Arm-only combined transarterial and transvenous access for neurointerventional procedures: a double-center retrospective study

OBJECTIVE

This study aims to share our experience with the arm-only combined transarterial and transvenous access approach for neurointerventional procedures and evaluate its efficacy and safety.

METHODS

The arm-only combined transarterial and transvenous access approach was performed using the right/bilateral proximal radial arteries and the right forearm superficial vein system, guided by ultrasonic guidance. Arterial access closure was achieved using a transradial band radial compression device, while manual compression was utilized for venous approach closure.

RESULTS

Thirteen procedures were successfully performed using the arm-only combined transarterial and transvenous access approach, yielding favorable outcomes. The procedures included dural arteriovenous fistula embolization (seven cases), cerebral arteriovenous malformation embolization (four cases), venous sinus thrombosis catheter-directed thrombolysis and intravenous thrombectomy (one case), and cerebral venous sinus stenosis manometry (one case). All procedures were uneventful, allowing patients to ambulate on the same day. At discharge, all patients exhibited modified Rankin scores of 0-2, without any access site or perioperative complications.

CONCLUSION

This double-center study preliminarily demonstrates the feasibility and safety of arm-only combined transarterial and transvenous access applied in neurointerventional procedures for complicated cerebrovascular diseases. The proximal radial artery and forearm superficial vein are recommended as the primary access sites. Unobstructed compression is strongly recommended for radial approach closure.

ADVANCES IN KNOWLEDGE

This study aimed to add evidence and experience on the arm-only combined transarterial and transvenous access, as a new approach, for neurointerventional treatment that required arteriovenous approaches.

Hemorrhagic Outcome of Brainstem Cavernous Malformations following Radiosurgery: Dose-Response Relationship

INTRODUCTION

This study aimed to assess the impact of gamma knife radiosurgery on brainstem cavernous malformations (CMs).

METHODS

A total of 85 patients (35 females; median age 41.0 years) who underwent gamma knife radiosurgery for brainstem CMs at our institute between 2006 and 2015 were enrolled in a prospective clinical observation trial. Risk factors for hemorrhagic outcomes were evaluated, and outcomes were compared across different margin doses.

RESULTS

The pre-radiosurgery annual hemorrhage rate (AHR) was 32.3% (44 hemorrhages during 136.2 patient-years). The median planning target volume was 1.292 cc. The median margin and maximum doses were 15.0 and 29.2 Gy, respectively, with a median isodose line of 50.0%. The post-radiosurgery AHR was 2.7% (21 hemorrhages during 769.9 patient-years), with a rate of 5.5% within the first 2 years and 2.0% thereafter. The post-radiosurgery AHR for patients with margin doses of ≤13.0 Gy (n = 15), 14.0-15.0 Gy (n = 50), and ≥16.0 Gy (n = 20) was 5.4, 2.7, and 0.6%, respectively. Correspondingly, transient adverse radiation effects were observed in 6.7 (1/15), 10.0 (5/50), and 30.0% (6/20) of cases, respectively. An increased margin dose per 1 Gy (hazard ratio: 0.530, 95% CI: 0.341-0.826, p = 0.005) was identified as an independent protective factor against post-radiosurgery hemorrhage. Margin doses of ≥16.0 Gy were associated with improved hemorrhagic outcomes (hazard ratio: 0.343, 95% confidence interval [CI]: 0.157-0.749, p = 0.007), but an increased risk of adverse radiation effects (odds ratio: 3.006, 95% CI: 1.041-8.677, p = 0.042).

CONCLUSION

The AHR of brainstem CMs decreased following radiosurgery, and our study revealed a significant dose-response relationship. Margin doses of 14-15 Gy were recommended. Further studies are required to validate our findings.

Application of epinephrine mixed with local anaesthetics in injection sclerotherapy of early-stage arteriovenous malformation

PURPOSE

To explore the effect of epinephrine mixed with local anaesthetic injection on blood flow control in early stage arteriovenous malformation (AVM) and explore suitable cases.

METHODS

Twenty-five patients with early stage (Schobinger clinical stage I/II) AVM were selected between September 2019 and March 2022. Local anaesthetics containing epinephrine were injected around the nourishing artery and into lesions under the guidance of ultrasound, and the blood flow distribution grade in the lesions as well as the changes in diameter, peak systolic velocity (PSV), and resistance index (RI) of the nourishing arteries and vessels in the lesions were observed to determine the type of AVM suitable for epinephrine injection. After blood flow was controlled, sclerosant agents were injected into the lesions for sclerotherapy.

RESULTS

After local injection of the epinephrine mixture, the blood flow distribution in the lesion decreased by one to three grades; the diameter and PSV also decreased, while RI increased. There were statistically significant differences before and after the injection (P < 0.05). The efficacy of the injection was 80% (20/25), especially in patients with lesion vessels, a nourishing artery lumen diameter <2 mm, and a PSV <40 cm/s in the lesion. Patients with Schobinger clinical stage I AWM showed good results.

