Treatment for brain arteriovenous malformation in the 1998-2011 period and review of the literature

Analysis of the incidence of death, hemorrhage, and neurological deficit in the treatment of intracranial arteriovenous malformations (AVMs): surgery versus other treatments - a systematic review

To evaluate the incidence of mortality, hemorrhage, and neurological deficits in treating intracranial arteriovenous malformations (AVMs) in patients over 18 through a comparative analysis of surgical approaches and other therapeutic modalities. A systematic review was conducted using MEDLINE, Embase, CENTRAL, and LILACS databases in November 2023. Inclusion criteria included clinical trials, cohorts studies, case-controls studies, and case series comparing patients over 18 undergoing surgery or microsurgery versus other treatments (radiosurgery, isolated embolization, and conservative treatment). Exclusions criteria included studies on non-AVM diseases, non-intracranial AVMs, cavernous malformations, pregnant patients, and those treated with both radiosurgery and microsurgery. Twelve studies included 1,555 patients, with an average age of 42.65 years. Of these, 711 underwent surgery (with or without prior embolization), and 844 underwent other procedures. In the surgery group, the incidence of death was 1.69%, while in the other procedures group, it was 2.96%. The incidence of neurological deficits and hemorrhage in the surgery group was 11.67% and 4.22%, respectively. In other procedures, these incidences were both 9.12%. The average obliteration rate in the surgery group was 97.45%, compared to 49.77% for radiosurgery, 38.46% for isolated embolization, and 0.6% for conservative treatment. This systematic review highlighs that surgery achieves the highest AVM obliteration rates but carries a higher risk neurological déficits. Radiosurgery minimizes these risks, while conservative treatment offers advantages in mortality and hemorrhage reduction. No single modality proves to be universally superior, emphasizing the need for personalized approaches and further randomized trials to clarify comparative safety and efficacy.

Intracranial arteriovenous malformation (AVM) or meningothelial meningioma (MM)? Outlining the similarities and differences on imaging studies for an accurate diagnosis, case report

INTRODUCTION AND IMPORTANCE

AVM and MM represent neurosurgical challenges, not only when involving eloquent brain, but also by posing a significant intraoperative haemorrhagic risk. It is a challenge in itself to establish a proper differential diagnosis between the two lesions, especially since they require distinct interventional plan of action. We present the case of a patient initially diagnosed by specialists with an intracranial AVM, which was revealed intraoperatively to be in fact an MM.

CASE PRESENTATION

A 29-years patient, transferred to our department by urgency. The patient symptoms started two weeks prior admission with severe headache and vomiting. A cerebral computer tomographic angiography (CTA) was performed and interpreted by radiologists, as a large left frontal AVM.

CLINICAL DISCUSSION

Upon through review the majority of surgical team believed the mass to be AVM. However, during surgery it turned out to be Meningioma. The patient underwent a left pterional craniotomy with removal of the tumour, classified as Simpson grade II. The pathological exam confirmed the lesion to be an MM.

CONCLUSIONS

Acquiring neuro-radiological expertise is vital for the neurosurgeon, as well as fast ability for adjusting the initial action plan with the intraoperative discoveries. An experienced eye can benefit the patient by obtain a correct diagnosis in most difficult cases.

Decision-Making for Patients With Cerebral Arteriovenous Malformations

Cerebral arteriovenous malformations (AVMs) are a complex and heterogeneous pathology which require an understanding of the natural history of these lesions, as well as the potential treatment options in order to manage them safely. While treatment is the agreed upon strategy for most ruptured AVMs, the management of unruptured AVMs continues to be debated. More recently, this debate has been fueled by the A Randomized Trial of Unruptured Arteriovenous Malformations (ARUBA) trial which attempts to define the natural history and treatment risk of AVMs. However, the trial has significant shortcomings which limit its broad applicability. In addition, the breadth, efficacy, and safety of potential treatment options continue to improve. This review focuses on defining the natural history of cerebral AVMs, an overview of the ARUBA trial, and the most current treatment paradigm for cerebral AVMs.

A novel proposed grading system for cerebellar arteriovenous malformations

OBJECTIVE

The objective of this study was to evaluate the existing Spetzler-Martin (SM), Spetzler-Ponce (SP), and Lawton-Young (LY) grading systems for cerebellar arteriovenous malformations (AVMs) and to propose a new grading system to estimate the risks associated with these lesions.

METHODS

Data for patients with cerebellar AVMs treated microsurgically in two tertiary medical centers were retrospectively reviewed. Data from patients at institution 1 were collected from September 1999 to February 2013, and at institution 2 from October 2008 to October 2015. Patient outcomes were classified as favorable (modified Rankin Scale [mRS] score 0-2) or poor (mRS score 3-6) at the time of discharge. Using chi-square and logistic regression analysis, variables associated with poor outcomes were assigned risk points to design the proposed grading system. The proposed system included neurological status prior to treatment (poor, +2 points), emergency surgery (+1 point), age > 60 years (+1 point), and deep venous drainage (deep, +1 point). Risk point totals of 0-1 comprised grade 1, 2-3 grade 2, and 4-5 grade 3.

