Supratentorial Arteriovenous Malformations Research Articles

Three-Pillar Expansive Craniotomy in Children with Acute Ruptured Supratentorial Brain Arteriovenous Malformations

Acute rupture and hemorrhage of pediatric brain arteriovenous malformations (AVMs) may lead to cerebral herniation or intractable intracranial hypertension, necessitating emerging surgical interventions to alleviate intracranial pressure. However, there is still controversy regarding the timing of treatment for ruptured AVMs. This study aimed to assess the feasibility of utilizing three-pillar expansive craniotomy (3PEC) at different times during the treatment of pediatric ruptured supratentorial AVMs. A retrospective analysis was conducted on all consecutive cases of acute rupture in supratentorial AVM children who underwent 3PEC at a single institution from 2020 to 2022. General information, clinical characteristics, radiological data, and prognosis were reviewed and analyzed. Thirteen children were included in the analysis. The intracranial pressure of all patients decreased to below 15mmHg within 10days. The expansion volume of the cranial cavity of the patients increased by 18.3cm3 (95% confidence interval, 10.2-26.3; P<0.001) compared to the hematoma volume. None of the patients required decompressive craniectomy due to intractable intracranial hypertension caused by cerebral swelling. The median waiting period for patients with delayed AVMs treatment was 8days, during which no rebleeding occurred. Emergency intervention with 3PEC in children experiencing acutely ruptured supratentorial AVMs appears to be feasible. For children requiring delayed management of the AVMs, 3PEC may diminish the risk of rebleeding during the waiting period and shorten the waiting period.

Arteriovenous malformations in the cerebellopontine angle: assessment of the "backdoor resection" technique and microsurgical results in 38 patients.

Posterior fossa arteriovenous malformations (AVMs) represent 7% to 15% of all intracranial AVMs and are associated with an increased risk of hemorrhage, morbidity, and mortality compared with supratentorial AVMs, thus prompting urgent and definitive treatment. Cerebellopontine angle (CPA) AVMs are a unique group of posterior fossa AVMs incorporating characteristics of brainstem and cerebellar lesions, which are particularly amenable to microsurgical resection. This study reports the clinical, radiological, operative, and outcome features of patients with CPA AVMs in a large cohort. The authors conducted a single-surgeon, 2-institution retrospective cohort study of all consecutive patients with CPA AVMs treated with microsurgical resection during a 25-year period. CPA AVMs represented 22% (38 of 176) of all infratentorial AVMs resected by the senior author. Overall, 38 patients (22 [58%] male and 16 [42%] female) met the study inclusion criteria and were analyzed. Most patients presented with hemorrhage (n = 29, 76%). The median age at surgery was 56 (range 6-82) years. Subtypes included 22 (58%) petrosal cerebellar AVMs, 11 (29%) lateral pontine AVMs, and 5 (13%) AVMs involving both the brainstem and cerebellum. Most AVM niduses were small (< 3 cm; n = 35, 92%) and compact (n = 31, 82%). Fourteen (37%) patients harbored flow-related aneurysms. Twenty (53%) patients underwent preoperative embolization. Complete angiographic obliteration was achieved with microsurgery in 35 (92%) patients. Five (13%) patients with poor neurological conditions at presentation died before hospital discharge. Of the 7 (18%) patients with new postoperative neurological deficits, 5 had transient deficits. The median (interquartile range) follow-up was 1.7 (0.5-3.2) years; 32 (84%) patients were alive at last follow-up, and 30 (79%) had achieved a favorable neurological outcome (modified Rankin Scale [mRS] score 0-2). The only independent predictor of unfavorable postoperative outcome (mRS score 3-6) was the preoperative mRS score (p = 0.002). CPA AVMs are unique posterior fossa lesions, including petrosal cerebellar and lateral pontine AVMs. The "backdoor resection" technique provides a safe and efficient strategy with high obliteration rates and a low risk of treatment-related morbidity. Microsurgical resection should be considered the frontline treatment for most CPA AVMs, except for those with a significant diffuse brainstem component.

Characterization of Pediatric Infratentorial Arteriovenous Malformations: A Retrospective, Multicenter Cohort Study.

