1 Embryological and Anatomical Introduction.... 1 1.1 Preliminary Remarks.................... 1 1.2 Leptomeninges....................... 21 1.3 Subpial Space........................ 22 1.3.1 Anatomy........................... 22 1.3.2 Relationships of the Subpial Space............ 23 1.3.3 Pathology.......................... 23 1.3.3.1 Inflammation........................ 23 1.3.3.2 Tumors............................ 24 2 Introduction and General Comments Regarding Pediatric Intracranial Arteriovenous Shunts.... 27 2.1 Introduction......................... 28 2.2 From Adults to Children.................. 28 2.3 Vascular Lesion Types and Disease Groups........ 31 2.3.1 Nonproliferative Lesions.................. 34 2.3.1.1 Arteriovenous Lesions................... 34 2.3.1.2 Isolated Brain AVMs.................... 35 2.3.1.3 Cerebral Arteriovenous Fistulas.............. 39 2.3.1.4 Vein of Galen Aneurysmal Malformations........ 39 2.3.1.5 Cerebrofacial Arteriovenous Metameric Syndromes... 39 2.3.1.6 Dural Lesions........................ 41 2.3.1.7 Telangiectasias....................... 41 2.3.1.8 The Blue Rubber-Bleb Nevus or Bean Syndrome..... 41 2.3.1.9 Venous Malformations (Cavernomas).......... 44 2.3.1.10 Venous Angiomas or Developmental Venous Anomalies 45 2.3.1.11 Cerebrofacial Venous Metameric Syndrome (Sturge-Weber Syndrome)................. 47 2.3.1.12 Induced Pial Shunts..................... 47 2.3.1.13 Spinal Cord AVM...................... 48 2.3.1.14 General Conclusions on Vascular Lesions......... 48 2.3.2 Proliferative Lesions.................... 49 2.3.2.1 PHACE or PHACES..................... 51 2.3.2.2 Diffuse Angiodysplasia................... 51
XII 2.4 Classification of CAVMs by Age Group.......... 56 2.4.1 Fetal Age........................... 56 2.4.2 Neonatal Age........................ 59 2.4.3 Infancy............................ 59 2.4.4 After 2 Years......................... 62 2.5 Classification by Symptom Group............. 63 2.5.1 Congestive Cardiac Manifestations............ 63 2.5.2 Hydrodynamic Disorders................. 64 2.5.3 Melting-Brain Syndrome.................. 73 2.6 Clinical Evaluation Scores................. 77 2.7 Revised Concept of the Congenital Nature of Vascular Malformations................. 85 2.7.1 Genetics........................... 85 2.7.1.1 Familial Hemiplegic Migraine............... 85 2.7.1.2 Familial Cerebral Aneurysms............... 86 2.7.1.3 PKD1 and Bourneville PDK1-PDK2............ 86 2.7.1.4 Ehlers-Danlos Type IV................... 87 2.7.1.5 Multiple Cutaneous Mucous Venous Malformations, Blue Rubber Bleb Nevus Syndrome............ 87 2.7.1.6 CADASIL........................... 87 2.7.1.7 Familial Paragangliomas.................. 87 2.7.1.8 Familial Cavernomas.................... 87 2.7.1.9 Neurofibromatosis-1 and Other Collagen Diseases... 88 2.7.1.10 Hemorrhagic Hereditary Telangiectasia or Rendu-Osler-Weber Disease.............. 88 2.8 Vascular Remodeling and the Congenital Nature of Arteriovenous Shunts.................. 93 2.8.1 Endothelium as a Sensor and Transducer of Signals... 94 2.8.2 Endothelium-Specific Receptor-Coupled Event..... 95 2.8.3 Endothelium and Mediator-Effector Molecules Involved with Remodeling...................... 95 2.8.4 Role of Matrix Modulators in Vascular Remodeling... 95 2.8.5 Clinical Implications of Vascular Remodeling...... 95 3 Vein of Galen Aneurysmal Malformation...... 105 3.1 Introduction......................... 106 3.2 Historical Landmarks................... 107 3.2.1 Lesions............................ 107 3.2.2 Clinical Aspects....................... 107 3.3 Modern Concept of Vein of Galen Aneurysmal Malformation........... 109 3.4 Vein of Galen Aneurysmal Dilatation........... 112 3.5 Dural Arteriovenous Shunts with Aneurysmal Dilatation of the Vein of Galen.... 117 3.6 Vein of Galen Varix..................... 117
