Hypofractionated stereotactic radiosurgery for treatment of cerebral arteriovenous malformations: outcome analysis with use of the modified arteriovenous malformation scoring system

Radiosurgery has long been an accepted modality for definitive treatment of cerebral arteriovenous malformations (AVM). Efforts to improve the therapeutic ratio for this indication include use of staged volume procedures and hypofractionation. This study reviews our experience with a cohort of patients treated with hypofractionated radiosurgery. Over a 3 year period, 38 patients harboring 39 cerebral AVM were treated with hypofractionated stereotactic radiotherapy. Seventeen of these patients presented due to hemorrhage, four were asymptomatic unruptured lesions and the remainder were symptomatic unruptured lesions. The median AVM volume was 11.43 cc and median modified Radiosurgery-Based Arteriovenous Malformation Score (mRBAS) was 2.02. The median follow-up was 7.32 years. Four patients harboring four AVM were lost to follow-up before a result could be ascertained leaving 35 AVM for analysis. Excellent outcomes (AVM obliteration without new deficits) occurred in 17 of 34 (50%) patients and in 18 of 35 (51%) AVM treated. AVM obliteration was seen in 26 of 35 (74%) lesions treated. Two patients died during the follow-up period (6%). A poor result (major deficit without obliteration) was seen in one patient. Of 19 patients harboring AVM with mRBAS >2.0, an excellent outcome was achieved in eight (42%). Hypofractionation for cerebral AVM can result in satisfactory obliteration rates, but with risk of significant complications commensurate with mRBAS. Further study of this technique will be needed to ascertain the degree of incremental improvement, if any, over other radiosurgery treatment methods.     

The occipital transtentorial approach for cerebellar arteriovenous malformation in a child

This report presents a case of arteriovenous malformation (AVM) in the region of the superior vermis and quadrigeminal plate, which was partially embolized using a endovascular technique and subsequently surgically excised. An occipital transtentorial approach was employed to excise the AVM, and the patient did well without neurological complications postoperatively. Comparing various surgical approaches, we believe the occipital transtentorial approach is the best for the AVM of this region. Received: 6 November 1998 Accepted: 26 February 1999     

Fatal glioblastoma after Gamma Knife radiosurgery for arteriovenous malformation in a child

We describe a fatal case of glioblastoma multiforme that was induced by Gamma Knife radiosurgery (GKS; Elekta AB, Stockholm, Sweden) for an arteriovenous malformation (AVM). A 4-year-old girl presented with repeated convulsions. Imaging studies revealed an AVM located in the right thalamus. One year after initial symptoms, GKS was performed to obliterate the nidus. The maximum and marginal radiation doses were 32 and 16 Gy, respectively. Seventy months after GKS, the patient represented with severe headache. MRI showed a poorly demarcated tumor with heterogeneous gadolinium enhancement in the right thalamus and adjacent to the white matter of the temporal lobe. After a generalised convulsion, the patient deteriorated into a deep coma. CT scans showed severe brain swelling with intratumoral hemorrhage. An emergency craniotomy was performed, and the hematoma was removed. During this surgery, a tumor mass, which was found adjacent to the hematoma, was resected. Microscopic examination revealed glioblastoma multiforme. Despite intensive treatment, the patient died 1 month after surgery. A GKS-induced secondary tumor is a rare but serious complication. It is important to be aware of the adverse effects of GKS, including secondary neoplasms, before its clinical application, especially in young patients.     

伽玛刀治疗脑动静脉畸形的长期随访

目的 分析伽玛刀(γ-刀)治疗脑动静脉畸形(cAVM)的疗效及影响因素.方法 对1995年后cAVM接受γ-刀治疗已经3年以上,并且随访资料完全的341例患者进行总结.随访内容包括性别、年龄、部位、有无出血、是否栓塞、处方剂量、体积、照射能量、定位方法、随访时间共10项.结果 通过多因素Logistic回归模型分析发现γ-刀治疗cAVM的疗效与患者是否有脑出血病史、处方剂量、随访时间有关.本组治疗过程中出现2例囊肿;顽固脑水肿15例,其中1例直接导致死亡;再出血10例,其中3例直接导致死亡;不明原因死亡1例.结论 .γ-刀是治疗cAVM的一种有效的方法,疗效受多因素影响,并发症较小,但需要长期随访.     

