Advanced Techniques in Canine and Feline Neurosurgery E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Sprache: Englisch
Advanced Techniques in Canine and Feline Neurosurgery An up-to-date discussion of the latest advanced neurosurgical techniques for dogs and cats In Advanced Techniques in Canine and Feline Neurosurgery, a team of distinguished veterinary practitioners delivers an authoritative and accessible compilation of current best practices for surgery of the spine, neck, and head in dogs and cats. The book focuses on advanced and cutting-edge techniques in the field, offering detailed and step-by-step descriptions of state-of-the-art procedures accompanied by video clips of most. The authors have developed a companion website that includes additional resources for the techniques described in the book, which provides coverage of percutaneous laser disk fenestration, spinal stabilization, and pituitary surgery. Each chapter presents a detailed description of an operative technique, indications, surgical anatomy, and related and detailed illustrations. Readers will also find: * A thorough introduction to the history of veterinary neurosurgery and applications of 3D printing in veterinary neurosurgery * In-depth treatments of post-operative radiation therapy of intracranial tumors * Comprehensive discussions of the more routine spinal procedures, including cervical ventral slot decompression * Explorations of intracranial procedures, including intraoperative ultrasound in intracranial surgery Perfect for veterinary surgeons and veterinary internal medicine specialists, Advanced Techniques in Canine and Feline Neurosurgery will also earn a place in the libraries of veterinary residents and interns.
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Veröffentlichungsjahr: 2023
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Table of Contents
Cover
Title Page
Copyright
Dedication
List of Contributors
ACVS Foreword
ACVIM Foreword
Preface
About the Companion Website
1 A History of Veterinary Neurosurgery: 1900–2000
Introduction
Advances in Imaging Techniques
Advances in Spinal Procedures
Advances in Intracranial Procedures
Epilogue
References
2 Applications of 3D Printing in Veterinary Neurosurgery
Steps of the 3D Printing Process
Current Spinal Applications
Customized Tools
Current Brain Applications
Future Applications of 3D Printing in Veterinary Neurosurgery
References
Note
3 Postoperative Radiation Therapy of Intracranial Tumors
Introduction
Overview of Radiation Therapy
Radiobiology
Radiation Physics and Treatment Planning
Specific Tumor Types
Stereotactic Radiosurgery and Stereotactic Radiation Therapy
References
4 Practice and Principles of Neuroanesthesia for Imaging and Neurosurgery
Introduction
Increases in ICP
Neurologic Monitoring: Monitoring Brain State During Anesthesia
Monitoring Nociception
Other Modalities
Sedation versus General Anesthesia for Imaging
References
Part 1: Spinal Procedures
5 Cervical Ventral Slot Decompression
Cervical IVD Syndrome
Indications for Surgery
Ventral Approach to the Cervical Spine
Decompression of the Cervical Spinal Cord
References
6 Thoracolumbar Decompression: Hemilaminectomy andMini‐Hemilaminectomy (Pediculectomy)
Indications
Procedures
Technique: Surgical Approach for Mini‐Hemilaminectomy (Video 6.1)
Technique: Mini‐Hemilaminectomy Procedure
Technique: Surgical Approach for Hemilaminectomy
Technique: Hemilaminectomy Procedure
Removal of Disk Material: Mini‐Hemilaminectomy and Hemilaminectomy
Closure
Complications
Postoperative Care
References
7 Thoracolumbar Disk Fenestration
Indications
Technique – Surgical Approach
Technique – Fenestration Procedure (Video 7.1)
Complications
Postoperative Care
References
8 Percutaneous Laser Disk Ablation
Introduction
Laser Ablation
Candidate Selection
Procedure Description
Procedure Complications and Recurrence
Diagnostic Evaluation of PLDA
Conclusion
References
9 The Cranial Thoracic Spine: Approach via Dorsolateral Hemilaminectomy
Indications
Surgical Anatomy
Patient Positioning
Surgical Technique
Postoperative Care
References
10 Principles in Surgical Management of Locked Cervical Facets in Dogs
Introduction
Unilateral Locked Cervical Facets in Humans
Clinical Presentation
Surgical Techniques
Postoperative Care
Summary/Conclusions
References
Note
11 Spinal Stabilization: Cervical Vertebral Column
Introduction
Preoperative Planning
Anatomical Considerations
Implant Selection
Positioning and Approach
Vertebral Distraction
Diskectomy
Intervertebral Spacer
Indication for Additional Decompression
Surgical Stabilization
Postoperative Assessment
Complications
References
12 Stabilization of the Thoracolumbar Spine
Preoperative Planning
Technique
Thoracolumbar Spine
Lumbosacral Spine
Postoperative Imaging
Complications
Aftercare
Acknowledgments
References
13 Surgical Management of Congenital Spinal Anomalies
Diagnostics
Treatment
Prognosis
Future Directions
Summary
References
14 Lumbosacral Decompression and Foraminotomy Techniques
Pathophysiology and Anatomy
Diagnosis
Treatment: Conservative and Medical Therapy
Surgery
Postoperative Management
References
15 Surgical Management of Spinal Nerve Root Tumors
Introduction
Clinical Presentations
Diagnosis
Imaging
Cytology/Histology
Surgery of PNST Within the Spinal Nerves
Cervical Approach
Lateral Surgical Approach to Caudal Cervical Foramen After Amputation
Dorsal Surgical Approach for Cervical Hemilaminectomy
Lumbar Approach
Approach to the L7–S1 Foramen
Postoperative Care
Prognosis
Radiation Therapy
References
Note
16 Surgical Management of Craniocervical Junction Anomalies
Indications
Surgical Anatomy
Patient Preparation and Positioning
Surgical Technique
Outcomes
References
Notes
17 Ventral Approach to the Cervicothoracic Spine
Introduction
Surgical Anatomy [10–12]
Surgical Technique [10, 12]
Clinical Results
Conclusion
References
Part 2: Intracranial Procedures
18 Intraoperative Ultrasound in Intracranial Surgery
Introduction
Artifacts in Imaging
Accuracy of Intraoperative Ultrasound
Scanning Procedure and Equipment
Appearance of Tumor on Ultrasound
Ultrasound Guided Procedures
Conclusion
References
19 Brain Biopsy Techniques
Introduction
Indications and Contraindications
Frame‐based Stereotactic Brain Biopsy (SBBfb)
SBBfb Technique
Frameless Stereotactic Brain Biopsy (SBBfl)
Conclusion
References
20 Surgical Management of Sellar Masses
Introduction
Case Selection
Preoperative Work up
Preoperative Testing and Diagnostics
Surgery
In Hospital Care
Postoperative Complications
Long term Follow Up
References
21 Surgical Management and Intraoperative Strategies for Tumors of the Skull
Osteosarcoma and Multilobular Osteochrondrosarcoma of the Cranium
Diagnosis and Characterization
Surgical Planning and Treatment
Complications and Risks
Cranioplasty
References
22 Surgical Management of Intracranial Meningiomas
Introduction
Anatomy
Transfrontal Craniotomy (Bilateral Transfrontal Craniotomy)
Rostrotentorial Craniectomy/Craniotomy (Lateral Craniectomy/Craniotomy)
Combined Rostrotentorial–Transfrontal Approach
Suboccipital Craniectomy (See Also Chapter 24 Surgery of Caudal Fossa Tumors)
Meningioma Resection and Instrumentation
Simpson Classification of Meningioma Resection in Humans (Table 22.2)
Substitutes for Resected Dura Mater
Complications and Mitigation Strategies
References
23 Lateral Ventricular Fenestration
Introduction
Rationale
Technique
Potential Complications
Discussion
References
Notes
24 Surgery of the Caudal Fossa
Anatomy
Indications for Surgery
Preoperative Assessment and Anesthetic Management
Surgical Positioning
Surgical Approach(es) to the Caudal Fossa
Closing and Reconstruction
Postoperative Care
Complications
References
25 Transzygomatic Approach to Ventrolateral Craniotomy/Craniectomy
Introduction
Patient Positioning/Preparation
Surgical Procedure
References
Index
End User License Agreement
List of Tables
Chapter 4
Table 4.1 Suggested craniotomy anesthesia drug protocol.
