scholarly journals Brainstem arteriovenous malformations: anatomical subtypes, assessment of “occlusion in situ” technique, and microsurgical results

2015 ◽  
Vol 122 (1) ◽  
pp. 107-117 ◽  
Author(s):  
Seunggu J. Han ◽  
Dario J. Englot ◽  
Helen Kim ◽  
Michael T. Lawton

OBJECT The surgical management of brainstem arteriovenous malformations (AVMs) might benefit from the definition of anatomical subtypes and refinements of resection techniques. Many brainstem AVMs sit extrinsically on pia mater rather than intrinsically in the parenchyma, allowing treatment by occluding feeding arteries circumferentially, interrupting draining veins after arteriovenous shunting is eliminated, and leaving the obliterated nidus behind. The authors report here the largest series of brainstem AVMs to define 6 subtypes, assess this “occlusion in situ” technique, and analyze the microsurgical results. METHODS Brainstem AVMs were categorized as 1 of 6 types: anterior midbrain, posterior midbrain, anterior pontine, lateral pontine, anterior medullary, and lateral medullary AVMs. Data from a prospectively maintained AVM registry were reviewed to evaluate multidisciplinary treatment results. RESULTS During a 15-year period, the authors treated 29 patients with brainstem AVMs located in the midbrain (1 anterior and 6 posterior), pons (6 anterior and 7 lateral), and medulla (1 anterior and 8 lateral). The nidus was pial in 26 cases and parenchymal in 3 cases. Twenty-three patients (79%) presented with hemorrhage. Brainstem AVMs were either resected (18 patients, 62%) or occluded in situ (11 patients, 38%). All lateral pontine AVMs were resected, and the occlusion in situ rate was highest with anterior pontine AVMs (83%). Angiography confirmed complete obliteration in 26 patients (89.6%). The surgical mortality rate was 6.9%, and the rate of permanent neurological deterioration was 13.8%. At follow-up (mean 1.3 years), good outcomes (modified Rankin Scale [mRS] score ≤ 2) were observed in 18 patients (66.7%) and poor outcomes (mRS score of 3–5) were observed in 9 patients (33.3%). The mRS scores in 21 patients (77.8%) were unchanged or improved. The best outcomes were observed with lateral pontine (100%) and lateral medullary (75%) AVMs, and the rate of worsening/death was greatest with posterior midbrain and anterior pontine AVMs (50% each). CONCLUSIONS Brainstem AVMs can be differentiated by their location in the brainstem (midbrain, pons, or medulla) and the surface on which they are based (anterior, posterior, or lateral). Anatomical subtypes can help the neurosurgeon determine how to advise patients, with lateral subtypes being a favorable surgical indication along with extrinsic pial location and hemorrhagic presentation. Most AVMs are dissected with the intention to resect them, and occlusion in situ is reserved for those AVMs that do not separate cleanly from the brainstem, that penetrate into the parenchyma, or are more anterior in location, where it is difficult to visualize and preserve perforating arteries (anterior pontine and lateral medullary AVMs). Although surgical morbidity is considerable, surgery results in a better obliteration rate than nonoperative management and is indicated in highly selected patients with high rerupture risks.

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 113-119 ◽  
Author(s):  
D. Hung-Chi Pan ◽  
Wan-Yuo Guo ◽  
Wen-Yuh Chung ◽  
Cheng-Ying Shiau ◽  
Yue-Cune Chang ◽  
...  

