Cardiac Malformations in Congenital Hypothyroidism: A Case Report

Introduction: Congenital hypothyroidism is the most common causes of preventable mental retardation. It is associated with other births defects like cardiac malformations. Descriptions in Sub Saharan Africa are rare, justifying the present report. Case Report: We reported the cases of 3 female patients, diagnosed with hypothyroidism, presenting in addition pulmonary stenosis. The diagnosis was late in all the patients and we noticed clinical improvement under levothyroxine. Conclusion: Association congenital hypothyroidism and cardiac defect is not rare. Our patients are female with no history of consanguinity, presenting congenital hypothyroidism with a gland in situ associated with pulmonary stenosis. Systematic screening of other births defects is thus recommended in affected patients.

Giant vascular malformations invading the skull:A case report

BACKGROUND Vascular malformations(VMs)arise as a result of errors in the process of angiogenesis and are usually present at birth,but may not become apparent until after birth.However,giant VMs of the head and face are uncommon,with few reported cases,and the prognosis for their surgical intervention is unclear.CASE SUMMARY A 12-year-old girl was admitted to the hospital with findings of an enlarged right temporal scalp.After admission,computed tomography(CT)angiography of cerebral ateries showed a right occlusal gap and a right temporal artery venous malformation.Furthermore,cerebral angiography showed a right temporal lobe VM with multiple vessels supplying blood.The patient underwent surgery to remove the malformed vessels and the eroded skull.Two hours after the surgery,the patient's right pupil was dilated,and an urgent CT scan of the skull showed a right subdural haematoma under the incision,which was urgently removed by a second operation.After surgery,we gave continuous antibiotic anti-infection treatment,and the patient recovered well and was discharged two weeks later.CONCLUSION Surgical removal of giant haemangiomas is risky and adequate preoperative(including interventional embolisation)and intraoperative preparations should be made.

Ectopic recurrence following treatment of arteriovenous malformations in an adult:A case report and review of literature

BACKGROUND Digital subtraction angiography(DSA),the gold standard for the diagnosis of intracranial arteriovenous malformations(AVMs),can show clean nidus resection,leading to a perceived cure.Most cases of intracranial AVM recurrence have been reported in pediatric patients.The conventional understanding indicates that AVMs arise when abnormal blood vessels develop between the fourth and eighth weeks of embryonic development,which coincides with the typical period of blood vessel formation in the brain.As such,recurrent ectopic AVM are rare in adults.CASE SUMMARY Herein,we present the case of a 31-year-old adult with a history of an intracranial AVM originally diagnosed with a symptomatic de novo cerebellar AVM formation.Recurrence was observed five years following angiographically-confirmed excision of the initial AVM.DSA performed prior to initial AVM resection indicated no cerebellar abnormalities.Moreover,the recurrent arteries exhibited differences in arteries and draining veins.In addition to reporting this case,we analyzed six previously-reported adult patients with similar ectopic recurrent AVMs.These cases are summarized to review and explore the potential causes of ectopic AVM recurrence in adults,which increase the likelihood of acquired AVM.CONCLUSION The clinical course of the reported patients demonstrated the possibility of ectopic AVM recurrence in adults.The median time between the diagnosis of the initial AVM and the occurrence of ectopic recurrent AVM in adults was 11 years(range:5–20 years).Magnetic resonance imaging follow-up for more than 10 years may be required in adult AVM-treated patients.

The generation and properties of human cortical organoids as a disease model for malformations of cortical development

As three-dimensional“organ-like”aggregates,human cortical organoids have emerged as powerful models for studying human brain evolution and brain disorders with unique advantages of humanspecificity,fidelity and manipulation.Human cortical organoids derived from human pluripotent stem cells can elaborately replicate many of the key properties of human cortical development at the molecular,cellular,structural,and functional levels,including the anatomy,functional neural network,and interaction among different brain regions,thus facilitating the discovery of brain development and evolution.In addition to studying the neuro-electrophysiological features of brain cortex development,human cortical organoids have been widely used to mimic the pathophysiological features of cortical-related disease,especially in mimicking malformations of cortical development,thus revealing pathological mechanism and identifying effective drugs.In this review,we provide an overview of the generation of human cortical organoids and the properties of recapitulated cortical development and further outline their applications in modeling malformations of cortical development including pathological phenotype,underlying mechanisms and rescue strategies.