RESULTS

A total of 125 cerebellar AVMs of 1328 brain AVMs were reviewed in 125 patients, 120 of which were treated microsurgically and included in the study. With our proposed grading system, we found poor outcomes differed significantly between each grade (p < 0.001), while with the SM, SP, and LY grading systems they did not (p = 0.22, p = 0.25, and p = 1, respectively). Logistic regression revealed grade 2 had 3.3 times the risk of experiencing a poor outcome (p = 0.008), while grade 3 had 9.9 times the risk (p < 0.001). The proposed grading system demonstrated a superior level of predictive accuracy (area under the receiver operating characteristic curve [AUROC] of 0.72) compared with the SM, SP, and LY grading systems (AUROC of 0.61, 0.57, and 0.51, respectively).

CONCLUSIONS

The authors propose a novel grading system for cerebellar AVMs based on emergency surgery, venous drainage, preoperative neurological status, and age that provides a superior prognostication power than the formerly proposed SM, SP, and LY grading systems. This grading system is clinically predictive of patient outcomes and can be used to better guide vascular neurosurgeons in clinical decision-making.

The Role of Matrix Metalloproteinase-3 in the Doxycycline Attenuation of Intracranial Venous Hypertension-Induced Angiogenesis

BACKGROUND

The molecular mechanism of brain arteriovenous malformation (BAVM) is largely unknown. Intracranial venous hypertension (VH) may enhance focal angiogenesis and promote BAVM development and progression. A rat VH model effectively simulates the hemodynamic microenvironment of this disease.

OBJECTIVE

To explore the effect of doxycycline in VH-related angiogenesis, as well as the role of matrix metalloproteinase-3 (MMP-3) and other molecular factors.

METHODS

A rat VH model was generated by common carotid artery and distal external jugular vein anastomosis. Microvessel density (MVD) in the perisinus area and expression of MMP-3/2/9, VEGF, TIMP-1, TGF-β, and HIF-1α were examined, with and without daily doxycycline treatment for 4 wk. The effects of doxycycline were verified in Vitro using human brain microvascular endothelial cells (HBMECs). MMP-3 overexpression or knockdown in HBMECs was used to confirm the role of MMP-3 in cell functions.

RESULTS

MVD in the perisinus cortex was greatly increased after VH. Doxycycline decreased MVD, suppressed MMP-3 overexpression, and reduced VEGF, TGF-β, and TIMP-1 levels compared with the controls (P < .05). In Vitro, doxycycline decreased HBMEC migration, tube formation, and the mRNA, protein, and enzymatic activity levels of MMP-3. MMP-3 overexpression in HBMECs promoted migration, while knockdown of MMP-3 significantly attenuated proliferation, migration, and tube formation (P < .05).

CONCLUSION

Our findings indicate that MMP-3 plays an important role in VH-related angiogenesis and the promotion of vascular remodeling. Suppression of MMP-3 overexpression by doxycycline may provide a potential strategy for inhibiting BAVM development.

Outcome of Microsurgery for Arteriovenous Malformations in a Resource-Restricted Environment: Single-Surgeon Series from Vietnam

BACKGROUND

The health care expenditure in Vietnam is equivalent to 1% of that in the United States. For most patients with brain arteriovenous malformations (AVM), surgery is the only available treatment modality. This study reports on the outcomes on AVM microsurgery in this resource-restricted environment.

METHODS

This is a prospectively collected, retrospectively analyzed case series of consecutive patients who underwent surgical resection of AVM by a single surgeon in Vietnam. All surgeries were performed in a 3-year period in Hanoi. The primary endpoints were obliteration of the AVM and surgical morbidity (modified Rankin Scale [mRS] > 1).

RESULTS

There were 86 patients and 62% presented with hemorrhage. Only 2 patients had preoperative embolization, and 47 patients (54%) had preoperative digital subtraction angiography. All patients underwent microsurgical resection of their AVM. Excluding the 4 patients who died, the AVM obliteration rate was 98%. The mean follow-up was 20.1 months. Before surgery, 36% of patients had at least some disability (mRS > 1). Postoperatively, this was reduced to 10% (McNemar P = 0.007). For the overall cohort, neurologic status was improved from initial encounter to final assessment (P = 0.001). Because of resource restrictions, some patients with hemorrhage experienced delays in treatment. There was no difference in outcome between patients who were admitted before or after 24 hours post ictus (P = 0.6). The days spent waiting for surgery did not correlate with final mRS in univariate regression (R² = 0.01).

CONCLUSIONS

Notwithstanding the limitation in health care resources in Vietnam, surgery for AVMs was successful in eliminating the malformation, with obliteration rates and morbidity comparable with international standards.

Risk factors for hemorrhage of brain arteriovenous malformation

Patients with brain arteriovenous malformation (bAVM) are at risk of intracranial hemorrhage (ICH). Overall, bAVM accounts for 25% of hemorrhagic strokes in adults <50 years of age. The treatment of unruptured bAVMs has become controversial, because the natural history of these patients may be less morbid than invasive therapies. Available treatments include observation, surgical resection, endovascular embolization, stereotactic radiosurgery, or combination thereof. Knowing the risk factors for bAVM hemorrhage is crucial for selecting appropriate therapeutic strategies. In this review, we discussed several biological risk factors, which may contribute to bAVM hemorrhage.

Single-stage planning for total cure of grade III-V brain arteriovenous malformations by embolization alone or in combination with microsurgical resection

PURPOSE

There are no established guidelines for treatment of Spetzler-Martin grade III-V brain arteriovenous malformations (bAVMs). The purpose of this study is to report our institutional experience in total obliteration/eradication of grade III-V bAVMs by single-stage planning of embolization combined with microsurgical resection when necessary.

