Brainstem Arteriovenous Malformations Research Articles

Management and outcome predictors of patients with ruptured deep-seated brain arteriovenous malformations.

Decision-making for the management of ruptured deep-seated brain arteriovenous malformations (bAVMs) is controversial. This study aimed to shed light on the treatment outcomes of patients with ruptured deep-seated bAVMs. Data on bAVM patients were retrieved from the authors' institutional database, spanning 1990-2021. The outcomes were annual hemorrhage risk (before and after intervention), number of follow-up hemorrhages, bAVM obliteration, poor modified Rankin Scale (mRS) score (i.e., mRS score > 2), worsened mRS score, and mortality. Multivariable Cox and logistic regression analyses were conducted to determine predictors of time-to-event and categorical outcomes, respectively. Of the 1066 patients in the database with brain bAVM, 177 patients harboring ruptured deep-seated bAVMs were included. The pretreatment annual hemorrhage risk was 8.24%, and the posttreatment risk was lowered to 1.65%. In multivariable Cox regression analysis, a prenidal aneurysm (HR 2.388, 95% CI 1.057-5.398; p = 0.036) was associated with a higher risk of follow-up hemorrhage, while definitive treatment (i.e., either surgery or radiosurgery vs endovascular embolization or conservative management) (HR 0.267, 95% CI 0.118-0.602; p = 0.001) was associated with a lower risk of follow-up hemorrhage. In multivariable logistic regression analysis, Spetzler-Martin grades IV and V (OR 0.404, 95% CI 0.171-0.917; p = 0.033) and brainstem arteriovenous malformation (AVM) (OR 0.325, 95% CI 0.128-0.778; p = 0.014) were associated with lower odds of obliteration, while definitive treatment (OR 8.864, 95% CI 3.604-25.399; p = 0.008) was associated with higher obliteration odds. Controlling for baseline mRS score, cerebellar AVM (OR 0.286, 95% CI 0.098-0.731; p = 0.013) and definitive treatment (OR 0.361, 95% CI 0.160-0.807; p = 0.013) were associated with lower odds of a poor mRS score, and definitive treatment (OR 0.208, 95% CI 0.076-0.553; p = 0.001) was associated with lower odds of a worsened mRS score. Furthermore, smoking (OR 6.068, 95% CI 1.531-25.581; p = 0.01) and definitive treatment (OR 0.101, 95% CI 0.024-0.361; p = 0.007) were associated with higher and lower mortality odds, respectively. A definitive treatment strategy seems to be beneficial in achieving higher obliteration and lower hemorrhage rates while decreasing the odds of a poor mRS score, worsened mRS score, and mortality. In this category of patients, prenidal aneurysms warrant treatment, and smoking cessation should be encouraged.

Ruptured brainstem arteriovenous malformation associated with a thalamoperforating artery aneurysm arising from the P1 segment of the right posterior cerebral artery: illustrative case.

Cerebral aneurysms of perforating arteries are rare and can be difficult to detect on computed tomography angiography (CTA) and digital subtraction angiography. Treatment is challenging and associated with a significant risk of morbidity. Endovascular treatment of a thalamoperforating artery (TPA) aneurysm within the midbrain has not previously been reported. A 13-year-old girl with no previous medical history presented with unconsciousness and anisocoria. Head computed tomography showed a right midbrain hemorrhage. CTA showed a midbrain arteriovenous malformation fed by a TPA aneurysm arising from the P1 segment of the right posterior cerebral artery. The feeder had a small distal aneurysm, which increased in size over time. Endovascular embolization was then performed. Cerebral aneurysms of perforating arteries are rare and can be difficult to treat. This is the first report of the endovascular treatment of a TPA aneurysm within the midbrain. Understanding the individual patient's brainstem perforator anatomy and the associated blood flow is essential before occluding a TPA aneurysm to avoid causing ischemia or infarction. Arteriovenous malformation embolization within the brainstem should be avoided because of interperforator anastomoses.