Infratentorial arteriovenous malformations (AVMs) harbor different characteristics compared with supratentorial AVMs. This study aims to explore the unique characteristics of pediatric infratentorial AVMs and their response to single session stereotactic radiosurgery (SRS). The International Radiosurgery Research Foundation database of pediatric patients with AVM (age <18 years) who underwent SRS was retrospectively reviewed. Baseline demographics, AVM characteristics, outcomes, and complications post-SRS were compared between infratentorial and supratentorial pediatric AVMs. Unfavorable outcome was defined as the absence of AVM obliteration, post-SRS hemorrhage, or permanent radiation-induced changes at last follow-up. A total of 535 pediatric AVMs managed with SRS with a median follow-up of 67 months (IQR 29.0-130.6) were included, with 69 being infratentorial and 466 supratentorial. The infratentorial group had a higher proportion of deep location (58.4% vs 30.3%, P = <.001), deep venous drainage (79.8% vs 61.8%, P = .004), and prior embolization (26.1% vs 15.7%, P = .032). There was a higher proportion of hemorrhagic presentation in the infratentorial group (79.7% vs 71.3%, P = .146). There was no statistically significant difference in the odds of an unfavorable outcome (odds ratio [OR] = 1.36 [0.82-2.28]), AVM obliteration (OR = 0.85 [0.5-1.43]), post-SRS hemorrhage (OR = 0.83 [0.31-2.18]), or radiologic radiation-induced changes (OR = 1.08 [0.63-1.84]) between both cohorts. No statistically significant difference on the rates of outcomes of interest and complications were found in the adjusted model. Despite baseline differences between infratentorial and supratentorial pediatric AVMs, SRS outcomes, including AVM obliteration and post-SRS hemorrhage rates, were comparable amongst both groups. SRS appears to have a similar risk profile and therapeutic benefit to infratentorial pediatric AVMs as it does for those with a supratentorial location.

Brain arteriovenous malformation flow after stereotactic radiosurgery: Role of quantitative MRA.

Stereotactic radiosurgery (SRS) is a current therapeutic option for treatment of arteriovenous malformations (AVMs) located in deep or eloquent brain regions. Obliteration usually occurs in a delayed fashion, with an expected latency of 3-5 years. Here, we assess how AVM flow correlates with volume before and after SRS treatment. Patients with supratentorial AVM treated with SRS at our institution between 2012-2022 were retrospectively reviewed. Patients were included if Quantitative Magnetic Resonance Angiography (QMRA) study was performed at baseline and at least at the first follow-up. Correlation between AVM flow and volume before and after treatment was evaluated. AVM flow and volume were additionally assessed for obliteration using the non-parametric receiver operating characteristic (ROC) curve. Twelve patients with radiologic follow-up imaging were included. Eight patients presented AVM rupture, one of which occurred after radiosurgical treatment. Three patients underwent embolization prior SRS. Mean AVM initial volume was 3.8 cc (0.1-12.4 cc), mean initial flow 174 ml/min (11-604 ml/min), both variables showed progressive reduction at follow-up (range 3-57 months); and flow decreased with volume reduction (p < 0.001). Area under the ROC was 0.914 for both AVM flow and volume with obliteration (p = 0.019). AVM flow significantly decreased after SRS treatment, reflecting volume reduction. Baseline AVM flow and volume both predicted obliteration. QMRA provides additional non-invasive information to monitor patients after radiosurgical treatment.

Relationship between the features of venous drainage of supratentorial arteriovenous malformations and the risk of intracranial hemorrhage

Intracranial hemorrhage is the most common complication of cerebral arteriovenous malformations (AVM). In recent years, most studies devoted to the features of AVM functioning consider venous drainage as important factor influencing the rupture of malformation. To review the literature data on the relationship between the features of venous drainage of cerebral arteriovenous malformations and intracranial hemorrhage. We found 43 studies discussing the features of AVM venous drainage for the period from 1982 to 2020. Most of reports were published between 2005 and 2020. Deep venous drainage and a single drainage vein were the most significant factors influencing the risk of hemorrhage. Venous ectasia, reflux, stenosis, number, length and tortuosity of drainage veins were less important for the risk of AVM rupture. Analysis of the features of AVM venous drainage can make it possible to predict the natural course of disease and risk of intracranial hemorrhage. These aspects are essential for neurosurgical treatment.