Object. A consecutive series of 240 patients with arteriovenous malformations (AVMs) treated by gamma knife radiosurgery (GKS) between March 1993 and March 1999 was evaluated to assess the efficacy and safety of radiosurgery for cerebral AVMs larger than 10 cm3 in volume. Methods. Seventy-six patients (32%) had AVM nidus volumes of more than 10 cm3. During radiosurgery, targeting and delineation of AVM nidi were based on integrated stereotactic magnetic resonance (MR) imaging and x-ray angiography. The radiation treatment was performed using multiple small isocenters to improve conformity of the treatment volume. The mean dose inside the nidus was kept between 20 Gy and 24 Gy. The margin dose ranged between 15 to 18 Gy placed at the 55 to 60% isodose centers. Follow up ranged from 12 to 73 months. There was complete obliteration in 24 patients with an AVM volume of more than 10 cm3 and in 91 patients with an AVM volume of less than 10 cm3. The latency for complete obliteration in larger-volume AVMs was significantly longer. In Kaplan—Meier analysis, the complete obliteration rate in 40 months was 77% in AVMs with volumes between 10 to 15 cm3, as compared with 25% for AVMs with a volume of more than 15 cm3. In the latter, the obliteration rate had increased to 58% at 50 months. The follow-up MR images revealed that large-volume AVMs had higher incidences of postradiosurgical edema, petechiae, and hemorrhage. The bleeding rate before cure was 9.2% (seven of 76) for AVMs with a volume exceeding 10 cm3, and 1.8% (three of 164) for AVMs with a volume less than 10 cm3. Although focal edema was more frequently found in large AVMs, most of the cases were reversible. Permanent neurological complications were found in 3.9% (three of 76) of the patients with an AVM volume of more than 10 cm3, 3.8% (three of 80) of those with AVM volume of 3 to 10 cm3, and 2.4% (two of 84) of those with an AVM volume less than 3 cm3. These differences in complications rate were not significant. Conclusions. Recent improvement of radiosurgery in conjunction with stereotactic MR targeting and multiplanar dose planning has permitted the treatment of larger AVMs. It is suggested that gamma knife radiosurgery is effective for treating AVMs as large as 30 cm3 in volume with an acceptable risk.


2021 ◽  
pp. 1-10
Author(s):  
Ann Mansur ◽  
Alex Kostynskyy ◽  
Timo Krings ◽  
Ronit Agid ◽  
Ivan Radovanovic ◽  
...  

OBJECTIVE The aim of this study was to 1) compare the safety and efficacy of acute targeted embolization of angiographic weak points in ruptured brain arteriovenous malformations (bAVMs) versus delayed treatment, and 2) explore the angioarchitectural changes that follow this intervention. METHODS The authors conducted a retrospective analysis of a prospectively acquired database of ruptured bAVMs. Three hundred sixteen patients with ruptured bAVMs who presented to the hospital within 48 hours of ictus were included in the analysis. The first analysis compared clinical and functional outcomes of acutely embolized patients to those with delayed management paradigms. The second analysis compared these outcomes of patients with acute embolization to those with angiographic targets who did not undergo acute embolization. Finally, a subset of 20 patients with immediate postembolization angiograms and follow-up angiograms within 6 weeks of treatment were studied to determine the angioarchitectural changes after acute targeted embolization. Kaplan-Meier curves for survival between the groups were devised. Multivariate logistical regression analysis was conducted. RESULTS There were three deaths (0.9%) and an overall rerupture rate of 4.8% per year. There was no statistical difference in demographic variables, mortality, and rerupture rate between patients with acute embolization and those with delayed management. Patients with acute embolization were more likely to present functionally worse (46.9% vs 69.8%, modified Rankin Scale score 0–2, p = 0.018) and to require an adjuvant therapy (71.9% vs 26.4%, p < 0.001). When comparing acutely embolized patients to those nonacutely embolized angiographic targets, there was a significant protective effect of acute targeted therapy on rerupture rate (annual risk 1.2% vs 4.3%, p = 0.025) and no difference in treatment complications. Differences in the survival curves for rerupture were statistically significant. Multivariate analyses significantly predicted lower rerupture in acute targeted treatment and higher rerupture in those with associated aneurysms, deep venous anatomy, and higher Spetzler-Martin grade. All patients with acute embolization experienced complete obliteration of the angiographic weak point with various degrees of resolution of the nidus; however, some had spontaneous recurrence of their bAVM, while others had spontaneous resolution over time. No patients developed new angiographic weak points. CONCLUSIONS This study demonstrates that acute targeted embolization of angiographic weak points, particularly aneurysms, is technically safe and protective in the early phase of recovery from ruptured bAVMs. Serial follow-up imaging is necessary to monitor the evolution of the nidus after targeted and definitive treatments. Larger prospective studies are needed to validate these findings.


2020 ◽  
Vol 26 (3) ◽  
pp. 275-282
Author(s):  
Michael M. McDowell ◽  
Nitin Agarwal ◽  
Gordon Mao ◽  
Stephen Johnson ◽  
Hideyuki Kano ◽  
...  