Benefit of Advanced 3D DSA and MRI/CT Fusion in Neurovascular Pathology

Digital subtraction angiography provides excellent spatial and temporal resolution; however, it lacks the capability to depict the nonvascular anatomy of the brain and spinal cord.A review of the institutional database identified five patients in whom a new integrated fusion workflow of cross-sectional imaging and 3D rotational angiography (3DRA) provided important diagnostic information and assisted in treatment planning. These included two acutely ruptured brain arteriovenous malformations (AVM), a small superficial brainstem AVM after radiosurgery, a thalamic microaneurysm, and a spine AVM, and fusion was crucial for diagnosis and influenced further treatment.Fusion of 3DRA and cross-sectional imaging may help to gain a deeper understanding of neurovascular diseases. This is advantageous for planning and providing treatment and, most importantly, may harbor the potential to minimize complication rates. Integrating image fusion in the work-up of cerebrovascular diseases is likely to have a major impact on the neurovascular field in the future.

Brainstem Arteriovenous Malformation and Symptomatic Excessive Daytime Somnolence

Brainstem Arteriovenous Malformation and Symptomatic Excessive Daytime Somnolence

Resection of Brainstem Arteriovenous Malformations: Pearls and Pitfalls for Minimizing Complications

The decision-making process surrounding resection of arteriovenous malformations (AVMs) in proximity to vital brainstem structures is a complex topic. Intricate vasculature in the setting of exquisite brainstem eloquence creates a high-risk operative landscape with the potential for devastating complications. Effective resections are driven by mastery of the relevant operative anatomy, preservation of pertinent vasculature, and technical experience and acumen. This article provides a narrative literature review on the resection of brainstem AVMs. Operative anatomy and approaches to AVMs of the midbrain (anterior/posterior), pons (anterior/lateral), and medulla (anterior/lateral) are discussed herein, with a focus on pearls and pitfalls for minimizing complications during resection. Careful consideration of the patient's clinical background, the natural history of the lesion, and expertise of the treating surgeon are paramount for improving the natural course of brainstem AVMs.

Ruptured Brainstem Arteriovenous Malformation Successfully Treated with Endovascular Surgery Used PHIL

Brainstem arteriovenous malformations (AVMs) are rare and complex, presenting mainly with hemorrhage, which can be catastrophic. The objective of its treatment is the angiographic obliteration of the lesion without worsening or with improvement of the neurological symptoms. Embolization is an efficient treatment for these AVMs but there are very few reported cases, although total obliteration is difficult, but it can also serve to reduce the nest and close the most dangerous factors of the AVM. Brainstem AVM is a rare pathology with high associated morbidity and mortality, with a high rate of rebleeding without treatment, which in selected cases embolization can be curative with a good neurological prognosis.

The predictors of clinical outcomes in brainstem arteriovenous malformations after stereotactic radiosurgery.

The brainstem arteriovenous malformations (BS-AVMs) have a high morbidity and mortality and stereotactic radiosurgery (SRS) has been widely used to treat BS-AVMs. However, no consensus is reached in the explicit predictors of obliteration for BS-AVMs after SRS.To identify the predictors of clinical outcomes for BS-AVMs treated by SRS, we performed a retrospective observational study of BS-AVMs patients treated by SRS at our institution from 2006 to 2016. The primary outcomes were obliteration of nidus and favorable outcomes (AVM nidus obliteration with mRS score ≤2). For getting the outcomes more accurate, we also pooled the results of previous studies as well as our study by meta-analysis.A total of 26 patients diagnosed with BS-AVMs, with mean volume of 2.6 ml, were treated with SRS. Hemorrhage presentation accounted for 69% of these patients. Overall obliteration rate was 42% with mean follow-up of more than five years and two patients (8%) had a post-SRS hemorrhage. Favorable outcomes were observed in 8 patients (31%). Higher margin dose (>15Gy) was associated with higher obliteration (P = .042) and small volume of nidus was associated with favorable outcomes (P = .036). After pooling the results of 7 studies and present study, non-prior embolization (P = .049) and higher margin dose (P = .04) were associated with higher obliteration rate, in addition, the lower Virginia Radiosurgery AVM Scale (VRAS) was associated with favorable outcomes (P = .02) of BS-AVMs after SRS.In the BS-AVMs patients treated by SRS, higher margin dose (19–24Gy) and non-prior embolization were the independent predictors of higher obliteration rate. In addition, smaller volume of nidus and lower VRAS were the potential predictors of long-term favorable outcomes for these patients.

