Kết quả điều trị dị dạng động tĩnh mạch não vỡ bằng phối hợp nút mạch và phẫu thuật TT TIENG ANH

MINISTRY OF EDUCATION AND TRAINING MINISTRY OF HEALTH HANOI MEDICAL UNIVERSITY ====== PHAM QUYNH TRANG TREATMENT OF CEREBRAL ARTERIOVENOUS MALFORMATION WITH COMBINATION OF EMBOLIZATION AND MICROSURGERY Specialism: Neurosurgery Code : 62.72.01.27 ABSTRACT OF THE THESIS HA NOI - 2021 The thesis has been completed at HANOI MEDICAL UNIVERSITY Supervisor: Prof NGUYEN THE HAO Supervisor 1: Prof Nguyen Trong Yen Supervisor 2: Prof Nguyen Van Lieu Supervisor 3: Prof Kieu Dinh Hung The thesis will be present in front of board of university examiner and reviewer lever at… on ….2021 This thesis can be found at: National Library National Medical Informatics Library Library of Hanoi Medical University THE LIST OF WORKS RELATED TO THE THESIS WHICH HAVE BEEN PUBLISHED Pham Quynh Trang, Nguyen The Hao (2020), Clinico-radiological features of ruptured cerebral arteriovenous malformations treated with combination of embolization and microsurgery, Vietnam Medicine, no Dec (497): 153-157 Pham Quynh Trang, Nguyen The Hao (2020), Results of combination of embolization and microsurgery in for ruptured cerebral arteriovenous malformations, Vietnam Medicine, no Dec (497): 38-43 Nguyen The Hao, Pham Quynh Trang, Tran Trung Kien (2017), Evaluating the advantages of pre-op embolization for high grade cerebral AVMs, Ho Chi Minh Medicine vol 21, no 6: 156-161 INTRODUCTION Cerebral arteriovenous malformation (AVM) is an abnormality of cerebral vascular system in which there is a direct flow between arterial and venous system, about 4% of intracranial haemorrhage cause and 30% of non traumatic haemorrhage in young people Beside severe consequences of AVM rupture, long lasting neurological symtoms have bad effects on patient's life Diagnosis of bleeding cerebral AVM includes clinical and radiological examinations Radiology also serves to analyze the vascular structure in order to plan the best treatmen strategy Unassisted microsurgery for large AVM can lead to important intraoperative blood loss or persistent parenchymal Embolization as a single treatment is not a radical method causing rebleeding postintervention Nowadays, treatment of large or high grade cerebral AVM requires a multimodality In Vietnam, since 2014, a combination of embolization and microsurgery has been applied for radical resection of cerebral AVM For this reason, we prceed this research with two following purposes Vì tiến hành nghiên cứu nhằm mục tiêu: Analyzing the clinico-radiological features of ruptured cerebral arteriovenous malformations treated with combination of embolization and microsurgery, Evaluating the results of combination of embolization and microsurgery for ruptured cerebral arteriovenous malformations Necessity of the thesis Incompleted treatment of bleeding cerebral AVM leads to important mortality and morbidity Management of high grade AVM remains complicated and controversial not only in Vietnam but also worldwide Many studies conclude that microsurgery associated with embolization for cerebral AVM has favorable results In Vietnam, management of cerebral AVM in general and especially high grade AVM has been carried out only in the medical centres specialized in radiology and neurosurgery Combination of embolization and microsurgery is a new multimodality method and in its first steps, encouraging results have been appearing However, beside several presentations in neurosurgical conferences, there is still no fundamental research about this method Therefore, this research is up to date, practical and very necessary for clinical treatment New contributions of the thesis First research in Vietnam about treatment of ruptured cerebral AVM with combination of embolization and One of recent studies in which indications, results and benifits of each step in the embolization-surgery combination is analyzed in detail Outline of the thesis The thesis consists 120 pages, including:: introduction (2 pages), overview (34 pages), object and medod of research (16 pages), results (33 pages), discussion (33 pages) and conclusions (2 pages) There are 52 tables, charts and 32 figures in the thesis Bibliography includes 109 references in Vietnamese and English Chapter OVERVIEW 1.1 Pathology of cerebral arteriovenous malformation 1.1.1 Anatomical pathology of cerebral arteriovenous malformations treated with combination of embolization and microsurgery - Nidus: Location where feeding arteries connect directly to draining veins without interposition of a normal capillary bed - Feeding arteries include types:: Terminal, Transit, Bystander, perforator, Choroidal Figure 1.1 Feeding