Childhood intracranial arteriovenous malformation in Saudi Arabia

Twenty-three patients in whom intracranial arteriovenous malformation (ICAVM) occurred while they were in the pediatric age group (16 years or less) were identified. The patients had presented to three major centers in Saudi Arabia (King Fahad Hospital of the University, King Faisal Specialist Hospital and Research Center, and Riyadh Military Hospital). The incidence of ICAVM in Saudi Arabia is estimated. ICAVM in the pediatric age group accounts for 7.72% of all ICAVM cases. Most of the pediatric patients presented with intracranial bleeding, and seizure was the only other mode of presentation. Spontaneous changes involving ICAVM occurred in 4 children, in the form of either increase or decrease in size or new vascularization. Most children had higher grade ICAVM and the morbidity rate was higher than in adults. The cure rate was 50% with different therapeutic modalities. This report represents the first study to provide the hospital-based frequency of pediatric ICAVM in Saudi Arabia. Received: 16 September 1998 Revised: 16 November 1998     

脑海绵状血管畸形与动静脉畸形对放疗的不同反应

目的 探究脑海绵状血管畸形(CMs)与动静脉畸形(AVMs)的结构差异和对于放射外科治疗反应的不同.方法 实验样本共33例,包括放射外科治疗后的CMs 3例,放射外科治疗后的AVMs 3例,未经照射的CMs 6例,未经照射的AVMs 17例和健康对照4例.取材后立即处理,并应用光学显微镜和透射电子显微镜观察5组间的超微结构差异.结果 CMs显示管腔直径与血管壁的厚度较大而且缺乏内皮下成纤维细胞,肌成纤维细胞和平滑肌细胞.CMs放射外科治疗后形成部分蛋白质凝块(管腔的19％ ～22％),在放射治疗后长达6年后也未出现完整的血管闭塞.AVMs观察到由纤维蛋白血栓组成永久性的血栓,使血管完整的闭塞(管腔的91％ ～ 98％).照射诱导病灶周围的脑组织发生神经元丢失和神经原纤维变性.结论 CMs与AVMs的血管结构及细胞成分的不同导致它们对放射外科治疗的反应不同.     

De novo development of a cerebral arteriovenous malformation following radiation therapy: Case report and an update to classical arteriovenous malformation nomenclature

Cerebral arteriovenous malformations (AVM) are traditionally considered primary congenital lesions that result from embryological aberrations in vasculogenesis. Recent insights, however, suggest that these lesions may be secondary to a vascular insult such as ischemia or trauma. Herein, the authors present a rare case of a secondary cerebral AVM, occurring in a young girl who received prior cranial radiation therapy. At age 3 years, she underwent surgical resection, chemotherapy, and photon radiation therapy for treatment of a fourth ventricular ependymoma. At age 19 years, she developed new onset seizures and was found to have a left medial temporal lobe AVM. Her seizures were managed successfully with anti-epileptic medications and the AVM was treated with proton radiation therapy. This case highlights a rare but possible vascular sequela of radiation therapy and adds to the growing body of evidence that cerebral AVM may arise as secondary lesions.     

Growing intracranial arteriovenous malformation in a newborn

A case is reported of a growing arteriovenous malformation in a newborn, premature baby. The reason for early operative intervention is emphasized, based on histological investigation of the malformation. The literature is reviewed.     

伽玛刀治疗脑动静脉畸形远期再出血分析

目的分析伽玛刀(γ-刀)治疗脑动静脉畸形(cAVM)的再出血率及相关因素。方法对1995年8月￣2002年12月间接受γ-刀治疗3年以上,并且随访资料完全的341例cAVM患者再出血情况进行统计。结果再出血10例(2.9%),其中3例直接导致死亡。结论γ-刀治疗cAVM后再出血率较低,出血较自然病程少,且有一定相关因素。     

脑动静脉畸形合并出血相关影响因素分析

目的 通过全脑DSA造影检测脑动静脉畸形血管构筑特征,分析探讨脑动静脉畸形合并出血的相关影响因素.方法 回顾性分析珠江医院神经外科收治的199例脑动静脉畸形患者的影像学资料,其中出血组107例,非出血组92例.采用单因素和多因素Logistic回归分析方法,分析畸形血管团大小、位置,供血动脉数目、位置,引流静脉数目、引流方向,合并动脉瘤数目、大小、与动脉瘤的位置关系,有无合并瘤样改变等因素与畸形血管团破裂出血的关系.结果 单因素分析表明微型(0.5～1.0 cm)和小型(1.0～2.0 cm)畸形血管团、深部畸形血管团、深部供血动脉、1～2支引流静脉、深部引流静脉、合并多个动脉瘤、合并小动脉瘤(＜5 mm)和位于供血动脉端动脉瘤是畸形血管团破裂出血的危险因素,合并瘤样变则降低出血的风险,供血动脉数目与出血无关.多因素Logistic回归分析发现畸形血管团破裂出血独立危险因素是微型和小型畸形血管团,深部引流静脉及合并供血动脉端动脉瘤.结论 微型、小型畸形血管团,深部引流静脉,供血动脉端动脉瘤与畸形血管团破裂出血密切相关.

