Management of giant intracranial aneurysms

Summary Based on an own material of 64 cases a survey is given on the management of giant intracranial aneurysms.Essential investigations are as well CT and Magnetic Resonance Scanning as detailed angiographic studies.With regard to the operative handling the following questions are discussed: approach; use of temporary vascular occlusion and related monitoring; preparation of the aneurysm neck for occlusion.In cases without recent subarachnoid haemorrhage morbidity and mortality were less than 10%. It was 15% in cases where recent haemorrhage had occurred.Invited Lecture, presented at the European Congress of Neurosurgery, Moscow, June 23–29, 1991.     

Natural history of giant intracranial aneurysms

The outcome of a consecutive series of 28 patients with giant aneurysm who had been followed without surgery from one month to 12 years after the diagnosis was made, are presented with reviewing their radiological and clinical features. Symptoms and signs were directly or indirectly attributable to the intracranial mass effect and nine patients (32%) presented subarachnoid hemorrhage. Subarachnoid hemorrhage was frequently associated with intraventricular or intracerebral hemorrhage, a poor clinical grading at admission and a high mortality. Subarachnoid hemorrhage was most often recorded from the giant aneurysm at the supraclinoid portion of the internal carotid artery and the vertebro-basilar artery, but the rupture from the intracavernous giant aneurysm, completely thrombosed giant aneurysm and the fusiform type of giant aneurysm was rare. The mortality rate in 28 cases for the above follow up period was 46% (13 in 28 cases) and major morbidity occurred in 11% (3 in 28 cases). The above outcome of non operated giant aneurysm cases may justify the surgical management of the giant aneurysm, but as the intracavernous giant aneurysm and thrombosed giant aneurysm are relatively harmless, surgical indication should be carefully decided, especially in the older patients.     

Clinico-radiological spectrum of giant intracranial aneurysms

A review of a series of 56 patients with a giant intracranial aneurysm showed that 28 presented with signs related to the mass effect and 19 with subarachnoid hemorrhage (SAH). Additional clinical signs observed were seizures, ischemia, and endocrinological disturbances. Fourty-five aneurysms involved the carotid artery territory and eleven the vertebrobasilar system. On computed tomography (CT) images partially thrombosed aneurysms (23 cases) showed 1) a marginal or central target appearance on contrast enhanced scans corresponding to the non-thrombosed lumen as demonstrated by angiography, 2) capsular enhancement in 16 cases and 3) calcifications in 9. SAH occured in 13 and 6 cases of non-thrombosed and partially thrombosed aneurysms, respectively. Magnetic resonance imaging (MRI) in 6 cases showed several layers of thrombosis in 4 cases and a small signal void close to the parent artery. In one case of a non-thrombosed aneuroysm, thrombosis was mimicked by flow artifacts of MRI.     

Surgical experiences with giant intracranial aneurysms

Summary The common method of presentation of intracranial aneurysms is at the time of their rupture (with subarachnoid haemorrhage) or on the occasion of their compression of neighbouring structures. While giant aneurysms may occasionally present with subarachnoid haemorrhage, their more common methods of presentation are due to their space occupying and neighbourhood effects²².Giant aneurysms are commonly defined as those with a diameter larger than 2.5cm. Previously this diameter was assessed either by arteriography, so that size meant internal diameter, or by the displacement of surrounding structures, as for example, small perforating vessels, which could be attributed positively to the presence of a larger mass. Before CT scanning however, the factor of a very considerable larger aneurysm, partly occluded by clot could occasionally cause unexpected operative difficulty. The advent of CT scan and now especially MR imaging has made the prediction of the size of the aneurysm much easier and the extent of the intraaneurysmal clot also clearly definable. This paper describes one surgeon's experience with 64 giant cerebral aneurysms operated on in the last 10 years (Table 1). It has emerged from this experience that the most satisfactory method of handling the lesion is to remove the intra-aneurysmal clot and clip the neck of the aneurysm, and the steps necessary to secure this laudable design form the burden of the paper.Presented at the EANS-Wintermeeting on High Risk Neurosurgery, Budapest, February 20–23, 1991.     

Surgical treatment of giant intracranial aneurysms.

The authors report the cases of 32 patients with aneurysms measuring 2.5 cm or greater in diameter found among 1080 patients with saccular cerebral aneurysms. Of the 32 patients, 24 patients were treated by direct operation, four by common carotid ligation, and the other four by conservative therapy. The appropriateness of surgery and surgical method are discussed.     