arteries Terminal, Transit, Bystander, Perforator, Choroidal - Draining veins: defined as the vascular structure which carries blood from nidus to principal venous systems or sinus Draining veins can merge in superficial or deep venous systems 1.1.2 Pathophysiology of cerebral arteriovenous malformations: AVM is a vascular abnormal in which there is a direct connection between arteries and veins This direct connection leads to consequences to surrounding cerebral tissue and even in remote regions Appearance of AVM is the cause of phenomenons: Arterio-venous direct flow, "blood stealing" and intravenous hypertension Cerebral blood circulation in arteriovenous malformations includes : macro-circulation (arteries and veins) micro -circulation (microarteries, capillary and microveins) Pathophysiology of cerebral blood perfusion includes mechanisms: neurological, metabolical and activites of vascular mural muscles 1.2 Diagnosis of cerebral arteriovenous malformations 1.2.1 Clinical characteristics Haemorrhage is the most frequent clinical signs of common cerebral AVM Clinical features change depending on location and size of hematoma and the existance of intraventricular haemorrhage 1.2.2 Radiology - Imaging techniques: CT scan, multi-slide CT scan, DSA - Diagnosis of location amd severity of haemorrhage: According to Spetzler, intraparenchymal hematoma's proportion is approximately 65,2% High grade AVM usually have complex location, not limited in one cerebral lobe - Grading of ruptured cerebral arteriovenous malformations: + For evaluating risks of haemorrhage::In 1996, Pollock proposed a grading system include risk factors of bleeding: history of bleeding, unique draining vein and diffuse nidus + For evaluating AVM surgical prognosis: The most well-known and practical grading created by Spetzler-Martin including grades (from I to V) Table 1.1 Spetzler-Martin grading Features a S1 E0 V0 S1 E0 V1 II A S1 E1 V0 S2 E0 V0 S1 E1 V1 (III-)b S2 E0 V1 (III)b III B S2 E1 V0 (III+)b S3 E0 V0 (III*)b S2 E1 V1 IV B S3 E0 V0 S3 E1 V0 V C S3 E1 V1 Note: - a S: Size (S16cm), E: Eloquent eloquent), V: Draining vein (V1 deep, V0 superficial) - b Sub-grading for grade III of Lawton Grade I Group A Treatment Surgery Surgery Combination Conbination Conservation brain (E1 Eloquent, E0 Non + For evaluating prognosis of radiosurgery: First grading system for evaluation of risk factors and results of radiosurgery belonged to Inoue in1995, based on AVM's size and hemodynamic features Pollock Flickinger (2002) proposed a grading system based on AVM's volume, age, location, history of previous embolization and amount of draining veins + For evaluating prognosis of embolisation: Grading system of Vinueala in 1995 based on nidus size, amount of feeding arteries, existance of feeding arteries originated from choroidal plexus, perforating arteries Feliciano (2010) proposed a similar grading to Spetzler-Martin to evaluate prognosis of embolization - Asocciated aneurysms:Phình động mạch não phối hợp: Acompanying neurysms divided into types (Fig 1.2) Hình 1.2 Aneurysm associated with cerebral AVM A) proximal feeding artery , (B) distal feeding artery, (C) intranidal, (D) within circle of Willis , (E) No relation with AVM [6] 1.2.3 Classification of cerebral arteriovenous malfomations 1.2.3.1 Anatomical classification: Lawton (2014) proposed a classification based on anatomical locations Table 1.2 Anatomical classification Type Frontal Temporal Parieto-occipital Ventricular-Periventricular Deep location Brain stem location Subtype Lateral Medial Paramedial Basal Sylvian Lateral Basal Sylvian Medial Lateral Medial Paramedial Basal Callosal Ventricular body Atrial Temporal horn Pure sylvian Insular Basal ganglial Thalamus Anterior midbrain Cerebellar Complex location Posterior midbrain Anterior pontine Lateral pontine Anterior medullary Lateral medullary Suboccipital Tentorial Vermian Tonsilar Petrosal More than location above 1.2.3.2 Particularly clinical variations: Prenancy, AVM rupture in children, familial history of AVM rupture 1.3 Treatment of ruptured cerebral arteriovenous malformation with combination of embolization and microsurgery 1.3.1 Indications Pre-op embolization is indicated with purposes: Reduction of AVM's size and blood flow, Occlusion of feeding arteries diffical to approach during dissection, Creation of clear border of nidus in order to symplicify AVM resection Therefore, embo-surgery combination indicated for ruptured high grade AVM (Grade Spetzler-Martin III, IV) 1.3.2 Process of combined embolization-microsurgery for ruptured cerebral arteriovenous malformation: The process of combined embolization-microsurgery for ruptured cerebral