METHODS

All patients harboring Spetzler-Martin (S-M) grade III-V bAVMs treated with single-stage planning between January 2006 and January 2018 were retrospectively reviewed. This treatment paradigm is applicable only to surgically accessible bAVMs and does not include deep-seated bAVMs. Indications for treatment, clinical presentation, imaging characteristics, and treatment outcomes were analyzed. Outcomes were assessed based on modified Rankin Scale.

RESULTS

A total of 31 patients were identified. Seventeen patients (54.8%) presented with hemorrhage, 10 (32.3%) with seizures, 3 (9.7%) with headaches, and 1 (3.2%) with progressive neurological deficit. Based on S-M grading system, 25 patients (80.6%) harbored grade III bAVM, 5 patients had grade IV bAVMs (16.1%), and 1 patient (3.2%) had a grade V bAVM. There were no treatment-related complications in 24/31 (77.4%) patients. Of the total of seven patients with complications, four patients had clinical deterioration. The long-term (> 6-month), non-disabling morbidity (mRS ≤ 2) rate was 6.5%. The long-term, disabling morbidity rate was 3.2% with a mortality of 3.2%. Complete angiographic obliteration was achieved in 30/31 (96.8%) patients.

CONCLUSION

Single-stage treatment strategy can be considered as an alternative to multistage embolization prior to surgery in grade III-V bAVMs. In this study, a high rate of total obliteration with relatively low rates of permanent morbidity and mortality was achieved.

Arteriovenous Malformations of the Posterior Fossa: Focus on Surgically Treated Patients Presenting with Hemorrhage

BACKGROUND

Arteriovenous malformations (AVMs) of the posterior fossa are demanding lesions that often present with rupture. Studies including outcome analyses in surgically operated patients with ruptured infratentorial AVMs are scarce. Certain anatomic and demographic features have shown associations with postoperative outcomes.

METHODS

Eighty-six patients with infratentorial AVM were collected from our AVM database. Fifty-four patients were admitted from 1990 onward, and their demographic, lesion, and treatment characteristics were analyzed. The cohort was further refined to 38 consecutive patients with surgically treated ruptured infratentorial AVM admitted to our center between 1990 and 2014, and statistical analyses of factors influencing outcomes were conducted.

RESULTS

Twenty-seven patients (69%) had a favorable outcome at early follow-up and 24 (67%) had a favorable outcome at final follow-up. Factors associated with poor outcome in early recovery on univariate analyses were deep venous drainage of the lesion (odds ratio [OR], 5.3; P = 0.037) and high Hunt & Hess score (P = 0.003). In the multivariate model, independent predictors for poor outcome were deep venous drainage (OR, 14.5; P = 0.010) and older age at admission (OR, 1.06; P = 0.028). The sole independent predictor for poor outcome at last follow-up was deep venous drainage (OR, 5.00; P = 0.046). The total follow-up time was 370 person-years.

CONCLUSIONS

AVMs of the posterior fossa usually present with rupture and thus require prompt clinical treatment. The majority of surgically treated patients recover favorably. Our data show that venous drainage patterns have the greatest influence on the patient's postoperative condition. Other influencing factors include the severity of hemorrhage and patient age at admission.

Safety and efficacy of endovascular therapy and gamma knife surgery for brain arteriovenous malformations in China: Study protocol for an observational clinical trial

Introduction

Brain arteriovenous malformations (BAVMs) are associated with high morbidity and mortality. The treatment of BAVM remains controversial. Microinvasive treatment, including endovascular therapy and gamma knife surgery, has been the first choice in many conditions. However, the overall clinical outcome of microinvasive treatment remains unknown and a prospective trial is needed.

Methods

This is a prospective, non-randomized, and multicenter observational registry clinical trial to evaluate the safety and efficacy of microinvasive treatment for BAVMs. The study will require up to 400 patients in approximately 12 or more centers in China, followed for 2 years. Main subjects of this study are BAVM patients underwent endovascular therapy and/or gamma knife surgery. The trial will not affect the choice of treatment modality. The primary outcomes are perioperative complications (safety), and postoperative hemorrhage incidence rate and complete occlusion rate (efficacy). Secondary outcomes are elimination of hemorrhage risk factors (coexisting aneurysms and arteriovenous fistula), volume reduction and remission of symptoms. Safety and efficacy of endovascular therapy, gamma knife surgery, and various combination modes of the two modalities will be compared. Operative complications and outcomes at pretreatment, post-treatment, at discharge and at 3 months, 6 months and 2 years follow-up intervals will be analyzed using the modified Rankin Scale (mRS).

Discussion

The most confusion on BAVM treatment is whether to choose interventional therapy or medical therapy, and the choice of interventional therapy modes. This study will provide evidence for evaluating the safety and efficacy of microinvasive treatment in China, to characterize the microinvasive treatment strategy for BAVMs.

A proposed classification for assessing rupture risk in patients with intracranial arteriovenous malformations

Background:

Whether cerebral arteriovenous malformations (AVMs) should be treated remains an ongoing debate. Nevertheless, there is a need for predictive factors that assist in labelling lesions as low or high risk for future rupture. Our aim was to design a new classification that would consider hemodynamic and anatomic factors in the rapid assessment of rupture risk in patients with AVMs.

