Spontaneous disappearance of a renal arteriovenous malformation

We describe herein a case of complete spontaneous disappearance of a congenital arteriovenous malformation (AVM). A 28-year-old male was hospitalized for right flank pain and gross hematuria, followed by bladder tamponade. To improve the patient's symptoms, bladder irrigation was performed. Cystoscopy demonstrated bloody urine from the right ureteral orifice. Right selective renal arteriography demonstrated tortuous, coiled vascular channels with early filling of the renal vein. Thus, right renal AVM was diagnosed. However, the patient refused further treatment and was discharged. One year later, massive hematuria recurred with bladder tamponade and the patient was rehospitalized. Renal arteriography did not show any evidence of AVM and there has been no hematuria since.     

Spontaneous angiographic obliteration of cerebral arteriovenous malformations

OBJECTIVE: The factors associated with spontaneous angiographic obliteration of cerebral arteriovenous malformations (AVMs) are not well understood. We present a review of the literature and a report of our experience with six cases (four with no previous treatment intervention and two postoperative residual malformations) that were identified as having occurred during a 20-year period and describe the clinical and lesion features associated with this rare phenomenon. We present the first detailed histological study of a spontaneously thrombosed AVM specimen, including immunohistochemical analysis of angiogenesis factor expression. METHODS: A combined experience in the management of approximately 700 AVMs during 20 years identified six cases of spontaneous angiographic obliteration of cerebral AVMs. A literature review revealed another 24 cases with angiographic documentation of the initial AVMs and follow-up data showing nonfilling of the lesions. Histological analysis of a recently excised lesion included immunostaining with monoclonal antibodies to the antigens of Factor VIII, Tie, vascular endothelial growth factor, and its receptors, Flt-1 and Flk. RESULTS: A single draining vein was a feature in each of our 6 cases and in 12 of 14 (86%) cases from the literature. Hemorrhage as the presenting symptom was identified in 5 of our 6 (83%) cases and in 17 of 24 (71%) of the literature cases. The size of the AVM was less than 6 cm in each of our 6 cases and in 22 of 24 (92%) of the literature cases. A histological examination of a thrombosed AVM surgical specimen revealed persistent patent vascular channels within the lesion. Immunohistochemical analysis with angiogenesis and endothelia-specific factors showed expression of these factors within the lumen of the thrombosed nidus vessels. CONCLUSION: We propose that the occlusion of a single draining vein may lead to total venous outflow obstruction and lesion thrombosis. Hemorrhagic presentation and small nidus may also predispose to this phenomenon. Immunohistochemical analysis of a thrombosed AVM revealed possible ongoing angiogenic changes within the AVM vessels 1 month after angiographically documented thrombosis. It is possible that neovascularization within a thrombosed AVM may lead to lesion recanalization; however, this phenomenon seems to be clinically exceedingly rare.     

Pulmonary arteriovenous fistula with cerebral arteriovenous malformation without hereditary hemorrhagic telangiectasia. Unusual case report and literature review

An unusual and rare case of a central pulmonary arteriovenous fistula (PAVF) with concomitant cerebral arteriovenous malformation (CAVM) in the absence of hereditary hemorrhagic telangiectasia is reported. Presentation was in the form of a cerebrovascular accident (CVA). Clinical presentations and management strategies of PAVF with associated CAVM are broadly discussed along with a pertinent literature review.     

Spontaneous subarachnoid hemorrhage first from an intracranial and then from a spinal arteriovenous malformation. Case report

A patient presented with spontaneous subarachnoid hemorrhage (SAH) from a cerebral arteriovenous malformation (AVM) which was later totally removed at surgery. The patient presented again with a new SAH from a spinal AVM that was also totally removed at surgery. Coexistence of spinal and cerebral arteriovenous malformations are exceedingly rare and hemorrhage from each is not previously reported. This case emphasizes the importance of investigating the spinal canal in otherwise unexplained spontaneous SAH.     

