incidental aneurysms and more than one therapeutic option need to be accurately informed about the advantages and disadvantages of the treatment options available to them. In case of emergency or when treating a mentally disabled patient who is incapable of making a sound judgment and has no legal guardian, the attending doctor will have to choose the best possible treatment option.

Treatment results for complex middle cerebral artery aneurysms. A prospective single-center series

BACKGROUND

The objective was to assess the surgical results in complex middle cerebral artery (MCA) aneurysms.

METHODS

From 1999 to 2009 the data of 330 patients with ruptured and unruptured MCA aneurysms were included into a prospective database. Degree of aneurysm occlusion and clinical outcomes were analysed after 271 surgical and 59 endovascular treatments assigned in an interdisciplinary approach. Aneurysms of large size and/or broad base, calcifications, and incorporation of M1 or M2 segments into the aneurysm base were defined as complex.

FINDINGS

At least one of the criteria for complexity mentioned above was met in 97.8% of the MCA aneurysms that were treated surgically and in 76.3% that were treated endovascularly. In MCA aneurysms treated surgically, complete occlusion was achieved in 264 of the 271 (97.4%) aneurysms. Aneurysms with remnants after surgical treatment were significantly larger in size (17 ± 3 mm vs 7 ± 5 mm), and exhibited significantly more often parent vessel involvement (M1: 86% vs 27%; M2: 100% vs 67%) compared with the group of aneurysms that could be treated without remnant. Compared with our institutional data (52.5% complete occlusion rate) and data of the literature (up to 46.1% complete occlusion rate), the occlusion rates of endovascularly treated MCA aneurysms were significantly lower compared with MCA aneurysms treated surgically.

CONCLUSIONS

Surgical treatment of ruptured and unruptured MCA aneurysms results in a significantly higher rate of complete aneurysm occlusion compared with endovascular treatment, despite a high rate of complex aneuryms in the surgically treated group.

Primary epileptogenic unruptured intracranial aneurysms: incidence and effect of treatment on epilepsy

BACKGROUND

Seizures as the unique initial manifestation of unruptured intracranial aneurysms have rarely been documented and not systematically described until now.

OBJECTIVE

The purpose of this large retrospective analysis was to focus on the incidence of primary epileptogenic aneurysms and the influence of treatment on epilepsy.

METHODS

Within a 16-year period, 347 unruptured aneurysms were surgically treated at centers in Munich (1992-2002) and Düsseldorf (2003-2008), Germany. Of this patient population, 9 patients presented exclusively with epileptic seizures or epileptic equivalents. In 3 of them, a high-lying internal carotid artery aneurysm was diagnosed that was buried in the parahippocampal gyrus. In 4 patients, a middle cerebral artery aneurysm also created contact with the mediotemporal lobe adjacent to the parahippocampal gyrus. An anterior communicating artery aneurysm and a pericallosal artery aneurysm were diagnosed in 2 additional patients. Two patients with a middle cerebral artery aneurysm were initially incompletely occluded with Guglielmi detachable coils and continued to have epilepsy after the intervention. In all but 1 patient, the aneurysms were clipped and completely removed.

RESULTS

In all 8 patients operated on, there was no sign of hemorrhage intraoperatively but cortical gliosis was seen around the dome of the aneurysm. In all cases, the aneurysm and the surrounding gliosis, if existent, were surgically removed. Freedom from seizures without medication resulted for all patients after microsurgery.

DISCUSSION

Seizures as a presenting symptom of unruptured intracranial aneurysms are rare. There seems to be a preponderance of aneurysms anatomically related to the temporomedial region. Elimination of the aneurysm and perifocal gliosis provides the possibility of a cure for the epilepsy.

Monitoring of motor evoked potentials compared with somatosensory evoked potentials and microvascular Doppler ultrasonography in cerebral aneurysm surgery

OBJECT

The aims of this study were to compare the efficiency of motor evoked potentials (MEPs), somatosensory evoked potentials (SSEPs), and microvascular Doppler ultrasonography (MDU) in the detection of impending motor impairment from subcortical ischemia in aneurysm surgery; to determine their sensitivity for specific intraoperative events; and to compare their impact on the surgical strategy used.

METHODS

Motor evoked potentials, SSEPs, and MDU were monitored during 100 operations for 129 aneurysms in 95 patients. Intraoperative events, monitoring results, and clinical outcome were correlated in a prospective observational design. Motor evoked potentials indicated inadequate temporary clipping, inadvertent occlusion, inadequate retraction, vasospasm, or compromise to perforating vessels in 21 of 33 instances and deteriorated despite stable SSEPs in 18 cases. Microvascular Doppler ultrasonography revealed inadvertent vessel occlusion in eight of 10 cases and insufficient clipping in four of four cases. Stable evoked potentials (EPs) allowed safe, permanent vessel occlusion or narrowing despite reduced flow on MDU in five cases. Two patients sustained permanent and 10 showed transient new weakness, which had been detected by SSEPs in two of 12 patients and MEPs in 10 of 11 monitored cases. The surgical strategy was directly altered in 33 instances: by MEPs in 16, SSEPs in four, and MDU in 13.

CONCLUSIONS

Monitoring of MEPs is superior to SSEP monitoring and MDU in detecting motor impairment, particularly that from subcortical ischemia. Microvascular Doppler ultrasonography is superior to EP monitoring in detecting inadvertent vessel occlusion, but cannot assess remote collateral flow. Motor evoked potentials are most sensitive to all other intraoperative conditions and have a direct influence on the course of surgery in the majority of events. A controlled study design is required to confirm the positive effect of monitoring on clinical outcome in aneurysm surgery.