Advanced Techniques in Canine and Feline Neurosurgery

List of Contributors xvii ACVS Foreword xix ACVIM Foreword xxi Preface xxiii About the Companion Website xxv 1 A History of Veterinary Neurosurgery: 1900–2000 1 Don Sorjonen Introduction 1 Advances in Imaging Techniques 1 Advances in Spinal Procedures 2 Thoracolumbar (T1–S1) 2 Cervical (C1–C7) 5 Advances in Intracranial Procedures 8 Epilogue 11 References 12 2 Applications of 3D Printing in Veterinary Neurosurgery 17 Fred Wininger Steps of the 3D Printing Process 18 Acquisition 18 Thresholding 18 Segmentation 18 File Format Creation 19 Manifold Manipulation 19 Anatomic Modeling 19 Printing 20 Current Spinal Applications 20 Customized Tools 20 Current Brain Applications 21 Future Applications of 3D Printing in Veterinary Neurosurgery 23 References 23 3 Postoperative Radiation Therapy of Intracranial Tumors 25 M. W. Nolan Introduction 25 Overview of Radiation Therapy 25 Radiobiology 25 DNA as The Target for Radiation 25 Normal Tissue Injury 26 Rationale for Radiation Fractionation 26 Radiation Physics and Treatment Planning 28 Beam Energy Selection 28 Dose Calculations 28 Target Localization Strategies 29 Delivery Systems 31 Plan Evaluation 32 Specific Tumor Types 33 Meningioma 33 Clinical Data 33 Radiotherapeutic Techniques 34 Glial Tumors 34 Clinical Data 34 Radiotherapeutic Techniques 35 Choroid Plexus Tumors 35 Clinical Data 35 Radiotherapeutic Techniques 35 Spinal Tumors 35 Clinical Data 35 Radiotherapeutic Techniques 36 Stereotactic Radiosurgery and Stereotactic Radiation Therapy 36 References 37 4 Practice and Principles of Neuroanesthesia for Imaging and Neurosurgery 39 Claudio C. Natalini Introduction 39 Increases in ICP 39 Clinical Signs 39 Dynamics 39 Cerebral Perfusion and Anesthesia 40 The Cushing Reflex and Anesthesia 40 Increases in ICP During Anesthesia 41 ICP and Contrast Myelography 42 Hydrocephalus 42 Neurologic Monitoring: Monitoring Brain State During Anesthesia 42 Modalities of Neurologic Monitoring 42 Electroencephalogram EEG 42 Sensory-Evoked Responses (SERs) and Somatosensory-Evoked Potentials (SSEPs) 42 Glycemic Control 42 Monitoring Nociception 42 Other Modalities 43 Sedation versus General Anesthesia for Imaging 43 Regional Anesthesia for Laminectomy, Hemilaminectomy, and Vertebral Fractures 43 Anesthesia Protocol for Intracranial Surgery 43 References 44 Part I Spinal Procedures 45 5 Cervical Ventral Slot Decompression 47 Andy Shores and Allison Mooney Cervical IVD Syndrome 47 History 47 Clinical Signs 47 Radiographic Signs 48 Advanced Imaging 49 Indications for Surgery 50 Ventral Approach to the Cervical Spine 50 Decompression of the Cervical Spinal Cord 54 Ventral Slot Method 54 Perioperative and Postoperative Care 58 References 58 6 Thoracolumbar Decompression: Hemilaminectomy and Mini-Hemilaminectomy (Pediculectomy) 59 Brigitte A. Brisson Indications 59 Procedures 59 Technique: Surgical Approach for Mini-Hemilaminectomy (Video 6.1) 60 Dorsolateral Approach [14–17] (Video 6.2) 60 Variation 61 Recommended Variation 61 Technique: Mini-Hemilaminectomy Procedure 63 Technique: Surgical Approach for Hemilaminectomy 64 Technique: Hemilaminectomy Procedure 65 Removal of Disk Material: Mini-Hemilaminectomy and Hemilaminectomy 66 Closure 67 Complications 67 Postoperative Care 68 References 68 7 Thoracolumbar Disk Fenestration 70 Brigitte A. Brisson Indications 70 Technique – Surgical Approach 71 Variations 72 Technique – Fenestration Procedure (Video 7.1) 72 Blade Fenestration 73 Power Fenestration 73 Other Requirements 75 Closure 75 Complications 75 Postoperative Care 76 References 76 8 Percutaneous Laser Disk Ablation 78 Danielle Dugat Introduction 78 Laser Ablation 78 Candidate Selection 79 Procedure Description 80 Procedure Complications and Recurrence 82 Diagnostic Evaluation of PLDA 83 Conclusion 84 References 84 9 The Cranial Thoracic Spine: