Endovascular management of unruptured intracranial aneurysms: does outcome justify treatment?

Trapping, dome puncture, and direct suction decompression in conjunction with assistant superficial temporal artery- middle cerebral artery bypass to clip giant internal carotid artery bifurcation aneurysm

Background:

Very large and giant aneurysms (≥20 mm) of the internal carotid artery (ICA) bifurcation (ICAbif) are definitely rare, and optimal treatment is not established. Endovascular treatments are reported as suboptimal due to difficulties of complete occlusion and tendencies to recanalization. Therefore, direct surgery remains an effective strategy if the clipping can be performed safely and reliably, although very difficult.

Case Description:

Two cases of ICAbif aneurysms (>20 mm) were treated. Prior assistant superficial temporal artery (STA)-middle cerebral artery (MCA) bypass was performed to avoid ischemic complications during prolonged temporary occlusion of the arteries in both cases. In Case 1 (22-mm aneurysm), the dome was inadvertently torn in applying the clip because trapping had resulted in insufficient decompression. Therefore, in Case 2 (28-mm aneurysm), almost complete trapping of the aneurysm and subsequent dome puncture was performed, and the aneurysm was totally deflated by suction from the incision. This complete aneurysm decompression allowed safe dissection and successful clipping.

Conclusion:

Trapping, deliberate aneurysm dome puncture, and suction decompression from the incision in conjunction with assistant STA-MCA bypass can achieve complete aneurysm deflation, and these techniques enable safe dissection of the aneurysm and direct clipping of the aneurysm neck. Direct clipping with this technique for very large and giant ICAbif aneurysms may be the optimal treatment choice with the acceptable outcome if endovascular treatment remains suboptimal.

Successful obliteration of unclippable large and giant middle cerebral artery aneurysms following extracranial-intracranial bypass and distal clip application

Large to giant middle cerebral artery aneurysm is a challenging disease, especially when incorporating important perforating arteries. Surgical risk increases by perforator infarction and anatomical complexity. In this clinical setting, extensive consideration of surgical options is needed. The two cases described here were unruptured and had rather stable wall. Because of their large and giant size, hardness and incorporated arteries, it was not affordable to isolate them by means of clipping or trapping. The procedure as the alternative to conventional treatment modalities, extracranial-intracranial bypass followed by clipping of only the efferent artery successfully treated the aneurysms.

The interdisciplinary treatment of unruptured intracranial aneurysms

INTRODUCTION

The purpose of this article is to present the results of microsurgical clipping or endovascular coil obliteration of unruptured intracranial aneurysms (UIA), in a single cerebrovascular center with regard to successful obliteration and periprocedural complications.

METHODS

Data concerning patients with UIA were recorded in the neurovascular database of the neurosurgical department at the University of Frankfurt. The outcome of treatment was assessed with the modified Rankin Scale.

RESULTS

126 patients were treated by open surgery and 74 patients by endovascular coil obliteration. After treatment, the rate of new, mostly transient neurological deficits was 5%, and there were no deaths related to any treatment in this series. The outcome was good in 124 (98.4%) of the surgically treated patients and 73 (98.6%) of the endovascularly treated patients, and only 3 patients (1.5%) had a treatment-related unfavorable outcome. 98% of the treated aneurysms were satisfactorily obliterated. Seven endovascularly treated patients required retreatment because of coil compaction leading to recanalization of the aneurysm.

CONCLUSIONS

The majority of patients with unruptured intracranial aneurysms, even complex ones, can be treated by microsurgery or endovascular aneurysm obliteration with very good clinical results and a very low percentage of unfavorable outcomes. With careful patient selection and individualized assignment of the best form of treatment to each patient, we were able to achieve a low overall complication rate and a very high rate of obliteration in our specialized neurovascular center.