Stereotaxic thrombosis of inaccessible intracranial aneurysms.

Some intracranial aneurysms that might be considered inoperable by open craniotomy are readily treatable by stereotaxic thrombosis. This is possible because the stereotaxic technique requires only that some point on the fundus of the aneurysm can be punctured with a needle. Illustrative cases are given describing the successful treatment of aneurysms arising at the origin of the ophthalmic artery, within the cavernous sinus, within the sella turcica, and from the vertebrobasilar and the posterior inferior cerebellar arteries ventral to the brain stem. The aneurysms within the sella or cavernous sinus can be approached through the sphenoid sinus, and the aneurysms ventral to the brain stem can be approached through the clivus without opening the dura.     

Direct surgical treatment of giant intracranial aneurysms.

The author has operated on 40 patients with giant intracranial aneurysms, using various surgical approaches. Giant aneurysms predominated in females (3:1) and were most common in the age group 30 to 60 years. Patients presented with subarachnoid hemorrhage (17), visual disturbance (18), chronic headache (14), transient or progressive hemispheric deficit (6), seizure (2), dementia (2), and cerebrospinal fluid rhinorrhea (1). Giant aneurysms were located at the carotid artery (25), the basovertebral artery (8), the anterior communicating artery (5), and the middle cerebral artery (2). Eight of 40 patients had one or more other aneurysms and/or associated arteriovenous malformations. Aneurysms were treated with intramural thrombosis (21), neck occlusion (7), trapping (10), proximal parent artery ligation (1), and aneurysmorrhaphy (1). After as much as 8 years of follow-up, 32 patients (80%) showed complete or marked improvement in signs and symptoms; two patients (5%) had a poor recovery. There were six surgical mortalities (15%). Giant aneurysms can be treated with respectable results if the surgeon selects the technique best suited to the particular aneurysm. In general, neck occlusion, trapping, and aneurysmorrhaphy are best for giant aneurysms of the anterior circulation, and intramural thrombosis is best for those of the posterior circulation. Extra- and intracranial vascular anastomotic techniques are also of value. For success, a flexible approach is essential.     

Surgery for giant intracranial aneurysms using advanced technology

PURPOSE: Outcome of surgery for giant intracranial aneurysms is still unsatisfactory. The reason for complications is occlusion of perforators or parent arteries by the aneurysmal clipping itself or temporary occlusion of the main arteries. We report the surgical outcome of treatment of giant aneurysms using several advanced techniques which we devised to prevent these complications. MATERIALS AND METHODS: The subjects were eight patients with giant intracranial aneurysms who underwent surgery during the recent five years. Six patients had ruptured and two had unruptured aneurysms. Aneurysms were located at the ICA in five and the MCA in three patients. Aneurysmal sizes ranged from 25 to 50 mm. Preoperative 3DCTA was performed to investigate the aneurysm and the surrounding vessels in all cases. Patients with unruptured aneurysms at the ICA underwent balloon occlusion tests to check the potential for safe temporary occlusion of the parent artery, with SEP monitoring and Xe-SPECT. Intraoperative angiography and neuroendoscopes were used to prevent problems and complications which might be caused by aneurysmal clipping. RESULTS: In seven of eight cases, the aneurysmal neck was completely obliterated with clips and in one case the aneurysm was trapped with STA-MCA anastomosis. Glasgow Outcome Scale of the patients showed good recovery in six, moderately disabled (MD) in one and dead in one. The patient demonstrating MD developed hemiparesis due to vasospasm. One patient died from rebleeding of the aneurysm caused by slippage of the aneurysmal clip despite the confirmation of complete obliteration by intraoperative angiography. CONCLUSIONS: A better surgical outcome of treatment for giant aneurysms was obtained by temporary clips whose placement was based on the results of balloon occlusion test, as well as the use of intraoperative angiography and neuroendoscopes.     

