Management of giant intracranial aneurysms

Clinical analysis of giant intracranial aneurysms with endovascular embolization

Objective

The purpose of this study was to perform a clinical analysis of nine patients with giant aneurysms managed with endovascular embolization.

Methods

From March 2000 to September 2009, nine cases of giant intracranial aneurysms were treated (five unruptured and four ruptured). The nine patients included two males and seven females who were 47 to 72 years old (mean, 59.2 years old). The types of giant intracranial aneurysms were eight internal carotid artery aneurysms and one vertebral artery aneurysm. Treatment for each aneurysm was chosen based on anatomic relationships, aneurysmal factors, and the patients' clinical state. Three patients underwent endovascular coiling with stent and six initially underwent endovascular coiling alone. Medical records, operation records, postoperative angiographies, and follow-up angiographies were reviewed retrospectively.

Results

Eight out of nine patients showed good clinical outcomes. (six were excellent and two were good) after a mean follow-up period of 27.9 months. Six (67%) of the nine patients had a near-complete occlusions on the post-operative angiogram (mean, 13.5 months after the procedure). Occlusion rates of 90% or higher were obtained for eight (89%) of all the patients. One patient died due to multiple organ failure. Stents were ultimately required at some point for managing four aneurysms. Two patients needed additional procedures because of aneurysm regrowth.

Conclusion

Endovascular treatment could be an alternative option for managing giant aneurysms adjuvant to surgical intervention.

Surgical Treatment of Giant Intracranial Aneurysms: Current Viewpoint

Objective:

Despite new endovascular techniques and technological advances in microsurgery, the treatment of giant intracranial aneurysms is still a daunting neurosurgical task. Many of these aneurysms have a large, calcified neck, directly involve parent and collateral branches, and are partly thrombosed. In this retrospective review, we focused our analysis on the indications for high-flow, extracranial-intracranial (EC-IC) bypass surgery using a saphenous vein graft.

Methods:

A series of 130 patients were treated between 1990 and 2004; 31 patients were managed endovascularly, and 99 patients were treated microsurgically (surgical clipping in 58 patients and high-flow EC-IC bypass followed by aneurysm trapping in 41 patients). We examined the patients’ clinical records and pre- and postoperative case notes for cerebral angiographic examinations. Graft patency was verified with cerebral angiography, computed tomographic angiography, Doppler ultrasound, or graft palpation.

Results:

The high-flow EC-IC bypass was used for all surgically treated prepetrous aneurysms (3 patients), intracavernous aneurysms (1 patient), intracavernous aneurysms with subarachnoid extension (23 patients), as well as for some supraclinoid aneurysms (12 of the 32 patients). It was also used for 1 of the 9 aneurysms located in the carotid bifurcation and 2 of 5 vertebrobasilar circulation aneurysms. Of the 58 patients managed by surgical clipping, 4 (6.9%) died, and 51 (94.4%) improved. Of the 41 patients managed with high-flow EC-IC bypass, 4 (9.8%) died and 34 (91.9%) improved. Graft patency at the follow-up examination was 92.7%.

Conclusion:

The “gold standard” for the treatment of giant aneurysms remains surgical clipping. When direct surgical clipping or endovascular repair is contraindicated, the high-flow EC-IC bypass is a viable surgical option.

Carotid interventions above and below the bulb

Atherosclerotic occlusive lesions of the common carotid artery (CCA), the internal carotid artery (ICA), and the intracranial branches are amenable to angioplasty and stenting. Non atheromatous occlusive lesions caused by fibromuscular dysplasia, arteritis, or trauma may also be treated by image guided intervention in selected patients. Aneurysmal lesions of the CCA, ICA and the intracranial branches of degenerative, mycotic or traumatic etiologies, as well as carotid cavernous fistulae are mostly best treated by embolization. Technological developments continuously expand the indications of interventional treatment in these vascular territories.

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.

Giant intracranial aneurysm of the anterior communicating artery treated by direct surgery using A3-A3 side-to-side anastomosis and A3-RA graft-STA anastomosis

We describe a giant aneurysm of the anterior communicating artery (ACoA) which was treated with a STA-RA graft-A3 bonnet bypass and A3-A3 side-to-side anastomosis. A giant and partially thrombosed ACoA aneurysm was partially coated 3 years before his current presentation, its gradual increase producing visual field disturbances. An A3-A3 side-to-side anastomosis and STA-RA graft-A3 bonnet bypass were performed. The aneurysm was dissected, and the thrombus removed under transient parent-artery occlusion. The aneurysmal neck was successfully clipped without encountering ischemic changes. This strategy may be useful for treating giant or thrombosed aneurysms in the region of the ACoA.

Giant aneurysms of the internal carotid artery: endovascular treatment and long-term follow-up

We report the long-term follow-up of 18 patients with giant aneurysms of the internal carotid artery (ICA) referred for endovascular occlusion of the parent vessel. There were 10 aneurysms involving the infra- and/or supraclinoid cavernous segment, six the ophthalmic segment, one the petrous segment and one the bifurcation. One patient who did not tolerate test occlusion was treated medically. Clinical and imaging follow-up were obtained in 16 patients for a mean of 30 months, range 6-80 months. Endovascular treatment led to excellent clinical outcome in 16 patients. One 34-year-old woman, who presented with subarachnoid haemorrhage (SAH), died from bilateral middle cerebral artery infarcts due to severe vasospasm 4 days after treatment. The patient treated medically died from SAH. Long-term imaging follow-up in 16 patients revealed a markedly smaller aneurysm sac in all cases.