The TEAM trial: safety and efficacy of endovascular treatment of unruptured intracranial aneurysms in the prevention of aneurysmal hemorrhages: a randomized comparison with indefinite deferral of treatment in 2002 patients followed for 10 years

The management of patients with unruptured aneurysms remains controversial. Patients with unruptured aneurysms may suffer intracranial haemorrhage, but the incidence of this event is still debated; endovascular treatment may prevent rupture, but involves immediate risks. Hence, the balance of risks and benefits of endovascular treatment is uncertain. Here, we report the design of the TEAM trial, the first international, randomized, controlled trial comparing conservative management with endovascular treatment. Primary endpoint is mortality and morbidity (modified Rankin Score >/= 3) from intracranial haemorrhage or treatment. Secondary endpoints include incidence of hemorrhagic events, morbidity related to endovascular coiling, morphological results, overall clinical outcome and quality of life. Statistical tests compare between probabilities at 5- and 10-years of 1) mortality from haemorrhage related to the lesion, excluding per-operative complications; 2) mortality from haemorrhage or from complications of treatment; 3) combined disease or treatment related mortality and morbidity in the absence of other causes of death or disability. The study will be conducted in 60 international centres and will enroll 2,002 patients equally divided between the two groups, a size sufficient to achieve 80% power at a 0.0167 significance to detect differences in 1) disease or treatment-related poor outcomes from 7-9% to 3-5%; 2) overall mortality from 16 to 11%. Duration of the study is 14 years, the first three years being for patient recruitment plus a minimum of 10 years of follow-up. The TEAM trial thus offers a means to reconcile the introduction of a new approach with the necessity to acknowledge uncertainties.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN62758344 http://www.controlled-trials.com.

Unruptured intracranial aneurysms and the Trial on Endovascular Aneurysm Management (TEAM): The principles behind the protocol

BACKGROUND

With the widespread availability of non-invasive imaging of the brain in an aging population, we are increasingly confronted with the problem of the incidental discovery of unruptured aneurysms. The management of these patients remains controversial. Endovascular treatment can prevent rupture, but involves immediate risks. Furthermore, successful treatment does not eliminate all risk of rupture. The safety and efficacy of endovascular treatment of unruptured aneurysms remain undetermined. Hence the balance of the risks and benefits is uncertain. A randomized trial is needed to assess the potential benefits of endovascular management of unruptured aneurysms.

THE TRIAL

TEAM (Trial on Endovascular Aneurysm Management) is a randomized trial comparing endovascular treatment versus conservative management of unruptured aneurysms. TEAM aims to recruit 2002 patients in 60 centers throughout the world over a 3-year period and to follow all patients for 10 years. The primary outcome is to verify if the clinical outcome (morbidity/mortality (modified Rankin scale > 2) related to the aneurysm or its treatment) can be improved from 8% to 4%. The study is funded by the Canadian Institutes of Health Research.

Treatment related morbidity of unruptured intracranial aneurysms: results of a prospective single centre series with an interdisciplinary approach over a 6 year period (1999-2005)

OBJECTIVES

To review the angiographic and clinical outcome of patients with unruptured intracranial aneurysm(s) (UIA) with regard to complications and successful obliteration by surgical clipping or endovascular coiling.

METHODS

Data were derived from a prospective database of intracranial aneurysms from June 1999 to May 2005. All patients were followed-up for 6 months using the modified Rankin Scale (mRS). Favourable outcome was classified as mRS 0-2. From a total of 691 patients included in the database, 173 harboured 206 UIA of whom 118 patients (133 UIA) were treated.

RESULTS

Primary treatment assignment was surgical repair in 91 UIA and endovascular treatment in 42. In 3 UIA (7.1%), endovascular treatment was not feasible and had to be abandoned. Definite treatment was surgery in 94 UIA (81 patients) and endovascular obliteration in 39 UIA (37 patients). There were no deaths related to any treatment. Immediately after treatment, 6.4% of the surgical and 7.7% of the endovascular patients showed new neurological deficits, mainly related to cerebral ischaemia. After 6 months, 3 (2.3%) patients had a treatment related unfavourable outcome, defined as mRS >2, 2 patients after surgical and 1 patient after endovascular aneurysm repair (not statistically different, p = 0.3; Fisher's exact test). This led to an overall satisfactory outcome in 97.9% of surgically and 97.4% of endovasculary treated UIA. After surgical clipping, complete occlusion of the aneurysm was achieved in 88 (93.6%) and near complete (small residual neck) in 4 (4.3%) of 94 UIA. Two small posterior communicating artery aneurysms with a fetal type posterior communicating artery were wrapped. After endovascular treatment, obliteration was complete in 26 (66.7%). Small residual neck was seen in 13 (33.3%), but none of the UIA showed residual aneurysm filling. Five patients in the endovascular group (13.9%) underwent repeated endovascular treatment after aneurysm recanalisation.