Chapter 8
Table 8.1 Criteria required for PLDA.
Chapter 12
Table 12.1 Suggested screw and pin sizes with corresponding drill bit size ...
Table 12.2 Recommended insertion angles and landmarks for spinal implants....
Chapter 15
Table 15.1 Classification of histologic subtypes of meningiomas in dogs.
Chapter 22
Table 22.1 Main approaches to the cranial vault for the extirpation of meni...
Table 22.2 Simpson classification of meningioma resection in humans [3,16–1...
List of Illustrations
Chapter 1
Figure 1.1 Dr James (1978) – Dr Greene was Dean of the Auburn University Col...
Figure 1.2 Dr Redding is pictured here in 1977 as a professor at the Auburn ...
Figure 1.3 Dr Hoerlein, shown here in a photo from 1977. In 1952, Dr Hoerlei...
Figure 1.4 Dr Steven F. Swaim, shown here in a 1985 photo as director of the...
Figure 1.5 Dr Eric developed the modified deep dorsal laminectomy in the dog...
Figure 1.6 Dr Charles (pictured here in 1984 at Auburn University) reported ...
Figure 1.7 Dr Dean (pictured here at Texas A&M University in 2016). Dr Gage ...
Figure 1.8 Dr John is considered the pioneer of canine intracranial surgery....
Chapter 2
Figure 2.1 Steps for creation of anatomic additive models. (a) CT acquisitio...
Figure 2.2 Steps for lumbosacral jig creation. (a) Trajectories are identifi...
Figure 2.3 A multilobular tumor of bone (blue arrow) shown in a 3D printed s...
Figure 2.4 Case example of a large skull osteoma in a two‐year‐old dog. (a) ...
Chapter 3
Figure 3.1 Graphical representation of radiation targets. This is a transver...
Figure 3.2 Three‐dimensional conformal radiotherapy (3DCRT; A1, A2) versus i...
Figure 3.3 On‐board imaging systems are commonly used to verify accurate pos...
Figure 3.4 Conventional C‐arm linear accelerator. The head of the linear acc...
Figure 3.5 The Cyberknife
®
is a small 6 MV linear accelerator mounted o...
Figure 3.6 Radiation treatment plan quality is assessed visually and graphic...
Chapter 4
Figure 4.1 The Monro–Kellie Doctrine states that the skull is a rigid and in...
Chapter 5
Figure 5.1 Sagittal and transverse CT images of an IVD extrusion that produc...
Figure 5.2 A Beagle presented for severe, persistent neck pain that was exhi...
Figure 5.3 A lateral radiograph demonstrating narrowing of the IVD space at ...
Figure 5.4 A lateral view of a myelogram study demonstrating an extramedulla...
Figure 5.5 CT images of an IVD extrusion at C5–C6 in a chondrodystrophic dog...
Figure 5.6 A CT‐myelogram transverse view demonstrating an IVD extrusion cau...
Figure 5.7 Sagittal and transverse T2‐weighted MRI sequences of a C6–C7 IVD ...
Figure 5.8 Two views of a patient positioned for a mid‐cervical ventral slot...
Figure 5.9 A ventral midline incision is made from the base of the larynx to...
Figure 5.10 Exposure of the paired sternohyoideus muscles on the ventral mid...
Figure 5.11 Separation and retraction of the sternohyoideus muscles reveals ...
Figure 5.12 After retraction of the trachea to the surgeon's right and the r...
Figure 5.13 (a) Ventral and (b) lateral anatomic representations of the land...
Figure 5.14 After identifying the correct IVD space, small, curved hemostats...
Figure 5.15 The longus coli muscle has been elevated over the ventral aspect...
Figure 5.16 A pneumatic bur drill is positioned to begin the ventral slot. N...
Figure 5.17 A partially completed slot. Notice that the slot is directly on ...
Figure 5.18 An anatomical illustration of a ventral view of the cervical ver...
Figure 5.19 Micro‐Kerrison 1 mm rongeurs are being placed into the canal and...
Figure 5.20 The completed slot. The inner cortical layer of the bone, the do...
Chapter 6
Figure 6.1 Illustrations depicting the approach and bony defect of (a) hemil...
Figure 6.2 Oblique patient positioning (midway between sternal and lateral) ...
Figure 6.3 Focal finger palpation between the fascicles of the iliocostalis ...
Figure 6.4 The incision is made midway between the articular processes and t...
Figure 6.5 The pedicle bone is identified and the incision is extended as re...
Figure 6.6 Short jawed (1‐in.), right‐angled Gelpi rectractors are preferred...
Figure 6.7 Mini‐hemilaminectomy performed to remove extruded disk material i...
Figure 6.8 Illustration demonstrating that the lateral pedicles of interest ...
Figure 6.9 Illustration of cross‐section and sagittal view of the vertebral ...
Figure 6.10 Intraoperative image showing a long pediculectomy with the bone ...
Figure 6.11 Bent needle (90°) and #11 blade used to enter the...
Figure 6.12 A approximately 3 cm long × 2 cm wide × 0.3 cm...
Figure 6.13 The thoracolumbar fascia is incised in a scalloped fashion, begi...
Figure 6.14 The hemilaminectomy. (a) Removal of the articular processes with...
Figure 6.15 Placement of Backhaus towel forceps through the spinous process ...
Figure 6.16 Placement of the Lempert rongeur tips in the small separation be...
Figure 6.17 (a) Illustration and (b) intraoperative photograph of the comple...
Chapter 7
Figure 7.1 Illustration of a transverse section through a canine lumbar inte...
Figure 7.2 Transverse section through an intervertebral disk after fenestrat...