Methods:

This was a retrospective study that included 639 patients with ruptured and unruptured AVMs. We proposed a new classification score (1–4 points) for AVM rupture risk using three factors: feeding artery mean velocity (Vm), nidus size, and type of venous drainage. We employed descriptive statistics and logistic regression analysis.

Results:

A total of 639 patients with cerebral AVMs, 388 (60%) had unruptured AVMs and 251 (40%) had ruptured AVMs. Logistic regression analysis revealed a significant effect of Vm, nidus size, and venous drainage type in accounting for the variability of rupture odds (P = 0.0001, R² = 0.437) for patients with AVMs. Based in the odds ratios, grades 1 and 2 of the proposed classification were corresponded to low risk of hemorrhage, while grades 3 and 4 were associated with hemorrhage: 1 point OR = (0.107 95% CI; 0.061–0.188), 2 point OR = (0.227 95% CI; 0.153–0.338), 3 point OR = (3.292 95% CI; 2.325–4.661), and 4 point OR = (23.304 95% CI; 11.077–49.027).

Conclusion:

This classification is useful and easy to use, and it may allow for the individualisation of each cerebral AVM and the assessment of rupture risk based on a model of categorisation.

Hemodynamics Associated With Intracerebral Arteriovenous Malformations: The Effects of Treatment Modalities

The understanding of the physiology of cerebral arteriovenous malformations (AVMs) continues to expand. Knowledge of the hemodynamics of blood flow associated with AVMs is also progressing as imaging and treatment modalities advance. The authors present a comprehensive literature review that reveals the physical hemodynamics of AVMs, and the effect that various treatment modalities have on AVM hemodynamics and the surrounding cortex and vasculature. The authors discuss feeding arteries, flow through the nidus, venous outflow, and the relative effects of radiosurgical monotherapy, endovascular embolization alone, and combined microsurgical treatments. The hemodynamics associated with intracranial AVMs is complex and likely changes over time with changes in the physical morphology and angioarchitecture of the lesions. Hemodynamic change may be even more of a factor as it pertains to the vast array of single and multimodal treatment options available. An understanding of AVM hemodynamics associated with differing treatment modalities can affect treatment strategies and should be considered for optimal clinical outcomes.

Cerebral arterio-venous malformations in the paediatric population: Angiographic characteristics, multimodal treatment strategies and outcome

OBJECTIVES

Cerebral arterio-venous malformations (AVM) are considered congenital lesions, emerging as an important cause of haemorrhagic stroke in children. The potential influence of age on clinical presentation and angio-architecture have been analysed extensively in the last years. Yet, comparative studies comprising ascending age groups may be limited in their conclusions, especially when comparing young children and adults. It is the aim of this study to evaluate characteristic clinical and angiographic features of AVM within a paediatric subgroup and their correlation to age at presentation.

PATIENTS AND METHODS

Between 1990-2015, 46 children harbouring AVMs were treated at our institution. Clinical presentation, radiological data, treatment strategies and outcome were evaluated retrospectively.

RESULTS

Of 46 consecutive patients, 18 were male and 28 female patients. Mean age was 11.6±4.3years, ranging from 2 to 17 years. 35 patients (76%) presented with haemorrhage. Seizures were found in 6 patients (13%) and progressive or transient focal neurological deficits in 4 individuals (9%). There was one incidental patient, only. Mean age of children presenting with haemorrhage was significantly lower as compared to those without a history of intracranial bleeding (p=0.1). The size of the AVM was small (n=27, 59%), corresponding a grade I AVM in the majority of patients (N=28, 61%). 41 patients (89%) underwent treatment of their AVM by an interdisciplinary approach achieving complete elimination of the lesion in 34 patients (83%). 34 patients (83%) showed at least a favourable outcome (mRS≤2) at last follow-up. An excellent recovery (mRS 0-1) was noted in 28 patients (68%).

CONCLUSION

From our data we suggest that patients' age impacts the clinical presentation. Particularly young children seem to bear a higher risk for haemorrhage from their AVM. Treatment of paediatric AVMs can be achieved safely in experienced hands with a high rate of complete elimination and good clinical outcome.

Endogenous hormone 2-methoxyestradiol suppresses venous hypertension-induced angiogenesis through up- and down-regulating p53 and id-1

Brain arteriovenous malformations (AVMs) which associate with angiogenesis due to local hypertension, chronic cerebral ischaemia and tissue hypoxia usually lead to haemorrhage, however, the therapeutic medicine for the disease is still lacking. 2‐methoxyestradiol (2‐ME) has been shown effective in the anti‐angiogenic treatment. This study was conducted to examine whether and how 2‐ME could improve the vascular malformations. Intracranial venous hypertension (VH) model produced in adult male Sprague‐Dawley rats and culture of human umbilical vein endothelial cells (HUVECs) at the anoxia condition were used to induce in vivo and in vitro angiogenesis, respectively. Lentiviral vectors of ID‐1 and p53 genes and of their siRNA were intracranially injected into rats and transfected into HUVECs to overexpress and down‐regulate these molecules. 2‐ME treatment not only reduced the in vivo progression of brain tissue angiogenesis in the intracranial VH rats and the in vitro increases in microvasculature formation, cellular migration and HIF‐1α expression induced by anoxia in HUVECs but also reversed the up‐regulation of ID‐1 and down‐regulation of p53 in both the in vivo and in vitro angiogenesis models. All of the anti‐angiogenesis effects of 2‐ME observed in VH rats and anoxic HUVECs were abrogated by ID‐1 overexpression and p53 knockdown. Our data collectively suggest that 2‐ME treatment inhibits hypoxia/anoxia‐induced angiogenesis dependently on ID‐1 down‐regulation and p53 up‐regulation, providing a potential alternative medical treatment for un‐ruptured AVM patients.

