Ruptured giant intracranial aneurysms. Part I. A study of rebleeding

Microsurgical and endovascular treatment of large and giant aneurysms of the anterior circulation: A systematic review

Introduction

Large and Giant intracranial aneurysms (LGIAs) have become the paradigm for which endovascular techniques do not provide satisfactory results. Yet, microsurgery is followed by non-negligible rates of morbimortality. This scenario may have changed since the introduction of flow-diversion devices.

Research question

Contemporary and standardised revision on microsurgical and endovascular results, with emphasis on anterior circulation LGIAs.

Materials and methods

A systematic literature search was conducted in two databases (PubMed and Embase) on treatment outcomes of LGIAs of the anterior circulation, after the introduction of flow-diverters 2008/01/01, till 2023/05/20. Small case series (<5 cases), series including >15% of posterior circulation aneurysms, and studies not reporting clinical and/or angiographic outcomes were excluded.

Results

44 relevant studies (observational cohorts) were identified, including 2923 LGIAs predominantly from anterior circulation. Mean follow-up 22 (±20) months. 1494 (51%) LGIAs were treated endovascularly and 1427 (49%) microsurgically. According to the random effects model, pooled rates of favourable clinical outcomes were 85.8% (CI 95% 82.6-88.4), complete occlusion 69.4% (CI 95% 63.7-7.46), complications 19.6% (CI 95%16-23.9) and mortality 5.6% (CI 95% 4.4-7.1). Focusing on type of treatment, occlusion rates are higher with microsurgical (842/993, 85% vs 874/1,299, 67%), although good outcomes are slightly more frequent with endovascular (1045/1,135, 92% vs 1120/1,294, 87%).

Discussion and conclusions

According to contemporary data about occlusion rates, functional outcomes, and complications, primary or secondary treatment of LGIAs of the anterior circulation seems justified. Microsurgical occlusion rates are higher in LGIAs. An expert consensus on reporting complications and management strategies is warranted.

Treatment of giant intracranial aneurysms using the Pipeline flow-diverting stent: Long-term results from the International Retrospective Study of the Pipeline Embolization Device (IntrePED) study

BACKGROUND

Traditional endovascular treatments of giant intracranial aneurysms are associated with high rates of complications and retreatment. Our objective was to examine the safety and long-term efficacy of the Pipeline Embolization Device for treatment of these aneurysms.

METHODS

This retrospective study using the IntrePED database included all patients with giant intracranial aneurysms treated with the Pipeline device between July 2008 and February 2013. Efficacy outcomes were stratified by using the Raymond-Roy Occlusion Classification. Predefined safety outcomes included spontaneous rupture of the target aneurysm; ipsilateral intracranial hemorrhage; ischemic stroke; parent artery stenosis; and sustained cranial neuropathy.

RESULTS

Sixty-six embolizations were performed to treat 63 giant intracranial aneurysms (including 2 ruptured): 49 (77.8%) in the anterior and 14 (22.2%) in the posterior circulation. The median follow-up was 22.4 (0.1-60.5) months. Class I angiographic occlusion was achieved in 72.0% (36/50). The neurological morbidity/mortality rate was 23.8% (15/63), with higher rates in the posterior circulation than in the anterior circulation (22.4% vs. 28.6%). Among seven deaths, five had neurological causes. The procedure-related neurological morbidity and mortality rates were 22.7% (15/66) and 7.6% (5/66), respectively. The spontaneous rupture rate was 4.5% (3/66). Two spontaneous ruptures (1 death), 4/4 postprocedural intracranial hemorrhages, and 6/9 ischemic events occurred within 30 days. In-stent stenosis and new-onset cranial neuropathy were not observed during the angiographic follow-up period.

CONCLUSIONS

Although procedure-related neurological morbidity/mortality rates were not insignificant, this study confirms the feasibility and long-term efficacy of the Pipeline Embolization Device to treat giant intracranial aneurysms.

A Retrospective Study in Microsurgical Procedures of Large and Giant Intracranial Aneurysms: An Outcome Analysis

OBJECTIVE

Intracranial aneurysms are considered large if >10 mm and giant if >25 mm. The risk of aneurysmal rupture compounds with increase in size of the aneurysm, thus, warranting appropriate intervention. In this study, we have analyzed the outcome and effectiveness of microsurgical procedures in large and giant aneurysms.

METHODS

A retrospective analysis of all the patients who underwent microsurgical procedures for large and giant cerebral aneurysms from 2014-2018 in our institute was conducted. There were a total of 52 patients, in which direct clipping was performed in 42 (80.7%) patients, proximal trapping in 3 (5.7%) patients, trapping with bypass in 3 (5.7%) patients, suction decompression in 3 (5.7%) patients, and 1 (1.9%) patient underwent surgical reconstruction.

RESULTS

Among the 52 patients, in the postoperative period, 1 (1.9%) patient became comatose, 1 (1.9%) patient developed hemiplegia, 1 (1.9%) patient had a transient hemiparesis, and 1 (1.9%) patient had transient lower cranial nerve palsy. Two (3.8%) patients had chronic subdural hematoma during the 3-month follow-up. There was no mortality in our series.