CONCLUSIONS

Local anaesthetics containing epinephrine play a positive role in reducing the distribution and velocity of blood flow in patients with AVM lesions and may be used as an experimental method for the treatment of AVM, which is beneficial for sclerotherapy in patients with early AVM.

Seven cases of hereditary haemorrhagic telangiectasia-like hepatic vascular abnormalities associated with EPHB4 pathogenic variants

BACKGROUND

EPHB4 loss of function is associated with type 2 capillary malformation-arteriovenous malformation syndrome, an autosomal dominant vascular disorder. The phenotype partially overlaps with hereditary haemorrhagic telangiectasia (HHT) due to epistaxis, telangiectases and cerebral arteriovenous malformations, but a similar liver involvement has never been described.

METHODS

Members of the French HHT network reported their cases of EPHB4 mutation identified after an initial suspicion of HHT. Clinical, radiological and genetic characteristics were analysed.

RESULTS

Among 21 patients with EPHB4, 15 had a liver imaging, including 7 with HHT-like abnormalities (2 female patients and 5 male patients, ages 43-69 years). Atypical epistaxis and telangiectases were noted in two cases each. They were significantly older than the eight patients with normal imaging (median: 51 vs 20 years, p<0.0006).The main hepatic artery was dilated in all the cases (diameter: 8-11 mm). Six patients had hepatic telangiectases. All kind of shunts were described (arteriosystemic: five patients, arterioportal: two patients, portosystemic: three patients). The overall liver appearance was considered as typical of HHT in six cases.Six EPHB4 variants were classified as pathogenic and one as likely pathogenic, with no specific hot spot.

CONCLUSION

EPHB4 loss-of-function variants can be associated with HHT-like hepatic abnormalities and should be tested for atypical HHT presentations.

Germline genetic mutations in pediatric cerebrovascular anomalies: a multidisciplinary approach to screening, testing, and management

OBJECTIVE

Genetic alterations are increasingly recognized as etiologic factors linked to the pathogenesis and development of cerebrovascular anomalies. Their identification allows for advanced screening and targeted therapeutic approaches. The authors aimed to describe the role of a collaborative approach to care and genetic testing in pediatric patients with neurovascular anomalies, with the objectives of identifying what genetic testing recommendations were made, the yield of genetic testing, and the implications for familial screening and management at present and in the future.

METHODS

The authors performed a descriptive retrospective cohort study examining pediatric patients genetically screened through the Pediatric Neurovascular Program of a single treatment center. Patients 18 years of age and younger with neurovascular anomalies, diagnosed radiographically or histopathologically, were evaluated for germline genetic testing. Patient demographic data and germline genetic testing and recommendation, clinical, treatment, and outcome data were collected and analyzed.

RESULTS

Sixty patients were included; 29 (47.5%) were female. The mean age at consultation was 11.0 ± 4.9 years. Diagnoses included cerebral arteriovenous malformations (AVMs) (n = 23), cerebral cavernous malformations (n = 19), non-neurofibromatosis/non-sickle cell moyamoya (n = 8), diffuse cerebral proliferative angiopathy, and megalencephaly-capillary malformation. Of the 56 patients recommended to have genetic testing, 40 completed it. Genetic alterations were found in 13 (23%) patients. Four patients with AVMs had RASA1, GDF2, and ACVRL1 mutations. Four patients with cavernous malformations had Krit1 mutations. One with moyamoya disease had an RNF213 mutation. Three patients with megalencephaly-capillary malformation had PIK3CA mutations, and 1 patient with a cavernous sinus lesion had an MED12 mutation. The majority of AVM patients were treated surgically. Patients with diffuse cerebral proliferative angiopathy were treated medically with sirolimus. At-risk relatives of 3 patients positive for genetic anomalies had also been tested.

CONCLUSIONS

This study demonstrates a role for exploring genetic alterations in the identification and treatment of pediatric neurovascular disease pathogenesis. Germline genetic mutations were found in almost one-quarter of the patients screened in this study, results that helped to identify medically targeted treatment modalities for some pediatric neurovascular patients. Insight into the genetic etiology of vascular anomalies may provide broader clinical implications for risk assessment, family screening, follow-up surveillance, and medical management.

Clinico-radiological features of cerebral proliferative angiopathy: A large case series from India

BACKGROUND

Based on angiographic features, a rare subgroup, different from classical brain AVMs, called cerebral proliferative angiopathy (CPA) was suggested by Lasjaunias et al. in 1989. There are only few reports of CPA described from Asia. Liu et al. has described 5 cases of CPA from China. The objective of study was to evaluate the clinico-radiological features of patients with CPA in our cohort and to find out the differences between our study and the study by Lasjaunias and Liu et al.