Quantitative evaluation of hemodynamics after partial embolization of brain arteriovenous malformations

BackgroundTo explore the hemodynamic changes after embolization of arteriovenous malformations (AVMs) using quantitative digital subtraction angiography (QDSA).MethodsWe reviewed 74 supratentorial AVMs that underwent endovascular embolization and performed a quantitative hemodynamic...

Multimodality treatment of supratentorial arteriovenous malformations with microsurgery after embolization: A retrospective two-center study in Vietnam

BackgroundPreoperative embolization with microsurgical resection has been used as a multimodality treatment of cerebral arteriovenous malformations (AVMs) in recent years. However, the role of this combined approach has not been well established. ObjectivesThis retrospective study aims to evaluate the outcomes of multimodality treatment with microsurgery after embolization for supratentorial AVMs in Vietnam. MethodsA two-center, retrospective case series of 26 patients with supratentorial AVMs who underwent treatment with surgical resection after embolization between January 2017 and August 2020 was performed. Sixty-three feeding arteries were embolized preoperatively in 29 sessions. We analyzed the AVM size, degree of preoperative obliteration, complications related to embolization, intraoperative blood loss, surgical complications, complete resection rate, and postoperative outcomes at 3 months after discharge. ResultsThe average size and Spetzler-Martin (SM) grade of AVMs were 4.98 cm (largest, 8 cm) and 3.19, respectively. The average preoperative volumetric obliteration was 55.38%. The intraoperative average blood loss was 573 ml. Complications related to embolization were post-embolization cerebral hemorrhage in 2 cases (7.69%), new-onset neurological deficits in 1 (3.38%). Surgical complications included death in 2 cases (7.69%) and new-onset neurological deficits in 5 (19.23%). At 3-month follow-up, four patients with new-onset neurological deficits had recovered completely or nearly completely. Complete resection of AVMs was confirmed by postoperative imaging modalities in 24/24 cases. Favorable outcome was achieved in 23 cases (88.46%). ConclusionMultimodality treatment with microsurgery after embolization is a relatively safe and effective method which can be considered for managing large and complex brain AVMs.

Combined strategies on the treatment of cerebellar arteriovenous malformation.

Cerebellar arteriovenous malformations (AVMs) comprise 10%–15% of all intracranial AVMs and have a higher risk for morbidity and mortality than supratentorial AVMs. Patients with cerebellar AVMs present with hemorrhage more often than patients with cerebral AVMs, justifying an interventional treatment. Patient outcome can be predicted with specific grade systems, guiding vascular neurosurgeons in decision-making. The authors present the case of a 42-year-old man incidentally diagnosed with an unruptured cerebellar inferior vermian AVM, which was managed through a combined strategy of preoperative endovascular embolization of the main arterial feeders followed by microsurgical resection via midline suboccipital craniotomy, with a favorable outcome.The video can be found here: https://youtu.be/3WESejZbk90

Microsurgical resection of unruptured cerebellar arteriovenous malformation presenting with trigeminal neuralgia.

Cerebellar arteriovenous malformations (AVMs) represent 10%–15% of all intracranial AVMs and are associated with a greater risk for hemorrhagic presentation compared with supratentorial AVMs. When they reach the cerebellopontine angle cistern, neurovascular compression syndromes, including trigeminal neuralgia and hemifacial spasm, can occur. Due to the aggressive natural history of cerebellar AVM, an effective treatment strategy is required. In this video, the authors demonstrate the technical nuances of microsurgical resection of an unruptured cerebellar AVM in a 24-year-old female presenting with trigeminal neuralgia. The patient underwent right retrosigmoid craniotomy and complete resection of the AVM with resolution of trigeminal neuralgia.The video can be found here: https://youtu.be/6GmNjgFQwx8

Microsurgical resection of an anterior medullary arteriovenous malformation.