Evaluation of the prognostic indicators of giant intracranial aneurysms

The indicators of poor outcome in giant intracranial aneurysms have been the subject of several studies in the literature. We conducted a retrospective analysis to evaluate the predictors of poor outcome in giant intracranial aneurysms. We studied consecutive cases with aneurysms admitted over a 9-year period in our institution. All the aneurysms were treated with clipping. Patient demographics, clinical profile, and aneurysm characteristics were evaluated in a multivariate analysis as probable indicators of Glasgow Outcome Scale (GOS) score. The outcome of the aneurysms (GOS score) was compared with the remaining non-giant aneurysms. A total of 41 giant and 348 non-giant aneurysms were identified in our series. In the multivariate analysis, the indicators of poor outcome were identified as poor clinical grade (p < 0.0004), intraoperative rupture (p < 0.007), and posterior circulation of the aneurysms (p < 0.01). Non-giant aneurysms had a better outcome compared with the giant aneurysms (p < 0.01). Giant aneurysms impose a relatively higher risk of morbidity and mortality to the patients. The predictors of the postsurgical outcome of the giant aneurysms include the clinical condition of the patient, location of the aneurysm, and intraoperative rupture.     

Magnetic resonance imaging of large and giant intracranial aneurysms.

Twelve large or giant intracranial aneurysms were studied with magnetic resonance (MR) imaging, and the findings were compared with those from computed tomographic (CT) scanning. Characteristic MR features of such aneurysms are: round, extra-axial mass with hypointensity rim; signal void, paradoxical enhancement, or even-echo rephasing due to blood flow; and laminated, eccentric thrombus with increased signal intensity when fresh, perianeurysmal hemorrhage occurs in the acute or subacute stage after aneurysmal rupture. MR imaging, however, often fails to identify or characterize the area of calcification. For the diagnosis of large or giant intracranial aneurysms, MR imaging is apparently superior to CT scanning in differentiating aneurysms from tumors, delineating the blood flow and intraluminal thrombus, and detecting the exact size of the aneurysm. It may also provide useful information concerning the growth mechanisms of aneurysms with or without thrombus formation.     

电凝血栓形成机制及其用于治疗颅内动脉瘤研究进展

电凝技术治疗颅内微小动脉瘤的效果较好,但目前对于电凝血栓形成的病理生理学机制及其手术、术后远期复发率等问题仍存在争议。本文就电凝血栓形成机制及其应用于颅内动脉瘤的研究进展进行综述。     

Saphenous vein bypass grafts for giant aneurysms and intracranial occlusive disease

The authors report their experience with the use of saphenous vein bypass grafts for treating advanced occlusive disease in the posterior circulation (77 patients, all of whom had failed medical management and showed severe ischemic symptoms), deteriorating patients with giant aneurysms of the posterior circulation (nine patients), progressive ischemia in the anterior circulation (26 patients, none of whom had a normal examination), and giant aneurysms in the anterior circulation (20 patients, all of whom presented with mass effect or subarachnoid hemorrhage). Graft patency in the first 65 cases treated was 74%. However, after significant technical changes of vein-graft preparation and construction of the proximal anastomosis, patency in the following 67 cases was 94%. Excellent or good results (including relief of deficits existing prior to surgery) were achieved in 71% of patients with advanced occlusive disease in the posterior circulation, 44% of those with giant aneurysms of the posterior circulation, 58% of those with ischemia of the anterior circulation, and 80% of those with giant aneurysms of the anterior circulation. Mean graft blood flow at surgery in the series was 100 ml/min for posterior circulation grafts and 110 ml/min for anterior circulation grafts. Experience to date indicates that this is a useful operation, and is particularly applicable to patients who are neurologically unstable from advanced intracranial occlusive disease in the posterior circulation or with giant aneurysms in the anterior circulation. The risk of hyperfusion breakthrough with intracerebral hematoma restricts the technique in patients with progressing ischemic symptoms in the anterior circulation, and the intolerance of patients with fusiform aneurysms in the posterior circulation to the iatrogenic vertebrobasilar occlusion limits the applicability of this approach to otherwise inoperable lesions in that system.     

Complete asymptomatic thrombosis and resorption of a congenital giant intracranial aneurysm

Intracranial aneurysms in infants are rare, but are associated with a high risk of rupture and subarachnoid hemorrhage. The authors report a case of an incidentally diagnosed, probably congenital, asymptomatic giant aneurysm of the posterior communicating artery in a 9-month-old girl, which completely thrombosed following a diagnostic superselective angiography without any neuropathological incident. Follow-up magnetic resonance imaging revealed that the aneurysm decreased further in size and was largely resorbed within 3 years after the initial finding. In single cases the natural history of congenital giant aneurysms may be better than previously assumed.