Technical Note: Extreme Lateral Supracerebellar Approach for Resection of Superior Cerebellar Peduncle Arteriovenous Malformations.

The surgical approaches to the region of the cerebello-mesencephalic sulcus and superior cerebellar peduncle (SCP) remain a neurosurgical challenge. To present the use of the extreme lateral supracerebellar infratentorial (SC-IT) approach to treat arteriovenous malformations (AVMs) of the SCP, which is a different entity compared to brainstem AVMs. We treated 4 patients with SCP AVMs in the last 5 yr at our institution. The mean age was 49.7 yr. The average nidus size was 2.12 cm. Of those, 3 patients presented with hemorrhage and 1 with headache and tinnitus. Extreme lateral SC-IT approach was used in all cases. Complete resection was achieved in all cases as verified with postoperative angiogram. In 1 case, intraoperative rupture with intraventricular hemorrhage was encountered, and the patient required temporary external ventricular drainage. There was no permanent complication or neurological deficit. The modified Rankin Scale (at discharge or follow-up) was less than 2 in all cases. The AVMs located primarily in the SCP are distinct compared to brainstem AVMs, and their management should be different. Extreme lateral SC-IT approach should be considered as a viable alternative surgical approach for resection of these AVMs, and excellent surgical results can be achieved.

Usefulness of the middle cerebellar peduncle approach for microsurgical resection of lateral pontine arteriovenous malformation.

Surgical treatment of brainstem arteriovenous malformation (AVM) is challenging and associated with a higher risk of complications and a lower rate of gross-total resection. The authors present their experience with the surgical management of lateral pontine AVM using the middle cerebellar peduncle approach. All cases presented with neurological deficits that were caused by hemorrhage before surgery. In all cases, the AVM was not visualized on postoperative angiography, and there was no deterioration of neurological symptoms. In this video, the authors report the treatment results of one case and describe the technique with a review of the literature.The video can be found here: https://youtu.be/bFvEMtMnrKw

Long-term outcomes of brainstem arteriovenous malformations after different management modalities: a single-centre experience

ObjectiveThe aims of this study are to clarify the long-term outcomes of brainstem arteriovenous malformations (AVMs) after different management modalities.MethodsThe authors retrospectively reviewed 61 brainstem AVMs in their institution between...

Microsurgical Resection of Brainstem Arteriovenous Malformation: 2-Dimensional Operative Video.

Brainstem arteriovenous malformations (AVMs) are rare lesions (2%-6% of all intracranial AVMs) that are surgically challenging because of the high eloquence of the brainstem, including dense fiber tracts, cranial nerves, and multiple vital cerebrovascular structures. All these lesions possess eloquence and deep venous drainage, making them innately Spetlzer-Martin grade III or above. This patient had a large midbrain AVM with a complex clinical course beginning with ventriculoperitoneal shunting due to mass effect; the patient experienced 4 hemorrhages, underwent radiation treatment, and finally underwent surgical resection. The surgical approach involved a large torcular craniotomy exposing all posterior sinuses at the confluence. The vein of Galen was exposed and carried deeply to permit ambient cistern opening and relaxation of the cerebellum. Because of earlier radiation therapy, the vessels had undergone hyalinosis, which resulted in difficult manipulation of the nidus but did permit excellent coagulation of the vessels. The complete nidus was removed, as confirmed on postoperative angiography. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

A Case of Brainstem Arteriovenous Malformation Cured by Transvenous Embolization with Onyx

A Case of Brainstem Arteriovenous Malformation Cured by Transvenous Embolization with Onyx

Surgical Outcomes in Brainstem Arteriovenous Malformations: A Systematic Review and Meta-Analysis