Whole mount of adult ear skin as a model to study vascular malformations

Background:Genetic analysis in human patients has linked mutations in PIK3CA,the catalytic subunit of PI-3′Kinase,to sporadic incidences of vascular malformations.Methods:We have developed a mouse model with inducible and endothelial-specific expression of PIK3CA H1047R,resulting in the development of vascular malformations.Systemic induction of this mutation in adult mice results in rapid lethality,limiting our ability to track and study these lesions;therefore,we developed a topical and local induction protocol using the active metabolite of tamoxifen,4OH-T,on the ear skin of adults.Results:This approach allows us to successfully model the human disease in a mature and established vascular bed and track the development of vascular malformations.To validate the utility of this model,we applied a topical rapamycin ointment,as rapamycin is therapeutically beneficial to patients in clinical trials.We found that the induced ear lesions showed significant attenuation after treatment,which was easily quantified.Conclusions:These data collectively provide evidence of a new model to study vascular malformations in adult tissues,which should be particularly useful in environments lacking specialized small-animal imaging facilities.

Overview of peripheral arteriovenous malformations:From diagnosis to treatment methods

Based on the latest classification by the International Society for the Study of Vascular Anomalies in 2018,vascular malformations(VMs)can be categorized into simple,combined,VMs of major named vessels,and VMs associated with other anomalies.Simple VMs include lymphatic,venous,capillary,and arteriovenous malformations(AVMs).AVMs represent disorders of direct arteriovenous shunts caused by the absence of a capillary bed between the involved arteries and veins.This abnormal vascular communication causes arterial blood to accumulate in the venous vessels,thus resulting in venous hypertension and characteristic clinical manifestations,such as pulsation,tremors,and elevated temperature.AVMs can occur sporadically or as manifestations of syndromic lesions and are considered among the most complex and challenging VMs.The diagnosis and treatment of AVMs can vary depending on the lesion location and associated clinical symptoms,thus complicating their management.Herein,we discuss peripheral AVMs in terms of their clinical manifestations,imaging examinations,and staging systems to provide a comprehensive reference for the treatment,evaluation methods,and follow-up procedures for this vascular anomaly.

Embolization of brain arteriovenous malformations with squid co-polymer embolic material:Initial experience

Objective:To analyze the safety and effectiveness of the ethylene-vinyl alcohol copolymer(EVOH)liquid embolic agent Squid(Emboflu,Switzerland)for the treatment of brain arteriovenous malformations.Materials and procedures:Between April 2015 and July 2017,46 embolization treatments for brain arteriovenous malformations(BAVM)were performed in 25 patients using two Squid formulations(18 and 12).Six female and 19 male patients with a mean age of 34 years(range,9–62 years)were included.A total of 46 procedures were performed.The BAVMs were classified as Spetzler-Martin gradeⅡin 4 procedures,Ⅲin 27 procedures,and 1V in 15 procedures.Among the 25 patients,15 presented with hemorrhage,5 with seizures,and 5 with headache and neurology.The BAVMs were located in the temporal lobe in 5 patients,parietal lobe in 7 patients,frontal lobe in 3 patients,posterior fossa in 6 patients,basal ganglia in 3 patients,and parasagittal lobe in 1 patient.Results:The obliteration rate of the BAVMs ranged from 10%to 100%,with a mean of 33%.Most patients underwent their first or second embolization procedure.Four patients(8%)developed intracranial bleeding post procedure,with one death(2%).One patient(2%)experienced a seizure during the procedure;however,no intracranial bleeding was observed.Seven patients(15%)experienced perforations during catheter manipulation.One case(2%)of fractured catheter was recorded,but no significant complications were observed.The average volume of copolymer injected was 0.6 ml per nidus.Thirteen procedures used the Squid-12 formulation,29 procedures used the Squid-18 formulation,and 3 procedures used a combination of Squid-12 and-18 formulations.Conclusion:Squid is a safe and effective embolic agent for treating BAVMs.