Arteriovenous malformations (AVMs) in the brainstem, specifically medullary AVMs, are exceedingly rare and difficult to treat. These lesions are commonly more aggressive than supratentorial AVMs and pose their own unique treatment challenges. Current treatment options for these AVMs consist of endovascular embolization or open surgery. Radiosurgery is not favored because it is associated with potential risk to the brainstem and lower obliteration rates. Here the authors report the case of a 27-year-old man with a ruptured anterior medullary AVM. The patient underwent a successful far-lateral craniotomy for resection of the AVM.The video can be found here: https://youtu.be/lyOfOQ3sBdU

Perinidal Angiogenesis Is a Predictor for Neurovascular Uncoupling in the Periphery of Brain Arteriovenous Malformations: A Task‐Based and Resting‐State fMRI Study

Potential neurovascular uncoupling (NVU) related to perinidal angiogenesis (PA) of brain arteriovenous malformations (AVMs) may cause inappropriate presurgical mapping using functional magnetic resonance imaging (fMRI), resulting in overconfident resection and postoperative morbidity. To evaluate the potential impact of PA upon fMRI blood oxygen level-dependent signal in the periphery of AVMs. Prospective. Twenty-one patients with AVMs located in the primary sensorimotor cortex (SM1) undergoing task-based fMRI (hand motor), and 19 patients with supratentorial AVMs undergoing resting-state fMRI. 3.0T, echo-planar, time-of-flight, and magnetization-prepared rapid gradient-echo. The presence of PA was determined by three observers (Y.C., J.W., and X.C.) according to digital subtraction angiography and MR angiography. Interhemispheric asymmetry of fMRI activations contralateral to hand movements was evaluated with the interhemispheric ratio of the average t-value within ipsilesional SM1 to contralesional SM1. Regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuations (fALFF) were extracted from ring-shaped perinidal regions and contralateral homologous regions, and the corresponding interhemispheric ratios were calculated. The effect of PA on the interhemispheric asymmetry of motor activations, ReHo, and fALFF was estimated. Pearson analysis, paired and independent t-test, multiple linear regression, Friedman test, and factorial analysis of variance were used. Motor activations were significantly reduced in ipsilesional SM1 compared to contralesional SM1 (P < 0.05). The presence of PA was the independent predictor of activation loss in ipsilateral SM1(P < 0.05). Furthermore, perinidal regions exhibited reduced ReHo compared to the homologous regions (P < 0.05). PA was significantly associated with the decline of ReHo and fALFF in perinidal regions (P < 0.05, for both). The presence of PA can predict perinidal NVU that may confound the interpretation of both task-based and resting-state fMRI, highlighting the importance of alternative approaches of brain functional localization in improving treatment of AVMs. 2 TECHNICAL EFFICACY STAGE: 2.

Ratio of Arteriovenous Malformation Draining Vein to Adjacent Venous Sinus Diameter Is Associated with Increased Risk of Venous Stenosis

The development of venous outflow stenosis in cerebral arteriovenous malformation (AVM) is poorly understood. The location of stenosis within the AVM draining vein in relation to the adjacent venous sinus and the hypothesis that the ratio of draining vein to adjacent sinus diameter might predict the development of venous stenosis were explored. Patients with supratentorial AVMs (1997-2018) were reviewed (N= 290). AVM draining vein and adjacent venous sinus diameters, degree of draining vein stenosis, and distance from the maximal stenotic point to the junction of the adjacent draining sinus were recorded. Correlation between percentage of AVM draining vein stenosis and the ratio of AVM draining vein to venous sinus diameters was analyzed. A total of 360 draining veins in 243 AVMs with complete angiographic data were measured. Venous stenosis (in 131 draining veins) was observed within 20 mm of the junction to the adjacent draining sinus in 85% of our sample. The ratio of draining vein to adjacent sinus diameter correlated positively with the percentage of venous stenosis (P < 0.01, r= 0.21). The ratio between 0.51-1.0 and >1.0 showed significant tighter stenosis compared with the ratio ≤0.5 (25.9% and 28.9% vs. 10.0%, respectively; P < 0.01). AVM venous outflow stenosis is observed close to the adjacent venous sinus junction. The degree of venous stenosis is greater when the ratio of AVM draining vein/adjacent venous sinus diameter is >0.5. This may be related to more turbulent flow at the junction of the draining vein and venous sinus, especially in larger draining veins, which causes venous stenosis to develop over time.