Assessing the Role of Preoperative Embolization in the Surgical Management of Cerebral Arteriovenous Malformations

BACKGROUND

Preoperative embolization is established as an advantageous adjunct in multimodality treatment of cerebral arteriovenous malformations (AVMs). However, the benefit of preoperative embolization in AVMs with favorable surgical risk profile is debatable, because it has yet to be supported by evidence in comparative studies. In this study, we assessed outcome of surgically treated patients in a comparative setting.

METHODS

Our institutional AVM database of retrospectively and prospectively collected data between 1990 and 2015 was reviewed. Patients with complete clinical data who underwent surgical resection for AVMs were included. We performed a 1:1 ratio propensity score match for baseline variables that differed between patients with or without preoperative embolization. Differences in surgical risk and outcomes were evaluated between these 2 groups.

RESULTS

AVM size, eloquence, deep drainage, middle cerebral artery feeder, and ruptured presentation differed significantly between the 2 groups. Forty-eight patients without preoperative embolization were matched to 48 with embolization, with no significant differences in baseline variables or AVM characteristics between the 2 groups. We found no significant differences in AVM obliteration and postoperative modified Rankin Scale (mRS) score between embolized and nonembolized patients, respectively. Change in mRS score from preoperative score was also not significant, although more embolized patients had a decline in mRS score. Secondary outcome measures including duration of surgery (P = 0.172), intraoperative bleeding (P = 0.280), duration of hospitalization (P = 0.368), and postoperative symptoms were also similar between both groups.

CONCLUSIONS

Our data do not support substantial benefit of preoperative embolization for patients with a favorable surgical risk profile. Because of risks and costs with this intervention, the prudent use of preoperative embolization should be individually considered.

Grade 1 Spetzler and Martin cerebral ruptured arteriovenous malformations treated by microsurgery: Poor functional outcome is related to injury from haemorrhage

INTRODUCTION

Ruptured arteriovenous malformations (rAVM) are life-threatening diseases.

OBJECTIVE

To evaluate the outcome of patients with grade 1 SPM rAVM after microsurgical treatment.

MATERIALS AND METHOD

We retrospectively included 64 consecutive operated patients with a grade 1 SPM rAVM in our institution between 2002 and 2012. Complications related to the surgical procedure were recorded. All patients were re-evaluated 3months after treatment using the modified Rankin Scale score (mRS). Persistent neurological disorders were evaluated 1year after bleeding. Conventional cerebral angiography was performed for each patient immediately after surgical treatment and 1year later.

RESULTS

The mean age at diagnosis was 30.8 years. Initial WFNS score was grade 1 in 25 patients, grade 2 in 11 patients, grade 3 in 10 patients, grade 4 in 9 patients and grade 5 in 9 patients. No remnant was left and a new surgery was performed only in a single patient who was initially operated-on under emergency conditions with limited preoperative investigations due to a poor clinical grade. Early postoperative complications related to the surgical procedure were recorded in 7 patients. The mRS score 3months after treatment was ≤2 in 53 patients (83%). Persistent neurological disorders were recorded in 40 patients (62.5%). High initial WFNS score (>2) and the hydrocephalus were significantly associated (P<0.05) to a bad functional outcome (mRS>2).

CONCLUSION

Grade 1 rAVM is a life-threatening disease concerning in most cases young patients. Long-term morbidity is often related to the hemorrhagic brain damage and rarely to the AVM resection.

Multimodal Treatment Strategy for Spetzler-Martin Grade III Arteriovenous Malformations of the Brain

The Spetzler–Martin (S–M) grading scale was developed to assess the risk of postoperative neurological complications after the surgical treatment of arteriovenous malformations (AVMs) of the brain. Treatment-associated morbidity and poor outcomes are particularly relevant to Grade III AVMs and improving the safety while attaining acceptable cure rates still poses a challenge. A multimodal treatment strategy combining surgery, embolization, and radiosurgery is recommended for S–M Grade III AVMs because of the surgical risk. Grade III AVMs are the heterogeneous group that has been further divided into subgroups according to the size, the location in eloquent cortex, and the presence of deep venous drainage. The risks associated with different treatment modalities vary depending on the subgroup, and the rating scales have been further refined to predict the risk more accurately and help determine the most appropriate treatment choice. Previous results for the treatment of S–M Grade III AVMs vary widely among studies, and the treatment modalities are also different in each study. Being familiar with previous treatment results is essential for improving treatment outcomes.

Intraoperative Anatomical and Hemodynamic Analysis of Intracerebral Arteriovenous Malformations by Semi-quantitative Color-coded Indocyanine Green Videoangiography

Objective and Background:

To evaluate possible roles for indocyanine green (ICG)-based FLOW 800 software in surgical treatment of cerebral arteriovenous malformations (AVMs).

Methods:

We perform ICG videoangiography several times for each step of AVM resection to elucidate feeders, drainers, and cerebral perfusion.

