Giant basilar artery aneurysms encorporating the posterior cerebral artery: bypass surgery and coil occlusion--two case reports.
(17/2635)
Giant aneurysms of the basilar artery are rare. With a diameter of 25 mm or more they are often partially thrombosed and show atheromatous plaques. There are some problems in the treatment especially when the aneurysm is broadbased with bulbous origin encorporating the origin of the posterior cerebral artery (PCA). In many of these cases neither operative clipping alone nor coil embolization alone will be practical without causing an ischemia in the depending brain areas. We will report about two patients with giant aneurysms of the basilar artery involving the origin of the PCA and a combined surgical and interventional neuroradiological approach. Preoperatively both patients showed only mild neurological symptoms (slight left hemiparesis, incomplete hemianopsia). We anastomosed the superficial temporal artery as an extracranial-intracranial bypass end-to-side to the PCA followed by clipping the PCA out of the aneurysm. Next day embolization of the aneurysm with Guglielmi ditachable coils was done. Both patients recovered without complications. An angiographic control showed no more filling of the aneurysm and a free running bypass feeding the PCA. In our opinion this combined approach is an effective method to treat giant aneurysms of the basilar artery which involve the origin of the PCA when clipping alone is impossible. (+info)
Clinical characteristics of vertebrobasilar artery dissection.
(18/2635)
Sixteen patients with the diagnosis of vertebral or basilar artery dissection who were admitted at the Seoul National University Hospital from 1972 to 1996 are described. During the same period, we encountered 76 patients with posterior circulation aneurysms, so the vertebrobasilar artery dissection was 21% of posterior circulation aneurysms. The mean age was 44 years, and male predominated. Nine patients presented with subarachnoid hemorrhage (SAH) and seven with ischemic symptoms. The characteristic angiographic finding of patients with SAH was aneurysmal dilatation (pseudoaneurysm) in eight of nine cases. In cases of ischemic symptoms, only one case had aneurysmal dilatation. Some other angiographic findings were demonstrated such as string sign, tapered narrowing, complete occlusion, or double lumen. Clinical course of SAH group was much different from that of ischemic group. Rebleeding occurred in three patients of SAH group; immediately after the rebleeding all patients became comatose, but after extraventricular drainage, all patients with rebleeding recovered rapidly. In SAH group, four of nine cases died but there was no mortality in the ischemic group. These four patients showed signs of stem failure, when computed tomography (CT) demonstrated no evidence of additional bleeding and follow-up CT showed the infarction at a part of stem and/or cerebellum. Vasospasm or sudden extensive extension of dissection could be the cause of death. Surgical management was performed in three patients, endovascular intervention in four, and conservative management in two. The patients with incomplete embolization or conservative management had poor outcome. In ischemic group, all underwent conservative management including anticoagulation and/or antiplatelet therapy. On follow-up, most of the patients with ischemic symptoms made complete or very good recoveries. (+info)
Multimodality treatment for large and critically located arteriovenous malformations.
(19/2635)
To define the current status of the multimodality treatment for large and critically located arteriovenous malformations (AVMs), we have made a retrospective review of 54 consecutive patients with Spetzler-Martin grade IV and V AVMs. The size of nidus is larger than 3 cm in diameter in all cases. Initially, all but one were treated by nidus embolization with the aim of size reduction. Only one patient had complete nidus occlusion by embolization alone. In 52 patients, the obliteration rate of nidus volume averaged 60% after embolization. Ten patients underwent complete surgical resection of AVMs following embolization with no postoperative neurological deterioration. Thirty-one patients underwent stereotactic radiosurgery following embolization. At the time of this analysis, 30 patients underwent follow-up angiography 2-3 years after radiosurgery. The results of radiosurgery correlated well with the preradiosurgical AVM volume. Of 16 patients with small residual AVMs (< 10 cm3, a mean volume of 4.7 cm3), nine (56%) had complete obliteration, and six (38%) had near-total or subtotal obliteration by 3 years after radiosurgery. In contrast, of 14 patients with large residual AVMs (> or = 10 cm3, a mean volume of 17.9 cm3), only two (14%) had complete obliteration, and eight (57%) had near-total or subtotal obliteration. Repeat radiosurgery was performed for the patients with remaining AVMs at 3-year follow-up review. This study indicates that a certain number of large and critically located AVMs can be safely treated by either microsurgery or radiosurgery following a significant volume reduction by nidus embolization. The present data also suggest the need and possible role of repeat radiosurgery in improving complete obliteration rate of large difficult AVMs, since many of those AVMs have significantly responded to initial radiosurgery. (+info)
Embolization of cerebral arteriovenous malformations (AVMs)--material selection, improved technique, and tactics in the initial therapy of cerebral AVMs.
(20/2635)
Successful embolization can be achieved only when the following three factors are correct and in co-operation: catheter tip position, flow control, and the setting time of normal-butyl cyanoacrylate (NBCA). Otherwise, the procedure may end with unsatisfactory results or complications. The current principle of safe and efficient embolization of cerebral arteriovenous malformation (AVM) is based on superselective cannulation of every strategically important feeding pedicle and injection of liquid embolic material under flow control. This study was based upon our experiences of embolizing 92 cases with cerebral AVM performed under the above conditions at our department. Results showed very encouraging new observations with implications for further procedures: total removal of the AVM nidus after embolization was achieved in 90% of the cases, preradiosurgical embolization achieved 52% volume reduction and successfully maneuvered all cases into the gamma knife focal spot. Recently improved microcatheters with increased flexibility and minimal friction made it possible to place the tip of the microcatheter into the nidus with a higher success rate and better safety factors. In order to obliterate a substantial amount of the AVM nidus and prevent penetration into the draining veins, the creation of optimal flow status, and optimal setting time of NBCA have paramount importance. (+info)
Microsurgical resection of incompletely obliterated intracranial arteriovenous malformations following stereotactic radiosurgery.