Delayed versus immediate intervention of ruptured brain arteriovenous malformations:A case report

BACKGROUND Brain arteriovenous malformations(bAVMs)remains one of the most prevalent causes of intracranial hemorrhage and stroke-like syndromes in the young adult population.Although it has been agreed upon that definitive treatment using either single or multi-modal approach is warranted for successful bAVM management,much debate still revolves regarding the optimal timing of definitive treatment.CASE SUMMARY In this report,we present a case of delayed,definitive endovascular treatment for ruptured bAVM in a 21-year-old female,3 mo post-ictus.The bAVM,with a left pericallosal feeding artery and cortical draining veins,was successfully obliterated through embolization using the Onyx 18.On follow-up the patient has recommenced her daily activities and experiences only mild occasional headaches with mild motor deficits.The report leads to our review on an important issue regarding the optimal timing of ruptured bAVM definitive management and bring forward the current evidence available on delayed vs immediate definitive bAVM intervention.We also highlight current issues that need to be addressed for clearer guidelines on definitive therapy initiation.CONCLUSION Current treatment paradigms of ruptured bAVM remains elusive,with substantial heterogeneity in the current literature.A consensus on the definition of“acute”vs“delayed”,management goal,follow-up length and outcome parameters are required to support formation of a clear paradigm.

Macroscopic Congenital Malformations at the Institute of Nutrition and Child Health (INSE)

Introduction: A congenital malformation is defined as a morphological abnormality of an organ or body region resulting from an abnormal developmental process during the formation of the embryo or fetus. Depending on their type, location and size, malformations can cause functional, psychological and aesthetic defects. The aim of this study is to document the frequency of congenital malformations, describe the characteristics of malformed newborns and their biological mothers, and identify the different types of malformations presented by newborns at the INSE. Methods: Descriptive cross-sectional study of clinically visible malformed newborns. It was carried out from January 1, 2021 to January 1, 2022 at the INSE neonatology unit. Epi info version 3.1 software was used for data entry and analysis. Results: Of a total of 2332 neonates hospitalized during the study period, 81 (3.5%) cases had at least one clinically visible congenital malformation. Nearly 84% had an age ≤ 7 days at the time of admission. The male sex was most concerned (60.5%). Newborns referred by a health facility accounted for 84%. Malformations of the digestive system accounted for 30.9% of cases, followed by those of the limbs (19.8%) and poly malformative syndrome (19.8%). Conclusion: This study shows that congenital malformations exist and are frequent in Guinea. Our results could therefore be the starting point for the future establishment of a national register of congenital malformations.

Absolute ethanol embolization for treatment of peripheral arteriovenous malformations

Arteriovenous malformations(AVMs)are aggressive congenital high-flow vascular anomalies,in which the feeding artery and draining vein are connected through fistulas without normal capillary networks.In severe cases,the condition may cause swelling,ulceration,bleeding,and even heart failure.Various treatment options are available for AVMs,including laser,surgical resection,embolization,and targeted drug therapy.With the development of endovascular treatment technology,absolute ethanol embolization of AVMs has become one of the first-line therapies owing to its sustained efficacy and low recurrence rate.However,administration of this therapy is challenging and may lead to serious complications if inappropriately managed.In this article,we reviewed and summarized previous clinical articles,literature reviews,and clinical trial data to comprehensively describe clinical manifestations of AVMs,the mechanism of ethanol embolotherapy,key points in treatment and management of complications,and issues that need to be addressed.We expect to provide a reliable information reference source for clinical physicians and researchers.

MEK inhibitors for the treatment of extracranial arteriovenous malformations

Arteriovenous malformations(AVMs)are serious congenital vascular anomalies in which the arteries connect directly with veins without capillaries.This condition will continue to worsen without proper intervention and cause ulcers,repeated hemorrhages,and even cardiac insufficiency.Primary treatment options for AVMs include surgery and interventional treatment;however,they are associated with high risk and recurrence rates.Recent studies revealed that excessive activation of the Ras/MAPK pathway can induce the formation and development of peripheral AVM,whereas MEK inhibitors can effectively control nidus progression,making them a potential novel treatment for AVM.This review provides an up-to-date overview of correlated laboratory and clinical research to provide information for further research and clinical practice.

Compound Heterozygous PLD1 Variants in Right-Sided Heart Malformations

We report a three-year-old male child who presented with congenital valvular defects,right ventricular malformation,and initial developmental delay.Genome sequencing showed rare deleterious biallelic missense variants in PLD1.In his parents’second pregnancy,echocardiogram at 13 weeks gestation revealed right-sided cardiac malformations resembling the clinical presentation of the family’s first child.Targeted DNA analysis showed that the fetus carried the same biallelic PLD1 variants as their older sibling.This case helps to further delineate the clinical spectrum of PLD1-related defects and highlights the value of both genome sequencing in congenital heart disease and early fetal echocardiography to establish phenotype.