CONCLUSIONS

There are several treatment strategies available to manage large and giant cerebral aneurysms. In this study, we had minimal morbidity (3.8%), favorable outcome (96.1%), and no mortality. Therefore, we would like to conclude that appropriate microsurgical procedures, in experienced hands, can be considered as first line in the management for large and giant intracranial aneurysms, especially those with complex anatomy, wide neck, mass effect, partial thrombosis, and the presence of critical perforating vessels from the aneurysm wall.

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis

BACKGROUND

Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear.

PURPOSE

To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices.

DATA SOURCES

Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion.

STUDY SELECTION

One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion.

DATA ANALYSIS

Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05).

DATA SYNTHESIS

Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001).

LIMITATIONS

Observational studies and case reports may be affected by reporting bias.

CONCLUSIONS

Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Posterior Fossa Craniectomy with Endovascular Therapy of Giant Fusiform Basilar Artery Aneurysms: A New Approach to Consider?

BACKGROUND

The prognosis of unruptured giant basilar artery (BA) aneurysms is very poor. No treatment has shown efficacy in survival. This pilot case-control study examines the overall survival (OS) benefit of combined surgical and endovascular management of giant BA aneurysms.

METHODS

Combined treatment including posterior fossa craniectomy followed by endovascular treatment was performed in 3 patients with giant BA aneurysms. OS of the 3 patients was compared with a control group of 6 patients (ratio 1:2) treated with the endovascular procedure only.

RESULTS

The mean survival time was 32.6 months in the craniectomy group (SD 9.01, 95% confidence interval [14.9, 50.3]) and 3.5 months in the control group (SD = 2.08, 95% confidence interval [0.001, 7.6]; Mantel-Cox test P < 0.04). At mean follow-up of 36.5 months (SD 10.2), 2 of 3 patients had a favorable outcome with a Glasgow Outcome Scale score of 5. Univariate analysis determined that women had a statistically higher OS than men (33.7 months vs. 3.058 months for men; log-rank test P = 0.011). A similar outcome was obtained in the presence of a circulating posterior communicating artery (P = 0.03) and in the presence of an endovascular right vertebral artery occlusion (P = 0.022).

CONCLUSIONS

Our study suggests that preventive posterior fossa craniectomy increases significantly OS of patients with giant BA aneurysms.

Surgical outcome of primary clipping for anterior circulation aneurysms of size 2 centimeters or larger

BACKGROUND

Aneurysms of the anterior circulation larger than 2cm have a complex relationship to the anterior skull base, requiring a multi-modality management approach. This retrospective study of 54 patients with such aneurysms who underwent clipping between 2001 and 2012 analyzes clinical and surgical data, aneurysm characteristics and correlates them with respect to the Glasgow outcome score at follow-up and immediate post-operative clinical status.

METHODS

Patients with an outcome score of 5 or 4 were categorized as "good", while those with score 3-1 were "poor". Fisher's exact test and paired T-test (p<0.5) were used to test statistical significance for discrete and continuous variables respectively.

RESULTS

44 (81.4%) patients had a good outcome. Patients with non-ophthalmic/paraclinoid aneurysms had significantly lower incidence of adverse intra-operative events (p=0.035). Patients older than 50 years (p=0.045), with adverse intra-operative events (p=0.015) and post-operative infarction (p<0.001) had a poor outcome compared to those younger than 50 years age and those without adverse intra-operative events or infarctions. The grouped age variable had maximum influence on patient outcome. Location and size of aneurysm did not have an overall impact on surgical outcome. There were 4 mortalities.

CONCLUSIONS

Primary clipping of proximal non-cavernous aneurysms on the internal carotid artery is associated with adverse intra-operative events. A multi-modality treatment approach in these aneurysms should be individualized, more so in patients older than 50 years.

French collaborative group series on giant intracranial aneurysms: Current management

OBJECTIVES

Giant intracranial aneurysms represent a major therapeutic challenge for each surgical team. The aim of our study was to extensively review the French contemporary experience in treating giant intracranial aneurysms in order to assess the current management.

PATIENTS AND METHODS

This retrospective multicenter study concerned consecutive patients treated for giant intracranial aneurysms (2004-2008) in different French university hospitals (Bordeaux, Caen, Clermont-Ferrand, Lille, Lyon, Nice, Paris-Lariboisière, Rouen et Toulouse). Different variables were analyzed: the diagnostic circumstances, the initial clinical status based on the WFNS scale, aneurysmal features and exclusion procedure. At 6 months, the outcome was evaluated according to the modified Rankin Scale (mRS): favorable (mRS 0-2) and unfavorable (mRS 3-6). A multivariate logistic regression model included all the independent variables with P<0.25 in the univariate analysis (P<0.05).