XIII 3.7 Vein of Galen Aneurysmal Malformation......... 117 3.8 Natural History of Vein of Galen Aneurysmal Malformation........... 141 3.9 Cardiac Manifestations................... 143 3.10 Macrocrania and Hydrocephalus............. 152 3.11 Late Natural History of Vein of Galen Aneurysmal Malformation with Patent Sinuses 162 3.12 Dural Sinus Occlusion and Supratentorial Pial Congestion and Reflux..... 167 3.13 Dural Sinus Thrombosis and Infratentorial Pial Reflux. 180 3.13.1 Spontaneous Thrombosis................. 184 3.14 Objectives and Methods of Treatment........... 191 3.14.1 General Remarks...................... 191 3.14.2 Neonates........................... 191 3.14.2.1 Reducing Oxygen Consumption.............. 197 3.14.2.2 Improving Oxygen Delivery................ 197 3.14.3 Infants and Children.................... 200 3.15 Technical Management................... 203 3.15.1 General Remarks...................... 203 3.15.2 Follow-Up.......................... 205 3.15.3 Complications: Morbidity................. 210 3.15.4 Overall Mortality...................... 220 3.15.5 Neurological Outcome by Age Group........... 221 3.16 Other Techniques...................... 221 3.16.1 Surgery............................ 221 3.16.2 Transvenous Treatment................... 223 3.16.3 Radiosurgery........................ 224 4 Cerebral Arteriovenous Fistulas............ 227 4.1 Definitions and Anatomic Spaces............. 227 4.2 Angioarchitecture...................... 228 4.2.1 Single CAVFs........................ 228 4.2.2 Multiple CAVFs....................... 231 4.3 Associated Conditions................... 236 4.3.1 Hereditary Hemorrhagic Telangiectasia......... 236 4.3.2 Encephalocraniocutaneous Lipomatosis......... 246 4.4 Presentation......................... 249 4.4.1 Natural History....................... 265 4.5 Management........................ 270
XIV 5 Cerebral Arteriovenous Malformations....... 291 5.1 General Remarks...................... 292 5.2 Angioarchitecture of Cerebral Arteriovenous Malformations............... 298 5.2.1 Single Nidus Versus Multifocal Niduses.......... 298 5.3 Conditions Associated with CAVMs............ 302 5.4 Conditions Mimicking CAVMs............... 306 5.4.1 False Pial Arteriovenous Malformations......... 306 5.4.2 Perinidal Angiogenesis................... 306 5.4.3 Postischemic Luxury Perfusion.............. 306 5.4.4 Proliferative Angiopathy.................. 306 5.4.5 Induced Pial AV Shunts Secondary to Dural Sinus High-Flow Lesions............. 309 5.5 Angioarchitectural Progression of CAVMs in Children. 311 5.5.1 Venous Angiopathy..................... 311 5.5.2 Dural Sinus High Flow................... 312 5.5.3 Venous Ischemia and Thrombosis............ 315 5.5.4 Venous Hemorrhage.................... 316 5.5.5 Venous Enlargement.................... 321 5.5.6 Arterial Angiopathy..................... 324 5.5.7 Spontaneous Thrombosis of Arteriovenous Malformations............. 330 5.6 Objectives of Treatment.................. 330 5.6.1 Complete Exclusion..................... 330 5.6.2 Partial Treatment...................... 336 5.6.3 Neonates and Infants.................... 340 5.6.3.1 Hydrodynamic Disorders................. 341 5.6.3.2 Multiple Arteriovenous Malformations.......... 342 5.6.4 Children........................... 342 5.6.5 Rebleeding.......................... 344 5.7 Technical Management................... 345 5.7.1 General Remarks...................... 345 5.7.2 Other Techniques...................... 345 5.7.2.1 Surgery............................ 345 5.7.2.2 Radiation Therapy..................... 352 6 Cerebrofacial Arteriovenous Metameric Syndrome 359 6.1 Introduction......................... 359 6.2 Clinical Manifestations................... 374 6.2.1 Retinal AVMs and AVMs Along the Optic Nerve and Chiasm......................... 374 6.2.1.1 Retinal AVMs........................ 374 6.2.1.2 Optic Nerve and Chiasmatic AVMs............ 376
XV 6.2.2 Cerebral AVMs....................... 376 6.2.3 Facial AVMs, Nasal AVMs, and Mandibular AVMs.... 382 6.2.4 Investigation for CAMS Patients.............. 384 6.3 CAMS and Angiogenic Activity.............. 384 7 Dural Arteriovenous Shunts.............. 389 7.1 Introduction......................... 389 7.2 Classification........................ 390 7.2.1 Age Groups......................... 392 7.2.2 Disease Groups....................... 392 7.3 Dural Sinus Malformations................ 396 7.3.1 DSM with Giant Pouches.................. 398 7.3.1.1 Fetal and Postnatal Changes of Sinuses.......... 398 7.3.2 DSM of the Jugular Bulb.................. 434 7.4 Infantile Dural Arteriovenous Shunts (AVS)....... 436 7.5 Adult Type of Dural Arteriovenous Shunts in Children. 444 7.6 Other Dural Shunts..................... 