OBJECTIVEThe study of pediatric arteriovenous malformations (pAVMs) is complicated by the rarity of the entity. Treatment choice has often been affected by the availability of different modalities and the experience of the providers present. The University of Pittsburgh experience of multimodality treatment of pAVMs is presented.METHODSThe authors conducted a retrospective cohort study examining 212 patients with pAVM presenting to the University of Pittsburgh between 1988 and 2018, during which patients had access to surgical, endovascular, and radiosurgical options. Univariate analysis was performed comparing good and poor outcomes. A poor outcome was defined as a modified Rankin Scale (mRS) score of ≥ 3. Multivariate analysis via logistic regression was performed on appropriate variables with a p value of ≤ 0.2. Seventy-five percent of the cohort had at least 3 years of follow-up.RESULTSFive patients (2.4%) did not receive any intervention, 131 (61.8%) had GKRS alone, 14 (6.6%) had craniotomies alone, and 2 (0.9%) had embolization alone. Twenty-two (10.4%) had embolization and Gamma Knife radiosurgery (GKRS); 20 (9.4%) had craniotomies and GKRS; 8 (3.8%) had embolization and craniotomies; and 10 (4.7%) had embolization, craniotomies, and GKRS. Thirty-one patients (14.6%) were found to have poor outcome on follow-up. The multivariate analysis performed in patients with poor outcomes was notable for associations with no treatment (OR 18.9, p = 0.02), hemorrhage requiring craniotomy for decompression alone (OR 6, p = 0.03), preoperative mRS score (OR 2.1, p = 0.004), and Spetzler-Martin score (OR 1.8, p = 0.0005). The mean follow-up was 79.7 ± 62.1 months. The confirmed radiographic obliteration rate was 79.4% and there were 5 recurrences found on average 9.5 years after treatment.CONCLUSIONSHigh rates of long-term functional independence (mRS score of ≤ 2) can be achieved with comprehensive multimodality treatment of pAVMs. At this center there was no difference in outcome based on treatment choice when accounting for factors such as Spetzler-Martin grade and presenting morbidity. Recurrences are rare but frequently occur years after treatment, emphasizing the need for long-term screening after obliteration.


Neurosurgery ◽  
2015 ◽  
Vol 77 (3) ◽  
pp. 362-370 ◽  
Author(s):  
Michael Kerin Morgan ◽  
Nazih Assaad ◽  
Miikka Korja

Abstract 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.


2009 ◽  
Vol 15 (3) ◽  
pp. 275-282 ◽  
Author(s):  
J. W. Pan ◽  
H.J. Zhou ◽  
R.Y. Zhan ◽  
S. Wan ◽  
M. Yan ◽  
...  

Onyx is increasingly used in endovascular therapy of intracranial arteriovenous malformations (AVMs). However, the embolic effect and post-embolization management are still under discussion. We report our experience in the treatment of supratentorial brain arteriovenous malformations (SBAVMs) with Onyx and discuss post-embolic management. From June 2006 to July 2008, 20 patients with SBAVM were embolized with Onyx. There were 14 men and six women ranging from 14 to 64 years of age (mean 38.3 years). Initial symptoms included spontaneous hemorrhage (n=12), headaches (n=4), seizure (n=3) and incidentally disclosed after head trauma (n=1). After the endovascular procedure, all had subsequent treatment (follow-up angiogram, stereotactic radiosurgery or microsurgery) according to the obliteration degree. At angiography, seven patients (35%, 7/20) were completely obliterated (over 95% closure) after embolization while one suffered a small subarachnoid hemorrhage without permanent clinical sequelae. Four patients (20%, 4/20) were subtotally obliterated (over 80% closure), one patient who suffered severe cerebral edema after embolization underwent decompressive craniectomy, two patients had additional radiosurgery and one patient had follow-up angiogram. Nine patients (45%, 9/20) were partially obliterated (20–80% closure), five patients had additional surgery, two patients had additional radiosurgery and two patients had follow-up angiogram (one patient had intraventricular hemorrhage three months after embolization). Of all 20 AVMs, an average of 2.2 ml Onyx was used per patient and average volume reduction was 80% (range, 30%–99%). Onyx is suitable for embolization of SBAVMs because of its diffuse controllable properties. We suggest clinical follow-up after complete obliteration, additional radiosurgery or angiographic follow-up after subtotal obliteration and additional surgery after partially obliteration. More cases with long-term follow-up are needed to evaluate the long-term prognosis of our post-embolization management.