RESULTS

A total of 79 patients with a mean age of 51.5 ± 1.6 years (median: 52 years; range: 16-79) were divided into two groups, with the ruptured group (n=26, 32.9%) significantly younger (P<0.05, Student's-t-test) than the unruptured group (n=53, 67.1%). After SAH, the initial clinical status was good in 12 patients (46.2%), and in the unruptured group, the predominant diagnosis circumstance was a pseudo-tumor syndrome occurring in 22 (41.5%). The first procedure of aneurysm treatment in the global population was endovascular in 42 patients (53.1%), microsurgical in 29 (36.7%) and conservative in 8 (10.2). An immediate neurological deterioration was reported in 38 patients (48.1%) after endovascular treatment in 19 (45.2% of endovascular procedures), after miscrosurgical in 15 (51.7% of microsurgical procedures) and after conservative in 4 (the half). At 6 months, the outcome was favorable in 45 patients (57%) and after multivariate analysis, the predictive factors of favorable outcome after management of giant cerebral aneurysm were the initial good clinical status in cases of SAH (P<0.002), the endovascular treatment (P<0.005), and the absence of neurological deterioration (P<0.006). The endovascular procedure was obtained as a predictive factor because of the low risk efficacy of indirect procedures, in particular a parent vessel occlusion.

CONCLUSION

The overall favorable outcome rate concerned 57% of patients at 6 months despite 53.8% of poor initial clinical status in cases of rupture. The predictive factors for favorable outcome were good clinical status, endovascular treatment and the absence of postoperative neurological deterioration. Endovascular treatment should be integrated into the therapeutic armenmatarium against giant cerebral aneurysms but the durability of exclusion should be taken into account during the multidisciplinary discussion by the neurovascular team.

Application of dual Willis covered stents in the management of large fusiform carotid aneurysms in a canine model

This study evaluates the efficacy of dual Willis covered stents for the treatment of large fusiform carotid aneurysms in a canine model. Carotid fusiform aneurysms >10 mm long were surgically created in 10 dogs and were then repaired using either single or dual covered stents. Clinical results were assessed by scheduled angiography and histological features by light and electron microscopy. Angiography immediately post-op and 6 months after surgery revealed aneurysm isolation rates of 60 and 20% for the single stent technique and 60 and 100% for the dual stent technique, respectively. The rate of complete obliteration of the aneurysm sac differed significantly between treatments ( P = 0.048). The dual stent technique also resulted in greater endothelialization. For large carotid fusiform aneurysms in a canine model, endovascular repair using dual Willis covered stents is technically feasible and more effectively obliterates the aneurysm sac than the use of a single stent.

Revascularized giant aneurysm of the anterior communicating artery after surgery and embolization, occluded by placement of a Leo+Baby intracranial stent. A case report

Balt (Montmorency, France) recently manufactured the Leo+Baby dedicated intracranial stent for arteries with a calibre between 1.5 and 3.10 mm. We describe a patient with a partially thrombosed giant sacciform aneurysm of the anterior communicating artery treated without success by surgery and coil embolization subsequently occluded by placement of a Leo+Baby stent (Balt, Montmorency, France). A 56-year-old man presented with a giant aneurysm in the anterior communicating artery region. Following successive surgical intervention and embolization procedures the patient was referred to us with a revascularized aneurysm measuring 15×9×8 cm. To stabilize the endovascular occlusion a combined treatment was scheduled with coil embolization and stent deployment after dual antiplatelet therapy started five days before the interventional procedure. Treatment was undertaken two weeks later under general anaesthesia and total heparinization. A microcatheter was inserted into the aneurysmal sac and four metal coils were released for a total of 61cm obtaining almost complete occlusion of the aneurysm from the circulation. A Leo+Baby stent (2.5×18 mm) was subsequently deployed across the aneurysm neck. At follow-up angiography two months later the aneurysm appeared substantially excluded from the arterial circulation except for a small portion in the neck. Six months later, four months after suspending antiplatelet therapy, follow-up angiography disclosed the complete exclusion of the aneurysm from the circulation. Deployment of the new ministent through the same microcatheter used to release the coils made the interventional procedure simpler and faster.

Pipeline embolization device in aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

The PED is an FDS designed for the treatment of intracranial aneurysms. Data regarding the use of this device in acute or subacute aSAH is limited to a few case reports or small series. We aimed to demonstrate the feasibility of using an FDS, the PED, for the treatment of ruptured intracranial aneurysms with challenging morphologies.

MATERIALS AND METHODS

We conducted a retrospective review of all known patients treated with the PED for aSAH at 4 institutions between June 2008 and January 2012. Pertinent clinical and radiologic information was submitted by individual centers for central collation. The decision to treat with the PED was made on a case-by-case basis by a multidisciplinary team under compassionate use.