447 7.6.1 Vein of Galen Aneurysmal Malformation......... 447 7.6.2 Dural Supply to Pial Cerebral Arteriovenous Malformations....................... 447 7.6.3 Proliferative Angiopathic Disease............. 448 7.6.4 Systemic Disorders..................... 448 7.6.5 Recurrence in Intradural AVS and Secondary Transdural Supply............. 449 7.7 General Remarks on Treatment.............. 451 8 Venous Anomalies and Malformations........ 455 8.1 Developmental Venous Anomalies............. 455 8.1.1 Single Abnormalities.................... 455 8.1.2 Associated Features..................... 459 8.1.3 Associated Cavernomas.................. 473 8.2 Segmental and Nonsegmental Cerebro-orbito-facial Venous Lesions........... 478 8.2.1 Sturge-Weber Syndrome.................. 478 8.2.2 From SWS to Cerebrofacial Venous Metameric Syndrome............... 485 8.2.3 Orbitofacial Venous Lesions................ 496 8.3 Complex Pseudo-metameric Cerebrofacial Venous Syndrome...................... 499 8.4 Blue Rubber Bleb Nevus (Bean Syndrome)........ 503 8.4.1 The Association of BRBN with DVA............ 504 8.4.2 Cerebral Venous Malformations in BRBN........ 507 8.4.3 BRBN and HHT1...................... 507
XVI 9 Craniopagus and Cranial Midline Epidural Venous Anomalies............... 509 9.1 Introduction......................... 509 9.2 Postulated Relationships Between the Superior Sagittal Sinus and Adjacent Structures... 511 9.3 Ladan and Laleh s Angiographic Anatomy........ 521 9.4 Technical Remarks and Functional Testing........ 531 9.5 Discussion on Surgical Management........... 534 10 Cerebral Venous Thrombosis.............. 537 10.1 Introduction......................... 537 10.2 Pathophysiology and Risk Factors............. 539 10.3 Imaging........................... 545 10.4 Symptoms.......................... 547 10.5 Treatment.......................... 556 10.6 Outcome........................... 557 11 Hemangiomas....................... 559 11.1 Introduction......................... 560 11.2 Pathogenesis......................... 562 11.3 Histological Findings.................... 563 11.4 Clinical Presentation of Hemangiomas.......... 564 11.5 Diagnosis.......................... 570 11.6 Complications in Hemangiomas............. 574 11.7 Management of Hemangiomas.............. 577 11.8 Pharmacological Therapy of Hemangiomas....... 578 11.8.1 Corticosteroids....................... 578 11.8.2 Interferon-Alpha 2a..................... 579 11.8.3 Vincristine.......................... 579 11.8.4 Aminocaproic Acid..................... 579 11.8.5 Other Treatments...................... 579 11.9 Laser Treatment of Hemangiomas............ 580 11.10 Endovascular Treatment of Hemangiomas........ 580 11.10.1 Arterial Embolization................... 580 11.10.2 Intralesional Embolization................. 582 11.11 Noninvoluting Capillary Hemangiomas......... 585 11.12 Subglottic Hemangiomas.................. 588 11.13 Periorbital Hemangiomas................. 590
XVII 11.14 Oral Hemangiomas..................... 592 11.15 Salivary Gland Hemangioma............... 592 11.16 Bone Hemangiomas.................... 595 11.17 Associated Anomalies.................... 598 11.18 Psychological Impact.................... 598 11.19 Kaposiform Hemangioendothelioma and Consumption Coagulopathy, the Kasabach-Merritt Syndrome Phenomena...... 602 12 PHACES........................... 607 12.1 Introduction......................... 607 12.2 Clinical Aspects....................... 609 12.2.1 Posterior Fossa Abnormalities............... 611 12.2.2 Hemangiomas........................ 618 12.2.3 Arterial Anomalies..................... 622 12.2.4 Coarctation and Congenital Heart Disease........ 623 12.2.5 Eye Abnormalities..................... 627 12.2.6 Sternal Cleft......................... 627 12.2.7 Stenotic Arterial Disease.................. 627 12.3 PHACES, a Congenital Malformation and a Proliferative Disease................. 631 13 Cervicofacial Vascular Malformations........ 633 13.1 Introduction......................... 634 13.2 Traditionally Postulated Embryogenesis......... 638 13.3 Diagnostic and Pretherapeutic Evaluation........ 640 13.4 Clinical Diagnosis of a Vascular Malformation..... 640 13.5 Arteriovenous Shunts.................... 641 13.5.1 Soft Tissue AVMs...................... 643 13.5.1.1 Intramuscular AVMs.................... 643 13.5.1.2 Cutaneous AVMs...................... 644 13.5.2 Intra-osseous AVMs.................... 646 13.5.2.1 Mandibular and Maxillary AVMs............. 646 13.5.2.2 Signs and Symptoms.................... 651 13.5.3 Metameric Cerebrofacial AVMs.............. 657 13.6 Intra-osseous Slow-Flow Malformations......... 659 13.7 Arteriolar-Capillary Malformations........... 659 13.8 Capillary Venous Malformations............. 659 13.9 Venous Vascular Malformations.............. 660
