Giant Arteriovenous Malformation Research Articles

Image registration and calculation of a biologically effective dose for multisession radiosurgical treatments

✓ The purpose of this study was to develop techniques for registering image sets associated with staged or multifraction radiosurgical treatments of large targets with the Leksell gamma knife to transform shot coordinates between treatment sessions and produce cumulative dose distributions and to investigate the theoretical biological effects of such protracted treatments by means of such concepts as the linear—quadratic model and biologically effective dose. An image registration technique based on normalized mutual information was adapted to produce one fused-image study from an imaging series acquired during distinct treatment sessions. A spreadsheet computer program was developed to determine coordinate transformations between the associated stereotactic coordinate systems based on digitized coordinates of fiducial markers appearing on the fused images. Coordinates of shots used during one treatment session could then be transformed to the stereotactic space of another session, and cumulative dose distributions could be computed. The procedure was applied to the two-stage treatment of a giant arteriovenous malformation (AVM). Overall uncertainty in each transformed shot position is approximately 0.7 mm. An effective single-fraction dose (Deff) was defined and computed for the two-stage AVM treatment. The simple summed dose distribution was compared with the Deff distribution. Because dose values differ significantly in overlap regions between the individual distributions, the clinical usefulness of the simple cumulative distribution is dubious. It may be useful for a future update of the GammaPlan treatment planning software to generate effective single-session dose distributions for such cases.

Combination of intraoperative embolisation with surgical resection for treatment of giant cerebral arteriovenous malformations

Objective: To reduce the risk of surgical resection of giant arteriovenous malformation (AVM) and prevent normal perfusion pressure breakthrough (NPPB) and thus to lower postoperative mortality.Methods: During the operation, which was carried out under general anaesthesia, the proximal ends of the feeding arteries were first ligated and 0.5 ml IBCA mixed with 0.5 ml of 5% glucose was injected into the vessels towards the AVM, then the malformed vessels were totally resected. Postoperative digital subtraction angiography (DSA) of the four vessels was performed in all patients.Results: Fifty patients with giant AVMs survived after operation, only 6 (12.0%) had transient neurological dysfunction and 44 (88.0%) recovered after a follow-up of 6–36 months. No patient suffered from NPPB.Conclusions: The embolisation could block the arteriovenous shunts sufficiently to decrease the blood flow away from the normal areas of the brain so as to prevent the incidence of intra- and post-operative rebleeding, especially in NPPB. Therefore, the combination of intraoperative embolisation with surgical resection is an effective strategy in the treatment of giant cerebral AVMs, which makes it possible to operate on patients who used to be regarded as inoperable cases.

ARTERIOVENOUS MALFORMATIONS IN FUNCTIONAL AREAS OF THE BRAIN.

For Arteriovenous Malformations (AVMs) in so-called \`non-eloquent' brain regions, the therapeutic regimen is rather straightforward unless they are giant (>6 cm): in experienced hands microsurgical removal has the highest success rates with regard to complete AVM elimination as well as to associated morbidity when compared with the other treatment modalities. In patients with giant AVMs or with AVMs in \`eloquent' (i.e. functional) regions, however, morbidity—transient and permanent—may be high. They may be subject to various therapeutic options from microsurgery or radiosurgery alone to combined approaches (e.g. embolization + radiosurgery or embolization + microsurgery + radiosurgery) depending on size and location. It needs to be pointed out that even in these difficult lesions the ultimate goal of any therapeutic approach in AVM patients remains complete DSA-controlled obliteration of the AVM in order to avoid subsequent rupture with the potential for life-threatening bleeding. Few books deal with cerebral AVMs in detail, and Professor Shokei Yamada has undertaken the task to report on his surgical experience with 135 AVMs located in `functional' brain regions. The book is structured in 12 chapters, with five written by Professor Yamada himself and the remaining seven by renowned experts in their respective fields. On initial browsing some technical shortcomings of the book become evident. First, most chapters of the book are subdivided into subsections, which are not mentioned in the index of contents. Secondly, many intraoperative photographs and angiographic pictures are dark and not in focus. Thirdly, the figures drawn by the medical illustrator tend to be too simplistic, in particular, when it comes to descriptions of surgical technique, where elaborate drawings could be of great value to foster understanding. Fourthly, some figure legends are incomplete: What is the meaning of the three arrows in Figure 10C, etc.? Last but not least, in the preface, the names …

Surgical treatment of pericentral arteriovenous malformation

Surgical treatment of pericentral arteriovenous malformation (AVM) near the central sulcus is discussed. Thirty-four patients with pericentral AVM were treated and they can be classified into four subtypes: operculofrontal AVM (nine cases); dorsolateral AVM (nine cases); parasagittal AVM (11 cases); and giant AVM involving sensorimotor cortices (five cases). In all surgically treated patients with operculofrontal AVM or dorsolateral AVM, nidi were totally removed and permanent morbidity was 6%. On the other hand, complete obliteration was usually difficult for parasagittal AVMs. Among six patients with surgically-treated parasagittal AVM, transient paralysis was found in three (50%) and permanent morbidity was observed in one (17%). Among four patients with parasagittal AVM who were treated by embolization therapy alone, transient paralysis was found in three (75%) and permanent morbidity was recognized in two cases (50%).

