Intention-to-treat analysis of Spetzler-Martin grades IV and V arteriovenous malformations: natural history and treatment paradigm

OBJECT: In this study the authors quantified a subgroup of patients with Spetzler-Martin Grades IV and V arteriovenous malformations (AVMs) recommended for complete, partial, or no treatment, and calculated the retrospective hemorrhage rate for these lesions. METHODS: Between July 1997 and May 2000, 73 consecutive patients with Grades IV and V AVMs were evaluated prospectively by the cerebrovascular team at Barrow Neurological Institute. Treatment recommendations given to the patients or referring physicians were classified as complete treatment, partial treatment, and no treatment. Retrospectively, the hemorrhage rates associated with these treatment groups were also calculated. In the prospective portion of the study (the intention-to-treat analysis), no treatment of the AVM, was recommended for 55 patients (75%) and partial treatment was recommended for seven patients (10%). Aneurysms associated with an AVM were obliterated by surgical or endovascular treatment in seven patients (10%), and complete surgical removal was recommended for four patients (5%). The overall hemorrhage rate for Grades IV and V AVMs was 1.5% per year. The annual risk of hemorrhage was 10.4% among patients who previously had received incomplete treatment, compared with patients without previous treatment. CONCLUSIONS: The hemorrhage risk of 1.5% per year, which was associated with Grades IV and V AVMs appears to be lower than that reported for Grades I through III AVMs. The authors recommend that no treatment be given for most Grades IV and V AVMs. No evidence indicates that partial treatment of an AVM reduces a patient's risk of hemorrhage. In fact, partial treatment may worsen the natural history of an AVM. The authors do not support palliative treatment of AVMs, except in the specific circumstances of arterial or intranidal aneurysms or progressive neurological deficits related to vascular steal. Complete treatment is warranted for patients with progressive neurological deficits caused by hemorrhage of the AVM. This selection process plays a significant role in the relatively low combined morbidity and mortality rates for Grade IV and Grade V AVMs (17 and 22%, respectively) reported by the cerebrovascular group in both retrospective and prospective studies.     

Surgical risks associated with the management of Grade I and II brain arteriovenous malformations

OBJECTIVE: Grade I and II arteriovenous malformations (AVMs) have been considered safe to resect. However, unoperated low-grade AVMs have not been considered in previously reported series. The aim of this study was to examine all cases, both operated and unoperated, to identify any characteristics of low-grade AVMs that comprise a subgroup that might pose a relatively higher risk. METHODS: A prospectively enrolled AVM database included 237 patients in Spetzler-Martin Grade I or II. These patients were analyzed on the basis of demographic characteristics, angiographic and magnetic resonance imaging features, clinical presentation, method of treatment, and outcome. RESULTS: Surgery was performed in 220 patients in Spetzler-Martin Grade I or II. Seventeen patients did not undergo treatment because of poor neurological condition (six patients), patient refusal (nine patients), and perceived surgical difficulty (AVM size approaching 3 cm adjacent to Broca's area) (two patients). The overall surgical morbidity rate was 0.9%, and the mortality rate was 0.5%. Adverse outcomes occurred in 1 (0.6%) of 180 patients with AVMs located away from eloquent cortex and in 2 (5%) of 40 patients with AVMs adjacent to eloquent cortex. None of 28 surgical patients with deep venous drainage had an adverse outcome. All 219 patients who survived surgery underwent postoperative angiography that confirmed cure. No postoperative hemorrhage has occurred in 1143 patient-years of follow-up (mean follow-up, 5.3 yr). CONCLUSION: When considering adverse outcome in the surgical series of Grade I and II AVMs alone, no statistical difference between non-eloquently located AVMs (0.6%) and eloquently located AVMs (5% adverse outcome) can be detected. However, consideration of all Grade I and II AVMs, both surgical and nonsurgical, may prove that a difference in outcome exists between these two groups masked by case selection. Generalization of the chances of adverse outcomes to all Grade I and II AVMs (both operated and unoperated) suggests that the risk of performing surgery on noneloquent brain in our series was 0.6% and that in eloquent brain could have been as high as 9.5%, had all such patients undergone surgery.     

Intracranial arteriovenous malformations

Intracranial arteriovenous malformations (AVM) are rare lesions that are often discovered fortuitously. They should be identified on CT scan and MRI before resorting to angiography; the latter is used to prepare the treatment. This article describes the various types of subpial or dural AVM and the specific characteristics that enable their differentiation with non-invasive imaging. The factors that determine the severity of these lesions, whether discovered before or after a haemorrhage, are described, as well as prognostic indicators.     

Spetzler-Martin Grade III arteriovenous malformations: surgical results and a modification of the grading scale

OBJECTIVE: To analyze surgical results for the highly variable Spetzler-Martin Grade III arteriovenous malformations (AVMs), to demonstrate that outcomes vary among the different types of Grade III lesions, and to introduce a simple modification of the grading scale that might improve its usefulness for these AVMs. METHODS: In a consecutive series of 174 brain AVMs resected from 174 patients during a period of 4.8 years, 76 AVMs (45.2%) were Grade III. There were 35 small AVMs (S1V1E1) (46.1%), 14 medium/deep AVMs (S2V1E0) (18.4%), and 27 medium/eloquent AVMs (S2V0E1) (35.5%). No large Grade III AVM (S3V0E0) was treated. RESULTS: Complete AVM resection was accomplished for 74 patients (surgical obliteration rate, 97.4%). Three patients (3.9%) experienced permanent, treatment-associated, neurological morbidity, and three patients died (surgical mortality rate, 3.9%). Good outcomes (Rankin scale scores of 相似文献   

Management of arteriovenous malformations

This article describes the clinical features, diagnosis, and management of arteriovenous malformation, capillary malformation-arteriovenous malformation, and PTEN-associated vascular anomaly.     