RESULTS

Twenty patients (15 women; median age, 54.5 years; IQR, 8.0 years) were found. There were 8 blister, 8 dissecting or dysplastic, 2 saccular, and 2 giant aneurysms. Median time to treatment was 4 days (range, 1-90 days; IQR, 12.75 days) from rupture. Three patients had previous failed treatment. Procedure-related symptomatic morbidity and mortality were 15%, with 1 (5%) procedure-related death. Two patients died relative to medical complications, and 1 patient was lost to follow-up. Sixteen patients were available for follow-up, 81% had a GOS of 5, and 13% had a GOS of 4 attributed to a poorer initial clinical presentation. One patient died of urosepsis at 4 months. Occlusion rates were 75% and 94% at 6 months and 12 months, respectively. There were 3 delayed complications (1 silent perforator infarct, 2 moderate asymptomatic in-stent stenoses). No symptomatic delayed complications or rehemorrhages occurred.

CONCLUSIONS

The FDS may be a feasible treatment option in the acute or subacute setting of selected ruptured aneurysms, especially blister aneurysms. Ruptured giant aneurysms remain challenging for both surgical and endovascular techniques; at this stage, FDSs should be used with caution in this aneurysm subtype.

Early and long-term outcome of surgically treated giant internal carotid artery aneurysms--comparison with smaller aneurysms

BACKGROUND

Internal carotid artery (ICA) is predominant localization of giant intracranial aneurysms (GIAs). The rupture of GIA is supposed to be related to higher risk of poor clinical outcome. Although endovascular techniques are still being developed, they seem to be unsatisfactory in the mean of GIAs.

METHODS

Included in the retrospective analysis were 78 giant and 250 smaller surgically treated ICA aneurysms. Exclusion criteria were multiple and blood blister-like aneurysms. Neurological deficit on admission, clinical and radiological presentation, gender, age, segment of ICA, surgical methods, accessory techniques and complications were analyzed. Death rate and short- and long-term outcome of giant aneurysms were compared with smaller aneurysms and risk factors for mortality, unfavorable short- and long-term outcome were determined.

RESULTS

There was no difference in general and surgical complications between ICA aneurysm size groups, as well as in occurrence of newly diagnosed neurological deficit after the operation. There were similar mortality rates, proportion of unfavorable outcome, and low health related quality of life for giant and smaller aneurysms. A 12.2% death rate for all ICA aneurysms was achieved. Trapping method as well as Fisher grades 3 and 4 increased mortality risk in the smaller aneurysm group. No significant factors were related to an unfavorable outcome in the ruptured giant aneurysm group. Patients older than 65, Hunt-Hess grades 4 and 5, Fisher grade 4, and newly diagnosed deficit after operation were connected with unfavorable outcome in the ruptured smaller aneurysm group. Newly diagnosed neurological deficit was also an unfavorable outcome risk factor in both giant and smaller ICA unruptured aneurysms. No difference was noted in long-term health-related quality of life between the giant and smaller ICA groups. Higher age and presence of concomitant disease were independent factors affecting quality of life, although obtained data were incomplete.

CONCLUSIONS

The study breaks the stereotype of unfavorable giant ICA aneurysms treatment results. Mortality rate, short- and long-term outcome after the operation of giant and smaller ICA aneurysms are similar. Higher age, patients' condition at admission, and the amount of extravasated blood and trapping method are poor prognostic factors in patients with smaller ICA aneurysm.

The orbitopterional approach for large and giant middle cerebral artery aneurysms: a report of two cases and literature review

We report two cases of complex middle cerebral artery aneurysms that were surgically treated using the orbitopterional approach in a two-piece method. The objective of this work is to discuss the usefulness of the orbitopterional approach in the surgical management of large and giant middle cerebral artery aneurysms. A 32-year-old man with a giant aneurysm and a 50-year-old woman with a large and complex aneurysm presented with subarachnoid hemorrhages. Both aneurysms were successfully clipped through an orbitopterional approach. This approach permits a more basal view of the vascular structures with only a minor retraction of frontal lobe. It also increases the view angle and amount of working space available. This approach should be considered as an alternative to the classic pterional craniotomy for the surgical management of such complex lesions.

Short-Term Antifibrinolytic Therapy Before Early Aneurysm Treatment in Subarachnoid Hemorrhage: Effects on Rehemorrhage, Cerebral Ischemia, and Hydrocephalus

BACKGROUND:

Long-term administration of the antifibrinolytic agent epsilon aminocaproic acid (EACA) reduces the rate of rehemorrhage in patients with aneurysmal subarachnoid hemorrhage (SAH), but is associated with cerebral ischemia.

OBJECTIVE:

To evaluate short-term administration of EACA before early surgery in patients with SAH.

METHODS:

Retrospective review of 356 patients admitted between June 2002 and December 2007 with a diagnosis of aneurysmal SAH. Medical records were reviewed to determine SAH risk factors, clinical grade at the time of admission, and incidence of rehemorrhage, permanent new-onset focal neurological deficits, computed tomography evidence of cerebral infarction, symptomatic vasospasm, and hydrocephalus.

RESULTS:

Patients underwent treatment of the ruptured aneurysm an average of 47.4 hours after admission and received an average total dose of 40.6 g of EACA. The mean length of time of administration of EACA was 35.6 hours. There was a total of 5 rehemorrhages, for an overall rebleeding rate of 1.4% and a rate of rehemorrhage per 24-hour period of 0.71%. Overall, the rates of symptomatic vasospasm and permanent neurological deficits attributable to ischemic stroke were 11.5% and 7.2%, respectively, and the incidence of shunt-dependent hydrocephalus was 42.3%. Patients who were treated with coiling had higher rates of symptomatic vasospasm and ischemic complications than patients who had surgery.

