Therapy Of Arteriovenous Malformations Research Articles

Comparison of Long-Term Outcomes in Ruptured Diffuse Brain Arteriovenous Malformations Between Interventional Therapy and Conservative Management.

Brain arteriovenous malformations (AVMs) with a diffuse nidus structure present a therapeutic challenge due to their complexity and elevated risk of hemorrhagic events. This study examines the long-term effectiveness of interventional therapy versus conservative management in reducing hemorrhagic stroke or death in patients with ruptured diffuse AVMs. The analysis was conducted based on a multi-institutional database in China. Patients were divided into two groups: conservative management and interventional therapy. Using propensity score matching, patients were compared for the primary outcome of hemorrhagic stroke or death and the secondary outcomes of disability and neurofunctional decline. Out of 4286 consecutive AVMs in the registry, 901 patients were eligible. After matching, 70 pairs of patients remained with a median follow-up of 4.0years. The conservative management group showed a trend toward higher rates of the primary outcome compared to the interventional group (4.15 vs. 1.87 per 100 patient-years, P = 0.090). While not statistically significant, intervention reduced the risk of hemorrhagic stroke or death by 55% (HR, 0.45 [95% CI 0.18-1.14], P = 0.094). No significant differences were observed in secondary outcomes of disability (OR, 0.89 [95% CI 0.35-2.26], P = 0.813) and neurofunctional decline (OR, 0.65 [95% CI 0.26 -1.63], P = 0.355). Subgroup analysis revealed particular benefits in interventional therapy for AVMs with a supplemented S-M grade of II-VI (HR, 0.10 [95% CI 0.01-0.79], P = 0.029). This study suggests atrend toward lower long-term hemorrhagic risks with intervention when compared to conservative management in ruptured diffuse AVMs, especially within supplemented S-M grade II-VI subgroups. No evidence indicated that interventional approaches worsen neurofunctional outcomes.

Extensive severe intraorbital arteriovenous malformations: report of a rare laser complication and successful management.

Arteriovenous malformations (AVMs) are rare congenital errors of vascular morphogenesis, characterised by abnormal direct communications between arteries and veins, bypassing the normal capillary bed. Apart from the central nervous system, typical locations include the head and neck, and less frequently limbs, trunk or internal organs. AVMs of the head and neck often become clinically evident and symptomatic only in later childhood and are characterised by a history of variable growth, sometimes leading to large, deforming, pulsating masses with a propensity to massive haemorrhage. Therapeutic strategy is based on selective embolisation, surgical excision, or a combination of both. Radical surgical excision of local AVMs is the only effective treatment but it may be mutilating, especially for AVMs of the head and neck. Laser therapy represents a good option to treat the cutaneous aspects of AVMs nevertheless, its efficacy is limited. To the date, pharmacological therapy for AVMs is still on debate due to its controversial outcomes as it seems not as effective as other treatments and usually requires a longer course of application. However, pharmacological therapy could be useful in selected patients and for AVMs nonresponsive to traditional treatment, allowing them to obtain acceptable results without serious complications. This paper reports the case of a serious laser complication of extensive intraorbital AVM successfully treated by local reconstruction and topical pharmacological treatment.

Pathogenesis and therapy of arteriovenous malformations: A case report and narrative review.

Arteriovenous malformations (AVMs) are abnormal communications between arteries and veins that lack intervening capillary beds. They have been described in almost every organ in the body, emerging sporadically or as part of well-described syndromes. Hereditary hemorrhagic telangiectasia (HHT) is a rare, progressive, and lifelong disease characterized by AVMs and recurrent hemorrhaging. In the last 2 decades, significant advances have been made in understanding the pathogenesis of this condition. The accumulation of knowledge has led to a natural evolution of therapy, from open surgery to endovascular procedures, and now to a role for medications in certain AVMs. Here, we review a case of HHT and describe the most up-to-date clinical practice, including diagnosis of HHT, subtypes of HHT, and medical therapy.

Transvenous Approach to Intracranial Arteriovenous Malformations: Challenging the Axioms of Arteriovenous Malformation Therapy?