Approach via Dorsolateral Hemilaminectomy 86 Yael Merbl and Annie Vivian Chen-Allen Indications 86 Surgical Anatomy 87 Patient Positioning 87 Surgical Technique 88 Postoperative Care 89 References 90 10 Principles in Surgical Management of Locked Cervical Facets in Dogs 91 Andy Shores and Ryan Gibson Introduction 91 Unilateral Locked Cervical Facets in Humans 91 Clinical Presentation 91 Surgical Techniques 92 Postoperative Care 94 Summary/Conclusions 94 References 95 11 Spinal Stabilization: Cervical Vertebral Column 96 Bianca F. Hettlich Introduction 96 Preoperative Planning 96 Anatomical Considerations 96 Implant Selection 97 Positioning and Approach 97 Vertebral Distraction 98 Diskectomy 99 Intervertebral Spacer 99 Indication for Additional Decompression 101 Surgical Stabilization 101 Monocortical Screw/PMMA Fixation 101 Vertebral Body Plates 102 Other Techniques 104 Stabilization of Multiple Spaces 105 Postoperative Assessment 105 Complications 106 References 107 12 Stabilization of the Thoracolumbar Spine 109 Simon T. Kornberg and Brigitte A. Brisson Preoperative Planning 109 Decompression with Stabilization 111 Technique 111 Implant Selection 111 Thoracolumbar Spine 114 Positioning and Approach 114 Implant Selection 114 Spinal Stapling/Segmental Fixation 116 Lumbosacral Spine 118 Anatomy 118 Positioning and Approach 118 Reduction 119 Implant Selection 119 Postoperative Imaging 120 Complications 120 Aftercare 122 Acknowledgments 122 References 122 13 Surgical Management of Congenital Spinal Anomalies 124 Sheila Carrera-Justiz and Gabriel Garcia Diagnostics 124 Treatment 125 Prognosis 126 Future Directions 127 Summary 127 References 127 14 Lumbosacral Decompression and Foraminotomy Techniques 129 Stef H. Y. Lim and Michaela Beasley Pathophysiology and Anatomy 129 L7–S1 Foramina Anatomy 129 Diagnosis 130 History and Clinical Signs 130 Physical Examination Findings 130 Orthopedic Examination Findings 130 Neurologic Examination Findings 131 Radiography 131 Myelography (Contrast Study) 132 Computed Tomography (CT) 132 Magnetic Resonance Imaging (MRI) 133 Force Plate Analysis 134 Electrodiagnostics 134 Treatment: Conservative and Medical Therapy 134 Surgery 134 Dorsal Laminectomy 135 Patient Preparation and Positioning 135 Surgical Technique 135 Foraminotomy 136 Facetectomy 137 Distraction, Fusion, and Stabilization 137 Pins and PMMA 137 SOP Plating 137 Surgical Technique 138 Pedicle Screw and Rod Fixation (PSRF) 138 Minimally-Invasive Transilial Vertebral (MTV) Blocking 138 Postoperative Management 139 References 139 15 Surgical Management of Spinal Nerve Root Tumors 143 Ane Uriarte Introduction 143 Clinical Presentations 143 Meningioma 143 Peripheral Nerve Sheath Tumors 143 Diagnosis 144 Imaging 144 Spinal Meningioma MRI 144 PNST MRI 144 Electrodiagnostics 147 Cytology/Histology 147 Meningiomas 147 PNST 147 Surgery of PNST Within the Spinal Nerves 148 Cervical Approach 148 Positioning 148 Lateral Surgical Approach to Caudal Cervical Foramen After Amputation 148 Dorsal Surgical Approach for Cervical Hemilaminectomy 149 Respiratory Compromise in Cervical Myelopathies 149 Lumbar Approach 150 Approach to the L7–S1 Foramen 150 Postoperative Care 150 Prognosis 151 Radiation Therapy 151 References 151 16 Surgical Management of Craniocervical Junction Anomalies 153 Sofia Cerda-Gonzalez Indications 153 Surgical Anatomy 154 Patient Preparation and Positioning 155 Surgical Technique 156 Outcomes 159 References 159 17 Ventral Approach to the Cervicothoracic Spine 161 Isidro Mateo Introduction 161 Surgical Anatomy [10–12] 161 Muscles 161 Vessels 163 Nerves 163 Viscera 163 Surgical Technique [10, 12] 163 Clinical Results 165 Conclusion 167 References 167 Part II Intracranial Procedures 169 18 Intraoperative Ultrasound in Intracranial Surgery 171 Alison M. Lee, Chris Tollefson and Andy Shores Introduction 171 Artifacts in Imaging 