Abstract：

Objective To explore the influencing factors of bleeding in patients with cerebral arteriovenous malformation (AVM) through observing the angioarchitecture of AVM with cerebral DSA.Methods The clinical and imaging data of 199 patients with AVM, including 107 with bleeding and 92without bleeding, were retrospectively analyzed. The relationships between bleeding and such factors as the site and size of masses, the type and site of supplying arteries, the number and pathway of venous drainage, having vascular tumor-like changes or not, the relation between AVM and aneurysm in terms of location, and the number and size of concurrent aneurysms were determined by univariate analyses and Binary logistic regression with SPSS13.0. Results Univariate analysis indicated that such factors as micro-sized (0.5-1.0 cra) and small-sized (1.0-2.0 cra) masses ofAVM, AVM underdeep location,having exclusively deep draining veins, fewer draining veins and deep feeding arteries, concurrent small aneurysms (＜5 mm), aneurysms at the end of the blood-supply artery were positively correlated to hemorrhagic presentation. The number of feeding arteries and the number of concurrent aneurysms were not correlated with hemorrhagic presentation. Having vascular tumor-like changes can decreased the risk of bleeding. When stepwise multiple logistic regression analysis was employed, only micro-sized and small-sized masses of AVM, having deep feeding arteries, and aneurysms at the end of the blood-supply artery were dependent predictors of hemorrhagic presentation. Conclusion Micro-sized and small-sized masses of AVM, having deep draining veins and aneurysms at the end of the blood-supply artery are the most powerful risk predictors for hemorrhagic AVM presentation.     

NBCA和ONYX栓塞治疗不同类型脑动静脉畸形的对比研究

目的对比分析NBCA和ONYX两种液态栓塞系统对不同类型脑动静脉畸形（AVM）的栓塞率，对NBCA和ONYX的有效性作出评价。方法选取1998年1月至2005年6月经过NBCA和ONYX栓塞治疗的50例脑AVM病人，NBCA组30例，ONYX组20例。男32例，女18例，平均33．5岁。对两组间不同大小、供血动脉类型、供血动脉支数脑AVM的栓塞率对比分析。全部数据采用秩和检验，应用SAS 6．12统计软件分析。结果对中型、皮质多支供血和浅部引流的脑AVM，ONYX的栓塞率高于NBCA。两者对小型、单支供血的脑AVM均有较高的栓塞率。结论对中型、皮质动脉多支供血的脑AVM，ONYX栓塞率比NBCA高。对大型和混合供血的脑AVM，NBCA与ONYX两者的栓塞率并无统计学意义。对于小型脑AVM，两种栓塞剂均有着较好的栓塞率。穿支供血的脑AVM不适合经动脉行血管内栓塞。对于体积较大的伴有广泛供血和位于功能区的AVM，可以分次栓塞，并结合手术和立体定向放射治疗。     

Leksell gamma knife radiosurgery for cerebral arteriovenous malformations in pediatric patients

Objects The authors report their experience of gamma knife radiosurgery (GKR) in a large series of pediatric cerebral arteriovenous malformations (cAVMs). The advantages, risks and failures of this approach are presented and discussed.Methods Gamma knife radiosurgery was performed on 63 children aged 16 years. Haemorrhage was the clinical onset in 50 out of 63 cases. The mean pre-GK cAVM volume was 3.8 cm³. Fifty-eight out of 63 cAVMs were Spetzler-Martin grades I–III. Most lesions (47 out of 63) were in eloquent or deep-seated brain regions.Conclusion Gamma knife radiosurgery-related complications occurred in 2 out of 47 cases with an available follow-up (1 had transient and 1 permanent morbidity). No bleeding occurred during the latency period. In 39 children with >36-month follow-up, complete cAVM occlusion was angiographically documented in 31, with a 3- and 4-year actuarial obliteration rate of 72 and 77% respectively. High rates of complete obliteration and very low frequency of permanent morbidity with no bleeding during the latency period encourage widespread application of GKR in the treatment of pediatric cAVMs.A commentary on this paper is available at     

Retained microcatheter after onyx embolization of intracranial arteriovenous malformation

Endovascular embolization is being increasingly used to treat intracranial arteriovenous malformations (AVMs). However, we experienced two patients with retained microcatheters after AVM embolization using Onyx.     