: A compartmental conceptualization of intracranial arteriovenous malformations (AVMs) allows recognition of feeding arteries, an intervening plexiform nidus, and draining veins. AVM therapy involves eliminating the nidus, which is the source of hemorrhage, without compromising normal arterial and venous drainage of the brain. Traditional methods of AVM therapy through microsurgery and endovascular embolization involve arterial devascularization, with preservation of AVM venous drainage, until the nidus is excluded. The transvenous approach in treating vascular malformations was popularized by successful treatment models for dural arteriovenous fistulas. More recently, high-flow intracranial AVMs are being managed with transvenous endovascular approaches, although this novel technique has its challenges and perils. We review the current literature on transvenous AVM therapy and highlight its role for AVM therapy in the present day.

The outcomes of stereotactic radiotherapy in patients with cerebral arteriovenous malformations

Cerebral arteriovenous malformations (AVMs) are the congenital anomalies of development of cerebral vessels during the embryonic period. The conventional therapy for AVMs currently includes endovascular management, microneurosurgical resection, and stereotactic irradiation. A total of 315 patients with brain AVMs were subjected to stereotactic radiotherapy in 2005-2011. 238 (76%) patients had previous subarachnoid hemorrhage (SAH) within different time (6 months to 5 years) before the therapy; 214 (68%) patients had headaches; 113 (36%) patients had focal neurological symptoms caused by localization; and 82 (26%) patients had seizures. Twenty-three patients were subjected to surgical resection of an intracerebral hematoma prior to radiotherapy and 119 (36%) patients received endovascular treatment including partial embolization of the stroma of AVM. 267 patients received single-fraction radiosurgical irradiation. In patients with large AVMs, we used the hypofractionation technique consisting in target irradiation with several (usually 2-7) fractions; the radiation dose per fraction exceeds 2 Gy. Forty-six patients were irradiated in the hypofractionation mode; two patients had a course of stereotactic radiotherapy in the standard fractionation mode. The marginal dose of radiosurgical irradiation was 13-30 Gy (the average dose was 24 Gy). The main group of patients (38 individuals) with large AVMs was treated using hypofractionation of 35 Gy per 5 fractions. Control angiography was carried out in 225 patients who had been followed up for at least 2 years after therapy showed that complete obliteration was achieved in 83% of cases. The rate of symptomatic radiation reactions was less than 10%. The higher risk of developing obliteration was observed for AVMs less than 2 cm3 in size at marginal doses more than 24 Gy. In the hypofractionation group consisting of 27 patients with complete follow-up data, obliteration was observed in 10 (37%) patients. The rate of symptomatic reactions was less than 35%. The radiosurgical method is a minimally invasive choice of treatment for patients with brain AVM, which allows one to achieve sufficiently high degree of obliteration with the minimum complication rate. The hypofractionation procedure is the method of choice for treating large AVMs. Stereotactic irradiation using the Novalis linear accelerator makes it possible to treat patients with AVMs of virtually any location and volume.

9:12 AM Abstract No. 107 - Management of chest and shoulder arteriovenous malformations

To determine the efficacy of Endovascular Repair of Shoulder arteriovenous malformations (AVMs). Fifteen patients (10 females, 5 males) presented for repair of shoulder AVMs. Three patients had extension of AVM to the supraclavicular and axillary areas. Two patients had multiple AVMs. Eight patients had previous failed therapies (embo: PVA/coils/gelfoam; surgeries: excisions/bypass). All patients underwent ethanol endovascular AVM repair; seven patients had additional coil embolizations (110 treatments). Patient age range 18-76 years; mean age 47. Thirteen patients are cured at long-term follow-up (37 months mean follow-up). One patient with bilateral shoulder AVM and multiple other AVMs therapy is on-going. Another patient’s treatment is on-going. Complications include two patients with minor superficial blisters, one patient with transient radial nerve injury with complete recovery and one patient with clot embolus to hand, treated with urokinase w/distal 3rd phalanx removed. A recent report of shoulder AVM repair in JVIR documented failure of nBCA approach. These authors stated that shoulder AVMs were not possible to treat. This report documents cure of these difficult lesions is possible with ethanol endovascular and direct puncture approaches. Long-term cures are documented in this patient series despite previous publications stating treatments of these lesions are not possible. One patient with a massive left shoulder AVM demonstrates persistent cure at 16 year follow-up.