CONCLUSION:

Short-term administration of EACA is associated with rates of rehemorrhage, ischemic stroke, and symptomatic vasospasm that compare favorably with historical controls. The rate of hydrocephalus is relatively high and may be attributable to EACA treatment.

Surgical treatment of complex intracranial aneurysms

Complex intracranial aneurysms include not only giant aneurysms (classically larger than 25 mm in diameter) but also smaller aneurysms in difficult locations of the human brain and cranial base. Such lesions are associated with a high risk of subarachnoid hemorrhage and progressive neurological deterioration or death caused by mass effect or stroke. In the past 30 years, the understanding and treatment of these lesions have progressed considerably. Nonetheless, a deep understanding of these lesions, including the nuances of blood flow dynamics, natural history, and potential therapeutic options, is necessary when one is managing such aneurysms. The senior author's (RFS) clinical experience with more than 5000 brain aneurysms was reviewed. We also reviewed recent literature on the surgical management of giant cerebral aneurysms, focusing on the most up-to-date microsurgical techniques. Combinations of therapies can be used in an attempt to provide a solution to various clinical dilemmas associated with the management of these difficult lesions. The synergistic association between microsurgery and endovascular modalities is also illustrated. On the basis of the knowledge obtained over the years, indirect and multimodality approaches are becoming more common as neurosurgeons strive to improve patient outcomes.

Endovascular treatment of giant intracranial aneurysms with willis covered stents: technical case report

OBJECTIVE

To evaluate the efficacy of endovascular treatment of giant intracranial aneurysms with Willis covered stents (Micro-Port, Shanghai, China).

CLINICAL PRESENTATION

The endovascular treatment of two cases of giant intracranial aneurysm was successfully accomplished by the placement of Willis covered stents specially designed for intracranial use. Both patients presented with symptoms of cavernous mass effect that resulted from a giant aneurysm in the cavernous segment of the internal carotid artery.

INTERVENTION

Three Willis covered stents were successfully placed in two patients. Immediate postprocedure angiograms demonstrated some endoleak of the aneurysms. In one patient, the endoleak was eliminated and complete exclusion of the aneurysms was confirmed with follow-up angiography. However, the other patient required the placement of a new Willis covered stent.

CONCLUSION

The use of covered stents in intracranial vascular structures is a feasible method to treat selected cases of intracranial giant aneurysms. It is suggested that patients who present with compressive mass effect caused by large or giant aneurysms are the best candidates for covered stent placement, but potential complications should be considered carefully before the stenting procedure.

Surgical management of giant intracranial aneurysms

OBJECTIVES

The natural history of giant intracranial aneurysms is generally morbid. Mortality and morbidity associated with giant aneurysms is also higher than for smaller aneurysms. This study was carried out to assess the demographic profile, presenting features, complications, and outcome after surgical treatment of giant intracranial aneurysms.

PATIENTS AND METHODS

A retrospective review of the medical records of all patients with giant intracranial aneurysms treated in the Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, New Delhi, from January 1995 through June 2007 was performed. The demographic profiles, presenting features, radiological findings, surgical treatments, and outcomes were assessed.

RESULTS

A total of 1412 patients harboring 1675 aneurysms were treated. Out of these, 222 patients had 229 (13.7%) giant aneurysms, and of those, 181 aneurysms in 177 patients were managed surgically while 48 were treated with endovascular therapy. In the patients treated with surgery, common clinical presentations included subarachnoid hemorrhage (SAH) in 110 (62%) cases followed by mass effect in 57 (32%) cases. In patients who presented with SAH, the Hunt and Hess SAH grading was: grade I in 43 (39%), grade II in 40 (36%), grade III in 23 (21%), grade IV in two (2%), and grade V in 2 (2%) patients. One hundred and seven aneurysms (in 103 patients) were treated using direct surgical clipping. Forty-six patients with good collateral circulation were treated by gradual occlusion and ligation of the internal carotid artery (ICA) in the neck with a Silverstone clamp. Another nine patients with good collateral circulation, but persisting symptoms after ICA ligation, required trapping for obliteration of the aneurysm. Eleven patients with poor collateral circulation required extracranial-intracranial (EC-IC) bypass before proximal ICA ligation. A post-operative digital subtraction angiography (DSA) was performed in 118 patients and revealed well-obliterated aneurysm in 106 patients. The total treatment mortality rate was 9%. In the last 5 years, 117 patients were operated on with four operative deaths. Overall, the outcome was excellent in 131 (74.0%), good in 22 (12.4%), and poor in eight (4.5%) cases.