Results:

Since 2010, 22 AVM surgeries in our department have been conducted using FLOW 800 intraoperatively. We demonstrated ICG angiograms, color-coded images, and semi-quantitative curves for AVMs. By reviewing all these modalities, we would define vascular structure of the AVM, proceed with resection, and finally recheck for any remnant.

Conclusions:

ICG FLOW 800 software helps the surgeon to recognize feeding and draining vessels of an AVM intraoperatively. Further studies to evaluate semi-quantitative acquired data regarding blood flow and tissue perfusion are warranted.

Multiple cerebral arterio-venous malformations: impact of multiplicity and hemodynamics on treatment strategies

BACKGROUND

Multiple AVMs are exceptionally rare lesions and only a few larger series have been published, including other vascular pathologies, such as arterio-venous fistulae (AVF) or patients with hereditary syndromes. Our study presents clinical, angiographic, and therapeutic characteristics of patients harboring sporadic multiple AVMs.

METHODS

Basic demographic data, vascular architecture, clinical presentation, treatment strategies, and treatment outcome were analyzed retrospectively from patients with cerebral AVMs treated in our department between 1990 and 2015.

RESULTS

Six out of 539 patients (1.1 %) harbored 15 multiple and distinct cerebral lesions. Nidus size was predominantly small, consequently determining a Spetzler-Martin grade °I-°II (three-tier grading system). In three patients, AVMs shared a proximal feeding artery supply, whereas each AVM displayed its own venous drainage. Five of six patients (83 %) presented with hemorrhage. Four patients received therapy of the AVMs with complete elimination in 3/4 patients (75 %) and 8/9 treated AVMs (89 %). All patients with treatment of the AVM showed good-to-excellent recovery (n = 4, mRS ≤ 2).

CONCLUSIONS

Multiple cerebral AVMs are complex vascular lesions. The multiplicity of hemodynamic and malformation-related variables influence treatment strategy and sequence. Thus, awareness of these parameters (of various malformations before and during treatment) is important. The high number of hemorrhagic events in the present series might justify a more aggressive treatment of multiple AVMs than previously thought.

Effective Surgical Management of Competitive Venous Outflow Restriction After Radiosurgery for Cerebral AVMs: Report of 2 Cases

BACKGROUND

Intracranial arteriovenous malformations (AVMs) are complex pathologies. For patients who do not present with hemorrhage, treatment strategies are often predicated on reducing the risk of hemorrhage and minimizing morbidity. Outcomes vary according to the efficacy of treatment selected. Radiosurgical treatment of certain AVMs can result in incomplete obliteration and may also have only a minimal effect on the presenting nonhemorrhagic symptoms.

CASE DESCRIPTIONS

We present 2 cases of patients with AVMs who were initially treated with radiosurgery. Both patients' primary clinical symptoms were headaches, which persisted after radiosurgical treatment but abated after subsequent microsurgical resection with or without endovascular embolization.

CONCLUSION

Venous outflow obstruction is likely a sizable contributive factor in occipital AVMs among patients who present with headaches and symptoms of intracranial hypertension. Because these high-flow lesions may be suboptimally responsive to stereotactic radiosurgery, microsurgical resection, with or without adjunctive endovascular embolization, should be considered as an initial and definitive treatment strategy. Optimal outcomes may be achieved in patients with a visual deficit that is anatomically correlated to their AVMs.

Microsurgical Outcome of Cerebellar Arteriovenous Malformations: Single-Center Experience

OBJECTIVE

We aimed to describe our single-center experience in treating cerebellar arteriovenous malformations (AVMs) with microsurgical resection.

METHODS

During a 16-year period, 181 patients with cerebellar AVMs were surgically treated at the Department of Neurosurgery in Beijing Tiantan Hospital. Patient functional status was evaluated using modified Rankin Scale (mRS) scores both before treatment and at the last follow-up. The mRS scores at the last follow-up were dichotomized as good outcome (mRS <3) and poor outcome (mRS ≥3). The treatment modalities, post-treatment complications, obliteration rate, and follow-up outcomes were analyzed.

RESULTS

Of the 181 patients, 172 (95%) patients presented with initial hemorrhage and 62 (34%) patients experienced rehemorrhage before microsurgical treatment. Complete obliteration of the AVMs was achieved in 177 (97.8%) patients. Good functional outcome was achieved in 144 (80%) of the patients. The surgical mortality rate was 4.4% (8/181), and overall mortality rate was 6.6% (12/181). Poor outcome was significantly associated with increasing age (P = 0.035; odds ratio [OR], 1.030; 95% CI 1.002-1.060), presurgical mRS ≥3 (P = 0.029; OR, 2.563; 95% CI 1.101-5.968), eloquent AVM location (P = 0.015; OR, 3.058; 95% CI 1.244-7.516), and presurgical rehemorrhage (P = 0.008; OR, 3.266; 95% CI 1.358-7.858).

CONCLUSION

Good outcome can be achieved by microsurgical resection in most patients with cerebellar AVMs. Increasing age at surgery, poor presurgical functional status, eloquent AVM location, and presurgical rehemorrhage are independent predictors of poor outcomes after AVM resection. We recommend early surgical resection for all surgically accessible cerebellar AVMs to prevent subsequent hemorrhage and resultant poor neurologic outcomes.