CONCLUSIONS

If patients are carefully selected and individually assigned to their optimum treatment modality, UIA can be obliterated by surgery or endovascular treatment in the majority of patients, with a low percentage of unfavourable outcomes. In this series, the outcome was not dependent on treatment. However, the rate of recanalisation of UIA is higher after endovascular obliteration. After diagnosis of an UIA, an individual interdisciplinary decision is essential for each patient to provide the optimum management.

Endovascular management of unruptured intracranial aneurysms

Endovascular coil embolisation is increasingly used to treat unruptured intracranial aneurysms (UIA). Endovascular coil embolisation of UIA is associated with a 5-10% risk of morbidity and nearly zero mortality from the procedure. Complete or near complete occlusion is usually achieved in >90% of cases, and endovascular therapy seems to reduce the risk of future rupture significantly. Specific selection criteria for endovascular embolisation and novel approaches to endovascular treatment of aneurysms are discussed. Endovascular therapy appears to be a safe and effective treatment for selected UIA. Treatment failure rates will probably decrease with greater experience and advances in techniques and devices. Further study with long term follow up, however, is still necessary to characterise the efficacy, durability, and cost efficiency of endovascular treatment of UIA.

Aggregate analysis of the literature for unruptured intracranial aneurysm treatment

BACKGROUND

Publication bias and/or true heterogeneity can skew aggregate impressions from scientific literature. To better determine aggregate measures for unruptured intracranial aneurysm (UIA) treatment, we analyzed adverse outcome rates of surgical clipping and endovascular coil embolization.

METHODS

Two independent reviewers searched MEDLINE for studies publishing adverse outcome rates for endovascular coiling and surgical clipping between January 1990 and July 2003. Studies were classified as single-center, multicenter, or community-based. We defined adverse outcome rates as combined all-cause early or in-hospital morbidity and mortality. We determined cumulative adverse outcome rates by plotting precision measure (sample size) against trial-specific effect (adverse outcome rate).

FINDINGS

We included 4 endovascular coiling multicenter/community-based studies (1019 patients) and 13 single-center studies (810 patients) and 5 surgical clipping multicenter/community-based studies (10,541 patients) and 23 single-center studies (1759 patients). Cumulative adverse outcome rates for endovascular coiling and surgical clipping were 8.8% (95% confidence interval [CI] 7.6%-10.1%) and 17.8% (95% CI 17.2%-18.6%).

INTERPRETATION

Scattergram distribution illustrated the magnitude of bias in current literature reporting UIAs. Major parts of the literature may have underestimated surgical clipping morbidity and mortality, which can be attributed to bias from smaller retrospective studies. Neuroradiologic coiling studies were less likely to include factors contributing to inaccurate adverse outcome rates.

A randomized trial on the safety and efficacy of endovascular treatment of unruptured intracranial aneurysms is feasible

SUMMARY

The safety and efficacy of endovascular treatment of unruptured intracranial aneurysms remain undetermined. A randomized trial may be the best way to demonstrate the potential benefits of endovascular management. We propose a randomized, prospective, controlled trial comparing the incidence of subarachnoid haemorrage of patients treated by endovascular coiling as compared to conservative management. We would also study a composite outcome combining SAH and the morbidity of treatment. All patients with one or more unruptured aneurysm >> 3 mm eligible for endovascular treatment would be proposed to participate. The study would be conducted in 40-50 centres. The entire study would enrol 1800 patients, recruited over three years and followed for five years, but would be preceded by a feasibility study on 200 patients. A randomized trial comparing endovascular and conservative treatment could have an important impact on the clinical management of intracranial aneurysms.

Long term visual and neurological prognosis in patients with treated and untreated cavernous sinus aneurysms

OBJECTIVE

To determine the long term visual and neurological outcome of patients diagnosed with cavernous sinus aneurysms (CCAs).