A child with severe inner ear malformations with favorable hearing utilization and balance functions after wearing hearing aids

Infants with congenital deafness caused by severe bilateral inner ear malformations frequently suffer from severe hearing loss and poor balance. Unfortunately, the use of hearing aids is usually ineffective in recovering hearing, necessitating cochlear implants. We report a case of a 6-year-old boy with congenital deafness and bilateral inner ear malformations(right side, incomplete partition type I [IP-I]; left side, common cavity deformity). Hearing aids had a remarkable effect in this patient, enabling sufficient and favorable hearing recovery such as to allow the patient to engage in daily conversations. Per-rotatory nystagmus was recorded on an electronystagmogram for both right and left rotations in a damped rotational chair test. It is rare for deaf children with severe bilateral inner ear malformation to demonstrate favorable development in hearing and good equilibrium function. Our findings suggest that auditoryevestibular hair cells in this patient may have been partially preserved despite IP-I in the right ear and common cavity deformity of the left ear.

Diagnosis and treatment of venous malformations in China: consensus document

Venous malformations(VMs) are the most common vascular developmental anomalies. There are many controversies over VMs in Chinese clinical medical practice. Experts on the panel from vascular-anomaly centers in China reviewed the etiology, pathophysiology, epidemiology, classification, clinical presentations, diagnosis, and treatment of VMs. The aim of this consensus document is to provide recommendations for, and assist clinicians and patients in, the diagnosis and treatment of VMs.

Current Controversies and the State of the Art in Endovascular Treatment of Vascular Malformations

Vascular anomalies constitute some of the most difficult diagnostic and therapeutic enigmas that can be encountered in the practice of medicine. The clinical presentations are extremely protean and can range from an asymptomatic birthmark to fulminant。

Prevalence and CT-Scan Presentations of Brain Malformations in Children at a University-Affiliated Mother and Child Hospital (Cameroon)

Background: Brain malformations (BMs) are congenital abnormalities of the shape or structure of the brain, with corpus callosum agenesis known as the most frequent. Diagnosis of most BMs can be prenatal with ultrasound and fetal magnetic resonance imaging (MRI);post-natal diagnosis is based on transfontanellar ultrasound, CT-scan, and head MRI which is the imaging gold standard technique. MRI has been recently introduced and the CT-scan was previously the reference technique for the diagnosis of BMs in our context. Almost no publication has been made in sub-Saharan Africa on the clinical and CT scan characteristics of Brain malformations in children. Objective: The aim of this study was, in the absence of MRI, to describe the clinical and CT-scan presentations of brain malformations in children at the Yaounde Gynaeco-Obstetric and Pediatric Hospital (YGOPH). Patients and method: This was a cross-sectional descriptive study conducted from February to May 2016 at the YGOPH, including all children of 15-year-old and less with BM diagnosed on CT-scan at YGOPH between April 2006 and March 2016. The studied variables were clinical (age at diagnosis, sex, clinical manifestations) and CT findings (type of cerebral malformation). The data was analyzed using the SPSS 20.0 software with the estimation of hospital prevalence of BMs, frequencies and associations. The chi-square test was used to seek for an association between variables. The threshold of significance was p Results: The prevalence of BMs was 0.52%, with 29 cases of BMs identified out of 5590 patients followed up at the pediatric neurology outpatient unit over a period of 10 years. The mean age at diagnosis was 37.2 months (3.1 years) and the most represented age groups were 0 - 1 year (37.9%) and 1 - 5 years (37.9%). The sex ratio was 0.81 (55.2% girls). The clinical presentation was represented by neurological signs (93.1%) with convulsions (65.5%) and psychomotor retardation (58.8%) associated with skin lesions (34.5%) and/or facial dysmorphic features (27.6%). BM was suspected on antenatal ultrasound in 14.3% of cases (4/28). Abnormalities of cortical development accounted for 65.5% of BM followed by abnormalities of brain separation (31%). Tuberous sclerosis complex was the most common BM (31%) followed by agenesis of the corpus callosum (27.6%). The presence of dysmorphic facial features was associated (p = 0.007) with disorders of brain separation (DBS) while the presence of cutaneous lesions was associated (p = 0.013) with anomalies of the cortical development (ACD) especially tuberous sclerosis complex. Conclusion: BMs are infrequent, dominated by tuberous sclerosis complex and agenesis of the corpus callosum. They are mainly revealed by convulsions and psychomotor retardation. Efforts are needed to improve antenatal diagnosis and facilitate access to cerebral MRI.