2015 ◽  
Vol 123 (4) ◽  
pp. 945-953 ◽  
Author(s):  
Or Cohen-Inbar ◽  
Cheng-Chia Lee ◽  
Zhiyuan Xu ◽  
David Schlesinger ◽  
Jason P. Sheehan

OBJECT The authors review outcomes following Gamma Knife radiosurgery (GKRS) of cerebral arteriovenous malformations (AVMs) and their correlation to postradiosurgery adverse radiation effects (AREs). METHODS From a prospective institutional review board–approved database, the authors identified patients with a minimum of 2 years of follow-up and thin-slice T2-weighted MRI sequences for volumetric analysis. A total of 105 AVM patients were included. The authors analyzed the incidence and quantitative changes in AREs as a function of time after GKRS. Statistical analysis was performed to identify factors related to ARE development and changes in the ARE index. RESULTS The median clinical follow-up was 53.8 months (range 24–212.4 months), and the median MRI follow-up was 36.8 months (range 24–212.4 months). 47.6% of patients had an AVM with a Spetzler-Martin grade ≥ III. The median administered margin and maximum doses were 22 and 40 Gy, respectively. The overall obliteration rate was 70.5%. Of patients who showed complete obliteration, 74.4% developed AREs within 4–6 months after GKRS. Late-onset AREs (i.e., > 12 months) correlated to a failure to obliterate the nidus. 58.1% of patients who developed appreciable AREs (defined as ARE index > 8) proceeded to have a complete nidus obliteration. Appreciable AREs were found to be influenced by AVM nidus volume > 3 ml, lobar location, number of draining veins and feeding arteries, prior embolization, and higher margin dose. On the other hand, a minimum ARE index > 8 predicted obliteration (p = 0.043). CONCLUSIONS ARE development after radiosurgery follows a temporal pattern peaking at 7–12 months after stereotactic radiosurgery. The ARE index serves as an important adjunct tool in patient follow-up and outcome prediction.


2008 ◽  
Vol 108 (6) ◽  
pp. 1152-1161 ◽  
Author(s):  
Michael E. Kelly ◽  
Raphael Guzman ◽  
John Sinclair ◽  
Teresa E. Bell-Stephens ◽  
Regina Bower ◽  
...  

Object Posterior fossa arteriovenous malformations (AVMs) are relatively uncommon and often difficult to treat. The authors present their experience with multimodality treatment of 76 posterior fossa AVMs, with an emphasis on Spetzler–Martin Grades III–V AVMs. Methods Seventy-six patients with posterior fossa AVMs treated with radiosurgery, surgery, and endovascular techniques were analyzed. Results Between 1982 and 2006, 36 patients with cerebellar AVMs, 33 with brainstem AVMs, and 7 with combined cerebellar–brainstem AVMs were treated. Natural history data were calculated for all 76 patients. The risk of hemorrhage from presentation until initial treatment was 8.4% per year, and it was 9.6% per year after treatment and before obliteration. Forty-eight patients had Grades III–V AVMs with a mean follow-up of 4.8 years (range 0.1–18.4 years, median 3.1 years). Fifty-two percent of patients with Grades III–V AVMs had complete obliteration at the last follow-up visit. Three (21.4%) of 14 patients were cured with a single radiosurgery treatment, and 4 (28.6%) of 14 with 1 or 2 radiosurgery treatments. Twenty-one (61.8%) of 34 patients were cured with multimodality treatment. The mean Glasgow Outcome Scale (GOS) score after treatment was 3.8. Multivariate analysis performed in the 48 patients with Grades III–V AVMs showed radiosurgery alone to be a negative predictor of cure (p = 0.0047). Radiosurgery treatment alone was not a positive predictor of excellent clinical outcome (GOS Score 5; p > 0.05). Nine (18.8%) of 48 patients had major neurological complications related to treatment. Conclusions Single-treatment radiosurgery has a low cure rate for posterior fossa Spetzler–Martin Grades III–V AVMs. Multimodality therapy nearly tripled this cure rate, with an acceptable risk of complications and excellent or good clinical outcomes in 81% of patients. Radiosurgery alone should be used for intrinsic brainstem AVMs, and multimodality treatment should be considered for all other posterior fossa AVMs.


Author(s):  
P Lopez-Ojeda ◽  
J Sanmillan ◽  
A Fernandez-Coello ◽  
I Fernandez-Conejero ◽  
Y Ali-Ciurana ◽  
...  