A comparative outcomes analysis of patients treated for arteriovenous malformation with LINAC-based stereotactic radiosurgery by a standard frame-based technique or a frameless technique utilizing 3-dimensional rotational angiography

Previous work at our institution treating arteriovenous malformation (AVM) with radiosurgery (RS) demonstrated superior nidus visualization and geometric accuracy with use of 3-dimensional rotational angiography (3DRA) compared to biplanar digital subtraction angiography. We have since adopted a unique radiosurgical protocol that utilizes 3DRA in the planning of linear accelerator (LINAC)-based RS delivered in a frameless manner. This study seeks to compare clinical outcomes between patients treated by this novel approach and those treated by our historic frame-based protocol. Clinical data were queried for all patients treated for AVM by single-fraction RS from 2003 to 2017. RICs were identified and classified as radiologic, symptomatic, or permanent. Excellent outcome was defined as nidus obliteration without intracranial hemorrhage (ICH) or symptomatic RIC. Clinical predictors of study outcomes were identified through univariate and multivariate logistic regression using backwards elimination to optimize a predictive model. 131 AVMs in 124 patients were included with a median follow-up of 88 months. 59 AVMs received frame-based RS and 72 AVMs received frameless RS. Rate of obliteration was 64% for frame-based RS and 61% for frameless RS (p = 0.70). Radiologic, symptomatic, and permanent RICs rates were 68%, 17%, and 8%, respectively, for frame-based cases, versus 40% (p < 0.01), 8% (p = 0.13), and 3% (p = 0.15), respectively, for frameless cases. Excellent outcome was achieved in 49% of frame-based cases and 53% of frameless cases (p = 0.68). These results illustrate the safety and effectiveness of frameless LINAC-based AVM RS utilizing 3DRA.     

Prospective evaluation of preoperative stereotactic radiosurgery followed by delayed resection of a high grade arteriovenous malformation

Reports of the utility of preoperative radiation for shrinking large arteriovenous malformations (AVM) in preparation for resection have produced conflicting results, and to our knowledge no prospective studies are available. A 28-year-old man presented with a ruptured right temporal Spetzler-Martin Grade 5 AVM with deep venous drainage, involvement of the internal capsule, deep perforator supply, and a diffuse nidus. He underwent staged embolization, a single Gamma Knife (Elekta AB, Stockholm, Sweden) radiation treatment to the deepest portion of the nidus followed by complete surgical resection 3 years later. He suffered no long-term neurological deficits and has since returned to work symptom-free (modified Rankin Scale score 0). Preoperative radiosurgery is an effective method for downgrading high-grade AVM in preparation for surgery by targeting the deeper portions that abut or involve eloquent territory. To our knowledge this is the first such successful prospective report in the literature.     

Intramedullary spinal arteriovenous malformation in a boy of familial cerebral cavernous hemangioma

Object The coexistence of spinal arteriovenous malformation (AVM) and a familial cerebral cavernous hemangioma (CCH) is extremely rare. Methods A 9-year-old boy suddenly developed severe paraplegia and urinary dysfunction. Spinal magnetic resonance imaging (MRI) scan revealed a cervical and upper thoracic intramedullary lesion. Due to acute neurological dysfunction, the patient underwent emergency surgical exploration. An intramedullary vascular lesion was found and excised. Pathologically, AVM was noted. After the surgery, the boy was ambulatory with left lower limb stiffness. MRI scan of the brain revealed multiple cerebral cavernous hemangioma. Symptomatic multiple CCH in his mother and grandmother were also noted. Conclusions We concluded that the presence of spinal AVM should be suspected if the patient with familial CCH develops the signs of space-occupying lesion of the spinal cord, facilitating early diagnosis of the spinal AVM.     