2:42 PM Abstract No. 159 - Management of chest and shoulder arteriovenous malformations

Purpose PURPOSE: To determine the efficacy of Endovascular Repair of Shoulder arteriovenous malformations (AVMs). Materials and Methods Fifteen patients (10 females, 5 males) presented for repair of shoulder AVMs. Three patients had extension of AVM to the supraclavicular and axillary areas. Two patients had multiple AVMs. Eight patients had previous failed therapies (embo: PVA/coils/gelfoam; surgeries: excisions/bypass). All patients underwent ethanol endovascular AVM repair; seven patients had additional coil embolizations (110 treatments). Patient age range 18-76 years; mean age 47. Results Thirteen patients are cured at long-term follow-up (37 months mean follow-up). One patient with bilateral shoulder AVM and multiple other AVMs therapy is on-going. Another patient’s treatment is on-going. Complications in-clude two patients with minor superficial blisters, one patient with transient nerve injury with complete recovery and one patient with clot embolus to hand, Rx with urokinase w/distal 3rd phalanx removed. Conclusion A recent report of shoulder AVM repair in JVIR documented failure of nBCA approach. These authors stated that shoulder AVMs were not possible to treat. This report documents cure of these difficult lesions is possible with ethanol endovascular and direct puncture approaches. Long-term cures are documented in this patient series despite previous publications stating treatments of these lesions are not possible.

Interventional AVM therapy against epileptic seizures

Symptomatic epileptic seizures constitute a common neurologic complication in patients with arteriovenous malformations (AVMs). In many patients, a first-ever seizure may be the clinical index event leading to the diagnosis of an otherwise asymptomatic AVM. This scenario seems to be particularly frequent in young adults, while during childhood and beyond the age of 60, AVMs are less likely to be diagnosed based on seizures alone.1 The occurrence of seizures is associated with …

Surgical treatment of giant intracranial arteriovenous malformations

To review surgical outcomes in treating intracranial Giant arteriovenous malformations (AVMs). To find out the prognosis factors of surgical treatment. We collected 46 consecutive cases of giant AVMs treated at Beijing Tiantan Hospital, reviewed the radiological and Spetzler-Martin grading. 25 of the patients selected were male (54%), and 21 were female (46%), with a mean age of 30.6. The major presenting symptoms were seizures, headaches, hemorrhage and neurological deficits. According to the Spetzler-Martin Grading, 8 patients were Grade III, 22 were Grade IV, and 16 were Grade V. All patients received surgical treatment and postoperative DSA were performed. Clinical results and long term follow-up (KPS) were gathered for analysis. One of the 35 patients who received postoperative DSA revealed residual AVMs. Among all patients, severe complications were observed in 9 patients, and 1 patient died in the hospital. Complications included hemiparalysis (15 cases), aphasia (6 cases), hemianopia (9 cases), cranial nerve dysfunction (5 cases), and seizure (5 cases). Normal perfusion pressure breakthrough (NPPB) was observed in 6 patients. After 6 - 108 months of follow-up, 33 of 37 survived follow-up patients presented normal function or minimal symptoms and ability to work or study, 4 patients died (2 were surgical-related). Pre-surgical evaluation of every candidates and treatment choice are the determining factors in giant AVMs therapy. Microsurgery remains one of the most effective ways for eliminating giant cerebral AVMs, and the complication rate was acceptable. For giant cerebral AVMs located superficially or do not involve critical components, a good outcome can be expected through surgical resection.

Radiosurgical management of pediatric arteriovenous malformations

Hemorrhage from an arteriovenous malformation (AVM) is the commonest cause of childhood stroke. Management options for children include observation and medical management, surgical resection, endovascular embolization, or stereotactic radiosurgery, alone or in combination. Radiosurgery is used for high-risk malformations in critical brain locations. While this goal is being achieved, there should be limited morbidity and hopefully no mortality from hemorrhage or radiation-induced brain injury. Physicians who consider AVM radiosurgery cite one or more of the following: (1) that radiosurgery is an effective therapy required for the management of deep-brain AVMs; (2) that radiosurgery is an effective therapy for residual AVMs after subtotal resection; (3) that radiosurgery is worthwhile in an attempt to lower management risks for AVMs in functional brain locations; (4) since embolization does not cure most AVMs, additional therapy such as radiosurgery may be required; and (5) microsurgical resection may not be the best choice for some children. Radiosurgery is the first and only biologic AVM therapy; it represents the beginnings of future cellular approaches to vascular malformation diseases. For this reason, the future of radiosurgery may be impacted positively by the development of other biologic strategies such as brain protection or endothelial sensitization.