METHODS

We retrospectively analysed cases of CPA from March 2012 to April 2020. All radiological images of the patients with AVMs were studied and findings suggestive of CPA were identified. We found 10 patients with CPA out of 272 cases of AVM (10/272) and described the various demographic and clinico-radiological features.

RESULTS

The age of the patients with CPA in our series varied from 14 to 53 years and the mean age was 28.6 years. There was male preponderance (60%) with male to female ratio of 3:2. The most common presentation was seizure (70%). Intracranial haemorrhage was present in five patients. One patient had cerebral infarction.

CONCLUSIONS

There were substantial differences in clinico-radiological profile of patients with CPA in our cohort as compared to the study by Lasjaunias et al. and Liu et al. in form of male dominance, higher rate of ICH and seizure. In our knowledge, this is the second largest series of CPA worldwide and the first largest series in Asia.

Arteriovenous Malformation Hemorrhage in Pregnancy: A Systematic Review and Meta-Analysis

Hemorrhage of arteriovenous malformation (AVM) is a rare condition during pregnancy. This study was proposed to pool the proportion of AVM hemorrhage per pregnancy. A systematic review and meta-analysis with three databases were performed to review the studies published until April 2022. The Newcastle Ottawa Scale was used for risk assessment of data quality. The meta-analysis was conducted by a generic inverse variance of double arcsine transformation with a random model using Stata software. Twelve studies were included in this review. The pooled proportion of AVM hemorrhage per pregnancy was 0.16 (95% CI: 0.08, 0.26). The subgroup analyses were carried out based on world regions and study designs, and the study duration with the highest proportion of each subgroup was Europe [0.35 (95% CI: 0.02, 0.79)], with retrospective review [0.18 (95% CI: 007, 0.32)] and 10 to 20 years of study duration [0.37 (95% CI: 0.06, 0.77)]. The AVM hemorrhage per pregnancy in this review was considered low. However, the conclusion must be carefully interpreted since this review had a small study limitation.

De novo brain AVM following radiotherapy for cerebral cavernous malformation in a child: A 15-year clinical course

Multiple de novo brain arteriovenous malformations (bAVM) have been reported in the literature, raising questions about the contended purely congenital nature of these lesions. We present the 15-year course of a pediatric patient, who initially presented at age 5 with a thalamic cavernous malformation and was treated with radiosurgery, and then subsequently developed a thalamic de novo bAVM immediately adjacent to the initial lesion location, discovered 2 years later. Treatment of the bAVM entailed two transarterial embolizations and one radiosurgery session which ultimately led to complete angiographic resolution. Finally, this patient's course was complicated by intraparenchymal hemorrhage and acute obstructive hydrocephalus, and further imaging revealed two newly formed cavernous malformations, also associated with the initial lesion's location, that have remained stable since their formation. This case likely represents the second-hit model for the formation of vascular malformations, as sparsely supported by the current literature. According to this, genetically aberrant, yet quiescent, brain areas might promote the de novo formation of vascular malformations after brain injury, including radiation.

Spontaneous thrombosis of a vein of Galen malformation associated with acute sinusitis: a case report

The vein of Galen malformation is caused by an abnormal shunting between choroidal arteries and the median prosencephalic vein during embryological development, leading to increased blood flow to the deep cerebral veins, intracranial damage, and systemic repercussions. Idiopathic spontaneous thrombosis of a vein of Galen malformation is rare, and its association with acute sinusitis has not been reported in the literature. We present the case of a girl with a postnatal diagnosis of a vein of Galen malformation at the age of 16 months, with secondary pulmonary hypertension that was adequately controlled with spironolactone. At 3 years old, while expecting elective endovascular treatment, the patient developed spontaneous thrombosis of the vein of Galen malformation, concomitant to an acute sinusitis episode, with complete resolution of the vascular malformation and secondary pulmonary hypertension. The patient continued with normal neurological development over a 5-year follow-up. We discuss the main pathophysiologic mechanisms that can explain spontaneous thrombosis of VOGMs and the patient's outcome. Awareness of different mechanisms that can lead to spontaneous thrombosis can help in the decision-making process and prompt targeted approaches to individual patients with a vein of Galen malformation.

Comparing health-related quality of life in modified Rankin Scale grades: 15D results from 323 patients with brain arteriovenous malformation and population controls

Background

We wanted to understand how patients with different modified Rankin Scale (mRS) grades differ regarding their health-related quality of life (HRQoL) and how this affects the interpretation and dichotomization of the grade.

Methods

In 2016, all adult patients in our brain arteriovenous malformation (AVM) database (n = 432) were asked to fill in mailed letters including a questionnaire about self-sufficiency and lifestyle and the 15D HRQoL questionnaire. The follow-up mRS was defined in 2016 using the electronic patient registry and the questionnaire data. The 15D profiles of each mRS grade were compared to those of the general population and to each other, using ANCOVA with age and sex standardization.