CONCLUSIONS

It is concluded that 14% of all intracranial aneurysms are giant. The most common clinical presentation is SAH followed by features of an intracranial mass lesion. The cavernous ICA is the most common portion of the ICA affected. Direct surgical clipping is a safe and effective method of treatment and should be considered the first line of treatment whenever possible. With proper case selection, optimal radiological evaluation, and appropriate surgical strategy, it is possible to achieve a favorable outcome in almost 90% of the cases.

Giant Cerebral Aneurysms: Endovascular Challenges

OBJECTIVE:

Giant (≥25 mm in diameter) cerebral aneurysms have a poor natural history, with high risks of subarachnoid hemorrhage or progressive disability or death caused by mass effect or stroke. Surgical treatment may be effective but carries a high burden of morbidity and mortality. Thus, attempts at endovascular solutions to these complex lesions have been developed to offer therapy at reduced risk.

METHODS:

The authors reviewed their clinical experience and the current body of literature concerning giant cerebral aneurysms and present their perspective on the current state of the art in endovascular therapy for these aneurysms. A variety of techniques are described that can be used in an attempt to provide a solution to the wide variety of clinical dilemmas associated with the management of these difficult lesions. Preprocedural planning and periprocedural considerations are discussed briefly. The use of intracranial balloons and stents are described in conjunction with the use of detachable platinum coils. The developing concept of using stents alone to treat aneurysms is discussed. Alternative methods of treating giant aneurysms are discussed.

RESULTS:

Current endovascular approaches, when properly selected and applied, can provide lower-risk therapies than conventional microsurgical approaches for patients harboring giant cerebral aneurysms. However, endovascular approaches do not, at present, provide results that are as durable as current surgical techniques for giant cerebral aneurysms.

CONCLUSION:

Treatment of giant cerebral aneurysms via endovascular therapeutics requires the interventionist to possess an extensive armamentarium. Meticulous preprocedure evaluation, patient selection, and execution of the treatment plan enable safe and effective management. Current therapies do not provide an ideal solution for every patient, so one must consider creative and evolving solutions to these difficult clinical challenges. The procedural morbidity of open surgery versus the decreased durability of current endovascular techniques must be assessed carefully.

Challenges in the Endovascular Treatment of Giant Intracranial Aneurysms

OBJECTIVE:

Giant intracranial aneurysms present unique therapeutic intricacies. The purpose of this study was to evaluate the anatomic and hemodynamic characteristics of these lesions and the current endovascular and combined surgical and endovascular techniques available for their treatment.

METHODS:

A review of the literature and the personal experiences of the authors with endovascular treatment of giant aneurysms are presented. This review included anatomic and hemodynamic features and analysis of the diverse endovascular techniques that have been reported for the management of these aneurysms.

RESULTS:

Anatomic features that create particular challenges in the therapeutic approach of giant aneurysms include size, shape (saccular, fusiform, serpentine), neck dimensions, branch involvement, intraluminal thrombosis, and location. Hemodynamic characteristics that affect endovascular treatment are lateral or terminal aneurysm type of flow and embolic material placement (inflow versus outflow aneurysmal region). The current endovascular therapeutic approaches include parent artery occlusion, trapping, endosaccular embolization with or without adjunctive techniques such as balloon-assisted or stent placement, and combined surgical and endovascular approaches, mainly with surgical revascularization and endovascular occlusion.

CONCLUSION:

Although there are a wide variety of endovascular therapeutic options for the treatment of giant intracranial aneurysms, none of the current techniques is completely successful and free of complications in the management of these complex lesions. A detailed and individualized analysis of each case in conjunction with sufficient understanding of the anatomy and hemodynamics of a particular aneurysm should guide the therapeutic decision. Further research advances will assist in elucidating the factors predisposing to genesis, progression, and aggressive clinical manifestations of these giant lesions.

The history and present status of deep hypothermia and circulatory arrest in cerebrovascular surgery

After the development of deep hypothermia and circulatory arrest for cardiothoracic procedures in the late 1950s, this technique was adopted by several neurosurgeons as an aid to complex cranial surgery. Woodhall and colleagues described its first use for a neurosurgical procedure in 1960. Although their case did not involve a cerebrovascular procedure, the technique was subsequently used for the surgical treatment of cerebrovascular lesions, especially complex and giant aneurysms as well as large and solid hemangioblastomas. At the beginning, incorporation of this technique into common neurosurgical practice was impeded by several factors. For example, postbypass coagulopathy had been a serious source of morbidity. Furthermore, the need for cooperation among multiple subspecialties and the requirements for expensive equipment had further limited the availability of this technique. Subsequent improvements in the technique and advances in the equipment designed for cardiopulmonary bypass have led to its more widespread use starting in the 1980s. Hypothermic circulatory arrest has been described in several reports as a safe and useful tool in the treatment of large and giant aneurysms. Nevertheless, improvements in endovascular procedures and further refinement in skull base surgical techniques have limited the indications for circulatory arrest and deep hypothermia. The authors describe the history of hypothermia and circulatory arrest, its implementation in cerebrovascular surgery, and the changes in indications for and results of its use over time.