Figure 7.3 Intraoperative image of incomplete mini‐hemilaminectomy (thin inn...
Figure 7.4 A Illustration of a Metzembaum scissor being used to split the il...
Figure 7.5 Approach for disk fenestration in a cadaver. Note that Gelpi retr...
Figure 7.6 A hypodermic needle is used to palpate each of the vertebral endp...
Figure 7.7 A #11 scalpel blade is used to remove a rectangular section of th...
Figure 7.8 A rongeur is used to remove the fenestrated section of lateral an...
Figure 7.9 (a–c) A curette is used to retrieve the nucleus pulposus from the...
Figure 7.10 A variety of neurological curettes are shown. The largest curett...
Figure 7.11 The disk space of a cadaver appears empty after fenestration has...
Figure 7.12 Postoperative view of a Miniature Schnauzer with abdominal wall ...
Figure 7.13 Lateral radiograph showing bur damage (arrow) along the vertebra...
Chapter 8
Figure 8.1 Post‐needle placement into each disk space. Note the increased in...
Figure 8.2 Positioning of the dog in right lateral recumbency once placed un...
Figure 8.3 The dog is positioned in lateral recumbency and the surgically pr...
Figure 8.4 Lateral fluoroscopic image demonstrating placement of a 20‐gauge,...
Figure 8.5 Ventrodorsal fluoroscopic image depicting accurate placement of e...
Figure 8.6 Accurate placement of the 320-μm low‐quartz l...
Figure 8.7 Pre‐contrast T1 TRANS sequence evaluated for vertebral endplate l...
Figure 8.8 Post‐contrast T1 TRANS sequence evaluated for vertebral endplate ...
Figure 8.9 T2 TRANS sequence revealing a hypointense lesion suggestive of ed...
Figure 8.10 T2+FS TRANS sequence revealing a hypointense lesion suggestive o...
Chapter 9
Figure 9.1 Magnetic resonance imaging. (a) Sagittal T2 weighted image depict...
Figure 9.2 Dorsolateral view of a canine model of the cranial thoracic verte...
Figure 9.3 Model of a dog at the level of the cranial thoracic region showin...
Figure 9.4 Positioning for approaching the cranial thoracic region via hemil...
Figure 9.5 Intraoperative pictures showing (a) the dorsolateral approach to ...
Chapter 10
Figure 10.1 Computed tomography (CT) images of a canine patient with unilate...
Figure 10.2 3D reconstruction of CT image showing override of the cranial le...
Figure 10.3 Point‐to‐point forceps used to rotate the luxated vertebra into ...
Figure 10.4 Use of bilateral SOP locking plates is generally considered the ...
Figure 10.5 Other forms of fixation include pins and wires and ventral plati...
Figure 10.6 A brace applied to support stabilization of the caudal cervical ...
Chapter 11
Figure 11.1 Axial CT images at different levels of C5 vertebra in a large br...
Figure 11.2 Photo of positioning of a dog for cervical distraction and stabi...
Figure 11.3 Caspar retractor with instrument specific distraction pins. The ...
Figure 11.4 Illustration of an intervertebral disk in situ (a); a partial di...
Figure 11.5 (a) A sagittal saw is use to cut a cortical allograft segment in...
Figure 11.6 (a) Instrumentation used to obtain a fresh cancellous autograph ...
Figure 11.7 Axial MR image of a Great Dane affected with osseous‐associated ...
Figure 11.8 Illustration of the monocortical screw/PMMA construct. Three scr...
Figure 11.9 Intraoperative photographs of monocortical screw/PMMA fixation. ...
Figure 11.10 Illustration of a 3.5 locking compression plate (LCP
®
, Syn...
Figure 11.11 Illustration and lateral radiographic projection of two locking...
Figure 11.12 Illustration of bicortical transverse process screw/PMMA fixati...
Figure 11.13 Postoperative radiographs of a Great Dane with two‐level cervic...
Figure 11.14 Radiographic follow‐up of a Great Dane after distraction/stabil...
Chapter 12
Figure 12.1 (a) Axial CT with superimposed pin insertion angle and location....
Figure 12.2 Illustration of the three compartments in the lumbar vertebrae. ...
Figure 12.3 Axial CT of thoracic vertebrae, two sequential CT slices (a is c...
Figure 12.4 Illustration of the application of a positive‐profile pin bicort...
Figure 12.5 Examples of available locking plate systems (a and b) bilateral ...
Figure 12.6 Intraoperative images of two different pin and PMMA constructs (...
Figure 12.7 Postoperative radiographs of a pin and PMMA construct for L1 ver...
Figure 12.8 Lateral (a) and dorsoventral (b) radiographic projections of spi...
Figure 12.9 (a) Image of lubra plates applied on a spine model. Note the com...
Figure 12.10 Illustration of pin and PMMA fixation of the lumbosacral joint....
Figure 12.11 Illustration of transarticular screw placement across the L7–S1...
Figure 12.12 (a and b) Pre‐ and postoperative lateral radiographic projectio...
Chapter 13
Figure 13.1 A sagittal computed tomography image of a dog spine illustrating...
Figure 13.2 A sagittal computed tomography image of a dog spine with a verte...
Figure 13.3 (a) Surgical image from the left side of the patient showing a b...
Figure 13.4 A one‐year‐old female spayed Doberman Pinscher presented for gai...
Chapter 14
Figure 14.1 Illustration of the foraminal zones for the L7 nerve roots (entr...
Figure 14.2 Both the lordosis test and tail jack have been described as meth...
Figure 14.3 We routinely use what we describe as a “sciatic entrapment test”...
Figure 14.4 Positioning for lateral radiographs of the lumbosacral joint of ...
Figure 14.5 (a) Bone window showing image of L7–S1 in flexion vs (b) bone wi...
Figure 14.6 Positioning of the patient on the surgery table with the pelvic ...
Figure 14.7 CT of a dog with DLSS. Sagittal and transverse images provided. ...
Figure 14.8 Sequential radiograph of a dog with diskospondylitis and seconda...
Chapter 15
Figure 15.1 Cutaneous trunci reflex: Absent ipsilateral cutaneous trunci (ct...
Figure 15.2 This feline patient is exhibiting Horner's Syndrome of the right...
Figure 15.3 Spinal meningioma – typical magnetic resonance imaging (MRI) cha...
Figure 15.4 (a) Dorsal and (b) transverse MRI T1-+-(c) images of a lumbar (L...
Figure 15.5 MRI of dog with PNST at C3–C4. (a) T2 sagittal; (b) T1–FS transv...
Figure 15.6 (a) Dorsal T1+C image of a cervical PNST in a dog. (b) Dorsal T1...
Figure 15.7 Cytological descriptions have a predominance of pleiomorphic str...
Chapter 16
Figure 16.1 T2‐weighted sagittal MR image of a Cavalier King Charles Spaniel...
Figure 16.2 T2‐weighted sagittal MR image of a Persian cat demonstrating pro...