Abstract INTRODUCTION Due to their propensity to hemorrhage and the surrounding eloquent tissue, brainstem arteriovenous malformations (BS-AVMs) carry significantly higher risk of morbidity and mortality compared to their supratentorial counterparts. In this study, we examined the literature for outcomes following microsurgery and performed an analysis to determine preoperative characteristics that can best predict outcome. METHODS We performed a Pubmed and Web of Science search using the terms “brainstem,” “AVM,” “arteriovenous malformation,” and “outcome.” We collected data on demographics, presentation, AVM characteristics, treatment modalities, angiographic obliteration, and functional outcome. We then ran a multivariate regression analysis to determine factors correlated to outcome. RESULTS We found 114 papers, of which 15 were included in our systematic review and 6 in our meta-analysis. There were 187 BS-AVM patients (59.7% male, mean age 37.8 yr, 70% hemorrhagic presentation) who underwent microsurgical resection. In total, 87% were <3 cm in size with 90% Spetzler-Martin III or less. The AVMs were located in the pons 44.5%, midbrain 38.7%, and medulla 16.8% of the time. Treatment methods included microsurgery alone 65.5%, radiation alone 10.3%, embolization alone 3.4%, microsurgery plus radiation 2.2%, microsurgery plus embolization 12%, radiation plus embolization 2.2%, and >3 modalities in 5.2% of cases. Postoperatively, 78% of AVMs were completely obliterated and 73% of patients were improved or unchanged in their functional outcome. Mean follow-up was 39.1 mo. Multivariate regression analysis showed hemorrhage (P < .001) to be significantly correlated with improved or unchanged functional outcome with medullary location (P = .067) and older age (P = .1) trending toward significance. CONCLUSION BS-AVMs occur in 20 to 50 yr old male patients and predominantly present with hemorrhage. They are most commonly located in the upper brainstem. Obliteration rates are favorable with nearly 3 quarters of patients improving or remaining unchanged in function. Factors associated with favorable functional outcome include hemorrhage, and to lesser degrees, medullary location and older age.

Clinical outcome of brainstem arteriovenous malformations after incomplete nidus obliteration

PurposeBrainstem arteriovenous malformations (AVMs) present a formidable therapeutic challenge, and a variety of surgical and non-surgical treatment strategies can be used to obliterate the AVM nidus, eliminating its risk of hemorrhage. However, complete obliteration of brainstem AVMs is often not possible. We aimed to investigate the natural history of brainstem AVMs with incomplete nidus obliteration after initial treatment. MethodsData from consecutive patients who presented to our institution during the study period with a brainstem AVM and residual nidus after treatment were retrospectively reviewed. We evaluated patients for the incidence of AVM rupture and calculated the risk of rupture after treatment resulted in incomplete nidus obliteration. ResultsA total of 14 patients were included, five of whom suffered rupture after incomplete nidus obliteration (36%). Annual risk of rupture was 4.9% (95% CI: 1.60–11.5) per patient over a median follow-up of 72 months. The most common treatment modality of these patients was SRS-alone (n = 6), and two (33%) patients who underwent this treatment later ruptured after 103 and 130 months. Of the five patients who ruptured after treatment, 80% had already ruptured once, and 80% had an intranidal and/or feeding artery aneurysm. ConclusionsBrainstem AVMs with incomplete nidus obliteration are at high risk of future rupture. Patients with brainstem AVMs who have a residual nidus after treatment should be counselled about the risk of AVM rupture and be recommended to undergo close follow-up imaging studies to monitor the nidus.

Brain stem arteriovenous malformations: Was preoperative diagnosis possible in this case?

Arteriovenous malformations (AVMs) involving brain stem in children are uncommon. These lesions usually present as hemorrhage as the first manifestation. When these lesions present both clinically and radiologically as a mass lesion without hemorrhage, it is very difficult to make a preoperative diagnosis of AVM as in the present case. With sophisticated imaging modalities, it may be possible to suspect this diagnosis; however, with limited facilities still, it will be difficult to approach these lesions as in present case.