Painless swollen calf muscles of a 75-year-old patient caused by bilateral venous malformations

A 75-year-old man presented with knee pain due to medial osteoarthritis of the knee in the orthopedic outpatient clinic. Conservative treatment was started with steroid infiltration. Besides his knee complaint reported a bilateral painless swollen calf muscle without traumatic cause, and also without any pain at night, fever or medical illness. On physical examination the soleus muscle had a swollen aspect in both calfs. The skin appeared normal without deformities and the arterial pulsations were intact. An X-ray did not show abnormalities in the tibia. Magnetic resonance imaging of the legs revealed bilateral multiple saccular intramuscular venous malformations involving the soleus muscle. Intramuscular venous malformations in skeletal muscles are rare, especially when the occurrence is bilateral. Bilateral venous malformations have the potential to be missed because of the intramuscular localization. Symptoms of intramuscular venous malformation can be often mild and overlap with nonexercise related compartment syndrome, claudication, lymphedema and post thrombotic syndrome or muscle strains.

Expression of angiogenic factors in cerebral arteriovenous malformations

BACKGROUND： In the process of vascularization, vascular endothelial growth factor （VEGF）, angiopoietin-2 and Tie2 are involved in the migration, differentiation and proliferation of vascular endothelial cells, and stimulate the rapid angiogenesis; Tiel and angiopoietin-1 play important roles in facilitating the formation of vascular lumen and maintaining the integrity of vascular wall. Thus the distributions and expressions may be associated with the occurrence of cerebral arteriovenous malformation. OBJECTIVE： To observe the biological effects of angiogenic factors in the occurrence and development of cerebral arteriovenous malformation. DESIGN： An observational comparative experiment. SETTINGS： Department of Neurosurgery, General Hospital of Shenyang Military Area Command of Chinese PLA; Department of Neurosurgery, General Hospital of Tianjin Medical University. PARTICIPANTS： Fresh samples of complete cerebral arteriovenous malformations resected in 47 patients were collected from the Department of Neurosurgery, General Hospital of Tianjin Medical University from August 1999 to May 2001, including 22 males and 25 females, the mean age was 34.5 years. Informed consents were obtained from all the patients or their relatives. The initial symptom was hemorrhage in 28 cases. All the patients were classified according to the clinical imaging data and Spetzler-Martin grading standard, including 11 cases of grade Ⅰ, 17 cases of grade Ⅱ, 11 cases of grade Ⅲ, and 8 cases of grade Ⅳ - Ⅴ. Normal brain tissues resected by decompression due to trauma were taken from 8 patients as controls, including 5 males and 3 females, aging 12 - 65 years. METHODS： ① The expressions of VEGF, Tie receptors, angiopoietin-1, angiopoietin-2, proto-oncogene c-myc and proliferating cell nuclear antigen（PCNA） in the samples of cerebral arteriovenous malformation were detected with immunohistochemical method. Under light microscope, the positively stained rat-anti-human factor Ⅷ-related antigens （specific marker of vascular endothelial cells） were counted, then the immuno-positive cells of the other antibodies in the visual field of neighboring section which was in ＂mirror＂ relation were counted, and the percentage of the latter to the former was considered as the labeling index of positive cells. The immunostaining intensity was classified negative （ - ）： no positive cells; positive （＋）： number of positive cells 〈 20%; moderately positive （＋＋）： number of positive cells 20% - 50%; strongly positive （＋＋＋）： number of positive cells 〉 50%. ② The differences of the enumeration data were compared with chi-squam test, and the correlation were analyzed with the linear correlation analysis. MAIN OUTCOME MEASURES： Expressions and distributions of VEGF, Tie 1 and Tie2 receptors, angiopoietin-1, angiopoietin-2, PCNA and c-myc in the samples of cerebral arteriovenons malformation and normal brain tissue. RESULTS： ① Expressions of angiogenic factors in the control group and cerebral arteriovenons malformation groups of each grade： The positive rates of VEGF, Tie2, angiopoietin-2, c-myc and PCNA expressions in the control group were significantly different from those in the cerebral arteriovenous malformation groups of each grade （ x^2=21.09 - 34.23, P 〈 0.05）, whereas the positive rates of Tiel and angiopoietin-1 expressions were close （ x^2=3.43 - 3.869, P 〉 0.05）. ② Expressions of angiogenic factors in hemorrhage group and non-hemorrhage group： The expressions of VEGF, angiopoietin-2 and PCNA in the hemorrhage group were significantly lower than those in the non-hemorrhage group （ x^2= 16.22 - 26.56, P 〈 0.05）. There ware no obvious differences in the expressions of Tiel and angiopoietin-1 expressions between the hemorrhage group and non-hemorrhage group （ x^2=3.22 - 3.78, P 〉 0.05）.The VEGF was positively correlated with the expressions of c-myc and PCNA （r = 0.728, 0.916, P 〈 0.05）. CONCLUSION： ①The expressions of angiogenic factors and related receptors may be involved in the process of cerebral arteriovenous malformation, and had important correlation the its clinical grading. ② Angiogenic factors may induce the expression of endothelial cell c-myc in cerebral arteriovenous malformation, and then interfere the cell proliferation and apoptosis.

