Clinical Features And Endovascular Treatment Of Cerebral Arteriovenous Malformations In Pediatric Patients

Background:Cerebral arteriovenous malformation (cAVMs) are congenital anomalies of blood vessel development thought to result from a failure of embryogenesis around the third to four week of gestation in the differentiation of primordial vascular channels into mature arteries, capillaries, and veins, which consist of direct arteriovenous shunts without an intervening capillary bed. However, familial arteriovenous malformations are extremely rare, so far there are no more that10family systrems have been reported around the world, and may be relevantion with hereditary telangiectasia (Hereditary hemorrhagic telangiectasia, HHT). cAVMs was firstly described by Luschka in1854, the nest is a mass of abnormal blood vessels abnormal development of blood vessels between arteries and veins lesions lack of normal capillary network, resulting in arteries and veins directly connected, a short circuit between the cerebral arteriovenous, which produces hemodynamic changes in the brain, resulting in a corresponding clinical signs and symptoms. According to foreign reports, cAVMs crowd in the morbidity is0.35%to4%, male have slightly higher incidence of this disease. There is still lack of large scale epidemiological investigation in our country, so its incidence is difficult to determine.Zhao Jizong et al findings2086cAVMs cases of patients have the same proportion of men with women about1.97as foreign roughly, the average age of diagnosis was28.3years, and the peaking at20to30-year-old segment. The study by Brown et al cAVMs detection rate has increased year by year trend that may be advanced imaging technology is widely used to improve the detection rate cAVMs. Clinical manifestations:(1) Bleeding:it is the most common clinical manifestations with cAVMs, bleeding can occur at any site. Location or size of the cAVMs and other factors may be associated with bleeding-related. Some patients may have headache, focal signs such as seizures or certain aura before the bleeding.(2) Epilepsy:may due to a short circuit arteriovenous malformation occurs " steal " phenomenon which causes local cerebral ischemia, followed by degeneration of brain tissue. Especially in the frontal, temporal, parietal area, prone to seizures, antiepileptic drugs usually hard to controlled.(3) Headache:may due to intracranial hemorrhage and may also occur alone persistent or recurrent headache. Symptomatic pain and other treatment can alleviate, but can repeat easily.(4) Focal neurological deficits:according to the location of cAVMs, cerebral blood circulation disorders and brain atrophy on the region, the common symptoms mental and emotional disorders, language disorders, sensory impairments, like hemianopia and spatial disorientation, aphasia, alexia, apraxia, ataxia, cranial nerve palsy.(5) Other non-typical symptoms:intracranial murmur, psychiatric symptoms, such as increased intracranial pressure. Should be particularly noted is that in infants and childhood, a short circuit due to intracranial blood circulation, heart failure can occur, especially involving the great cerebral vein malformation group who heart failure and may even be the only clinical symptoms.Cerebral arteriovenous malformation diagnosis relies on CTA, MRA and DSA examination, treatment mainly microsurgical resection, stereotactic radiosurgery, endovascular embolization, conservative treatment and integrated treatment approach. The main aim of treatment is to reduce or eliminate rupture risk of bleeding, relieve existing variety of clinical symptoms, In recent years, with the development of scientific and technological progress, microscopic imaging equipment and precise positioning technology, endovascular embolization materials and micro-catheter technology constantly updated, cAVMs treatment can be greatly improved. Endovascular embolization become one of the main treatments to cAVMs with its relatively small trauma, shorter treatment cycles and the repeatbility, and its applicability, effectiveness, and explore the prognosis has become a top research.Cerebral arteriovenous malformations is one of the most main reasons for children’s spontaneous intracerebral hemorrhage. The mortality rate due to bleeding up to10-20%. Di Rocco C et al reported that children account for3-20%of patients with the same period of treatment cAVMs. Complete obliteration of the malformation is especially important in the pediatric population for many reasons. Children obviously have a longer life expectancy than adults and thus they more commonly present with a hemorrhage (up to70～85%vs50～65%), and they are thought to have a higher annual bleeding risk (2～4vs1～3%). Furthermore, the incidence of posterior fossa and basal ganglia malformations are higher in children, and malformations in these locations are thought to be more prone to rupture. Perhaps most importantly, the morbidity and mortality related to each intracerebral hemorrhage is higher in children. So far children cAVMs need aggressive treatment, and possible causes malformation or complete occlusion removal, reducing the risk of bleeding and relieve existing symptoms. Studies in adults have identified specific angioarchitectural features of AVMs that are associated with hemorrhagic presentation and future hemorrhage. Small size, deep venous drainage, deep location, single draining vein and intranidal aneurysms have all been implicated as morphological risk factors of hemorrhage. Similar studies in children are absent and treatment decision making is therefore always extrapolated from adult data. Children cAVMs whether bleeding associated with these risk factors, remains to be further studied. Currently on children with cerebral arteriovenous malformations lack of knowledge of the clinical features and treatment, research and analysis and prognosis rare child cAVMs endovascular embolization in the treatment of adults we tend to reference the existing research data, so the children with cerebral arteriovenous malformation clinical characteristics and treatment analysis is particularly important.The study by collecting children cAVMs cases, the clinical features of children in general, cAVMs imaging data, treatment, complications and risk factors for system