Stereotactic Radiosurgery for Brainstem Arteriovenous Malformations: A Multicenter Study.

The management of brainstem arteriovenous malformations (bAVMs) is a formidable challenge. bAVMs harbor higher morbidity and mortality compared to other locations. To review the outcomes following stereotactic radiosurgery (SRS) of bAVMs in a multicenter study. Six medical centers contributed data from 205 patients through the International Gamma Knife Research Foundation. Median age was 32 yr (6-81). Median nidus volume was 1.4 mL (0.1-69 mL). Favorable outcome (FO) was defined as AVM obliteration and no post-treatment hemorrhage or permanent symptomatic radiation-induced complications. Overall obliteration was reported in 65.4% (n = 134) at a mean follow-up of 69 mo. Obliteration was angiographically proven in 53.2% (n = 109) and on MRA in 12.2% (n = 25). Actuarial rate of obliteration at 2, 3, 5, 7, and 10 yr after SRS was 24.5%, 43.3%, 62.3%, 73%, and 81.8% respectively. Patients treated with a margin dose >20 Gy were more likely to achieve obliteration (P = .001). Obliteration occurred earlier in patients who received a higher prescribed margin dose (P = .05) and maximum dose (P = .041). Post-SRS hemorrhage occurred in 8.8% (n = 18). Annual postgamma knife latency period hemorrhage was 1.5%. Radiation-induced complications were radiologically evident in 35.6% (n = 73), symptomatic in 14.6% (n = 30), and permanent in 14.6% (n = 30, which included long-tract signs and new cranial nerve deficits). FO was achieved in 64.4% (n = 132). Predictors of an FO were a higher Virginia radiosurgery AVM scale score (P = .003), prior hemorrhage (P = .045), and a lower prescribed maximum dose (P = .006). SRS for bAVMs results in obliteration and avoids permanent complications in the majority of patients.

A challenging entity of endovascular embolization with ONYX for brainstem arteriovenous malformation: Experience from 13 cases.

Objective Brainstem arteriovenous malformations (AVMs) are rare lesions with a high risk of intracranial hemorrhage and are challenging to treat. We present our experience of endovascular embolization with Onyx in these aggressive lesions. Materials and methods Between 2007 and 2016, 13 patients with brainstem AVMs were embolized with Onyx at our center. Twelve patients presented with intracranial hemorrhage and one with headache. Retrospective examinations of patient demographics, clinical presentation, angiographic features, treatment modalities, postoperative complications and outcomes were carried out. Results The AVMs were in the midbrain in 10 patients (one anterior and nine posterior or dorsal), in the posterior pons in two and pontomedullary in one. Complete occlusion was achieved in three patients. Gamma knife radiosurgery was performed in six patients who were near-completely or partially embolized. Postoperative complications, including five cases of ischemia and one case of hemorrhage, resulted in four cases of neurological deterioration and two deaths. Clinical follow-up was obtained in 10 patients at a mean period of 45.2 months (range 3 to 93 months). During the follow-up, good clinical outcomes were observed in seven patients with posterior or dorsal midbrain AVMs, and one patient with a posterior pons AVM that was partially occluded died of intracranial hemorrhage. Conclusion Endovascular embolization for brainstem AVM with Onyx is a technical challenge and the reflux of Onyx may cause severe complications. Individualized treatment is needed based on the specific subtype of brainstem AVM.

Embolization of ruptured arteriovenous malformations in the cerebellopontine angle cistern.