Outcome from treatment for spinal arteriovenous malformation

BACKGROUND: prospective studies have demonstrated that a predominance of small, dense LDL particles (pattern B) precedes the clinical onset of coronary heart disease. Prevalence and characteristics of subjects with this LDL size abnormality were studied in young, nonobese, Japanese normolipidemic men. METHODS AND RESULTS: LDL peak particle diameter (PPD) was measured by continuous disc polyacrylamide gel electrophoresis in 223 nonobese normolipidemic men aged 18-20 years (mean+/-S.D. body mass index: 21.9+/-3.7 kg/m2, total cholesterol: 180+/-29 mg/dl, triglyceride: 62+/-34 mg/dl, HDL cholesterol: 58+/-12 mg/dl). Men with small LDL (PPD < 25.8 nm) were found in only 5.4% (n=12) whereas 197 men (88.3%) had a preponderance of large LDL (PPD 26.3 nm). As compared with men in a top tertile (PPD 27.5 nm) those in a low tertile (PPD < 26.9 nm) had higher serum levels of LDL cholesterol (120+/-31 vs 104+/-24 mg/dl), triglyceride (72+/-39 vs 49+/-16 mg/dl) and apolipoprotein (apo) B (84+/-21 vs 68+/-14 mg/dl), and lower HDL cholesterol (54+/-10 vs 60+/-12 mg/dl). They also had greater body mass index (23.2+/-4.6 vs 20.9+/-3.1 kg/m2) and percent body fat (21.5+/-7.7 vs 17.5+/-4.9%). LDL-PPD was positively correlated with HDL cholesterol (R=0.20, P=0.002) and was negatively correlated with apoB (R=0.34, P < 0.001), triglyceride (R=0.32, P < 0.001). percent body fat (R=0.26, P < 0.001), body mass index (R=0.24, P < 0.001), fat mass (R=0.23, P=0.001), total cholesterol (R=0.20, P=0.002). In multiple regression analysis, apoB, triglyceride, HDL cholesterol, apoAI and percent body fat explained 18% of LDLPPD variability. CONCLUSION: even in young, nonobese, normolipidemic men, LDL size appears to be associated with triglyceride-rich lipoprotein metabolism and body fat.     

Endovascular treatment of an external carotid arteriovenous malformation

Herein we describe a case of a hemorrhagic adrenal pseudocyst that had been initially suspected as being a renal adenocarcinoma. The intraoperative anatomopathological study of the specimen permitted performing conservative surgery. The diagnosis and pathogenesis of this uncommon disease entity are discussed.     

Association of cerebral venous malformation with glioblastoma--case report

Despite an abundance of literature investigating arch structure and musculoskeletal injury, there seems to be little consensus regarding the most appropriate technique of measuring dynamic arch motion. In this study, digitized videofluoroscopy was used to determine the sagittal plane motion of the medial longitudinal arch during dynamic gait. Nine female subjects requiring diagnostic foot radiographs underwent videofluoroscopy during a normal gait cycle. The calcaneal inclination angle, calcaneal-first metatarsal angle (CI-MT1) and height-to-length ratio of the arch, all reputed to measure arch alignment, were digitally analyzed from static radiographic images. Both the calcaneal inclination angle (0.96) and CI-MT1 (-0.98) angles were highly correlated with the criterion measure of height-to-length ratio. Repeated measures analysis of variance (ANOVA) identified a significant increase in the mean CI-MT1 angle during stance, suggesting a continual lowering and elongation of the arch. This study questions the validity of characterizing foot motion based on static measures of arch shape and recommends that further research be conducted to establish whether the observed trends reflect normal or pathological foot function.     

Treatment of scalp arteriovenous malformation

We report seven patients with scalp arteriovenous malformations, including two patients with lesions > 10 cm in diameter, who were successfully treated. The principal complaint of each patient was a deforming mass. Each of four patients had a history of blunt traumatic injury. The lesions, each consisting of the nidus, feeders, and draining veins, evolved in all patients. The nidus consisted of fistulae, which exhibited various angioarchitectures as revealed by angiography. A hemangiomatous component was histologically recognized in one patient. In five patients, in whom the lesions were relatively small and whose nidi included only large fistulae, the malformations were remedied by surgical intervention alone or were cured with embolization alone using liquid adhesives. In the two patients with lesions > 10 cm, the nidi consisted of numerous large fistulae and plexiform fistulae in one patient and plexiform fistulae and a hemangiomatous component in the other patient. These patients were treated with a combination of transarterial embolization and surgical intervention. Preoperative embolization greatly reduced blood loss during resection. Total excision and scalp reconstruction using a soft tissue expander were performed in both patients. The cosmetic results were excellent in all of the patients, and no recurrence has been recognized during the follow-up period, which ranges from 31 to 99 months. The treatment of scalp arteriovenous malformations should strive to improve deforming features and to attain a permanent cure. Because each nidus includes a variety of anomalous angioarchitectural features, there should be different means and a combination of treatments for each patient. Embolization alone could be adequate treatment in relatively small lesions, the nidi of which consist only of several large fistulae. For malformations with more extensive, large fistulae or with anomalous components other than large fistulae, a combined endovascular and surgical approach and scalp reconstruction seems to be the best treatment.     