The Role of Neuroendovascular Therapy for the Treatment of Brain Arteriovenous Malformations

Neuroendovascular embolization represents a critical component of the multidisciplinary management of cerebral arteriovenous malformations. Safe and effective embolization may be performed only in the context of a well-designed, rational treatment plan that is fundamentally based on a clear understanding of the natural history of the lesion, as well as the cumulative risks of multimodality treatment. This article outlines the role of neuroendovascular embolization in arteriovenous malformation therapy with a specific emphasis on decision making in the context of formulating a treatment plan. The authors also provide a summary of the available embolic agents and their technical application, potential intraprocedural and periprocedural complications, and postprocedural management.

The evolution of endovascular treatment for intracranial arteriovenous malformations

Endovascular therapy for arteriovenous malformations (AVMs) remains a relatively new approach. Beginning in the 1960s with the use of flow-directed techniques for selective embolization, hemodynamic alterations have been used to treat these lesions. In every aspect of treatment, technological advances, including catheters, embolic materials, angiography suites, and pharmacological agents, have improved outcomes while lowering the risk to patients. In this article, the authors review the technical evolution of endovascular AVM therapy. Developments in embolic materials, beginning with foreign bodies and autografts and continuing through to highly engineered contemporary substances, are discussed. Finally, changes in treatment paradigms that have occurred over the years are traced. Within neurosurgery, this specialty has shown some of the fastest growth and development in recent decades. As minimally invasive approaches are embraced in all areas of medicine, it is clear that this treatment modality will continue to be refined.

ARUBA – A Randomized Trial of Unruptured Brain AVMs

Rationale: Current invasive treatment for brain arteriovenous malformations (AVMs) is varied and includes endovascular procedures, neurosurgery, and radiotherapy alone and in combination, largely dependent on the decisions of the local clinical team. However, no controlled treatment data on invasive AVM therapy exist and recent data raise serious doubt about the treatment benefit for unruptured brain AVMs. We propose a randomized treatment trial testing the hypothesis that medical management improves long-term outcomes of patients with unruptured AVMs compared to invasive treatment.

Determinants of Staged Endovascular and Surgical Treatment Outcome of Brain Arteriovenous Malformations

Therapy of brain arteriovenous malformations (AVMs) often requires the combination of different treatment modalities. Independently assessed data on neurologic outcome after multidisciplinary AVM therapy are scarce. The 119 consecutive patients (49% women, mean age 34+/-13 years) with brain AVMs receiving endovascular embolization followed by surgical treatment were analyzed. Neurologic impairment was assessed prospectively by a neurologist using the modified Rankin Scale (mRS) before, during, and after completed AVM therapy. The association of demographic, clinical, and morphologic characteristics with new treatment-related neurologic deficits was calculated. The 119 patients were treated with 240 superselective embolizations (median, 2; range, 1 to 8) using n-butyl cyanoacrylate. Mean follow-up time after surgery was 9.6+/-13.2 months. On the Spetzler-Martin scale, 8% of the AVMs were grade 1, 27% grade 2, 40% grade 3, 22% grade 4, and 3% grade 5. Disabling treatment-related complications (mRS> or =3) occurred in 5% (95% confidence interval [CI], 1% to 9%) of the patients. Nondisabling new deficits were observed in another 42% (95% CI, 33% to 51%). No patient died. Nonhemorrhagic AVM presentation (odds ratio [OR], 5.00; 95% CI, 1.75 to 14.29), deep venous drainage (OR, 3.09; 95% CI, 1.43 to 6.64), AVM location in an eloquent brain region (OR, 2.42; 95% CI, 1.10 to 5.33), and large AVM size (OR, 1.05; 95% CI, 1.01 to 1.09) were independently associated with new treatment-related deficits. Our results suggest an increased treatment risk for patients with previously unbled AVMs from combined endovascular and surgical AVM therapy. Additional risk factors for treatment-related neurologic deficits may be large AVM size, deep venous drainage, and AVM location in eloquent brain regions.