(21/2635)
Radiosurgery is effective in obliterating small arteriovenous malformations (AVMs), but less successful in thrombosing larger AVMs. This study reviewed patients who underwent surgical resection of their large AVMs following failed radiosurgical obliteration. AVMs from 36 patients (aged 7 to 64 years, mean 29.9) were surgically resected 1 to 11 years after radiosurgery. Initial AVM volumes were 0.7 to 117 cm3 (mean 21.6 cm3), and radiosurgical doses ranged from 4.6 to 45 Gray equivalent (GyE) (mean 21.1 GyE). Thirty AVMs (83%) were located in eloquent tissue. Venous drainage was deep (14), superficial (13), or both (9). Spetzler grades were II (2), III (12), IV (18), and V (4). Nine patients suffered rehemorrhage after radiosurgery but prior to surgery, while three patients developed radiation necrosis. Twenty-seven patients underwent endovascular embolization prior to surgery. During microsurgical resection, the AVMs were found to be significantly less vascular and more easily resected, compared to AVMs in patients who had not received radiosurgery. Histology showed endothelial proliferation with hyaline and mineralization in vessel walls. Partial or complete thrombosis of some AVM vessels, and evidence of vessel and brain necrosis were noted in many cases. Clinical outcome was excellent or good in 34 cases, with two patients dying of rebleeding from residual AVM. Five patients were neurologically worse following microsurgical resection. Final outcome was largely related to the pretreatment grade. Radiosurgery several years prior to surgical resection appears useful in treating unusually large and complex AVMs. (+info)
Management of pericentral arteriovenous malformations.
(22/2635)
Pericentral arteriovenous malformations (AVMs) have more often been deemed inoperable lesions because of their complexity, owing to their critical locations and dismal outcome. This study discusses the management of this group of patients with a variety of treatments which includes surgery, nidus embolization, and radiosurgery. Out of 89 patients treated for AVMs in our institute over a period of 30 months (1992 through May 1995), we present a case series of 34 patients who had AVMs located in the pericentral region. All the treated AVMs were Spetzler and Martin grade III (6 patients), grade IV (13 patients), and grade V (15 patients). The neurological outcome remained, normal or improved from baseline in 68% of patients following treatments; of the remaining 32%, 19% remained in the same condition (with continuing preoperative deficits) and 10% showed some deterioration from their pretreatment condition. Thus 87% were unchanged or improved after the treatment regime. There was a 3% mortality (one patient who died as result of initial hemorrhage) in the series. Our multimodality treatment for this group of AVMs confirms the efficacy of the practiced strategies for their management. The results derived from the experience with this selected group of patients with AVMs lead us to recommend treating these patients with multimodality regimen rather than awaiting the natural history of the disease in the best interest of the patients. (+info)
Surgery for deeply seated arteriovenous malformation: with special reference to thalamic and striatal arteriovenous malformation.
(23/2635)
Surgery for deeply seated arteriovenous malformation (AVM) is controversial because stereotactic irradiation is applicable to the lesion. We have, however, experienced 30 deeply seated AVMs treated by direct surgery and/or endovascular treatment. The present study shows profiles of those patients and results of surgery. They include AVM in the thalamus in 12 cases, striatum in four cases, paraventricular area in five cases, medial temporal lobe in three cases, intraventricular area in three cases, and other regions in three cases. They were treated by surgery alone in 23 cases, embolization followed by surgery in four cases, and embolization alone in three cases. AVM in the mediodorsal thalamus and fornix (5 cases) was best treated by transcallosal approach. Venous aneurysm was commonly found in the AVM of this region and was a good navigator to the AVM. Pulvinar AVM was accessible through posterior interhemispheric approach (2 cases). None of these cases had additional neurological deficits. Cadaver dissection was useful for acquisition of surgical approach. Striatal AVM was approached through hematoma cavity with minimal manipulation to the surrounding structures, yet two of four cases showed progression of their weakness. The present study indicates that thalamic AVM can be approached surgically with careful selection of the approach. On the other hand, striatal AVM is not a good candidate for direct surgery and better treated by stereotactic irradiation. (+info)
Treatment strategies and results in spinal vascular malformations.
(24/2635)
We report the treatment strategies and results of 70 patients with spinal vascular malformations. Forty-six had dural arteriovenous fistulas, 12 spinal cavernous angiomas, nine intramedullary angiomas, and three intradural arteriovenous fistulas. The diagnosis was established for cavernomas by magnetic resonance images only and in the other cases by selective spinal angiography in patients whose neurological deficits, myelograms or magnetic resonance images suggested the presence of a spinal vascular malformation. All patients had symptomatic vascular malformations and were treated microsurgically. Intramedullary angiomas were operated when embolization seemed too dangerous or impossible and when they had a contact to the dorsal or lateral surface of the spinal cord. All but one were completely resected. In one angioma a small ventral residual fistula area was left. Complete obliteration of all fistulas was achieved. The cavernomas were primarily resected. Apart from one postoperative permanent deterioration with a paresis of the left arm in a patient with an intramedullary angioma, 16 cases presented only a transitory worsening of their neurological status after surgery. The long-term outcome of all these patients was good. Five patients had to be operated on again: three patients showed difficult localizations of dural fistulas which were still visible in the postoperative angiograms, one patient suffered a spinal epidural hematoma, and another patient showed a cerebrospinal fluid accumulation. We conclude that spinal dural arteriovenous fistulas, small intradural fistulas, spinal cavernomas, and symptomatic spinal angiomas with contact to the lateral or dorsal surface can be treated microsurgically with low perioperative morbidity. (+info)