Surgical and embolic treatment of cerebral arteriovenous malformations

Twenty-eight cases of cerebral arteriovenous malformations in which the treatment consisted of embolization and/or surgical excision are reviewed. Embolization was considered an adjuvant procedure; carried out to reduce the size of the malformation or eliminate the deep arterial supply to it prior to excision. In sixteen of the cases the combined treatment was carried out with one death and one significant postoperative deficit. In the other twelve cases surgical operation or embolization alone was carried out. The anatomy of the lesion determined the applicability of embolization. Although embolization has a high degree of safety, certain pitfalls must be avoided. Changing patterns in the cerebral circulation following embolization and operation as well as the role of collateral circulation to cerebral arteriovenous malformations are discussed.     

Failure in radiosurgery treatment of cerebral arteriovenous malformations

OBJECTIVE: The aim of this study was to retrospectively analyze the reasons for the failure of radiosurgical treatment of cerebral arteriovenous malformations (AVMs). METHODS: Seventeen cases of noncured AVMs were reviewed 3 years after radiosurgical treatment. Follow-up ranged from 33 to 54 months (mean, 44.3 mo). Lesion dimensions varied from 9 to 55 mm (mean, 29.2 mm). The lesions were located in critical or near-critical brain regions. Angiography was performed under Talairach's stereotactic conditions. Two large AVMs bled 36 and 39 months after receiving irradiation, respectively. These two AVMs had been incompletely irradiated. RESULTS: Retrospectively, in four cases (23.5%) we observed errors in determining AVM target shape and size because of inaccurate definition of the nidus and/or because of stereoangiographic incompleteness (absence of external carotid artery injections). In five large and/or irregularly shaped AVMs (29.4%), a strategy of partial volume irradiation had been used. In one patient (5.8%), we observed the recanalization of previously embolized AVMs. In another case (5.8%), the target had been partially missed. The AVMs in one case (5.8%) had been treated with an ineffective peripheral dose. In one (5.8%), the failure occurred because of the lesion angio-architecture. In four cases (23.5%), no evident reasons for failure were determined. CONCLUSION: The results of this study suggest the necessity of complete irradiation of the nidus. The strategy of partial volume irradiation might be avoided, even if it necessitates lowering the doses to treat large AVMs. Accuracy in the target determination is required, and complete stereoangiography is necessary.     

Quantitative cerebral magnetic resonance imaging during ACTH treatment of multiple sclerosis

Serial MR scans were performed with the 2DFT imaging method and the filtered backprojection imaging method on 12 patients with multiple sclerosis in acute phase, 4 in a relapsing/remitting form, and 8 in a progressive form, before, during and after ACTH treatment. Both T1 and T2mono relaxation times, obtained by fitting transverse magnetization decay curves with a monoexponential function within the apparently normal white matter and the areas of increased signal, were measured. With the backprojection method it was possible to fit the transverse magnetization decay curve with a biexponential function and obtain T2long and T2short relaxation times. The T2mono and T1 relaxation times of the apparently normal white matter were significantly different from those obtained for volunteers, but no significant differences were found before, during, or after treatment. The transverse magnetization decay curves of the areas of increased signal were better fitted by a biexponential function. No significant changes in these relaxation times were observed after ACTH treatment. These results argue against an anti-oedematous action of ACTH and may suggest that it has an immunosuppressant effect.     