Figure 16.3 3‐D‐reconstructed image including the caudal half of the skull t...
Figure 16.4 This patient, a young Yorkshire Terrier, was originally presente...
Figure 16.5 The bony and ligamentous anatomy of the craniocervical junction ...
Figure 16.6 A craniectomy is performed first; the margins of this exposure i...
Chapter 17
Figure 17.1 Sagittal CT myelogram (a) and CT (b) reconstruction and transver...
Figure 17.2 The cranial is to the left and caudal to the right in all of the...
Figure 17.3 The cranial is to the left and caudal to the right in all of the...
Figure 17.4 Positioning for manubriotomy and ventral access to the caudal ce...
Figure 17.5 Deep ventral cervical spine with closed (a) and split (b) manubr...
Figure 17.6 Ventrodorsal radiography of the cervical spine (a) and CT at C7–...
Chapter 18
Figure 18.1 Transverse (a) T2, (b) T1 FSGR with Doteram, and (c) ultrasound ...
Figure 18.2 Sagittal (a) T2 MRI and (b) ultrasound images of a patient with ...
Figure 18.3 Following partial debulking of a mass. A common complication is ...
Figure 18.4 (Same patient as in Figure 18.2.) Transverse (a) T2 MRI and (b) ...
Figure 18.5 A. sagittal computed tomography, brain window W:-150 L:-50 and B...
Figure 18.6 (a) Dorsal computed tomographic image of the same dog in Figure ...
Figure 18.7 (a) Preoperative and (b), postoperative images of a high‐grade g...
Figure 18.8 Ultrasound image of a chronic, intraparenchymal hematoma in an E...
Figure 18.9 Transverse ultrasound images (a) with the placement of a
Cavitro
...
Figure 18.10 Sagittal ultrasound image. The sharply marginated linear line t...
Chapter 19
Figure 19.1 Instrumentation used for frame‐based stereotactic brain biopsy. ...
Figure 19.2 Frame‐based stereotactic brain biopsy planning procedure with si...
Figure 19.3 CT‐guided stereotactic brain biopsy of an oligodendroglioma in t...
Figure 19.4 Components of the Brainsight
TM
stereotactic system include a sta...
Figure 19.5 Dental bite block. (A) Thermoplastic dental material is softened...
Figure 19.6 The skull is attached to the surgical C‐shaped headclamp using f...
Chapter 20
Figure 20.1 MR images of a dog with a pituitary adenoma (a), a meningioma (b...
Figure 20.2 With the 90° VITOM exoscope in place,...
Figure 20.3 The VITOM exoscope (STORZ, Karl Storz‐Endoskope, Tuttlingen, Ger...
Figure 20.4 Tew (KLS Martin, Jacksonville, FL) neurosurgical instruments are...
Chapter 21
Figure 21.1 (a) Transverse CT image a showing an MLO lesion of the basal sku...
Figure 21.2 Patient positioning. Cadaver specimen demonstration of the autho...
Figure 21.3 MLO lesions are typically sharply marginated masses but can be v...
Figure 21.4 Three‐dimensional image (a) reconstruction of a CT scan shows en...
Figure 21.5 Time‐of‐flight MRI imaging of the dorsal sagittal and transverse...
Figure 21.6 Schematic illustration of dorsal sagittal sinus catheterization ...
Figure 21.7 Extension and expansion of an MLO lesion on to the tentorium cer...
Figure 21.8 Polymethylmethacrylate cranioplasty with mesh strips for a large...
Chapter 22
Figure 22.1 Caudal cerebellar meningioma in a dog. The white dura mater (Bis...
Figure 22.2 Placement of three ligatures around the dorsal sagittal sinus (D...
Figure 22.3 A conventional diamond‐shaped bone flap for a transfrontal crani...
Figure 22.4 Using osteotomes to elevate a Purdue diamond. A Purdue diamond b...
Figure 22.5 Bilateral Purdue diamond. Top left: a CT image of a dolichocepha...
Figure 22.6 A 23‐gauge needle is bent 90°, then used to...
Figure 22.7 Placing an L‐hole when an insufficient ledge has been left in th...
Figure 22.8 Preparing a falcine strip for sutures after bilateral transfront...
Figure 22.9 Same case as Figure 22.8. Three DSS ligatures have been placed (...
Figure 22.10 A “falcine strip” and left fronto
‐
olfactory meningioma re...
Figure 22.11 A left rostrotentorial craniectomy on a normal dog cadaver.
Sou
...
Figure 22.12 Preoperative (left) and six‐months postoperative (right) post‐c...
Figure 22.13 Cerebellar meningioma resection after suboccipital craniectomy ...
Figure 22.14 Placement of a temporalis fascial graft (same case as Figures 2...
Chapter 23
Figure 23.1 A graphic representation of the lateral ventricular fenestration...
Figure 23.2 This patient is seven-months old and was diagnosed with unilater...
Figure 23.3 A small craniectomy through the parietal bone is being performed...
Figure 23.4 Transverse T1-+-C image showing the approximate entry point for ...
Figure 23.5 Dural incision using a #12 scalpel blade.
Figure 23.6 After completing the dural incision, a stay suture in placed in ...
Figure 23.7 The
anal sac balloon catheter
is preferred over the Foley type c...
Figure 23.8 A cellulose eye spear is used to remove blood or tissue debris a...
Figure 23.9 A 4‐ply SIS
b
patch is shaped to the size of the dural defect and...
Figure 23.10 Polypropylene mesh is sutured to the underlayer of the temporal...
Figure 23.11 This is an image (transverse CT) of a young (four‐month‐old) mi...
Chapter 24
Figure 24.1 Venous system of the caudal fossa. Venous sinuses of the caudal ...
Figure 24.2 Positioning for caudal fossa surgery. Proper positioning is impo...
Figure 24.3 Midline occipital craniectomy to decompress caudal occipital mal...
Figure 24.4 Midline occipital craniectomy combined with C1 laminotomy to exc...
Figure 24.5 Superficial muscle dissection. The broad expanse of flat superfi...
Figure 24.6 Deep muscle dissection. The paired semispinalis capitis (
bivente
...
Figure 24.7 Completed dissection with craniectomy outline (and inset). The l...
Figure 24.8 Lateralized occipital approach with occlusion of the transverse ...
Figure 24.9 A lateralized approach with occlusion of transverse sinus to exc...
Figure 24.10 A lateralized approach with occlusion of transverse sinus to re...
Figure 24.11 A lateralized approach with occlusion of transverse sinus to re...
Figure 24.12 A lateralized approach with occlusion of transverse sinus and p...
Figure 24.13 Occipital approach used to excise bony mass. Mid‐sagittal and t...
Figure 24.14 Feline caudal fossa anatomy and lateral surgical approach. Cran...
Figure 24.15 Lateral approach to the feline caudal fossa. MR images from an ...
Figure 24.16 Postoperative complication.
Multiple echo recombined gradient e
...