arteriovenous malformation varies, depending on clinical features and evolution of each patient 1.3.3 Pre-op embolization 1.3.3.1 Embolization timing after bleeding: There is no fixed time for embolization after the bleeding moment 1.3.3.2 Amount of preop embolizations: Embolization can be carried out in one or more than one times, depending on AVM's size and diffusal characteristic If the target is purely the feeding arteries, this can be fullfilled in an unique embolization 1.3.3.3 Embolization's materials for cerebral arteriovenous malfomations : N-Butyl cyanoacrylate, Onyx PHIL 1.3.3.4 Benefits of pre-op embolizations: Pre-op embolization aims to reduce surgery's time, intraoperative haemorrhage, post-op morbility and improve the surgical results 1.3.3.5 Complications of embolization: Complications during intervention caused by intra-interventive accidents, medical allergy or renal toxidity, including haemorrhage and ischemia, which lead to permanent or temporary neurological deficits Post-embolization complications consist of technical reasons and hemodynamic changes 1.3.4 Microsurgery following embolization 1.3.4.1 Surgical timing: It is considered that the ideal timing is between to weeks This period is adequate for post-embolization formation of intranidal thrombosis 1.3.4.2 Microsurgical principles: General principle is excluding all feeding arteries and draining veins at the end During resection, damaging the draining veins must be absolutely avoided 1.3.4.3 Limits of microsurgery: If the nidus locates mostly or totally within the eloquent brain, there will be high risk of post-operative neurological deficits Pre-op radiological embolization or radio-surgery may reduce the surgical complications 1.4 Surgical techniques for cerebral arteriovenous malformations 1.4.1 Exposure 1.4.1.1 "The box” principles 1.4.1.2 Surfaces: Surface exposure (free surfaces) is the first step of the AVM resection 1.4.1.3 Craniotomy: Craniotomy should be large enough for the exposure of the free surfaces of AVM 1.4.1.4 Angle of attack: Is an term that describes the axis that run through the center of the box There are two kind of angle of attack: parallel and perpendicular 1.7 Other methods of management for high grade cerebral arteriovenous malformation: Beside embolization-microsurgery combination, there are other multimodality method - Combination of embolization and radiosurgery - Combination of radiosurgery and microsurgery - Combination of all methods Chapter OBJECTS AND METHODS OF RESEARCH 2.1 Objects 2.1.1 Criteria for selection of patients: - Spetzler-Martin III or IV - Patients underwent embolization(s) following by microsurgery - Anatomical pathology tests confirm the lesion is AVM - Patients and their relatives agree to participate in this research - Patients have post-op follow-up 2.1.2 Criteria for elimination of patients: - Spetzler-Martin I, II, V - Intracranial haemorrhage caused by other pathologies - Patients underwent radiosurgery Patients with GCS ≤ - Patients suffering from other diseases that altered results of treatment: Renal failure, consumption of anticoagulants - Patients over age of 75 - Patients having any other reason affecting the follw-ups or refusing to continue their participation in this research 2.2 Method of research: Cross-sectional, clinical-intervention nonrandomized study 2.3 Sample size: Calculated with formula below n = Z2 (1- α/2) x p x (1- p) (p.ε)2 2.4 Steps of research conduction: - Diagnosis of rupture cerebral arteriovenous malformation - Treatment planning Processing each steps of treatment Evaluation of post-embolization complications Intra-op description of embolized AVM Evaluation of post-operative complications Summarization, data analyzation, thesis composing 2.5 Research protocols 2.6 Variables of research: 2.6.1 Patient demographics - Tần suất biểu theo tuổi: 40 - Giới: Tỷ lệ nam/nữ 2.6.2 Khám lâm sàng lúc vào viện: - Chief complaints: Symtoms of intracranial hypertension - Duration between onset and time of admission - Conscious evaluation: Alert (13-15), Stupor (9-12), Coma (3-8) - Signs of intracranial hypertension - Meningeal irritation - Focal neurological deficits 2.6.3 Radiological features: 2.6.3.1 Haemorrhagic charateristics - Type of haemorrhage - Size and location of intraparenchymal hematoma - Graebs score for intraventricular haemorrhage 2.6.3.2 Characteristics of cerebral arteriovenous malformation - Feeding arteries - Size of nidus - Draining veins - Associated arterial aneurysms - Eloquent brain area - Compact and diffuse AVM 2.6.4 Variables of embolization - Duration between onset and first embolization - Number of embolizations - Occlusion percentage: :