High re-bleeding rate in young adults after subarachnoid haemorrhage from giant aneurysms

Low re-bleeding rates within the first 14 days of aneurysmal subarachnoid haemorrhage are reported in young patients. Furthermore, re-bleeding rate for giant aneurysms does not exceed 20% according to the literature. Our own clinical impression is that the re-bleeding rate seems to be much higher in giant aneurysms than reported, particularly in young patients. The aim of this study was to evaluate re-bleeding rate after subarachnoid haemorrhage following rupture of giant aneurysms in a younger population. We reviewed records of 23 patients who were treated in our institution for subarachnoid haemorrhage from giant aneurysms between 1994 and 2003. By definition, the aneurysms were larger than 25 mm in diameter. Five patients were younger than 40 years of age at the time of the aneurysmal subarachnoid haemorrhage. All younger patients (<40 years of age) showed re-bleeding after the first subarachnoid haemorrhage within the first 14 days of the initial event. In four patients (20%) older than 40 years at the time of the haemorrhage re-bleeding could be observed within the first 14 days of subarachnoid haemorrhage. We can confirm the re-bleeding rate of approximately 20% in patients suffering from subarachnoid haemorrhage (SAH) in the group of patients older than 40 years of age. However, younger patients seem to be at much higher risk of re-bleeding from giant aneurysms.

The presence of tandem endothelial nitric oxide synthase gene polymorphisms identifying brain aneurysms more prone to rupture

Object. It is becoming apparent that the presence of certain genetic variations (polymorphisms) may increase the individual's susceptibility to cardiovascular diseases, even in the absence of a family history. We hypothesized that brain aneurysms more prone to rupture may be identified on the basis of an individual's genotype for endothelial nitric oxide synthase (eNOS), a critical vasomodulatory protein found to be increasingly relevant to the pathobiology of aneurysms.

Methods. Patients' clinical data were recorded prospectively. Genomic DNA was isolated from blood samples obtained from individuals presenting consecutively to the Mayo Clinic with ruptured (58 patients) or unruptured (49 patients) intracranial saccular aneurysms. Using polymerase chain reaction and gene microarray technology, the following eNOS genetic polymorphisms were studied: intron-4 27—base pair variable number of tandem repeats (27 VNTR); promoter single nucleotide polymorphism (T-786C SNP); and exon-7 SNP (G894T SNP).

Both groups of patients had similar demographic and clinical characteristics. For all three polymorphisms, variant alleles (p ≤ 0.003) and their corresponding genotypes (p ≤ 0.006) were found two to four times more frequently in patients with ruptured aneurysms than in patients with unruptured aneurysms. Strikingly, the odds ratio for presenting with a ruptured brain aneurysm among individuals demonstrating the copresence of all three variant alleles was 11.4 (95% confidence interval 1.7–75.9, p = 0.004).

Conclusions. The authors have uniquely identified a set of tandem eNOS gene variations whose presence can be used to identify patients with aneurysms likely to rupture. We believe that if this finding is reproducible in a large multicenter study, in addition to known anatomical factors a rapid and cost-effective screening tool will become available to clinicians as a genetic aid to predict the risks of rupture in patients presenting with unruptured intracranial aneurysms.

Endothelial nitric oxide synthase gene polymorphisms predict susceptibility to aneurysmal subarachnoid hemorrhage and cerebral vasospasm

Rupture of an intracranial aneurysm (subarachnoid hemorrhage) is a potentially devastating condition frequently complicated by delayed cerebral ischemia from sustained contraction of intracranial arteries (cerebral vasospasm). There is mounting evidence linking the formation of intracranial aneurysms and the pathogenesis of post-subarachnoid hemorrhage vasospasm to aberrant bioavailability and action of the vasodilator molecule nitric oxide generated by isoforms of nitric oxide synthase. In humans, the gene encoding the endothelial isoform of nitric oxide synthase (eNOS) is known to be polymorphic, with certain polymorphisms associated with increased cardiovascular disease susceptibility. In this prospective clinical study involving 141 participants, we used gene microarray technology to demonstrate that the eNOS gene intron-4 27-base pair variable number tandem repeat polymorphism (eNOS 27 VNTR) predicts susceptibility to intracranial aneurysm rupture, while the eNOS gene promoter T-786C single nucleotide polymorphism (eNOS T-786C SNP) predicts susceptibility to post-subarachnoid hemorrhage vasospasm. We believe that genetic information such as this, which can be obtained expeditiously at the time of diagnosis, may be used as a helpful adjunct to other clinical information aimed at predicting and favorably modifying the clinical course of persons with intracranial aneurysms.