Chapter 25
Figure 25.1 A T1+C transverse MRI image of a dog with a trigeminal nerve she...
Figure 25.2 A stainless‐steel headframe made that allows rotation of the hea...
Figure 25.3 A headstand designed to securely position the patient for the tr...
Figure 25.4 The dotted line represents the location of an incision made betw...
Figure 25.5 The zygomatic arch has three parts: the zygomatic bone (1), the ...
Figure 25.6 This illustrates the margins (white dotted lines) of the zygomat...
Figure 25.7 Intraoperative view showing placement of the right angle Gelpi r...
Figure 25.8 In this illustration, the area located within the circle shows t...
Figure 25.9 The ventral margin of the craniectomy begins at the junction of ...
Guide
Cover
Table of Contents
Title Page
Copyright
Dedication
List of Contributors
ACVS Foreword
ACVIM Foreword
Preface
Begin Reading
Index
WILEY END USER LICENSE AGREEMENT
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Advanced Techniques in Canine and Feline Neurosurgery
Edited by
Andy Shores
Clinical Professor and Chief, Neurosurgery and Neurology Mississippi State University College of Veterinary Medicine The Veterinary Specialty Center Mississippi State, Starkville, MS, USA
Brigitte A. Brisson
Professor of Small Animal Surgery Department of Clinical Studies Ontario Veterinary College University of Guelph Guelph, Ontario, Canada
This edition first published 2023
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The contents of this work are intended to further general scientific research, understanding, and discussion only and are not intended and should not be relied upon as recommending or promoting scientific method, diagnosis, or treatment by physicians for any particular patient. In view of ongoing research, equipment modifications, changes in governmental regulations, and the constant flow of information relating to the use of medicines, equipment, and devices, the reader is urged to review and evaluate the information provided in the package insert or instructions for each medicine, equipment, or device for, among other things, any changes in the instructions or indication of usage and for added warnings and precautions. While the publisher and authors have used their best efforts in preparing this work, they make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives, written sales materials or promotional statements for this work. The fact that an organization, website, or product is referred to in this work as a citation and/or potential source of further information does not mean that the publisher and authors endorse the information or services the organization, website, or product may provide or recommendations it may make. This work is sold with the understanding that the publisher is not engaged in rendering professional services. The advice and strategies contained herein may not be suitable for your situation. You should consult with a specialist where appropriate. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages.
Library of Congress Cataloging‐in‐Publication Data applied for:
ISBN 9781119790426 (hardback)
Cover Design: Wiley
Cover Images: Courtesy of Andy Shores
To all those professionals and paraprofessionals, devoted to the supportive care and rehabilitation of the small animal neurosurgical patients. We deal with many complex and challenging procedures and the care of these patients requires a team of individuals with a heart.
To my colleagues who have supported my efforts in completion of this volume.
To my family that means the world to me with special recognition of the new addition, Derek Alejandro Shores – you are a blessing.
Andy Shores
To my girls, Julia and Éloïse – watching you grow into strong, confident young women is the best gift a parent could ask for. I love you to the moon and back. Always and forever. No matter what.
To my husband – thank you for your continued love and support. I couldn't do it without you.
To my dad –thank you for pushing me to do what I love and to always strive for being the best I can be. I miss you every day.
To my residents – stay thirsty for new knowledge and continue to grow the excellent neurosurgical skills you have developed throughout your training.
Brigitte A. Brisson
List of Contributors
Michaela Beasley, ACVIM
Mississippi State UniversityMississippi State, Mississippi, USA
R. Timothy Bentley, ACVIM
Purdue UniversityWest Lafayette, Indiana, USA
Brigitte A. Brisson, ACVS
University of GuelphGuelph, Ontario, Canada
Sheila Carrera‐Justiz, ACVIM
University of FloridaGainesville, Florida, USA
Sofia Cerda‐Gonzalez, ACVIM
MedVet ChicagoChicago, Illinois, USA
Sandy Chen
Bush Veterinary Neurology ServiceSpringfield, Virginia, USA
Annie Vivian Chen‐Allen, ACVIM
Washington State UniversityPullman, Washington, USA
Danielle Dugat, ACVS
Oklahoma State UniversityStillwater, Oklahoma, USA
Gabriel Garcia, ACVIM
University of FloridaGainesville, Florida, USA
Ryan Gibson, ACVIM
Auburn UniversityAuburn, AL, USA
B. F. Hettlich, ACVS
University of BernBern, Switzerland
Simon T. Kornberg, ACVIM
Southeast Veterinary NeurologyMiami, Florida, USA
Alison M. Lee, ACVR
Mississippi State UniversityStarkville, Mississippi, USA
Stef H. Y. Lim
Bush Veterinary Neurology ServiceLeesburg, Virginia, USA
Linda Martin, ECC
Washington State UniversityPullman, Washington, USA
Isidro Mateo, ECVN
Neurology and Neurosurgery DepartmentHospital Veterinario VETSIA,Leganés, Madrid, Spain
Jonathan F. McAnulty, ACVS
University of Wisconsin‐MadisonMadison, Wisconsin, USA
Yael Merbl, ECVN
Washington State University Pullman, Washington, USA
Allison Mooney, ACVIM
Allison Mooney, ACVIMWestVet, Boise, Idaho, USA
Claudio C. Natalini, ACVAA
Mississippi State UniversityStarkville, Mississippi, USA
M. W. Nolan, ACVR
North Carolina State UniversityRaleigh, North Carolina, USA
Tina Owen, ACVS
Washington State University Pullman, Washington, USA
John Rossmeisl, ACVIM
Virginia Tech, BlacksburgVirginia, USA
Andy Shores, ACVIM
Mississippi State UniversityMississippi State, Mississippi, USA
Don Sorjonen, ACVIM
Auburn University College of Veterinary MedicineAuburn, Alabama, USA
Beverly K. Sturges, ACVIM
University of CaliforniaDavis, California, USA
Chris Tollefson, ACVR
Cornell UniversityIthaca, New York, USA
Fred Wininger, ACVIM
CARE Charlotte Animal Referral and Emergency Charlotte, North Carolina, USA
Ane Uriarte, ECVN, EBVS
European Specialist in Veterinary NeurologyHead of Neurology at Southfields Veterinary Specialist,UK
Martin Young, ACVIM
Bush Veterinary Neurology ServiceRichmond, Virgina, USA
ACVS Foreword
The American College of Veterinary Surgeons Foundation is pleased to present Advanced Techniques in Canine and Feline Neurosurgery in the book series entitled Advances in Veterinary Surgery.
The ACVS Foundation is an independently charted philanthropic organization that supports the advancement of surgical care of all animals through funding of educational and research opportunities for veterinary surgical residents and board‐certified veterinary surgeons.
Our collaboration with Wiley Publishing Company brings unique contributions that can benefit and enhance the learning process to all interested in veterinary surgery.