Stasis index from hemodynamic analysis using quantitative DSA correlates with hemorrhage of supratentorial arteriovenous malformation: a cross-sectional study.

Assessments of hemorrhage risk based on angioarchitecture have yielded inconsistent results, and quantitative hemodynamic studies have been limited to small numbers of patients. The authors examined whether cerebral hemodynamic analysis using quantitative digital subtraction angiography (QDSA) can outperform conventional DSA angioarchitecture analysis in evaluating the risk of hemorrhage associated with supratentorial arteriovenous malformations (AVMs). A cross-sectional study was performed by retrospectively reviewing adult supratentorial AVM patients who had undergone both DSA and MRI studies between 2011 and 2017. Angioarchitecture characteristics, DSA parameters, age, sex, and nidus volume were analyzed using univariate and multivariate logistic regression, and QDSA software analysis was performed on DSA images. Based on the QDSA analysis, a stasis index, defined as the inflow gradient divided by the absolute value of the outflow gradient, was determined. The receiver operating characteristic (ROC) curve was used to compare diagnostic performances of conventional DSA angioarchitecture analysis and analysis using hemodynamic parameters based on QDSA. A total of 119 supratentorial AVM patients were included. After adjustment for age at diagnosis, sex, and nidus volume, the exclusive deep venous drainage (p < 0.01), observed through conventional angioarchitecture examination using DSA, and the stasis index of the most dominant drainage vein (p = 0.02), measured with QDSA hemodynamic analysis, were independent risk factors for hemorrhage. The areas under the ROC curves for the conventional DSA method (0.75) and QDSA hemodynamics analysis (0.73) were similar. A venous stasis index greater than 2.18 discriminated the hemorrhage group with a sensitivity of 52.6% and a specificity of 81.5%. In QDSA, a higher stasis index of the most dominant drainage vein is an objective warning sign associated with supratentorial AVM rupture. Risk assessments of AVMs using QDSA and conventional DSA angioarchitecture were equivalent. Because QDSA is a complementary noninvasive approach without extra radiation or contrast media, comprehensive hemorrhagic risk assessment of cerebral AVMs should include both DSA angioarchitecture and QDSA analyses.

Removal of superior vermian arteriovenous malformation through the occipital transtentorial approach

Abstract Background Arteriovenous malformations (AVMs) of the superior vermis are extremely rare. Although they have a higher rate of hemorrhagic presentations than supratentorial AVMs, the surgical approaches for AVMs at this location remain controversial. Case description We report the case of a 73-year-old man with a hemorrhagic superior vermian AVM that was treated with surgical resection through the occipital transtentorial approach (OTA). This approach, with a direct perpendicular view of the whole lesion, enabled us to control the feeding arteries safely and to finally accomplish a total resection. Conclusions The OTA is an elegant approach for the resection of superior vermian AVMs. Detailed assessment of angiographic features is mandatory in selecting an effective and safe surgical approach for posterior fossa AVMs depending on their location.

Abstract TP579: Ratio of Arteriovenous Malformation Draining Vein to Adjacent Venous Sinus Diameter is Associated With Increased Risks of Vein Stenosis