Results

Patients in mRS 0 (mean 15D score = 0.954 ± 0.060) had significantly better HRQoL than the general population (mean = 0.927 ± 0.028), p < 0.0001, whereas patients in mRS 1–4 had worse HRQoL than the general population, p < 0.0001. Patients in mRS 1 (mean = 0.844 ± 0.100) and mRS 2 (mean = 0.838 ± 0.107) had a similar HRQoL. In the recently published AVM research, the most commonly used cut points for mRS dichotomization were between mRS 1 and 2 and between mRS 2 and 3.

Conclusions

Using 15D, we were able to find significant differences in the HRQoL between mRS 0 and mRS 1 AVM patients, against the recent findings on stroke patients using EQ-5D in their analyses. Although the dichotomization cut point is commonly set between mRS 1 and 2, patients in these grades had a similar HRQoL and a decreased ability to continue their premorbid lifestyle, in contrast to patients in mRS 0.

Congenital renal arteriovenous malformation with cirsoid and cavernosal-type characteristics: a case report

Renal arteriovenous malformations (AVMs) are infrequent vascular morphological anomalies. About 20% of AVMs are congenital renal AVMs (CRAVMs). A 53-year-old female patient presented with a 5-day history of gross hematuria and right flank pain. The patient underwent the selective renal arteriography and embolization under local anesthesia. Renal computed tomography angiography (CTA) and digital subtraction angiography (DSA) results showed bleeding of the right renal arteriovenous malformation, both nidus and aneurysm, which indicated that the patient had both cirsoid and cavernosal types of CRAVM. Endovascular management was chosen to treat the patient. The patient was cured and discharged, then followed-up for 3 months. These results show that early identification using radiologic tests is important for diagnosis and treatment of CRAVM.

Multimodal Assessment of Cerebral Autoregulation and Autonomic Function After Pediatric Cerebral Arteriovenous Malformation Rupture

BACKGROUND

Management after cerebral arteriovenous malformation (AVM) rupture aims toward preventing hemorrhagic expansion while maintaining cerebral perfusion to avoid secondary injury. We investigated associations of model-based indices of cerebral autoregulation (CA) and autonomic function (AF) with outcomes after pediatric cerebral AVM rupture.

METHODS

Multimodal neurologic monitoring data from the initial 3 days after cerebral AVM rupture were retrospectively analyzed in children (< 18 years). AF indices included standard deviation of heart rate (HRsd), root-mean-square of successive differences in heart rate (HRrmssd), low-high frequency ratio (LHF), and baroreflex sensitivity (BRS). CA indices include pressure reactivity index (PRx), wavelet pressure reactivity indices (wPRx and wPRx-thr), pulse amplitude index (PAx), and correlation coefficient between intracranial pressure pulse amplitude and cerebral perfusion pressure (RAC). Percent time of cerebral perfusion pressure (CPP) below lower limits of autoregulation (LLA) was also computed for each CA index. Primary outcomes were determined using Pediatric Glasgow Outcome Score Extended-Pediatrics (GOSE-PEDs) at 12 months and acquired epilepsy. Association of biomarkers with outcomes was investigated using linear regression, Wilcoxon signed-rank, or Chi-square.

RESULTS

Fourteen children were analyzed. Lower AF indices were associated with poor outcomes (BRS [p = 0.04], HRsd [p = 0.04], and HRrmssd [p = 0.00]; and acquired epilepsy (LHF [p = 0.027]). Higher CA indices were associated with poor outcomes (PRx [p = 0.00], wPRx [p = 0.00], and wPRx-thr [p = 0.01]), and acquired epilepsy (PRx [p = 0.02] and wPRx [p = 0.00]). Increased time below LLA was associated with poor outcome (percent time below LLA based on PRx [p = 0.00], PAx [p = 0.04], wPRx-thr [p = 0.03], and RAC [p = 0.01]; and acquired epilepsy (PRx [p = 0.00], PAx [p = 0.00], wPRx-thr [p = 0.03], and RAC [p = 0.01]).

CONCLUSIONS

After pediatric cerebral AVM rupture, poor outcomes are associated with AF and CA when applying various neurophysiologic model-based indices. Prospective work is needed to assess these indices of CA and AF in clinical decision support.

Facial Artery Arteriovenous Malformation Endovascular and Surgical Treatment: Liquid Embolic Device an Advantage for Both Technique

Facial ArterioVenous Malformations (AVM) are rare lesions and present great difficulty in their diagnosis and treatment. We report a case of a 24-year-old male who has been diagnosed a right facial AVM that underwent endovascular embolization with a liquid embolic device and consequently surgical resection. The type of liquid embolic device used has given advantage for both treatment techniques.