Among brainstem arteriovenous malformations (AVMs), there exist small AVMs predominantly located in the cerebellopontine angle cistern (CPAC) with minimal extension into the pial surface of the brainstem. However, previous studies of CPAC AVMs did not particularly discuss the role of embolization in the treatment of these lesions. This study was conducted to clarify the effectiveness and validity of embolization in the treatment of CPAC AVMs. We retrospectively reviewed five patients with CPAC AVMs who underwent endovascular treatment. These patients were treated with embolization followed by open surgery or gamma knife (GK) radiosurgery. Radiological findings and clinical course for these patients were then assessed. All five patients presented with a hemorrhage. Angiography revealed that the main feeder contained a dilated pontine perforating artery in all cases. Embolization through the dilated pontine perforating artery effectively reduced shunt flow within the nidus or obliterated associated aneurysms. Magnetic resonance imaging showed infarction on the lateral pons in four patients, one of which developed transient mild dizziness and mild ataxia of the right side. Subsequent open surgery was performed in three patients, and GK radiosurgery was performed in two patients without complications. At the end of the follow-up period, all patients demonstrated favorable outcomes. Postoperative rebleeding did not occur in any of the patients. Disappearance of the AVM was confirmed in four patients, except in the one patient treated with GK. Although ischemic complications should be noted, embolization of CPAC AVMs may be an appropriate treatment option to reduce the risk of subsequent surgery or radiosurgery.

Feasibility of eliciting the H reflex in the masseter muscle in patients under general anesthesia.

To explore the feasibility of eliciting the brainstem H reflex in the masseter muscle in patients under general anesthesia. We electrically stimulated the masseteric nerve, a branch of the trigeminal nerve, and recorded ipsilateral masseteric and temporalis muscle responses. We tested eight patients who presented with trigeminal neuralgia; one patient had a temporal bone tumor and one patient had a brainstem arteriovenous malformation. All responses were elicited when patients were under general anesthesia and before the initiation of surgery. The H reflex in the masseter muscle was reliably elicited in 70% of the patients. The reflexes met the usual criteria for the H reflex because they were elicited below the threshold of the direct M response, and their amplitudes decreased when the M response increased with stronger stimuli. The mean onset latencies of the masseter H reflex and the M response were 5.4±1.3ms and 2.6±0.6ms, respectively. In the present study, we provide evidence of the feasibility of eliciting the H reflex in the masseter muscles of patients under general anesthesia. The H reflex of the masseter muscle may represent a new method available for intraoperative monitoring. Specifically, this method may be important for the monitoring of brainstem functional integrity, particularly in the midbrain and mid-pons, in addition to the trigeminal nerve path.

Management Outcome of Brainstem Arteriovenous Malformations: The Role of Radiosurgery

Management decisions for brainstem arteriovenous malformations (AVMs) are complicated by balancing the risks of treatment and natural progression to hemorrhage. The present study seeks to compare radiosurgery and conservative management outcomes in brainstem AVMs. We performed a retrospective review of patients with brainstem AVM seen at our institution from 1990 to 2013. Patients missing baseline information or those lost to follow-up were excluded. Clinical and angiographic characteristics and subsequent hemorrhagic risk were evaluated according to brainstem AVM location and treatment modality. We identified 30 patients with brainstem AVM with complete data. Mean age was 41.6 ± 20.3 years, and 53.3% (n= 16) were male. Sixteen (53.3%) presented with hemorrhage. Twelve patients (40.0%) were conservatively managed, and 18 were treated. Sixteen (88.9%) of the treated patients underwent radiosurgery, 1 (5.6%) underwent surgery, and 1 (5.6%) underwent embolization only. Average follow-up period was 4.7 ± 5.7 years, and 5 patients (16.7%) experienced recurrent hemorrhage, 3 of whom were in the radiosurgery group and 2 in the conservative group, giving an annual recurrent hemorrhage risk of 3.7% and 4.8%, respectively. Lesion obliteration was achieved in 8 patients (26.7%). Baseline clinical and angiographic factors were similar between the radiosurgery and conservative group. Obliteration was achieved in 43.8% of those treated with radiosurgery (P= 0.008). Despite similar baseline modified Rankin Scale scores, more patients had improvement of modified Rankin Scale score at last follow-up in the radiosurgery group (P= 0.004). Recurrent hemorrhage during follow-up was similar between the 2 groups (P= 0.887). Our results suggest that when patients with brainstem AVM are selected cautiously, radiosurgery may achieve obliteration and symptom relief without increasing subsequent hemorrhage risk.