Introduction: Venous outflow stenosis in cerebral arteriovenous malformation (AVM) remains the main risk factor associated with AVM rupture. The hemodynamic process underlying the development of venous outflow stenosis is poorly understood. Here, we compared the location of stenosis within the draining vein of the AVM in relation to the adjacent venous sinus and explored the hypothesis that the ratio of draining vein to adjacent sinus diameter might predict the development of venous stenosis. Methods: Patient demographic parameters, and cerebral angiograms of 290 patients with supratentorial AVMs seen at our institution between 1997 and 2018 were reviewed. AVM draining vein and adjacent venous sinus diameters, degree of draining vein stenosis, and distance (mm) from the stenotic point of the draining vein to the junction of the adjacent draining sinus were recorded. The correlation between percentage of AVM draining vein stenosis and the ratio of venous sinus to AVM draining vein diameters was analyzed. Results: 247 AVMs in 242 patients with complete angiographic data were included, and a total of 361 draining veins were measured. Venous stenosis was present in 131 draining veins (36.3%). Venous stenosis was observed within 20 mm of the junction to the adjacent major draining sinus in 85% of our sample (Fig 1A). The ratio of draining vein to adjacent sinus diameter correlated positively with the percentage of venous stenosis (P=0.0001, r=0.21; Fig 1B). Conclusion: AVM venous outflow stenosis is observed closer to the adjacent venous sinus junction. The degree of venous stenosis is greater when the ratio of AVM draining vein/adjacent venous sinus diameter approaches or is larger than 1. This may be related to more turbulent flow at the junction of the draining vein and venous sinus, especially in larger draining veins, thus leading to venous stenosis with time. Further studies are needed to explore the pathophysiology of venous stenosis.

Arterial-spin labeling MRI identifies residual cerebral arteriovenous malformation following stereotactic radiosurgery treatment

Background and purposeBrain arteriovenous malformation (AVM) treatment by stereotactic radiosurgery (SRS) is effective, but AVM obliteration following SRS may take two years or longer. MRI with arterial-spin labeling (ASL) may detect brain AVMs with high sensitivity. We determined whether brain MRI with ASL may accurately detect residual AVM following SRS treatment. Materials and methodsWe performed a retrospective cohort study of patients who underwent brain AVM evaluation by DSA between June 2010 and June 2015. Inclusion criteria were: (1) AVM treatment by SRS, (2) follow-up MRI with ASL at least 30 months after SRS, (3) DSA within 3 months of the follow-up MRI with ASL, and (4) no intervening AVM treatment between the MRI and DSA. Four neuroradiologists blindly and independently reviewed follow-up MRIs. Primary outcome measure was residual AVM indicated by abnormal venous ASL signal. Results15 patients (12 females, mean age 29 years) met inclusion criteria. There were three posterior fossa AVMs and 12 supratentorial AVMs. Spetzler–Martin (SM) Grades were: SM1 (8%), SM2 (33%), SM3 (17%), SM4 (25%), and SM5 (17%). DSA demonstrated residual AVM in 10 patients. The pooled sensitivity, specificity, positive predictive value, and negative predictive value of venous ASL signal for predicting residual AVM were 100% (95% CI: 0.9-1.0), 95% (95% CI: 0.7–1.0), 98% (95% CI: 0.9–1.0), and 100% (95% CI: 0.8–1.0), respectively. High inter-reader agreement as found by Fleiss’ Kappa analysis (k = 0.92; 95% CI: 0.8–1.0; P < 0.0001). ConclusionsASL is highly sensitive and specific in the detection of residual cerebral AVM following SRS treatment.

Contrast Time-Density Time on Digital Subtraction Angiography Correlates With Cerebral Arteriovenous Malformation Flow Measured by Quantitative Magnetic Resonance Angiography, Angioarchitecture, and Hemorrhage.

Digital subtraction angiography (DSA) currently provides angioarchitectural features of cerebral arteriovenous malformations (AVMs) but its role in the hemodynamic evaluation of AVMs is poorly understood. To assess contrast time-density time (TT) on DSA relative to AVM flow measured using quantitative magnetic resonance angiography (QMRA). Patients seen at our institution between 2007 and 2014 with a supratentorial AVM and DSA and QMRA obtained prior to any treatment were retrospectively reviewed. Regions of interest were selected on the draining veins at the point closest to the nidus. TT on DSA was defined as time needed for contrast to change image intensity from 10% to 100%, 100% to 10%, and 25% to 25%. TT was correlated to AVM total flow, angioarchitectural features, and hemorrhage. Twenty-eight patients (mean age 35.6 yr) were included. Six patients presented with hemorrhage. Mean AVM volume was 11.42 mL (range 0.3-57.7 mL). Higher total AVM flow significantly correlated with shorter TT100%-10% and TT25%-25% (P = .02, .02, respectively). Presence of venous stenosis correlated significantly with shorter TT100%-10% (P = .04) and TT25%-25% (P = .04). AVMs with a single draining vein exhibited longer TT25%-25% compared to those with multiple draining veins (P = .04). Ruptured AVMs had significantly shorter TT10%-100% compared to unruptured AVMs (P = .05). TT on DSA correlates with cerebral AVM flow measured using QMRA and with AVM angioarchitecture and hemorrhagic presentation. Thus, TT may be used to indirectly estimate AVM flow during angiography in real-time and may also be an indicator of important AVM characteristics associated with outflow resistance and increased rupture risk, such as venous stenosis.