METHODS

Prospective follow up for at least five years or until death of 31 retrospectively recruited patients (27 women, 4 men) with treated and untreated CCAs.

RESULTS

There were 40 aneurysms in all. Mean age at diagnosis was 60.4 years (range 25 to 86; median 64). The most common symptoms were diplopia (61%), headache (53%), and facial or orbital pain (32%). Fifteen patients (48%) were diagnosed after they developed cranial nerve pareses, four (13%) after they developed carotid-cavernous sinus fistulas (CCFs), and 12 (39%) by neuroimaging studies done for unrelated symptoms. Twenty one patients (68%) had treatment to exclude the aneurysm from circulation, 10 shortly after diagnosis and 11 after worsening symptoms. Immediate complications of treatment occurred in six patients and included neurological impairment, acute ophthalmoparesis, and visual loss. Ten patients (32%) were observed without intervention. Over a mean (SD) follow up period of 11.8 (7.7) years, eight had improvement in symptoms, five remained stable, and eight deteriorated. Among the 10 patients followed without intervention, none improved spontaneously, three remained stable, and seven worsened.

CONCLUSIONS

Most treated patients in this series improved or remained stable after treatment, but none improved without treatment. The long term prognosis for treated cases is relatively good, with most complications occurring immediately after the procedure. Endovascular surgery has decreased the morbidity and mortality of treatment so should be considered for any patient with a CCA.

Three-Year Retrospective Study of Complications Arising during Interventional Procedures

SUMMARY

This retrospective study aimed to assess the percentage of complications arising in our daily practice of interventional procedures, comparing our findings with those of leading international reference centers and accepted guidelines for endovascular treatment. During the threeyear period considered (2000-2002), we performed 246 interventional procedures, divided into seven different pathological conditions: aneurysms, brain AVMs dural and carotid cavernous fistulae, spine-spinal cord tumours, headneck tumours, carotid stenosis and thrombolysis. Aneurysmal disease accounted for 45% of all endovascular procedures. In conclusion, four periprocedural complications arose in the course of 246 procedures resulting in one death and three cases of permanent neurological deficit (2%).

In-hospital morbidity and mortality after endovascular treatment of unruptured intracranial aneurysms in the United States, 1996-2000: effect of hospital and physician volume

BACKGROUND AND PURPOSE

Endovascular therapy is increasingly being used for the treatment of unruptured intracranial aneurysms. Our purpose was to determine the risk of adverse outcomes after contemporary endovascular treatment of unruptured intracranial aneurysms in the United States. Patient, treating physician, and hospital characteristics were tested as potential outcome predictors, with particular attention paid to volume of care.

METHODS

We conducted a retrospective cohort study by using the Nationwide Inpatient Sample, 1996-2000. Multivariate logistic and ordinal regressions were used with end points of mortality, discharge other than to home, length of stay, and total hospital charges.

RESULTS

Four hundred twenty-one patients underwent endovascular treatment at 81 hospitals. The in-hospital mortality rate was 1.7%, and 7.6% were discharged to institutions other than home. Analysis was adjusted for age, sex, race, primary payer, year of treatment, and four variables measuring acuity of treatment and medical comorbidity. Median annual number of unruptured aneurysms treated was nine per hospital and three per treating physician. Higher volume hospitals had fewer adverse outcomes; discharge other than to home occurred after 5.2% of operations at high volume hospitals (>23 admissions per year) compared with 17.6% at low volume hospitals (fewer than four admissions per year) (P<.001). Higher physician volume had a similar effect (0% versus 16.4%, P=.03). The mortality rate was lower at high volume hospitals (1.0% versus 3.7%) but not significantly so. At high volume hospitals, length of stay was shorter (P<.001) and total hospital charges were lower (P<.001).

CONCLUSION

For patients with unruptured aneurysms treated in the United States from 1996 to 2000, endovascular treatment at high volume institutions or by high volume physicians was associated with significantly lower morbidity rates and modestly lower mortality rates. Length of stay was shorter and total hospital charges lower at high volume centers.