Symbolic representation of brain vascular network with Arteriovenous Malformations from 3DRA images

Vascular imaging is crucial in the treatment of many diseases. In the case of cerebral ArterioVenous Malformation (AVM), where the vascular network can be deeply altered, an accurate knowledge of its topology is required. For this purpose, after a vessels segmentation and skeletization applied on 3D rotational angiographic images (3DRA), we build a symbolic tree representation of the vascular network thanks to topological descriptors, such as end points, junctions and branches. This leads to an efficient tool to assist the neuroradiologist to understand the feeding and the draining of the AVM and to apprehend its complex architecture in order to determine the best therapeutic strategy before and during embolization interventions.

Digital Subtraction Angiography is Superior to Magnetic Resonance Angiography in Diagnosis of Cerebral Arteriovenous Malformation

This study was carried out to compare MRA and DSA in diagnosis of cerebral AVM. It was a retrospective observational study conducted in the Department of Neurology Dhaka Medical College Hospital (DMCH), Dhaka during the period of January 2010 to December 2010. Thirty patients with haemorrhagic stroke age ranging from 13 to 65 years were selected on the basis of inclusion and exclusion criteria as the study sample. MRA and DSA were done in all the selected patients. The mean age of the patients of haemorrhagic stroke was 30.3 ± 14.3 years and male female ratio was 2.7:1. Regarding the venous drainage of AVM 13 and 12 were superficial and deep respectively, and evaluated 100% by MRA. In the diagnosis of cerebral AVM nidus size S1: <3 and S2: 3-6 cm sensitivity was 100% but accuracy was 100% and 73.3% respectively. DSA was 100% sensitive in the diagnosis of superficial and deep venous drainage AVM. Regarding the eloquence of brain area 15 had no eloquence by both MRA and DSA and identification of eloquence of brain area sensitivity was 73.3% and accuracy was 86.7%. The main feeding vessels was found (22, 73.3%) in both DSA and MRA findings. Distal vessels was seen (8, 26.7%) in DSA but not seen in MRA findings. Intranidal aneurysm and Angiopathic AVM were seen in 3(10.0%) and 4(13.3%) respectively in DSA. This study was carried out to diagnose the patients presented with cerebral AVM by MRA and DSA. MRA could not be evaluated flow status of AVM, distal feeding arteries, intranidal aneurysm and angiopathic AVM which could be detected by DSA. So, DSA is superior to MRA in diagnosis of cerebral AVM.

[Combined surgical and endovascular treatments of complex cerebral arteriovenous malformation in hybrid operating room]

OBJECTIVE

To summarize the clinical experiences of microsurgical and endovascular treatments of complicated arteriovenous malformation (AVM) in the conditions of hybrid operating room.

METHODS

The clinical data were collected and analyzed for 8 patients of complex AVM between June 2012 to June 2013. There were Spetzler grade III (n = 2) and grade IV (n = 6). And the lesions were complicated with intracranial aneurysms (n = 3) and located in motor area (n = 2) and basal ganglia (n = 2). Five cases of AVM with cerebral hemorrhage underwent emergency surgery, including digital subtraction angiography (DSA) plus intraoperative embolization plus surgical resection of AVM plus intraoperative DSA (iDSA). Two cases underwent embolization plus aneurysm surgery while another had AVM embolization plus AVM resection and γ knife treatment.

RESULTS

All surgical procedures, including iDSA, were completed in the same hybrid operating room. There was no change of surgical position or intraoperative mortality. Five patients of AVM hemorrhage undergoing emergency hematoma evacuation had no residue of AVM on iDSA. Their postoperative consciousness improved without neurological dysfunction. Two patients of limb paralysis recovered to paresis at 3 months postoperation. One case with blurry vision improved somewhat. Two cases undergoing elective surgery had a complete resection of AVM after embolization.

CONCLUSION

Surgery plus endovascular treatment in hybrid operating room is efficacious for complex cerebral AVM. It avoids multiple surgeries and inspections. And any lesion residue may be assessed immediately with postoperative DSA.

[Expression and role of Caveolin-1 in the angiogenesis of cerebral arteriovenous malformation]

OBJECTIVE

To explore the expression and role of Caveolin-1 in the angiogenesis of cerebral arteriovenous malformation (AVM).

METHODS

A total of 55 fresh AVM samples at Affiliated Hospital, Inner Mongolia Medical University and Beijing Tiantan Hospital from August 2013 to May 2014 were collected to test the expressions of Caveolin-1, vascular endothelial growth factor (VEGF), vascular endothelial growth factor-receptor 2 (VEGF-R2) and endothelial nitric oxide synthase (eNOS) by immunohistochemistry and Western blot. And the relationship between the expressions of Caveolin-1 and VEGF, VEGF-R2 and eNOS was analysed.

RESULTS

The expression rates of Caveolin-1, VEGF, VEGF-R2 and eNOS in human AVM were 100%, 87.27%, 76.36% and 85.45%. And the values were significantly higher than those in normal superficial temporal artery. Western blot showed that the expressions of Caveolin-1, VEGF, VEGF-R2 and eNOS in hemorrahge AVM were higher than those in non-hemorrahge counterpart (P < 0.05). The expressions of Caveolin-1, VEGF, VEGF-R2 and eNOS were consistent.