Giant intracranial aneurysms: development, clinical presentation and treatment

The natural history of giant intracranial aneurysms are grave. More than 50% of patients suffer from rupture of these aneurysms and mortality is >60% in 2 years. Modern technology and advancement of knowledge in neurosurgery and interventional neuroradiology have altered its natural course for the better. As many reports have shown, the majority of these aneurysms can be treated either by surgery or by endovascular approach, even though morbidity is higher than when treating smaller aneurysms. Certain aneurysms are more suitable to direct surgical clipping and others may have better chances of good clinical outcome by endovascular treatment. It is imperative to analyse the location, morphology, hemodynamics and circulation of normal brain of each aneurysm before the mode of treatment is decided. Needless to say, the individual patient's age, neurological and medical condition should be considered. For endovascular treatment, application of each technique, endosaccular occlusion or parent artery occlusion depends on the aneurysm location and geometry as well as its pathology. Several reports indicated that clinical outcome is better in patients treated by parent artery occlusion since it eliminates any blood flow to the aneurysm and it provides a more effective reduction of the mass effect. However, not all parent arteries can be sacrificed. In addition, endosaccular treatment is effective in preventing haemorrhage if the aneurysm is not re-canalised. It is also demonstrated that symptoms of mass effect can be reversed by endosaccular coiling. The patients who are treated this way should be closely monitored for re-canalisation.

Preoperative ventriculostomy and rebleeding after aneurysmal subarachnoid hemorrhage

OBJECT

Despite the widespread use of ventriculostomy in the treatment of acute hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH), there is no consensus regarding the risk of rebleeding associated with ventriculostomy before aneurysm repair. This present study was conducted to assess the risk of rebleeding after preoperative ventriculostomy in patients with aneurysmal SAH.

METHODS

The authors reviewed the records of all patients with acute SAH who were treated at a single institution between 1990 and 1997. Thus, the records of 304 consecutive patients in whom an aneurysmal SAH source was documented on angiographic studies and who had presented to the authors' institution within 7 days of ictus were analyzed. Re-bleeding was confirmed by evidence of recurrent hemorrhage on computerized tomography scans in all cases. Forty-five patients underwent ventriculostomy for acute hydrocephalus after aneurysmal SAH at least 24 hours before aneurysm repair. Ventriculostomy was performed within 24 hours of SAH in 38 patients, within 24 to 48 hours in three patients, and more than 48 hours after SAH in four patients. The mean time interval between SAH and surgery in patients who did not undergo ventriculostomy was no different from the mean interval between ventriculostomy and surgery in patients who underwent preoperative ventriculostomy (3.6 compared with 3.8 days, p = 0.81). Fourteen (5.4%) of the 259 patients who did not undergo ventriculostomy suffered preoperative aneurysm rebleeding, whereas two (4.4%) of the 45 patients who underwent preoperative ventriculostomy had aneurysm rebleeding.

CONCLUSIONS

No evidence was found that preoperative ventriculostomy performed after aneurysmal SAH is associated with an increased risk of aneurysm rebleeding when early aneurysm surgery is performed.

Occult rupture of a giant vertebral artery aneurysm following proximal occlusion and intrasaccular thrombosis. Case report

The authors describe a unique clinicopathological phenomenon in a patient who presented with an unruptured giant vertebral artery aneurysm and who underwent endovascular proximal occlusion of the parent artery followed, several days later, by surgical trapping of the aneurysm after delayed subarachnoid hemorrhage (SAH). The intraoperative finding of a thrombus extruding from the wall of the aneurysm at a site remote from the origin of the SAH underscores the possibility that occult rupture of an aneurysmal sac can occur in patients with thrombosed giant aneurysms.

Acute deterioration from thrombosis and rerupture of a giant intracranial aneurysm

The authors describe a patient with an unusual clinicopathologic picture of giant aneurysmal hemorrhage followed by sudden deterioration due to acute intra-aneurysmal thrombosis and fatal rebleeding. This patient underscores the poor natural history associated with this devastating disease and serves to highlight the dangers inherent in the delayed treatment of these life-threatening lesions.

Ruptured giant intracranial aneurysms. Part II. A retrospective analysis of timing and outcome of surgical treatment

OBJECT

This retrospective study was made to determine the relationship between surgical timing and outcome in all patients with ruptured giant intracranial aneurysms undergoing surgical treatment at the Mayo Clinic between 1973 and 1996.

METHODS

The authors studied 109 patients, 102 of whom were referred from other medical centers. The ruptured giant aneurysms were 25 to 60 mm in diameter. One hundred five of the patients survived the rupturing of the aneurysm to undergo operation, with direct surgery possible in 84% of cases. Excluding delayed referrals, the average time to surgery after admission to the Mayo Clinic was approximately 4 to 5 days. Patients admitted earlier tended to be in poorer condition, often undergoing earlier operation. On average, surgical treatment was administered later for patients with ruptured aneurysms of the posterior circulation than for those with aneurysms in the anterior circulation. Temporary occlusion of the parent vessel was necessary in 67% of direct procedures, with an average occlusion time of 15.5 minutes. Among surgically treated patients, a favorable outcome was achieved in 72% harboring ruptured anterior circulation aneurysms and in 78% with ruptured posterior circulation lesions.

CONCLUSIONS

The overall management mortality rate was 21.1%, and the mortality rate for surgical management was 8.6%. The authors believe that because of the technical difficulties and risk of rebleeding associated with ruptured giant intracranial aneurysms, timely referral to and well-planned treatment at medical centers specializing in management of these lesions are essential to effect a more favorable outcome.