172 Accuracy of Intraoperative Ultrasound 173 Scanning Procedure and Equipment 173 Appearance of Tumor on Ultrasound 175 Ultrasound Guided Procedures 177 Conclusion 177 References 177 19 Brain Biopsy Techniques 179 John Rossmeisl and Annie Chen Introduction 179 Indications and Contraindications 179 Frame-based Stereotactic Brain Biopsy (SBBfb) 179 SBBfb Technique 181 Preoperative Evaluation 181 Headframe Placement and Acquisition of Stereotactic Images 181 SBBfb Planning 181 SBBfb Procedure 183 Postoperative Care and Adverse Events 184 Processing of Brain Biopsy Specimens 184 Frameless Stereotactic Brain Biopsy (SBBfl) 185 SBBfl Technique 185 Attachment of the Fiducial Markers 185 Acquisition of Magnetic Resonance Images 186 Registration Procedure 186 Trajectory Planning 187 Brain Biopsy 187 Biopsy Sample Processing 187 Conclusion 187 References 188 20 Surgical Management of Sellar Masses 190 Tina Owen, Annie Chen-Allen and Linda Martin Introduction 190 Case Selection 191 Preoperative Work up 192 Neurologic Exam 192 Preoperative Testing and Diagnostics 193 Endocrine Testing 193 Brain Imaging 193 Imaging of Pituitary Masses 194 Imaging of Non-Pituitary Sellar Masses 195 Surgery 196 Anatomy 196 Localization 196 Positioning 197 Approach 197 Surgical Outcome 198 In Hospital Care 200 Postoperative Management and Monitoring 200 Postoperative Complications 200 Endocrine and Metabolic Complications 200 Respiratory Complications 203 Neurologic Complications 204 Procedural Related Complications 204 Long term Follow Up 205 References 206 21 Surgical Management and Intraoperative Strategies for Tumors of the Skull 211 Jonathan F. McAnulty Osteosarcoma and Multilobular Osteochrondrosarcoma of the Cranium 211 Diagnosis and Characterization 212 Surgical Planning and Treatment 212 Exposure 212 Challenges in Skull Tumor Resection 214 Parietal Calvarial and Dorsal Frontal Bone Lesions 214 Frontal Bone within the Orbit and Sphenoid Bone Lesions 215 Occipital Bone Lesions 215 MRI Assessment of Blood Flow to the Transverse Sinuses 216 Slow Occlusion of Flow from the DSS to the Transverse Sinus Using a Balloon Catheter 217 Extension of Tumor to the tentorium Cerebelli 218 Zygomatic Arch and Ramus of the Mandible 218 Complications and Risks 219 Cranioplasty 220 References 221 22 Surgical Management of Intracranial Meningiomas 223 R. Timothy Bentley Introduction 223 Anatomy 223 Transfrontal Craniotomy (Bilateral Transfrontal Craniotomy) 225 Technique 225 Closure 227 Modifications 228 The Falx Cerebri and the Dorsal Sagittal Sinus (DSS) 229 Rostrotentorial Craniectomy/Craniotomy (Lateral Craniectomy/Craniotomy) 231 Technique 232 Closure: Craniectomy vs Craniotomy 233 Combined Rostrotentorial–Transfrontal Approach 234 Suboccipital Craniectomy (See Also Chapter 24 Surgery of Caudal Fossa Tumors) 235 Technique 235 Closure 236 Meningioma Resection and Instrumentation 236 Simpson Classification of Meningioma Resection in Humans (Table 22.2) 237 Substitutes for Resected Dura Mater 237 Complications and Mitigation Strategies 239 References 239 23 Lateral Ventricular Fenestration 241 Andy Shores Introduction 241 Rationale 241 Technique 242 Potential Complications 243 Discussion 243 References 248 24 Surgery of the Caudal Fossa 249 Beverly K. Sturges Anatomy 249 Indications for Surgery 250 Preoperative Assessment and Anesthetic Management 251 Surgical Positioning 251 Surgical Approach(es) to the Caudal Fossa 252 Midline Occipital Approach [3–5] 252 Extended Lateral Approach with Occlusion of The Transverse Sinus [3, 6] 255 Lateral Approach to The Cerebellum in Cats [8] 258 Closing and Reconstruction 258 Postoperative Care 259 Complications 260 References 261 25 Transzygomatic Approach to Ventrolateral Craniotomy/Craniectomy 262 Martin Young and Sandy Chen Introduction 262 Patient Positioning/Preparation 262 Surgical Procedure 263 References 266 Index 269