Continuous monitoring of regional cerebral blood flow during temporary arterial occlusion in aneurysm surgery

OBJECT

Temporary arterial occlusion (TAO) during aneurysm surgery carries the risk of ischemic sequelae. Because monitoring of regional cerebral blood flow (rCBF) may limit neurological damage, the authors evaluated a novel thermal diffusion (TD) microprobe for use in the continuous and quantitative assessment of rCBF during TAO.

METHODS

Following subcortical implantation of the device at a depth of 20 mm in the middle cerebral artery or anterior cerebral artery territory, rCBF was continuously monitored by TD microprobe (TD-rCBF) throughout surgery in 20 patients harboring anterior circulation aneurysms; 46 occlusive episodes were recorded. Postoperative radiographic evidence of new infarction was used as the threshold for failure of occlusion tolerance. The mean subcortical TD-rCBF decreased from 27.8+/-8.4 ml/100 g/min at baseline to 13.7+/-11.1 ml/100 g/min (p < 0.0001) during TAO. The TD microprobe showed an immediate exponential decline of TD-rCBF on clip placement. On average, 50% of the total decrease was reached after 12 seconds, thus rapidly indicating the severity of hypoperfusion. Following clip removal, TD-rCBF returned to baseline levels after an average interval of 32 seconds, and subsequently demonstrated a transient hyperperfusion to 41.4+/-18.3 ml/l 00 g/min (p < 0.001). The occurrence of postoperative infarction (15%) and the extent of postischemic hyperperfusion correlated with the depth of occlusion-induced ischemia.

CONCLUSIONS

The new TD microprobe provides a sensitive, continuous, and real-time assessment of intraoperative rCBF during TAO. Occlusion-induced ischemia is reliably detected within the 1st minute after clip application. In the future, this may enable the surgeon to alter the surgical strategy early after TAO to prevent ischemic brain injury.

Clinical and angiographic results of endosaccular coiling treatment of giant and very large intracranial aneurysms: a 7-year, single-center experience

OBJECTIVE

To evaluate whether the objectives of surgical treatment, i.e., prevention of aneurysmal rebleeding, relief of aneurysmal mass effect, and prevention of embolic complications, are met by endosaccular coiling treatment applied to giant and very large wide-necked aneurysms.

METHODS

Thirty patients with 31 giant or very large aneurysms were considered to show unacceptable risk/benefit ratios for open surgery and were treated using the Guglielmi detachable coil (GDC) method between 1992 and 1998.

RESULTS

With endosaccular GDC treatment, 73.3% of the population experienced excellent to good recoveries (Glasgow Outcome Scale scores of 4 or 5), with a 13.3% procedure-related morbidity rate and a 6.7% procedure-related mortality rate. Two hemorrhaging episodes occurred after GDC treatment (annual bleeding rate, 2.5%; 2 hemorrhaging episodes/79.2 patient-yr). Symptoms related to aneurysmal mass effect were improved for 45.5% of the patients presenting with signs of neural compression. Among 23 patients with 24 aneurysms who were available for angiographic follow-up assessment, complete or nearly complete occlusion was observed for 17 aneurysms (71%; angiographic follow-up period, 24.3 +/- 19.6 mo, mean +/- standard deviation). A single total embolization served as definitive treatment for only 12.5% of the giant aneurysms and 31% of the very large aneurysms.

CONCLUSION

Endosaccular GDC treatment of giant and very large aneurysms was accomplished with procedure-related morbidity and mortality rates comparable to those for open surgery performed by experts. However, because coil stability was unsatisfactory, we suggest that the GDC method should currently be reserved for individuals who are considered poor candidates for open surgery.

Mortality and morbidity of surgery for unruptured intracranial aneurysms: a meta-analysis

BACKGROUND AND PURPOSE

Greater availability and improvement of neuroradiological techniques have resulted in more frequent detection of unruptured aneurysms. Because prognosis of subarachnoid hemorrhage is still poor, preventive surgery is increasingly considered as a therapeutic option. Elective surgery requires reliable data on its risks. Therefore, we performed a meta-analysis on the mortality and morbidity of surgery for unruptured intracranial aneurysms.

METHODS

Through Medline and additional searches by hand, we retrieved studies on clipping of unruptured (additional, symptomatic, or incidental) aneurysms published from 1966 through June 1996. Two authors independently extracted data. We used weighted linear regression for data analysis.

RESULTS

We included 61 studies that involved 2460 patients (57% female; mean age, 50 years) and at least 2568 unruptured aneurysms (27% >25 mm, 30% located in the posterior circulation). Mortality was 2.6% (95% confidence interval [CI], 2.0% to 3.3%). Permanent morbidity occurred in 10.9% (95% CI, 9.6% to 12.2%) of patients. Postoperative mortality was significantly lower in more recent years for nongiant aneurysms and aneurysms with an anterior location; the last 2 characteristics were also associated with a significantly lower morbidity.

CONCLUSIONS

In studies published between 1966 and 1996 on clipping of unruptured aneurysms, mortality was 2.6% and morbidity was 10.9%. In calculating the pros and cons of preventive surgery, these proportions should be taken into account.

Giant aneurysm of the proximal anterior cerebral artery

BACKGROUND

Giant aneurysms originating from the proximal anterior cerebral artery (A1) are extremely rare. Only 12 cases have been reported previously.

CASE REPORT

A case of giant A1 aneurysm, which occurred in a patient with a progressive visual loss, is presented. The previous 12 cases are reviewed and discussed. This patient was treated by trapping and decompression of the aneurysm. These aneurysms bleed very rarely; they usually present with signs and symptoms secondary to the mass effect, including visual loss and progressive dementia. Most of these aneurysms have been treated by direct trapping of the aneurysm or by occlusion of the proximal anterior cerebral artery.

CONCLUSIONS

In most cases, trapping and decompression of the aneurysm is the treatment of choice, since they involve a long segment of the A1 that does not allow preservation of the parent artery if direct clipping is performed.