One of the key missions of the ACVS Foundation is to promote innovative education for residents in training and diplomates. This book underscores our intent, focusing on achievements made by scientists, their latest key findings, along with new techniques made possible by state‐of‐the‐art equipment. This book will inspire, inform, and provide direction for residents in training as well as surgeons already employing neurosurgical procedures in their practices.
Advanced Techniques in Canine and Feline Neurosurgery is edited by Drs. Andy Shores and Brigitte Brisson. I'd like to congratulate and thank them for helping to move this fast‐growing field forward. They have chosen an international group of strong contributing authors to cover canine and feline neurosurgical skills, equipment, techniques, and procedures. I am sure you will find this reference extremely valuable.
The ACVS Foundation is proud to collaborate with Wiley in this important series and is honored to present this newest book in the Advances in Veterinary Surgery series.
R. Reid Hanson, DVM, ACVS, ACVECC
Chair, Board of Trustees
ACVS Foundation
ACVIM Foreword
It is my pleasure on behalf of the ACVIM to introduce the book, Advanced Techniques in Canine and Feline Neurosurgery, edited by Drs. Andy Shores and Brigitte Brisson. The content provided includes basic and advanced knowledge of veterinary neurosurgery shared by many who are ACVS, ACVIM, and ECVN trained. The information is practical and focuses on techniques that are directly applicable and relevant to practice of neurosurgery. Veterinary neurosurgery continues to grow and certainly has reached an area of expertise in our profession. Our veterinary patients must have access to neurosurgeons who are experts in the most current surgical techniques.
The neurosurgical topics are comprehensive and bring forth new techniques and technologies in performing spinal and intracranial procedures. Neurosurgery will be forever evolving as we adopt human neurosurgical principles and procedures into veterinary medicine. Of special note is the chapter on the history of neurosurgery. Many have paved the way to our learning and understanding of veterinary neurosurgery and let us not forget those who led us in our neurosurgical training. Trainees and their mentors will utilize this textbook as a comprehensive guide, which provides accurate and concise information of neurosurgery. The videos on the website also are a valuable resource and innovative way to demonstrate techniques and procedures. This dynamic resource enables visual learning on another scale.
My colleagues who have contributed to this textbook are to be commended on their efforts especially during a pandemic that posed many challenges. It is because of their time and talents, and those of our fellow ACVIM Diplomates, that ACVIM is able to continually advance our mission to be the trusted leader in veterinary education, discovery, and medical excellence.
Joan R. Coates, DVM, MS, DACVIM (Neurology)
ACVIM Neurology Specialty President
Preface
The interest of many and the many advancements in the field of veterinary neurosurgery prompted the development of this book. And while some routine or standard approaches are included in these chapters, much of the content is devoted to advanced techniques being performed by many of the top veterinary neurosurgeons in the world. Some are ACVS trained, some are ACVIM (Neurology) or ECVN trained, but we share the same vocation: veterinary neurosurgery. Veterinary neurosurgery continues to grow and certainly has reached a point of being a very important subspecialty in our profession. The hours of training and devotion to this discipline by my fellow neurosurgeons is noteworthy and certainly deserving of formal recognition for what it has become – its own entity. And while I do not expect a major change in my lifetime, I sincerely hope this work will foster the continued development of our subspecialty by the many fine individuals currently engaged and for those to come. As such, I believe formal recognition should and will come with time: the ABVS should give strong consideration to the development of a separate specialty or a sub‐pecialty.
This book contains many spinal and intracranial procedures, several of those (such as the surgical management of sellar masses) are on the cutting edge of our discipline. I am very grateful for the many hours my colleagues have put into these works and they are well deserving of my heartfelt thanks. In the midst of a pandemic, these colleagues came through with outstanding works.
I trust the readers will benefit from the content and especially from the number of accompanying videos on the website.
I sincerely appreciate the tremendous effort put forth by my colleagues that contributed to this volume.
Andy Shores
Mississippi State, MS, USA 2023
About the Companion Website
This book is accompanied by a companion website.
http://www.wiley.com/go/shores/advanced
The website features procedural videos.
Video 3.1 Radiation therapy in a 7‐year‐old spayed female dog, 3 weeks following surgical resection of a choroid plexus carcinoma.
Video 4.1 Balanced anesthetic protocol procedure for a 17‐year‐old female/spayed cat for craniectomy to remove a large intracranial mass.
Video 5.1 The ventral midline surgical approach to the cervical spine.
Video 5.2 Ventral slot decompression of a cervical disk extrusion.
Video 6.1 Pediculectomy performed at T13‐L1 through a dorsolateral approach on the left side (entire procedure).
Video 6.2 Modified dorsolateral surgical approach for pediculectomy.
Video 6.3 Following the initial approach through a dorsolateral incision, the spinal musculature is elevated using a periosteal elevator to identify the appropriate site for pediculectomy at T13‐L1 on the left.
Video 6.4 An air drill is used to create a pediculectomy for removal of herniated disc material from the spinal canal.
Video 6.5 After drilling through cortical, medullary and inner cortical bone, the spinal canal is entered by removing the remaining, thin inner periosteum using an iris spatula or 90 degree bent needle and #11 blade.
Video 6.6 Using a bent iris spatula to retrieve herniated disc material from the spinal canal. The spatula is manipulated from craniodorsal and dorsocaudal toward the mid section of the pediculectomy ventrally to avoid pushing disc away from the pediculectomy window.
Video 6.7 Surgical closure of the modified dorsolateral approach used for pediculectomy.
Video 7.1 Blade fenestration performed at T13‐L1 on the left following a pediculectomy procedure.
Video 8.1 Video showing the positioning the patient, placement of needles using fluoroscopy and application of the laser to perform the fenestrations.
Video 9.1 A live surgical video of the approach to the cranial thoracic spine with instructive narration.
Video 13.1 Video depicting a pre‐operative and post‐operative videos of a patient that underwent surgical management of a congenital spinal anomaly using the biological in situ technique.
Video 14.1 Video of Lumbosacral Decompression and Foraminotomy Techniques.
Video 14.2 Video demonstrating the sciatic nerve entrapment test exam in a dog.
Video 15.1 Removal of lumbar PNST / Limb sparing technique.
Video 15.2 Removal of cervical PNST / with limb amputation.
Video 17.1 Video showing the integrity of the mediastinum in a cadaveric model in which median manubriotomy has been performed and 200 ml of air injected into the thoracic cavity through a catheter. The video shows an expansion of the pleura without any evident leak in the cranial mediastinum.
Video 18.1 This video depicts the use of intraoperative ultrasound in the removal of a supratentorial mass in a canine patient.
Video 19.1 Video demonstrating a brain biopsy procedure using the BrainsightTM Frameless Stereotactic Biopsy Device.
Video 20.1 Video depicting a transshphenoidal hypophysectomy in an 8 year‐old female/spayed mixed breed dog.
Video 21.1 Guidelines for surgical management of tumors of the Canine Skull.