Angiographically occult arteriovenous malformations

Angiographically occult arteriovenous malformations not associated with clinically recognizable intracranial hemorrhage appear to be rare. We are reporting three cases of histologically proven arteriovenous malformations of the brain that were angiographically occult. These cases presented with seizures or attacks of dizziness, and were detected by computed tomography scan, radionuclide scan, or both. The preoperative diagnosis was granuloma in the first case and meningioma in the other two. After surgical exploration, biopsy revealed an arteriovenous malformation in each case. A review of 47 cases in the literature is tabulated and etiologies of the angiographically occult arteriovenous malformations are discussed. The routine use of computed tomography scan and timely, appropriate surgical intervention with the operating microscope for the removal of these deeply situated lesions is necessary for the diagnosis and therapy.     

Congenital renal arteriovenous malformations

Congenital renal arteriovenous malformations are rare, but their incidence and frequency of recognition are rising. Six cases of both cirsoid and idiopathic varieties are described. Patients were either asymptomatic or presented with gross hematuria and flank pain. Physical findings included hypertension, cardiomegaly, flank tenderness, and an abdominal bruit. IVP findings included filling defects in the renal pelvis from blood clots, irregular mucosal pattern, or mass effect. Angiography demonstrated either single, simple, vascular channels or multiple, complex, varix-like communications. In both there was early filling of the renal vein, a normal caliber to the feeding artery and draining vein, and no displacement of parenchymal vessels. Asymptomatic patients required no treatment. Surgical procedures that spare renal parenchyma are preferred.     

Sylvian fissure arteriovenous malformations

We have operated on 16 cases of arteriovenous malformation (AVM) in and around the sylvian fissure. We call these lesions "sylvian fissure AVMs" and classify them into four subdivisions, namely, pure, lateral, medial, and deep AVMs. By others, they have been variously called AVMs of the basal ganglia, insula, anterior choroidal artery, frontal lobe, or temporal lobe. These sylvian fissure AVMs showed similar angiographic findings: the feeders in all cases were branches of the middle cerebral artery; in some cases, additional feeders from the anterior and posterior choroidal and posterior communicating arteries were present also. We describe the characteristic features of these AVMs from the anatomical and surgical points of view. The surgical results were satisfactory in 15 cases (no additional neurological deficits), and 1 patient died.     

Pulmonary arteriovenous malformations]

This study concerns 11 patients; 7 had a Rendu-Osler-Weber disease. They were 5 males and 6 females, including 3 children. In addition to the thoracic symptoms of cyanosis, clubbing and polycythemia, 4 had been treated for a cerebral abscess. Standard chest films were normal in 2 cases. The anatomy of the malformations was studied by CT scans and angiographies. The 11 patients had 25 malformations, bilateral in 5 cases. All were hypoxennic. Four solitary lesions were resected by 3 lobectomies and 1 excision. Seven multiple lesions were treated by 1 pneumonectomy, 1 lobectomy, 1 segmentectomy + 1 excision and by 1 excision. In 2 of these cases radiology and surgery were associated. Two patients were treated by radiological vaso-occlusion. The 9 operated patients have remained cured with a mean 4.7 year follow-up, one still has a small, non evolutive anomaly. The 2 radiologically treated patients still have 2 non evolutive lesions. This cases allow a discussion concerning the diagnosis and treatment of arteriovenous malformations of the lung which can provoke grave complications. A long follow-up of treated patients is necessary.     

Angiographically occult arteriovenous malformations

Eight cases of histopathologically proven arteriovenous malformations (AVM's) which were not visualized on angiography are presented. As is typical with these lesions, most of the patients in this series presented with hemorrhage, seizures, or episodic or progressive neurological symptoms suggestive of a neoplasm. The diagnosis of angiographically occult AVM was highly suspected preoperatively in each case based on the combination of computerized tomography (CT) and magnetic resonance (MR) findings. The CT scans in all cases showed moderately hyperdense lesions which enhanced mildly or moderately in a nonhomogeneous pattern with administration of contrast material. The MR image showed one or more bright areas interspersed with areas of low or absent signal peripherally or centrally on both T1- and T2-weighted images. The AVM was totally excised in seven patients and partially excised in one patient, with favorable results in all. The clinical management and differential diagnosis of angiographically occult AVM's are discussed. In patients with a clinical course and radiological studies suggestive of an occult AVM, removal of the lesion, if accessible, should be performed in order to rule out a neoplasm and prevent subsequent hemorrhage and progression of symptoms.     

Posterior fossa arteriovenous malformations

The authors report their treatment of 66 infratentorial arteriovenous malformations (AVM's) in patients aged 5 to 69 years. Sixty-one of them presented with hemorrhage, three with headache, and two with focal neurological deficits. Five patients underwent surgical exploration only, one was treated with ventriculostomy, three had ligation of the AVM feeding arteries, four underwent intraoperative embolization, and two had pontine hematomas removed; complete excision was attempted in 51 patients and accomplished in 47. Twelve of the patients also had aneurysms (nine of which had ruptured). Of this series, 71% had a good result, 14% a poor result, and 15% died. Most of the operative morbidity was due to massive postoperative hemorrhage, probably related to inadequate hemostasis.