XVIII 13.10 Complex Cerebrofacial Venous Syndromes (CVMS or Sturge-Weber Syndrome)............ 670 13.11 Lymphatic Malformations................. 670 13.12 Mixed Vascular Malformations.............. 681 13.13 Multifocal AVMs....................... 681 13.14 False Maxillofacial Vascular Malformations....... 681 13.14.1 Idiopathic Facial Vascular (Venous) Dilatations..... 681 13.14.2 Facial Venous Dilatation Associated with Intracranial Vascular Lesions............. 685 14 Parachordal Arteriovenous Fistulas (Extracranial and Extraspinal Arteriovenous Fistulas)....... 687 14.1 Introduction......................... 687 14.2 Specific Clinical Features.................. 689 14.3 Topographic Approach................... 696 14.4 Branchial Arteriovenous Shunts.............. 696 14.4.1 Maxillary Artery/Vein Arteriovenous Fistulas...... 697 14.4.2 Ascending Pharyngeal-Internal Jugular Arteriovenous Fistulas................... 699 14.5 Vertebro-vertebral Arteriovenous Fistulas........ 700 14.6 Paraspinal Arteriovenous Fistulas............ 714 14.7 Technical Management of High-Flow Fistulas...... 719 15 Spinal Cord Arteriovenous Malformations..... 721 15.1 Introduction......................... 721 15.2 Classification........................ 722 15.3 Natural History and Clinical Aspects........... 737 15.4 Neonatal and Infants.................... 737 15.5 Children Over 2 Years of Age................ 743 15.6 Diagnosis.......................... 750 15.7 Angioarchitecture...................... 750 15.8 Treatment.......................... 758 15.8.1 Therapeutic Abstention.................. 758 15.8.2 Embolization........................ 759 15.8.3 Results............................ 761
XIX 16 Vascular Trauma and Epistaxis............. 767 16.1 Introduction......................... 767 16.2 Traumatic Carotid-Cavernous Fistulas.......... 768 16.3 Post-traumatic Sinus Thrombosis............. 776 16.4 Traumatic Dissections................... 777 16.5 Intracranial Arterial Aneurysms............. 779 16.6 Iatrogenic Injury...................... 780 16.7 Traumatic Insult of Vascular Malformation....... 783 16.8 Epistaxis........................... 785 16.9 Technical Remarks..................... 787 17 Intracranial Aneurysms in Children......... 789 17.1 Introduction......................... 789 17.2 Incidence........................... 793 17.3 Presentation......................... 795 17.4 Etiology........................... 797 17.5 Traumatic Aneurysms................... 798 17.6 Infectious Aneurysms.................... 803 17.7 Saccular Aneurysms.................... 813 17.8 Dissecting Aneurysms................... 823 17.9 Location........................... 835 17.10 Therapeutic Strategies................... 836 18 Arterial Ischemic Stroke................. 851 18.1 Introduction......................... 851 18.2 Epidemiology........................ 852 18.3 Pathophysiology....................... 852 18.4 Clinical Presentation.................... 853 18.5 Imaging of Arterial Stroke in Children.......... 856 18.6 Outcome and Prognosis.................. 860 18.7 Etiology........................... 866 18.8 Cardiac Disorders...................... 867 18.9 Acute Regressive Cerebral Arteriopathy......... 870 18.10 Dissections.......................... 878 18.11 Moyamoya Disease..................... 885
XX 18.12 Hematological Disorders and Coagulopathies...... 892 18.13 Metabolic Disorders.................... 893 18.14 Proliferative Angiopathy.................. 893 18.15 PHACE............................ 899 18.16 Hereditary Hemorrhagic Telangiectasia, or Rendu-Osler-Weber Disease............... 899 18.17 Spinal Cord Strokes..................... 899 18.18 Treatment and Management................ 905 19 References......................... 909 Subject Index....................... 967