Comparative surgical outcome associated with the management of brain arteriovenous malformation in a regional neurosurgical centre

OBJECTIVES

Microsurgical resection of brain arteriovenous malformation (AVMs) is challenging, however, expert surgical series from large volume centres, have reported over 95% occlusion rates with 2 to 8% risk of morbidity & mortality. Data from a regional neurosurgical unit was analysed and compared with published series for the purposes of quality control. We also compared our surgical result with other treatment modalities from the whole AVM cohort managed over the same study period.

DESIGN

Retrospective analysis of a locally held AVM database.

SUBJECTS

Of the 141 AVM patients, 54 (35M, 19F, age range 9-68 years) underwent microsurgical removal of AVM by the senior author, from 2006 to 2012. 27 (19%), 18 (13%), 20 (14%), 22 (16%) had endovascular therapy only, radiosurgery only, combination therapy (endovascular and radiosurgery) and conservative management, respectively.

METHODS

Case notes were reviewed to determine clinical and radiological outcomes. Statistical analysis performed using SPSS with p < 0.05 defined as statistical significance.

RESULTS

In the surgical series, the Spetzler-Martin (SM) grade distribution was as follows: 17 grade I (32%), 31 grade II (57%), and 6 grade III (11%). 31 patients (57%) presented with intracranial haemorrhage, 12 patients (22%) with seizures. Of the 54 patients, 51 (94%) had angiographically confirmed obliteration of their AVM. Median follow-up for the entire cohort was 7 years. 83% of surgical patients have mRS 0-1, compared to 78%, 67%, 45%, 18% of patients managed by endovascular therapy, radiosurgery, combination therapy, conservative surveillance, respectively (p < 0.0001). However, the groups were not comparable in terms of SM grade or clinical presentation and the numbers in each group were relatively small. Seizure presentations were encountered in 23% (32/141) of the overall patients, and all the surviving patients were on anticonvulsants, except in the surgical arm, 7/12 (58%) patients were off their antiepileptic medications at last follow-up.

CONCLUSIONS

The results demonstrate a 94% surgical obliteration rate and 11% long-term neurological deficits for brain AVM patients managed surgically and were comparable to expert series. Achieving acceptable results is possible in lower volume settings, however, patient selection is important and the role of an experienced neurovascular team cannot be overstated.

Clinical experience with navigated 3D ultrasound angiography (power Doppler) in microsurgical treatment of brain arteriovenous malformations

Introduction

We have previously described a method that has the potential to improve surgery of arteriovenous malformations (AVMs). In the present paper, we present our clinical results.

Materials and methods

Of 78 patients referred for AVMs to our University Hospital from our geographical catchment region from 2005 through 2013, 31 patients were operated on with microsurgical technique. 3D MR angiography (MRA) with neuronavigation was used for planning. Navigated 3D ultrasound angiography (USA) was used to identify and clip feeders in the initial phase of the operation. None of our patients was embolized preoperatively as part of the surgical procedure. The niduses were extirpated based on the 3D USA. After extirpation, controls were done with 3D USA to verify that the AVMs were completely removed. The Spetzler three-tier classification of the patients was: A: 21, B: 6, C: 4.

Results

Sixty-eight feeders were identified on preoperative MRA and DSA and 67 feeders were identified and clipped by guidance of intraoperative 3D USA. Six feeders identified preoperatively were missed by 3D USA, while five preoperatively unknown feeders were found and clipped. The overall average bleeding was 440 ml. There was a significant reduction in average bleeding in the last 15 operations compared to the first 16 (340 vs. 559 ml, p = 0.019). We had no serious morbidity (GOS 3 or less). New deficits due to surgery were two patients with quadrantanopia (one class B and one class C), the latter (C) also acquired epilepsy. One patient (class A) acquired a hardly noticeable paresis in two fingers. One hundred percent angiographic cure was achieved in all patients, as evaluated by postoperative DSA.

Conclusions

Navigated intraoperative 3D USA is a useful tool to identify and clip AVM feeders. Microsurgical extirpation assisted by navigated 3D USA is an effective and safe method for removing AVMs.

Comparing monomodality treatments of low-grade intracranial arteriovenous malformation at Hospital Kuala Lumpur between 2008 and 2011: A retrospective study

Introduction:

Intracranial arteriovenous malformations (AVMs) of Spetzler-Martin grades (SMGs) I-III are treated using either monomodality treatments of microsurgical excision, embolization or stereotactic radiosurgery (SRS), or a combination of two or more of these treatment options. At Hospital Kuala Lumpur, we still practice monomodality treatments for AVMs of these three grades. In this study, we wanted to achieve an understanding whether monomodality treatments can achieve a satisfactory outcome of AVM nidi for patients, for up to 3 years, and to gather an objective data for AVM treatment for the Malaysian population.

Subjects and Methods:

This is a retrospective review of records study. The data are acquired from case notes of patients with intracranial AVM of SMGs I to III who underwent monomodality treatment at Hospital Kuala Lumpur between 2008 and 2011. The patients were followed up with imaging for up to 3 years from the date of treatment. A total of 81 patients were recruited in this study, where 30 underwent microsurgical treatment, 27 underwent embolization, and 24 underwent SRS.

Results:

Total obliteration of AVM nidus was achieved in 96.7% of patients who underwent microsurgery, 8.7% of patients who underwent embolization, and 79.2% of patients who underwent SRS. The modified Rankin scale (mRS) for all three groups showed an improving trend, with the microsurgery group showing the best improvement (from 70% at 3 months to 92.3% at 3 years showing favorable mRS scores).