Video 22.1 This video demonstrates the Purdue Diamond transfrontal craniotomy.
Video 22.2 Exposure of the olfactory bulbs using the Purdue Diamond frontal craniotomy approach.
Video 22.3 Video of the removal of a cerebellar meningioma using traction in a cat through a suboccipital craniectomy.
Video 23.1 Lateral ventricular fenestration.
Video 24.1 This video depicts a 4th Ventricular Mass Excision via Occipital Craniectomy in a live patient.
Video 25.1 Demonstration of the Transzygomatic Approach in a Cadaver.
1A History of Veterinary Neurosurgery: 1900–2000
Don Sorjonen
Auburn University College of Veterinary Medicine, Auburn, Alabama, USA
Introduction
Any treatise of merit regarding the history of veterinary neurosurgery must include, as a preamble, a brief history of veterinary medicine [1, 2]. Early writings suggest that the practice of veterinary medicine was born from human necessity. Diseases that afflicted domestic animals were also a threat to a principal source of food and transportation for humans. Consequently, most of the notable early practices of veterinary medicine focused on diseases of cattle, sheep, and horses. Economic losses from animal plagues (example, rinderpest, anthrax, blackleg) were so consequential that in 1762 the first college of veterinary medicine was created in Lyons, France. Between 1762 and 1862, 17 additional schools of veterinary medicine were established throughout Europe, England, and Scotland; in the United States, the New York College of Veterinary Surgeons was established in 1857. It is through the growth and maturation of the worldwide veterinary schools that veterinary neurosurgery was born. This review considers the historical events that promoted advances in veterinary neurosurgery from its inception through the end of the twentieth century. Although attempts have been made to faithfully include every contribution to the advancement of veterinary neurosurgery, with any work of this time expanse some contributions may have been missed.
Advances in Imaging Techniques
It is worth noting that seminal advances in human neurosurgery are typically credited with the development of cerebral localization theory, antiseptic/aseptic technique, and anesthesia [3]. While these are important tenets, they were developed before the inception of the specialized practice of veterinary neurosurgery; consequently, they have been largely adopted en bloc from human medicine. Important advances in veterinary neurosurgery more commonly followed advances in diagnostic imaging techniques of the central nervous system (CNS). In fact, with the development of radiographic techniques that offered more exquisite anatomic detail came neurosurgical techniques that offered more positive outcomes. This relationship is best illustrated by the progress made in veterinary neurosurgery following the advent of computed tomography (CT) and magnetic resonance imaging (MRI) of CNS tissues.
Obtaining diagnostic imaging is foundational to any successful surgery of the CNS. While articles regarding veterinary radiology first appeared in 1896 [4], just one year after the discovery of x‐ray, routine use of radiographs to confirm a clinical diagnosis of pathology of the CNS of animals did not occur for nearly a half century later [5]. Initially, conventional radiological images were the only technique available for veterinary neurosurgeons to confirm a neurological lesion. However, because of the relatively small size of the offending pathology and the isodense nature of CNS tissue, researchers sought new techniques that offered better tissue discernment. In Sweden (1951), Olsson [6] reported on myelography as part of a more comprehensive monograph on disk disease. In 1953, Hoerlein [7] at Auburn University, published a report evaluating several aqueous‐ and oil‐based iodized contrast media for myelography. Many of these early contrast media were subsequently abandoned because of poor flow qualities and various sequelae from toxicity like seizures, general muscular fasciculation, cord malacia, fibrotic leptomeningitis, and death [8, 9]. The continued quest for improved diagnostic quality imaging lead to studies utilizing epidurography [7, 10, 11] diskography [12] and venography [13]. In the 1970s, clinical trials in humans using the non‐ionic, biologically inert contrast agent metrizamide (Amipaque®) were reported [14]. Metrizamide and other non‐ionic contrast medias were also found to be of value for the confirmation of various spinal cord diseases in veterinary patients and were used extensively until the advent of diagnostic CT and MRI.
Advances in imaging techniques of the skull and brain of animals followed a pattern similar to spinal studies. Early reports utilizing plain film radiographs of the skull emphasized the importance of head position to achieve precise symmetry [5], the most essential criterion for interpretation of brain and skull radiographs [15]. While these early radiographic methods were typically adequate to confirm bony lesions, they were inadequate to confirm most intracranial forms of pathology. Several early investigators [16–19] experimented with various head positions, contrast agents, and injection techniques for cerebral angiography and venography; however, these images were difficult to interpret because of imprecise head positioning and consistent variations in vessel patterns. In 1961, Hoerlein and Petty [20] and Cobb [21] published articles describing pneumoencephalography in dogs. Again, positioning difficulties and filing artifacts made clinical application uncommon. In his 1961 article, Hoerlein [20] reported the result of injection of air or opaque medium into one or both lateral ventricles and concluded that “ventriculography in clinical practice is of value in demonstrating either unilateral or bilateral ventricular dropsy as well as a space‐occupying lesions.”
All of the neuroradiographic techniques previously discussed are restricted by their invasive nature, inconsistent reproducibility, limited visualization of the pathologic lesion, and undesirable morbidity and mortality. Before the 1980s most veterinary neurosurgeons experienced frustration dealing with these restrictions. To the relief of the veterinary neurosurgeon and to the benefit of the animal patient and their owners, a remedy to the earlier restrictions was found in CT and MRI technology. The principles of computed tomography were first elucidated by Hounsfield in 1973 [22] and the first clinical report of CT application in veterinary medicine was published in 1980 by Marineck and Young [23] followed in 1981 by LeCouter et al. [24]. Interestingly, both reports involved canine patients with neoplasia of the CNS. Although the theory of nuclear magnetic resonance (NMR) was first advanced in the 1950s [25], MRI technology became clinically relevant in the 1970s following the development of a mechanism of encoding spatial information from NMR data [26]. Veterinary reports involving MRI studies of the canine head and brain first appeared in the 1980s [27, 28] with clinical reports of spinal disease occurring in the 1990s [29].
Advances in Spinal Procedures
Thoracolumbar (T1–S1)
The vast majority of the veterinary publications that chronicle surgery of the thoracolumbar spine involved degenerative disk disease. However, Olsson [6] and Vaughn [30], both notable early authors, regarded both hemilaminectomy and laminectomy too hazardous a surgical procedure to be recommended as a treatment for disk protrusion in the dog. These authors observed dogs with spinal cord injury from a ruptured disk could recover without surgery and theorized it imprudent to risk a potential permanent surgically induced spinal cord damage in dog that may recover without surgery. In 1951, Olsson recommended a dorsolateral approach for disk fenestration but not “intervention into the vertebral canal” for dogs with disk protrusion, ascribing the reduced risk of injury to the nerves and spinal cord and prophylaxis as benefits of fenestration. After Olsson's report, multiple fenestration procedures were proposed for the dog. In 1971 Leonard [31] proposed ventral fenestration; in 1969 Ross [32] and in 1965 Northway [33] each proposed ventrolateral fenestration; in 1968 Hoerlein [34], in 1975 Flo [35] and in 1973 Yturraspe [36] proposed dorsolateral fenestration; in 1968 Seemann [37] proposed a lateral muscle separation approaches for disk fenestration and in 1976 Braund et al. [38] proposed a lateral approach for both spinal decompression and disk fenestration.