脑动静脉畸形的伽玛刀(Y-刀)治疗研究(附70例报道)

目的:观察伽玛刀(Y-刀)治疗脑动静脉畸形(AVM)的治疗效果。方法:对70例脑动静脉畸形的患者,采用Leksell-B型伽玛刀实施立体定向放射外科治疗,予处方剂量18～25Gy,平均21.8Gy。结果:获随访资料70例(随访时间1149个月,平均27个月),复查MRI显示畸形血管流空明显减少8例,占14.8%,完全消失42例,占77.8%,多数患者临床症状于伽玛刀治疗后消失或明显改善。结论:伽玛刀(Y-刀)是一种治疗脑动静脉畸形安全、有效的手段,可作为治疗脑动静脉畸形的首选方法。     

Effects of nidus microarchitecture on cerebral arteriovenous malformation hemodynamics

Intranidal vessel geometry and organization underlying flow within cerebral arteriovenous malformations (AVM) is poorly understood. We examine the relationship between intranidal vessel characteristics and AVM flow. Records of patients with AVM evaluated at our institution between 2007 and 2013 were retrospectively reviewed. Patients were included if surgical specimens were available and flows were obtained before treatment using quantitative magnetic resonance angiography. Intranidal vessels were identified and the diameter and cross-sectional area of each vessel were measured from digitized images of specimen slides. The relationship between vessel diameter, vessel cross-sectional area, AVM volume, and AVM flow was assessed. Twenty-nine patients were included. Mean total number of vessels per specimen was 133. Mean total AVM flow was 340 ± 276 mL/min. Mean vessel diameter ranged from 0.18–2.37 mm and mean vessel cross-sectional area ranged from 0.09–9.46 mm². Linear regression analysis showed that total flow is significantly associated with larger AVM volume (R² = 0.28, P = 0.007), but not with number of vessels per section of the specimen (P = 0.20) or mean vessel diameter (P = 0.92). Exponential regression analysis demonstrated that AVM flow is significantly correlated to the sum of the cross-sectional vessel areas within each specimen (R² = 0.16, P = 0.05). Total AVM flow is significantly related to sum of the cross-sectional areas of all vessels within each nidus, rather than to total number of vessels or mean nidal vessel diameter. This finding suggests that the sum of the cross-sectional areas of intranidal vessels likely determines the resistance to flow within a cerebral AVM.     

Recurrence of a cerebral arteriovenous malformation after surgical excision

Complete resection of a cerebral arteriovenous malformation (AVM) should eliminate the future risk of an associated intracranial bleeding. Because total removal of an AVM may be difficult to assess at the time of surgery, postoperative angiography has become the accepted standard for documenting that complete removal has been achieved. However, even angiographically confirmed excision of an AVM does not completely exclude the possibility of rebleeding. Regrowth of an AVM with subsequent haemorrhage has been documented in children and is attributed to forces acting on the immature vasculature. The authors report the case of a 21-year-old man whose AVM recurred 5 years after angiographically proven complete excision. According to the presented case, the authors emphasise that, even in adults, angiographic documentation of total removal does not always eliminate the risk of reformation of an AVM.     

Long term treatment efficacy & complications of hypofractionated stereotactic radiosurgery in brain arteriovenous malformations

ObjectiveTo evaluate long term treatment efficacy and complications of hypofractionated stereotactic radiosurgery (hfSRS) and identify factors that predict outcomes.MethodsA retrospective review was conducted on 34 consecutive patients who received hfSRS from 2008 to 2017. Demographic, clinical, angio-architectural characteristics, and radiosurgery data were extracted from the Clinical Data Analysis and Reporting System and our unit’s iPlan (BrainLAB, Munich) system. Data was analysed using SPSS.Results5-year obliteration rate was 39.1%. Most patients (n = 29, 85.3%) recovered well with GOS of 4–5. 26.9% (n = 9) patients have at least one post-radiosurgery complication including hemorrhage, neurological deficits, radionecrosis. Neurological morbidity and mortality was 17.6% (n = 6). A higher modified radiosurgery arteriovenous malformation score (mRBAS) is associated with a lower 5-year obliteration rate (Rho = -0.486, p = 0.025). None of the bAVM were obliterated once mRBAS exceeds 5.35. As expected, a larger 20-Gy volume outside lesion is associated with more complications and poorer GOS. Interestingly, irradiated drainage vein volume indexed to AVM volume (iiDVV) correlates with increased risks of post-hfSRS haemorrhage (Rho = 0.472, p = 0.031) and reduced event-free survival (Rho = −0.472, p = 0.031). Once iiDVV exceeds 20%, a high rebleeding rate after hfSRS is anticipated (AUC under ROC 0.889).ConclusionHypofractionated stereotactic radiosurgery is an alternative radiosurgery treatment for bAVM unsuitable for single-fraction SRS. mRBAS predicts obliteration rate and morbidity in hfSRS. Index irradiated drainage vein volume (iiDVV) is associated with event-free survival and rebleeding and should be minimized if feasible.