Risk of cerebral angiography in patients with subarachnoid hemorrhage, cerebral aneurysm, and arteriovenous malformation: a meta-analysis

OBJECTIVE: To evaluate the utility of "clinic room" case presentation in the ambulatory care setting. BACKGROUND: Neurology is increasingly an outpatient specialty. The transition from ward to clinic presents challenges for student and resident education. Interaction between attending physician and trainee is limited by busy patient schedules. New educational strategies must be developed to address the particular challenges of the outpatient clinic. One strategy to increase the quality and length of attending-trainee interaction is case presentation in the patient's presence. METHODS: The authors randomized 100 patients seen in an academic neuromuscular clinic to presentation in a conference room or clinic room. In the latter, all interaction between the trainee and attending occurred in the patient's presence. The attending recorded the time spent with the trainee and patient. The patient was asked to complete a survey and provide certain demographic information. RESULTS: The two groups were similar demographically. Time spent by the attending physician was similar between the two settings. Although there was no difference in patient satisfaction, those randomized to clinic room presentation were significantly more likely (p < 0.002) to feel their questions were answered adequately. There were trends toward these patients feeling less embarrassed, feeling that they were treated respectfully, and feeling that adequate time was spent with them. CONCLUSIONS: Although clinic room presentation does not save attending time, it allows for a more dynamic and intensive interaction among teacher, student, and patient.     

The endovascular treatment of cerebral arteriovenous aneurysms and malformations

Despite the progress made in cerebral aneurysm microneurosurgery, some morphologic and anatomic characteristics, or also clinical reasons, make surgical clipping of the aneurysmatic column difficult or unfeasible, justifying an endovascular therapeutic alternative. Despite the great progress made, the risk of endovascular intervention with microballoons is significant, particularly in the acute post-haemorrhagic phase: 17.9% mortality and 10.7% morbidity in endosaccular embolisation therapy with the detachable balloon maintaining the arterial lumen permeable. The use of the GDC system (Guglielmi Detachable Coil) has permitted the treatment of proximal and distal aneurysms in the carotid and vertebrobasilar arterial regions. Microcatheterisation also allows intravascular treatment of the vasospasm, by mechanical means--angioplasty, or by pharmacological vasodilatation. With the GDC system one can obtain a complete occlusion of small and medium aneurysms in over 85% of cases, definitive morbidity of 5% to 7% and mortality of 1% to 3%. The objective of AVM endarterial occlusions is to obliterate the nidus through the arterial pedicles that can be microcatheterised by means of a certain embolic agent (Cyanocrilate, PVA or other embolic products). Thus, it is possible to reduce the dimension of the nidus as well as diminish the severity of the arteriovenous shunt, later facilitating the operation or radiosurgery, with the possibility of complete surgical removal in 96% of patients after embolisation. The mortality directly related to this endovascular therapy is approximately 0.9% with severe morbidity below 2%. Complete obliteration of a cerebral AVM can be achieved with endovascular techniques in 15% to 20% of cases, particularly in small lesions, sustain AVMs require careful multidisciplinary discussion aimed at finding the best treatment for each case.     

Successful management of a giant spinal arteriovenous malformation with multiple communications between primitive arterial and venous structures by embolization: report of a case

A 47-year-old woman was admitted to our hospital with a giant spinal arteriovenous malformation (AVM) causing heart failure and thoracic myelopathy. Angiography revealed that the spinal AVM had multiple feeding vessels branching from the 5th through 12th intercostal arteries. The drainage vein flowed to the azygos vein and superior vena cava. The AVM destroyed the 7th thoracic vertebra. The cardiac output was 16.7l/min and the shunt ratio was 64% before treatment. Embolization with cyanoacrylate was performed because the operation was considered to be associated with a significant risk of paraplegia and organ ischemia. The cardiac output decreased to 11.6l/min and the shunt ratio was reduced to 32%. After embolization the patient demonstrated no symptoms of either heart failure or sensory deficits. During embolization, provocative tests using sodium amytal and lidocaine with magnetic stimulation were also performed. The above findings suggest that provocative tests and magnetic stimulation are useful to predict paraplegia, which could result from embolization while, in addition, embolization is considered to be a useful treatment for multiple shunt and nidus in this region.     

Radiosurgery of cerebral arteriovenous malformations with a linear accelerator: preliminary report

The authors present the results obtained in seven patients with arteriovenous malformations treated with radiosurgery on a linear accelerator. In four patients obliteration of the malformation was obtained after one year. Two of the patients had a transient period of acute brain oedema surrounding the radionecrotic nidus with neurological signs. The present position of radiosurgery in the treatment of arteriovenous malformations is discussed.