CONCLUSION

Caveolin-1 plays a positive regulatory role in the angiogenesis of AVM through the PI3K/Akt signaling pathway. In cerebral AVM, Caveolin-1 plays an important role in occurrence, progression, hemorrahge and degradation of brain AVM.

[Cyberknife radiosurgery for cerebral arteriovenous malformations: outlining of the radiosurgical target and obliteration]

OBJECTIVE

To explore the therapeutic outcomes of cyberknife for patients with arteriovenous malformations (AVM) and outline the content of AVM targets.

METHODS

Between January 2008 and October 2011, 51 patients underwent cyberknife radiosurgery for cerebral AVMs. The mean age was 27 (8-47) years. The procedures included prior embolization (n = 24), gamma knife before cyberknife (n = 2) and cyberknife initially (n = 25). The delineation of AVM targets was as follows: AVM with prior embolization, radiosurgical targets included AVM nidus, embolization areas and some small draining veins. However, low radiation dose was delivered to embolization parts and draining veins. For 25 patients without embolization, the radiosurgical target was AVM nidus. The mean target volume was 7.8 (1.2-22.0) cm³ and 15 of them were larger than 10.0 cm³. In patients harboring AVM with target volumes < 4 cm³, cyberknife radiation was delivered in a single session. And the remainder had 2 (n = 25) or 3 (n = 19) sessions. The mean marginal dose was 23(18-28) Gy.

RESULTS

AVM obliteration was confirmed by magnetic resonance imaging (MRI) or angiography in 40 (78%) patients during a mean follow-up of 46 (36-70) months. Marked size reduction of AVM was obtained in 11 incompletely obliterated patients. Among them, there were second cyberknife treatment (n = 3), third embolization for complex AVM (n = 1), gamma knife (n = 1) and further follow-ups (n = 6). The higher obliteration rate of AVM was correlated with small volume of AVM in noncritical areas, prior embolization and radiation target of embolization areas. Three patients had hemorrhage during the follow-up period and recovered. Brain edema was found in patients with basal ganglion or parietal AVMs. A permanent neurological deficit (paralysis) due to adverse radiation effects developed in 1 patient.

CONCLUSION

Cyberknife radiosurgery is particularly effective for patients with smaller AVMs in noncritical areas of brain. In patients with prior embolization, delineation of AVM targets including embolization areas is essential for a higher rate of obliteration.

[Spontaneous disappearance of intracranial arteriovenous malformation after living-donor liver transplantation: a case report]

In this report, the authors describe a 35-year-old male whose intracranial arteriovenous malformation (AVM) spontaneously disappeared about 2 years after successful living-donor liver transplantation for alcohol-induced liver cirrhosis. Preoperative screening MRI revealed intracranial arteriovenous malformation (AVM) around the midbrain. Cerebral angiography demonstrated that the AVM was fed by the paramedian mesencephalic arteries and was drained via the vein of Galen. He successfully underwent living-donor liver transplantation, and his postoperative course was uneventful. Follow-up MRI and MRA revealed spontaneous disappearance of the AVM 27 months after surgery. The authors discuss precisely the underlying mechanism of this rare phenomenon, based on thorough literature review.

Segmental Neurovascular Syndromes in Children

The concept of segmental vascular syndromes with different, seemingly unrelated, diseases is based on the embryology of the neural crest and the mesoderm migration of cells that share the same metameric origin. Migrating patterns of these cells link the brain, the cranial bones, and the face on the same side. A somatic mutation developing in the region of the neural crest or the adjacent cephalic mesoderm before migration can, therefore, be postulated to produce arterial or venous metameric syndromes, including PHACES, CAMS, Cobb syndrome, and Sturge-Weber syndrome. Although these diseases may be rare, their relationships among each other and their postulated linkage with the development of the neural crest and the cephalic mesoderm may shed light on the complex pathology and etiology of various cerebral vascular disorders.

Treatment of arteriovenous malformations of the brain

The treatment of ruptured and unruptured brain arteriovenous malformations (AVMs) is driven by the need to prevent incident or recurrent intracranial hemorrhages. Improving feasibility of the rapidly developing endovascular, neurosurgical, and radiotherapeutic procedures leads to invasive treatment of an increasing number of neurologically intact patients with accidentally diagnosed AVMs. Recent data confirm that the natural history risk of unruptured AVMs is significantly lower than the risk of those presenting with rupture, and the treatment risk of invasive management of unruptured AVMs seems higher than their natural history risk. The treatment decision algorithm for these patients remains unsettled, as no randomized clinical trial data exist on the benefit of invasive AVM treatment for patients with bled or with unbled AVMs. The recently launched study A Randomized Trial of Unruptured Brain AVMs (ARUBA) will be the first trial randomizing patients with nonhemorrhaged AVMs to invasive versus conservative management.