Basics and Principles in the Application of Onyx LD Liquid Embolic System in the Endovascular Treatment of Cerebral Arteriovenous Malformations

Onyx is a new liquid embolic system (Micro Therapeutics, Inc., Irvine, CA) consisting of ethylene-vinyl alcohol copolymer (EVOH), formed of 48 mol/L ethylene and 52 mol/L vinyl alcohol, dissolved in dimethyl-sulfoxide (DMSO) and mixed with micronized tantalum powder (35% weight per volume) for radiopaque visualization. In its low density form it is predominantly used worldwide in the treatment of cerebral 1-6 or spinal7,8 arteriovenous malformations (AVMs), other more rare indications are hypervascularized tumors9, peripheral AVMs or arteriovenous fistulas (AVFs)10, and there is also an extensive use in experimental work 11-12. Onyx LD means low density of EVOH in the range of 6 to 8 % (Onyx 18 to 34) compared to high density Onyx 500+ (containing 20 % of EVOH) used for aneurysm occlusions. The basics of Onyx LD liquid system and the main principles of its application in endovascular AVM therapy are described and discussed in this chapter.

Does multimodality therapy of arteriovenous malformations improve patient outcome?

The strategy for treating arteriovenous malformations (AVMs) has undergone changes and long-term follow-up results remain unclear. To compare the outcomes of different treatment strategies, we divided 112 patients with 113 AVMs into groups with hemorrhagic (n = 71, 62.8%) and nonhemorrhagic (n = 42, 37.2%) AVMs and subdivided these according to the period in which they were treated (before/after 1990). In the more recent period, treatment more frequently involved the use of the γ-knife and microembolization to the AVM as well as combination therapy. Long-term follow-up showed that the complication rate was lower and the Rankin scale better, in the more recently treated group. Based on our findings we suggest that AVMs should be treated aggressively using a multimodality strategy.

Prediction of AVM obliteration after stereotactic radiotherapy using radiobiological modelling

This study was carried out in order to derive the radiobiological parameters of the dose–response relation for the obliteration of arteriovenous malformation (AVM) following single fraction stereotactic radiotherapy. Furthermore, the accuracy by which the linear Poisson model predicts the probability of obliteration and how the haemorrhage history, location and volume of the AVM influence its radiosensitivity are investigated. The study patient material consists of 85 patients who received radiation for AVM therapy. Radiation-induced AVM obliterations were assessed on the basis of post-irradiation angiographies and other radiological findings. For each patient the dose delivered to the clinical target volume and the clinical treatment outcome were available. These data were used in a maximum likelihood analysis to calculate the best estimates of the parameters of the linear Poisson model. The uncertainties of these parameters were also calculated and their individual influence on the dose–response curve was studied. AVM radiosensitivity was assumed to be the same for all the patients. The radiobiological model used was proved suitable for predicting the treatment outcome pattern of the studied patient material. The radiobiological parameters of the model were calculated for different AVM locations, bleeding histories and AVM sizes. The range of parameter variability had considerable effect on the dose–response curve of AVM. The correlation between the dosimetric data and their corresponding clinical effect could be accurately modelled using the linear Poisson model. The derived response parameters can be introduced into the clinical routine with the calculated accuracy assuming the same methodology in target definition and delineation. The known volume dependence of AVM radiosensitivity was confirmed. Moreover, a trend relating AVM location with its radiosensitivity was observed.

Functional evaluation of arteriovenous malformations

Detailed knowledge of the angioarchitecture of arteriovenous malformations (AVMs) is necessary in determining the optimal timing and method of treatment of these challenging lesions. Many techniques are available for studying the functionality of surrounding cortical structures of AVMs. These include the use of positron emission tomography, functional magnetic resonance imaging, magnetoencephalography, and direct provocative testing of cortical function. The use of these methods to determine flow dynamics and tissue perfusion is also reviewed. These techniques are discussed in the present study, and their judicious utilization will enhance the safety of AVM therapy.

Deep central arteriovenous malformations of the brain: the role of endovascular treatment.

Cerebral deep central arteriovenous malformations (AVMs) are uncommon lesions associated with considerable difficulty in treatment. The authors report a series of 14 deep central AVMs treated by endovascular methods and examine the present role of endovascular treatment. This treatment used alone resulted in complete obliteration of AVMs in approximately 15% of case and reduction in 50% to a size permitting treatment by means of radiosurgery. Reversal of previous neurological signs and symptoms occurred in 35.7% of embolized patients. Overall, nearly 80% of patients had either complete obliteration of the lesion, reduction to a size allowing radiosurgical treatment, or reversal of previous neurological deficits. There were treatment complications in 14.3% of the cases. Endovascular treatment methods may make a significant contribution to the therapy of AVMs that have a particularly poor course and are difficult to treat by other means.