Normal perfusion pressure breakthrough syndrome in giant arteriovenous malformations

The treatment of largel high-flow cerebral arteriovenous malformations is one of the most difficult operations which neurosurgeons encounter because of the complex surgery and the post-operative effects on the brain. We have evaluated 10 patients with largel high-flow AVMs who underwent surgical resection. Patients were investigated with contrast-enhanced computed tomography and magnetic resonance imagingl 1231-IMP single photon emission computed tomography (SPECT) studies of cerebral flow and cerebral vasodilatory functionl intraoperative Laser Doppler flowmetry (4 or 10 patients)1 and conventional angiography. The volume of the arteriovenous malformation nidi ranged from 32.8 to 210.5 cc. SPECT imaging performed on the first post-operative day showed marked hyperperfusion in the brain tissue surrounding the resected nidusl and these regions were normal on images on the 7th post-operative day. Laser Doppler flo wmetry showed suddenl and marked increase in CBF immediately following placement of temporary clips on the main feeding artery. Angiograms done on 7-14 days following surgery showed a stagnating arterYI fragile vessell and a prolonged circulation time. Our results indicate that pre- and post-operative SPECT studYI especially a dynamic SPECT study done on the first post-operative daYI was the most useful examination for ascertaining the post-operative normal perfusion pressure breakthrough. [Neural Res 1997; 19: 117–123]

後頭蓋窩AVMに対する摘出術

The authors have already reported surgical problems of poor-risk patients with hemorrhagic infratentorial arteriovenous malformations (AVMs). In the presents study, fifteen good-risk patients of infratentorial AVMs, whose levels of consciousness was 0 to 30 according to the Japan Coma Scale, were reviewed and the problems of the surgical treatment are reported. Of this series, 12 patients had a good result, and 3 patients a poor result. Giant AVM and AVM extending from the cerebellum to the brainstem showed an unsatisfactory surgical result. Two out of 3 poor results were due to massive postoperative hemorrhage, related to a residual nidus in the brainstem in one patient, and probably related to a sudden rise in intravascular pressure after removal of giant AVM in one. The present study suggests that presurgical multiple-staged embolization of nidus and a strict control of postoperative systemic blood pressure are important in order to reduce surgical risks of giant AVMs. Furthermore, stereotactic radiosurgery must be considered in combination with surgical treatment for an AVM involving the brainstem.

術前塞栓術により劇的に神経脱落症候が改善し全摘出に成功した巨大脳動静脈奇形の1症例

術前塞栓術により劇的に神経脱落症候が改善し全摘出に成功した巨大脳動静脈奇形の1症例

Congenital Giant Arteriovenous Malformation in a 31 - Year-old Male

In this case presentation we report the history of a 31-year-old male suffering from a congenital giant arteriovenous malformation (AVM) of the neck and the right chest wall over the course of 12 years. This vascular tumor was fed by dilated arteries, branches of the right external carotid, and both subclavian arteries. The first therapeutic procedure was an isolated ligation of the draining arteries, which was not successful as angiography showed two years later. As the patient rejected any further therapy, the enormous growing tumor was again treated 9 years later. At this time an interdisciplinary management involving radiologists and surgeons was arranged. Superselective embolization preceding surgical radical tumor resection was performed. After a follow-up period of almost 1 year no further signs of progression were seen, except the postsurgical embolization of one collateral external carotid branch and a beginning skin necrosis which was to be expected. However, recently progression has become evident, but the patient has refused further treatment.

大型AVMの手術成績に関連する諸因子と対策

大型AVMの手術成績に関連する諸因子と対策

Surgical management of large AVM's by staged embolization and operative excision.

A series of 20 patients with giant arteriovenous malformations (AVM's) managed with staged embolization and surgical resection is presented. Complete excision was accomplished in 18 of these patients. There were no deaths and only three complications, of which one was disabling. Further evidence for the presence of low perfusion surrounding the AVM, emphasizing the risk of normal perfusion pressure breakthrough, is provided by cortical perfusion pressure, cortical cerebral blood flow (CBF), and stable xenon computerized tomography CBF measurements. The staged approach to giant AVM management is a proposed method to render AVM's that were previously considered inoperable or marginally operable into totally excisable lesions, while maintaining an acceptable level of morbidity and mortality.

Pineal region: Surgical management of tumours and vascular malformations

From August, 1977, to April, 1980, 11 patients were operated on for lesions in and around the pineal region. The pathology consisted of 8 tumours, 1 giant arteriovenous malformation of the vein of Galen, 1 giant aneurysm of the posterior cerebral artery, and 1 venous malformation of the vein of Galen. A different tactical approach was used, depending upon the location and the type of lesion. The present series documents the feasibility of the direct surgical attack on vascular and tumoural lesions of the pineal region with low mortality and no morbidity. Tactical and technical aspects are discussed.

Giant arteriovenous malformations of infancy and childhood.

✓ Twelve patients are presented with giant arteriovenous malformations of the brain requiring therapy in the neonatal or infant period. Eight patients were operated on, and six survived with no neurological deficit. Four patients were not operated on and all died. The diagnostic clinical triad of enlarged head, cranial bruit, and cardiac failure or enlargement is described, and angiographic characteristics and surgical therapy discussed.