Optimizing the latest neuroradiology tools. New techniques are particularly useful in stroke management

In the past several years, advances in central nervous system imaging and interventional techniques have directly and dramatically improved healthcare. In this article, Drs Naul and Santiago discuss developments in magnetic resonance imaging (MRI) and interventional neuroradiology. In addition, the role of these techniques in the management of strokes is highlighted.

Anaesthesia for caesarean section in a patient with an intracranial arteriovenous malformation

Intracranial haemorrhage from an arteriovenous malformation (AVM) during pregnancy is rare but may result in significant maternal and fetal morbidity and mortality. In the untreated patient with an AVM, the best mode of delivery remains debatable with most obstetricians preferring a caesarean section in order to avoid Valsalva manoeuvres associated with vaginal delivery. We describe the administration of epidural anaesthesia for such a parturient undergoing Caesarean section and the anaesthetic implications.

Endothelial cell culture from human cerebral cavernous malformations

BACKGROUND AND PURPOSE

The cerebral cavernous malformation (CCM) is a common and frequently unrecognized cause of stroke and epilepsy. It consists of blood-filled caverns lined by endothelial cells (EC) and devoid of mature vessel wall structure. Cultured EC obtained from CCM may express phenotypic and genotypic alterations contributing to CCM pathogenesis. We report the first successful isolation and growth in vitro of primary EC lines from human CCM lesions.

METHODS

We developed a procedure for the isolation and growth of EC from human CCM, confirmed their EC origin by a panel of molecular markers, and determined by immunocytochemistry the basic expression patterns of 6 transmembrane receptor protein kinases comparing brain, skin, and CCM primary EC lines grown identically.

RESULTS

Several CCM EC lines were established from 2 patients after we treated the excised specimens with 0.3% trypsin/1% EDTA, selective cloning, and growth in MCDB107 containing 0.3 g/L heparin, 0.15 g/L endothelial cell growth supplement, and 15% FBS. The CCM EC showed contact inhibition and a rounded cobblestone appearance. The cells expressed CD31, CD105, von Willebrand factor, and binding sites for Ulex europaeus agglutinin, type 1 and acetylated LDL. They showed low levels of Flt-1, Flk-1, transforming growth factor (TGF)-beta RI, and TGF-beta RII expression but stained strongly with antibodies against Tie-1 and Tie-2.

CONCLUSIONS

Cultured CCM EC retained their endothelial phenotype. Brain, skin, and CCM EC lines did not significantly differ in their staining patterns with antibodies against Flt-1, Flk-1, TGF-beta RI, TGF-beta RII, Tie-1, and Tie-2. These cell lines will assist in defining molecular phenotype and genotype alterations in association with CCM.

Enhanced cervical MRI in identifying intracranial dural arteriovenous fistulae with spinal perimedullary venous drainage

Diagnosis of an intracranial dural arteriovenous fistula (DAVF) with spinal perimedullary venous drainage is challenging because the presenting symptoms are usually related to dysfunction of the spine, not of the brain. Repeated spinal angiograms are usually performed before the diagnosis is finally made by cerebral angiography. We report two cases of intracranial DAVFs with spinal perimedullary venous drainage. In both cases contrast-enhanced cervical MRI demonstrated dilated lower brainstem and upper spinal veins, which, we believe, is a good indicator of the existence of such drainage. We suggest that, in cases with perimedullary serpentine enhancement on thoracic or lumbar MR images, additional Gd-enhanced cervical spinal MR imaging should be performed. The simple process of tracing the veins upwards may avoid a lot of unnecessary examinations and delay in the diagnosis.

A theoretical model of cerebral hemodynamics: application to the study of arteriovenous malformations

A comprehensive computer model of the cerebral circulation, based on both hydrodynamics and electrical network analysis, was used to investigate the influences of arteriovenous malformations (AVM) on regional cerebral hemodynamics. The basic model contained 114 normal compartments: 55 arteries, 37 veins, 20 microvessel groups (MVG), one compartment representing systemic and extracranial vascular resistance, and one representing the heart. Each microvessel group, which represented the arteriolar bed, consisted of 5000 microvessels. Cerebral blood flow autoregulation was simulated by a formula that determined the resistance and therefore the flow rate of the microvessel groups (arterioles) as a function of perfusion pressure. Elasticity was introduced to describe the compliance of each vessel. Flow rate was made a controlling factor for the positive regulation of the diameters of conductance vessels by calculation of shear stress on the vessel wall (vessel dilation). Models containing an AVM were constructed by adding an AVM compartment and its feeding arteries and draining veins. In addition to the basic model, AVM models were simulated with and without autoregulation and flow-induced conductance vessel dilation to evaluate the contributions of these factors on cerebral hemodynamics. Results for the model with vessel dilation were more similar to clinical observations than those without vessel dilation. Even in the presence of total vasoparalysis of the arteriolar bed equivalent, obliteration of a large (1000 mL/min) shunt flow AVM resulted in a near-field CBF increase from a baseline of 21 to a post-occlusion value of no more than 74 mL/100 g/min, casting doubt on a purely hemodynamic basis for severe hyperemia after treatment. The results of the simulations suggest that our model may be a useful tool to study hemodynamic problems of the cerebral circulation.