Conclusions:

The AVM nidus obliteration for each treatment group is comparable to the meta-analysis published in 2011. Each modality had its own set of complications; however, most of the patients in all three groups had either static or improved mRS at the end of the 3-year follow-up.

Pathological Evaluation of Radiation-Induced Vascular Lesions of the Brain: Distinct from De Novo Cavernous Hemangioma

PURPOSE

We aimed to evaluate the histologic and radiologic findings of vascular lesions after stereotactic radiosurgery (SRS) categorized as radiation-induced cavernous hemangioma (RICH).

MATERIALS AND METHODS

Among 89 patients who underwent neurosurgery for cavernous hemangioma, eight RICHs from 7 patients and 10 de novo CHs from 10 patients were selected for histopathological and radiological comparison.

RESULTS

Histologically, RICHs showed hematoma-like gross appearance. Microscopically, RICH exhibited a hematoma-like area accompanied by proliferation of thin-walled vasculature with fibrin deposits and infiltrating foamy macrophages. In contrast, CHs demonstrated localized malformed vasculature containing fresh and old clotted blood on gross examination. Typically, CHs consisted of thick, ectatic hyalinized vessels lined by endothelium under a light microscope. Magnetic resonance imaging of RICHs revealed some overlapping but distinct features with CHs, including enhancing cystic and solid components with absence or incomplete popcorn-like appearance and partial hemosiderin rims.

CONCLUSION

Together with histologic and radiologic findings, RICH may result from blood-filled space after tissue destruction by SRS, accompanied with radiation-induced reactive changes rather than vascular malformation. Thus, the term "RICH" would be inappropriate, because it is more likely to be an inactive organizing hematoma rather than proliferation of malformed vasculature.

Brain arteriovenous malformations in elderly patients: clinical features and treatment outcome

BACKGROUND

In this aging society, attention has not been fully given to brain arteriovenous malformations (AVMs) in elderly patients. This study sought to describe a single institution's experience treating arteriovenous malformations (AVMs) in elderly patients.

METHODS

We conducted a retrospective review of brain AVMs in elderly patients treated at our institution between 1990 and 2012 with a focus on the clinical features, risk of hemorrhage and treatment outcomes.

RESULTS

Of the 2790 patients in our AVM database, 98 patients were over the age of 60 at presentation. Forty-eight percent presented with hemorrhage. Risks of initial hemorrhage were history of hypertension, smaller AVM size (<3 cm) and exclusively deep venous drainage. Treatment modalities were microsurgical resection in 65 %, embolization alone in 10 %, stereotactic radiosurgery (SRS) in 11 % and observation in 14 %. Preoperative embolization was performed in 32 % in the surgical group. Complete obliteration was achieved in 95 % by microsurgery, 30 % by embolization alone and 45 % by SRS. Good functional outcome (modified Rankin Scale, mRS <2) was achieved in 69 % after a median follow-up of 5.8 years. Multivariate logistic analysis revealed that a pretreatment mRS score ≥2, eloquent location and higher S-M grade (IV or V) were associated with worsening functional status, whereas surgical resection was a negative factor. Posttreatment hemorrhage occurred in 8 %. AVM-related death occurred in three patients (2 by surgery and 1 by observation).

CONCLUSIONS

Brain AVMs in elderly patients still pose a high risk of hemorrhage. Initial hemorrhage may be associated with a history of hypertension, AVM size and exclusively deep venous drainage. Initial mRS score ≥2, eloquent location and higher S-M grade may be associated with worsening functional status. Microsurgical resection can be safe and effective for selected patients. Preoperative embolization is helpful in patients with S-M grade IV-V AVMs. For those with surgical contraindications, SRS and observation are treatment alternatives.

Surgery for Unruptured Spetzler-Martin Grade 3 Brain Arteriovenous Malformations

BACKGROUND:

There is uncertainty regarding the management of unruptured Spetzler-Martin grade 3 brain arteriovenous malformations (SMG3 ubAVM).

OBJECTIVE:

To analyze our series of patients treated by surgery.

METHODS:

A single-surgeon database of consecutively enrolled bAVMs (between 1989 and 2014) was analyzed. Adverse outcomes due to surgery were assigned within the first 6 weeks following surgery and outcome was prospectively recorded and assigned at the last follow-up visit by using modified Rankin Scale (mRS) score.

RESULTS:

Of the 137 reviewed patients, 112 (82%) were treated by surgery, 15 (11%) were treated elsewhere or by radiosurgery, and 10 (7%) were recommended for conservative management. Surgery for SMG3 ubAVM was associated with adverse outcomes with a new permanent neurological deficit of mRS &gt;1 in 23 of 112 (21%) patients. Permanent neurological deficit leading to a mRS &gt;2 from surgery was 3.6% (95% confidence interval, 1.1%-9.1%). Late recurrence of a bAVM occurred in 3 of 103 (2.9%) patients who had complete obliteration of bAVM confirmed immediately after surgery and who were subsequently later followed with radiological studies during the mean follow-up period of 3.0 years (range, 6 days to 18.8 years).

CONCLUSION:

When discussing surgical options for SMG3 ubAVM, a thorough understanding of the significance and incidence of adverse events and outcomes is required to fully inform patients. For our series, the additional subclassification of SMG ubAVM (based on variables contributing to the SMG or age) would not have been of use.