Conotruncal heart malformations in Egypt: An epidemiological study

Conotruncal malformations of the heart are a major category of birth defects. No previous epidemiological studies on these malformations have been carried out in Egypt;therefore our study aimed to describe associations with maternal and infant factors in order to identify possible risk factors. Cases (N = 255) were children up to two years of age whose heart malformations were confirmed by echocardiography;they were enrolled at the Cardiology Department of the Pediatric Hospital of Cairo University. Controls (N = 155) were free of congenital heart malformations, matched to the cases by age, and recruited from outpatients of the same hospital. Mothers of cases (97%) and controls (89%) provided consent to participate in an interview about their medical, familial, and occupational histories. Odds ratios (OR) and exact 95% confidence intervals (CI) assessed the magnitude and statistical significance of case-control differences. Cases were divided into two groups based on the presence of d-transposition of the great arteries (TGA): there were 139 with TGA and 116 with normally-related great arteries (NGA). Maternal diabetes prevalence was elevated in both the TGA (OR = 3.4) and NGA (OR = 5.5) subgroups. Several agricultural factors were associated with increased risk: raising animals (for TGA: OR = 2.4, 95% CI 1.2-4.6), raising poultry (for NGA: OR = 1.8, 95% CI 1.1-3.2), and using chemical rodenticides (for all conotruncal cases: OR = 3.2, 95% CI 1.1-13.2). These results are consistent with previous studies of associations of maternal diabetes and pesticide exposure with conotruncal malformations. Further research is warranted to explore such associations and determine avenues for prevention.

Embolizing intracranial arteriovenous malformations with Onyx: experience at a single center with 250 patients

Objective The aim of this study is to evaluate the embolization techniques, as well as the effects and complications, using the non-adhesive liquid embolic material Onyx in intracranial arteriovenous malformations(AVMs). Methods The study comprises a retrospective analysis of 250 patients with intracranial AVMs treated with Onyx in Guangdong General Hospital from Jan 2010 to Dec 2017. The therapeutic strategies, as well as embolization effects and complications, of Onyx are summarized. Results Of 250 cases, 170 were male and 80 were female. Following the Spetzler–Martin(S-M) grading system, there were 35 cases of grade Ⅰ, 77 of grade Ⅱ, 72 of grade Ⅲ, 39 of grade Ⅳ, and 27 of grade V. All cases were treated with Onyx. In addition, 69 cases were treated with Glubran glue. The injected volume of Onyx per patient ranged from 1 mL to 10 mL. The largest volume of Onyx injected in one procedure was 10 mL. The cure rate was 67.9%(76/112) of grade Ⅰ-Ⅱ patients, 15.0%(11/72) of grade Ⅲ patients, 7.7%(3/39) of grade Ⅳ patients, and 0%(0/27) of grade V patients. The total cure rate was 36.0%(90/250). The average number of targeted vascular branches per patient was 2.28. The microcatheter broke off in two cases. There were two patients who suffered an intracranial hemorrhage during the embolic procedure; in one of these two patients, the microcatheter also broke off. There were two patients who suffered an intracranial hemorrhage after the embolic procedure; one of them died. Seven cases suffered new-onset neurological deficits or their original symptoms deteriorated. Six of them improved or recovered within 3–6 months. The total complication rate was 5.2%(13/250). Conclusion The application of Onyx in intracranial AVMs is flexible, effective and safe, and may also reduce the complications.