[Clinical usefulness of three-D cerebral mensional MR imaging in the diagnosis of medullary venous malformation]

Medullary venous malformation (MVM) is one of the most common vascular malformations encountered pathologically. In fact, it is generally discovered incidentally during the workup of other disorders. In 18 cases (19 lesions) of MVM, we evaluated retrospectively the diagnostic value of CT and MRI. We set four evaluations, excellent, good, fair and poor, to assess the diagnostic value of each imaging method. Contrast enhanced CT and pre-contrast MRI could detect the abnormality in 80% of the cases, but it was difficult to demonstrate the umbrella like medullary vein. Contrast enhanced MRI showed the umbrella sign in 60%. Images reformated with three-dimensional (3-D) MR imaging were better able to demonstrate this structure. Medullary vein collection, drainage into a single central vein and termination into a superficial cortical vein or a dural sinus were clearly demonstrated in all cases. Thus, all cases were diagnosed correctly as MVM. Contrast enhanced 3-D MR imaging was superior to other imaging techniques except angiography.

[Anesthesia for cesarean section in a patient with intracranial A-V malformation]

We presented a case of intracranial vascular malformations associated with pregnancy. A 32 year-old woman who was at 36 weeks of gestation had been experiencing loss of consciousness and convulsions for 3 years. MRI revealed an intracerebral AVM measuring 3.5 x 3.0cm in the left temporal lobe. Cesarean section was carried out under general anesthesia and epidural anesthesia to prevent the rise of blood pressure and intracranial pressure owing to stress of delivery and labor pain. Intermittent injection of nicardipine was quite effective to control the hypertension during anesthesia.

Potential toxic effects of superselective injection of amobarbital sodium on microvasculature: a study in an animal model

PURPOSE

To determine whether microvascular damage occurs from superselective intraarterial injection of amobarbital sodium using the swine endovascular embolization model.

METHODS

Thirty-four swine underwent percutaneous femoral puncture for superselective catheterization of the proximal artery of the rete. Varying concentrations of amobarbital sodium were prepared (12.5 to 100 mg/mL solution) in either normal saline or sterile water (105 mOsm/L to 1138 mOsm/L) of which one concentration was infused slowly into one ipsilateral rete. Control infusions were also performed. Histopathologic changes were evaluated at 30 minutes and 10 days after infusion, using standard light and electron microscopy techniques.

RESULTS

Moderate vasospasm occurred only in three swine at 100 mg/mL amobarbital sodium in normal saline. Light microscopy showed no significant histologic changes in the retia at any of the tested concentrations of amobarbital sodium. Electron microscopy showed ultrastructural alterations in the intima only at the higher amobarbital sodium concentrations.

CONCLUSIONS

Concerns for inducing significant damage to cerebral microvasculature by superselective injection of amobarbital sodium at the usually recommended concentrations and doses are probably not justified.

[Peridural anesthesia for cesarean section in a patient with inoperable cerebral angioma]

Anaesthesia for caesarean section in patients with cerebral artero-venous malformations (CAVM) is a controversial matter. We describe a case of a primiparus woman with an inoperable CAVM delivered by CS under epidural anaesthesia. Epidural anaesthesia can be a valid alternative to general anaesthesia as it provides excellent analgesia allowing an accurate assessment of the neurological conditions of the mother and avoiding opioids and/or hypotensive drugs, potentially dangerous to the foetus, to blunt the hypertensive response to intubation. The accidental dural puncture is to be avoided with extra-careful technique. The epidural injection must be made either very slowly or with an incremental technique to avoid any increase in intracranial pressure. Hypotension must be corrected promptly to maintain cerebral perfusion pressure.

Intracerebral arteriovenous fistula: report of one case

Intracranial arteriovenous fistula (AVF) is rare. Of the 320 arteriovenous malformations (AVMs) treated by Halbach over the past ten years, only five (1.6%) had a single arteriovenous connection. In the present study, a male infant developed focal seizure and intracranial hemorrhage without cardiac decompensation at the age of 42 days. When he was 3 years and 4 months old, status epileptics occurred, and AVF was discovered via CT scan and cerebral angiographic examination. The AVF was fed by a middle cerebral artery and drained into a huge cortical vein over the left parietooccipital area. Endovascular therapy and/or surgery were suggested, but the family refused. Though seizures occurred occasionally, the patient's consciousness level had become more clear, and he was discharged after three weeks' hospitalization. The patient was noted to be lethargic and only could roll over partially at the age of 3 year and 8 months, in the latest follow-up.