Background: Surgical resection of arteriovenous malformations (AVMs) in eloquent areas is significantly associated with greater surgical morbidity. We describe a functional approach for surgical treatment of these lesions Methods: A total of 20 patients with AVMs in eloquent areas were surgically treated and retrospectively analyzed. Individualized functional approach, using brain mapping and/or neurophysiological monitoring was performed in each case according to every case specific features and location. Seventeen patients underwent surgery under assleep conditions and 3 -patients underwent awake intraoperative mapping Results: There was no mortality. Four patients had hemorrhagic complications (20%). Ten (50%) presented neurological immediate postoperative worsening. Eight of them achieved complete recovery in follow up and 2 showed a permanent deficit. At 6 months follow up all the patients (100%) had good clinical outcome (mRS less than 2). There were no intraoperative seizures but 5 patients (26.3%) developed postoperative seizures. Fifteen patients (75%) had total AVM resection. Language and/or motor function were identified in all but one patient (95%). Each case required changes in surgical strategy to preserve the motor and/or language functions during surgery. Conclusions: Intraoperative monitoring and brain mapping are valuable and safe for the treatment of eloquent AVMs by indentifying and protecting motor and language function during resection.


2018 ◽  
Vol 16 (2) ◽  
pp. E44-E44
Author(s):  
M Neil Woodall ◽  
Robert F Spetzler

Abstract Arteriovenous malformations (AVMs) involving the conus medullaris have a unique angioarchitecture due to their involvement of the arterial basket of the conus medullaris, which represents an arterial anastomotic network between the anterior spinal artery (ASA) and posterior spinal arteries (PSAs) at the level of the conus medullaris.1 These lesions consist of a combination of a true AVM nidus, which is usually extramedullary, and direct shunts between the ASA, PSAs, and the venous system. Patients may present with radiculopathy, myelopathy, or subarachnoid hemorrhage.2 A 40-yr-old woman status post T11-L1 laminoplasty for resection of a ruptured conus AVM 6 yr prior presented with routine follow-up angiography suggestive of an arteriovenous fistula. She was counseled regarding treatment options including endovascular embolization and microsurgical ligation or resection, and she elected to proceed with surgical treatment. At the time of surgery, a recurrent AVM was noted. A 2-dimensional intraoperative video illustrates the microsurgical treatment of her recurrent conus AVM. The patient recovered well postoperatively. Spinal angiography demonstrated complete obliteration of the lesion. The patient experienced transient urinary retention that was self-limited but otherwise was without any new neurological deficit. Due to the retrospective nature of this report, informed consent was not required. Video used with permission from Barrow Neurological Institute, all rights reserved.


2014 ◽  
Vol 20 (6) ◽  
pp. 722-728 ◽  
Author(s):  
Jie Liu ◽  
Ming Lv ◽  
Xianli Lv ◽  
Hongwei He ◽  
Aihua Liu ◽  
...  

The liquid embolic agents currently used for embolization of cerebral arteriovenous malformations are Onyx and NBCA. Glubran 2, a cyanoacrylate-based synthetic glue, has recently been applied for embolization of cerebral arteriovenous malformations (AVMs). We report the clinical results of selected cerebral AVMs treated with Glubran 2 targeting for curative embolization. Between October 2011 and March 2013, 31 patients with cerebral AVMs were selected for curative embolization with Glubran 2. There were 19 men and 12 women with a mean age of 32 years (range 4–65 years). Initial clinical presentation included hemorrhage in 28 and seizures in three patients. AVM location was frontal in eight patients, parietal in four, occipital in eight temporal in six, cerebellar in two and cerebellar vermis in three patients. Follow-up was performed clinically and with angiography examination at three to six months. Clinical outcomes were evaluated based on the modified Rankin Scale (mRS). A mean of 2.5 (range, 1–12) feeding pedicles were embolized per patient. Complete angiographic obliteration of AVM was achieved in 27 patients. A hemorrhagic complication was observed in one patient, an ischemic complication in one patient and technical complications in four patients. There was no procedure-related disabling neurological deficit or death at discharge. Additional gamma knife radiosurgery was performed in five patients, including one patient with recurrent AVM. All of the patients had favorable clinical outcomes at three to six month follow-up (mRS≤2). The curative embolization technique with Glubran 2 for selected cerebral AVMs achieved a high initial complete obliteration rate with an acceptable complication frequency.


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