analysis, to explore the risk factors of children cAVMs bleeding, while focusing on analysis of endovascular treatment of vascular children build characteristics, prognosis, complications and associated risk factors, provide a theoretical basis for the future of children at high risk of bleeding cAVMs prevention and treatment.Objective:To evaluate children with cerebral arteriovenous malformations general clinical features and analysis of relevant risk factors for children cAVMs bleeding. Assess clinical outcomes for children cAVMs endovascular embolization and prognosis after treatment, focusing on analysis of complete occlusion after endovascular embolization cases Angioarchitecture characteristics and analysis of complications and risk factors associated with providing the theoretical future children cAVMs embolization based and empirical guidance.Methods:A retrospective analysis from2000to2013, Zhujiang Hospital, Southern Medical University, diagnosed cAVMs cases. Retrieval of cases in our hospital database, enter the search term " cerebral arteriovenous malformation "," arteriovenous malformation ","AVM", but need except for venous malformations, cavernous angioma, dural arteriovenous malformations and other parts of the extracranial vascular malformations. And read the medical records, imaging data, collected a total of154cases of children (≤18years) patients admitted mRS score, clinical manifestations, cAVMs angioarchitecture and S-M classification, treatment, embolization number, volume and number of feeding artery embolization, type and concentration of glue, postoperative complications and final mRS score and so on. All enrolled patients with clinical features of patients and their families required to determine the final treatment method. Treatment options can be selected endovascular embolization, microsurgical resection, conservative treatment, stereotactic radiosurgery. Endovascular treatment of postoperative observation for at least48hours in the ICU, continuous ECG monitoring, bed rest, actively calm and strictly controlled hypotension for at least72hours, to avoid the normal cerebral perfusion pressure breakthrough caused bleeding again. Follow-up of patients after discharge. Follow-up includes general information on the patient, recovery, mRs score, new symptoms, then bleeding and treatment, quality of life and so on. Follow-up time was4to48months, an average of9.6months. Frequencies and percentages were calculated for categorical variables, and means and standard deviations (SD) for continuous variables. Categorical data were analysed using Fisher’s exact test or the chi-squared test, as appropriate. Analyses of continuous data with normal distribution were performed with the Student’s t-test. Multivariate analysis using Logistic regression analysis. Variables selected into the selection criteria have been identified or associated risk factors reported in the literature (such as gender, draining veins, accompanied by an aneurysm, malformation group size, malformation and other parts). A P<0.05was used as the level of statistical significance. The statistical analysis was performed with the Statistical Package for the Social Sciences version13.Results:The proportion of patients in this study for treatment of children cAVMs cAVMs the same period accounted for approximately24.4%.92males and62females, mean age at presentation was12.87years (range3～18years). The main clinical manifestations including hemorrhage, epilepsy, headaches, and other neurological damage, including bleeding109cases (70.8%), seizures in25cases (16.2%), headache in14patients (9.1%),4(2.6%) with neurological deficits and2(1.3%) were asymptomatic;133cases located on supratentorial,21cases for infratentorial; malformation size<3cm83cases,3～6cm58cases,>6cm13cases;14cases combined aneurysms, which11cases related to the artery aneurysm or within the nest; deep venous drainage in65cases, of which14cases bi-directional drainage; S-M grading:I grade11cases, Ⅱ grade50cases, III grade63cases, IV grade22cases, V class8cases. Univariate analysis revealed three features to be significantly associated with initial hemorrhagic presentation:smaller cAVMs size (P=0.000), deep venous drainage (P=0.012) and infratentorial location (P=0.033). Only smaller cAVMs size (P=0.001) and deep venous drainage (P=0.021) were independently associated with hemorrhagic presentation in multivariate analysis.154cases of children cAVMs treatment in88cases of endovascular treatment choice, the remaining66cases choose craniotomy surgery, stereotactic radiation therapy, conservative therapy or combined therapy. The88patients with brain cAVMs underwent an aggregate total of163embolization procedures, ranging from1to8per patient, every two embolization intervals for at least2months. The88patients had an aggregate total of264feeding pedicles embolized, ranging from1to9per patient. Average estimated size reduction was78%(range20%-100%). Initial complete obliteration at the end of all embolization procedures was achieved in19/88patients (21.6%). Angiomorphologic characteristics of the19initially completely obliterated cAVMs were the following:15cases of cAVMs size<3cm,4cases3～6cm, whereas no case of>6cm;16cAVMs had2or fewer arterial feeders, and3cAVMs had>2feeders. Children without totally obliteration was continue to choose surgery, radiation therapy and regular follow-up. In163embolization, treatment-related complications occurred in13embolization procedures (7.98%). None of the patients suffered a permanent neurological deficit or morbidity. There was no mortality in the study population. There were no statistically differences between patients who did and those who did not experience complications in terms of sex, age, cAVMs location, number of pedicles embolized, Spetzler-Martin grade of cAVMs, deep venous drainage and devascularization percentage (P>0.05).Conclusion:Cerebral hemorrhage was the major clinical manifestations for cAVMs in pediatric patients. cAVMs size and deep venous drainage were independently associated with hemorrhage in pediatric patients. Endovascular procedure is feasible and safe for pediatric cAVMs, and complete embolization can be achieved in small cAVMs, while large cAVMs can be adequately reduced in size for additional microsurgery or stereotactic radiosurgery.