Intractable brain swelling during cerebral arteriovenous malformation surgery due to contralateral acute subdural haematoma.

Severe brain swelling during routine neurosurgery can herald serious consequences. Failure to control brain swelling despite adequate measures warns of a surgical cause and should be dealt efficiently. We report a case of an adult female who developed intraoperative acute subdural haematoma (SDH) and consequent intractable brain swelling during surgery of supratentorial arteriovenous malformation (AVM). Such a manifestation of contralateral acute SDH during supratentorial AVM surgery has not been reported earlier.

Timing of surgery for ruptured supratentorial arteriovenous malformations.

There are conflicting opinions regarding the optimal waiting time to perform surgery after rupture of supratentorial arteriovenous malformations (AVMs) to achieve the best possible outcome. To analyze factors influencing outcomes for ruptured supratentorial AVMs after surgery, paying particular attention to the timing of the surgery. We retrospectively investigated 59 patients admitted to our center between 2000 and 2014 for surgical treatment of ruptured supratentorial AVMs. We evaluated the effect of timing of surgery and other variables on the outcome at 2-4months (early outcome), at 12months (intermediate outcome) after surgery, and at final follow-up at the end of 2016 (late outcome). Age over 40years (OR 18.4; 95% CI 1.9-172.1; p=0.011), high Hunt and Hess grade (4 or 5) before surgery (OR 13.5; 95% CI 2.1-89.2; p=0.007), hydrocephalus on admission (OR 12.9; 95% CI 1.8-94.4; p=0.011), and over 400cm3 bleeding during surgery (OR 11.5; 95% CI 1.5-86.6; p=0.017) were associated with an unfavorable early outcome. Age over 40years (OR 62.8; 95% CI 2.6-1524.9; p=0.011), associated aneurysms (OR 34.7; 95% CI 1.4-829.9; p=0.029), high Hunt and Hess grade before surgery (OR 29.2; 95% CI 2.6-332.6; p=0.007), and over 400cm3 bleeding during surgery (OR 35.3; 95% CI 1.7-748.7; p=0.022) were associated with an unfavorable intermediate outcome. Associated aneurysms (OR 8.2; 95% CI 1.2-55.7; p=0.031), high Hunt and Hess grade before surgery (OR 5.7; 95% CI 1.3-24.3; p=0.019), and over 400cm3 bleeding during surgery (OR 5.8; 95% CI 1.2-27.3; p=0.027) were associated with an unfavorable outcome at last follow-up. Elapsed time between rupture and surgery did not affect early or final outcome. Early surgery in patients with ruptured supratentorial arteriovenous malformation is feasible strategy, with late results comparable to those achieved with delayed surgery. Many other factors than timing of surgery play significant roles in long-term outcomes for surgically treated ruptured supratentorial AVMs.

Motor cortex arteriovenous malformation.

Supratentorial arteriovenous malformations in eloquent territories can be difficult to resect. This video presents the treatment of a patient with a symptomatic 3-cm arteriovenous malformation in the left motor strip. At the authors' institution, per the surgeon's discretion, preoperative angiography is performed to evaluate the need for preoperative embolization. Multimodality treatment reduced the microsurgical risk by allowing early occlusion of a draining vein, by decreasing overall intraoperative hemorrhage, and by allowing minimal pial dissection in the deep aspect of the arteriovenous malformation that abutted the corticospinal tract. The choice of embolysate was an additional nuance of the embolization. The video can be found here: https://youtu.be/HWZ0RjgPEXg .