Numerous neurosurgeons differed with Olsson and Vaughn regarding the prohibition of spinal cord decompressive procedures for disk disease. Although reports of disk protrusion creating neurologic disability in dogs was recognized as early as 1913 [39], the introduction of myelography in the early 1950s heralded the use of hemilaminectomy and laminectomy for the treatment of intervertebral disk protrusion. In 1951, Greene [10] at Alabama Polytechnic Institute (later Auburn University) described a dorsolateral approach for a hemilaminectomy (Figure 1.1). Also, in 1951, Redding [40] at the University of California Davis published a laminectomy technique that he originally developed at Ohio State University (Figure 1.2). In 1956, Hoerlein [41] at Auburn University reported the benefits of dorsolateral hemilaminectomy with prophylactic fenestration that he originally worked on at Cornell (Figure 1.3). Interestingly, by the mid‐1950s, Greene et al., all surgical pioneers, were actively engaged in the field of neurology and neurosurgery at Auburn University. In 1976 [42] and again in 1977 [43], Swaim at Auburn University published on the use of bilateral hemilaminectomy for extensive spinal cord decompression (Figure 1.4).
Figure 1.1 Dr James (1978) – Dr Greene was Dean of the Auburn University College of Veterinary Medicine at the time of this photo. He is credited with first describing the dorsolateral approach for a hemilaminectomy in the dog.
Source: Photo courtesy of The Auburn Speculum – 1978.
Figure 1.2 Dr Redding is pictured here in 1977 as a professor at the Auburn University College of Veterinary Medicine. Dr Redding published his technique for the dorsal laminectomy in 1951.
Source: Photo courtesy of The Auburn Speculum – 1977.
Figure 1.3 Dr Hoerlein, shown here in a photo from 1977. In 1952, Dr Hoerlein described the treatment of canine intervertebral disk disease using the hemilaminectomy. He made several pioneering contributions to the field of veterinary neurosurgery, including his groundbreaking textbooks on canine neurology.
Source: Photo courtesy of The Auburn Speculum – 1977.
Figure 1.4 Dr Steven F. Swaim, shown here in a 1985 photo as director of the Scott‐Ritchey Research Centre. Earlier in his career, Dr Swaim made many significant contributions to veterinary neurosurgery, including his description of the ventral slot technique for cervical intervertebral disk disease in dogs in 1973.
Source: Photo courtesy of the Auburn University Library System.
Some workers saw a benefit to dorsal laminectomy as a treatment for spinal cord compression. In 1962, Funkquist [44] at the Royal Veterinary College in Stockholm, Sweden published a comprehensive volume on dorsal decompressive laminectomy. She prescribed an extensive thoracolumbar laminectomy (method A) for the treatment of disk protrusion that involved removal of both dorsal arches to a level equal to approximately one‐half the height of the spinal cord. However, this technique most often resulted in a secondary cicatrix compression of the spinal cord at the surgical site. In method B, Funkquist proposed a modification of her method A where the compact bone of the dorsolateral portion of the dorsal arch, including the articular process, remained intact. This modification helped to prevent the unwanted sequela of dorsoventral compression of the spinal cord from cicatrix formation. In 1975, Trotter (Figure 1.5) and de Lahunta [45] at Cornell University, proposed a modified deep dorsal laminectomy as a remedy to the postoperative cicatrix sequela noted with the Funkquist method A technique. Trotter's technique removed the laminae and pedicles to the level of the vertebral body resulting in a spinal cord laid bare at the surgical site. Trotter contended that the deep dorsal laminectomy technique was “superior for the excision of intra‐ and extradural neoplasm within the vertebral canal in the thoracic, thoracolumbar, and lumbar regions of the vertebral column.” Trotter also commended the deep dorsal technique for the management of dogs with massive disk extrusion in the thoracolumbar and lumbar regions [45]. In 1981, Prata [46] at the Animal Medical Center New York (AMCNY) strongly advocated for the dorsal laminectomy as the treatment of choice in dogs with peracute and chronic disk disease. Prata recommended a laminectomy over two vertebral bodies with bilateral facetectomy and foraminotomy at the site of disk extrusion. In addition, bilateral pediculectomy was performed to facilitate removal of extruded disk material. Hoerlein [47] contended that laminectomy surgery was not indicated for disk protrusions because of the need for excessive spinal cord manipulation, risk of postoperative vertebral instability, excessive muscle dissection, and difficulty in performing a prophylactic disk fenestration. These two competing philosophies resulted in a north(east) versus south(east) debate regarding the best treatment for disk protrusions that continued into the 1990s. From then, the prevailing wisdom among veterinary neurosurgeons has favored hemilaminectomy as the treatment of choice for the management of dogs with thoracolumbar intervertebral disk disease [48].
Figure 1.5 Dr Eric developed the modified deep dorsal laminectomy in the dog and published a 10‐year review of surgical correction of caudal cervical vertebral malarticulation‐malformation in Great Danes and Doberman Pinchers.
Source: Photo courtesy of Dr. Eric Trotter.
In 1953, Hoerlein [49] reported on the successful use of a spinal plate applied dorsally to the spinous processes to correct a fracture of the fourth lumbar vertebra. In 1956, Hoerlein [50] published a comprehensive article on immobilization techniques for fractures and dislocations of the thoracolumbar spine. These procedures included placement of vertebral body plates for immobilization and bone grafts for fusion; application of bone plates with various fasteners to the spinous processes and ventral vertebral surfaces (Auburn Spinal Plates, Richards Manufacturing Co., Memphis TN); wiring the spinous processes together and placement of vinylidene fluoride resin plates (Lubra plates, Lubra Co., Fort Collins, CO) using a series of bolts fastened with nuts and applied to the spinous processes through the interspinous ligament. Swaim [51] modified Hoerlein's body plating technique and Gage at Auburn University devised a cross‐body pinning technique [52] and a “stapling” technique for small dogs [53]. One of the earliest reports of methyl methacrylate (MMA) for repair of a spinal fractures was reported by Rouse and Miller [54] in 1975. Subsequently, numerous authors have advocated for the use of MMA combined with pins or screws applied to numerous areas of the spine to stabilize fractures/luxations and other causes of vertebral instability [55, 56].
In 1972, Brasmer and Lumb [57] and in 1975, Yturraspe et al. [58] reported on experimental techniques for spondylectomy of L2 which was replaced with a vertebral prosthesis and stabilized with dorsal spinous plating. These procedures were indicated in cases of gross vertebra infection, neoplasia, or severe trauma. Also in 1972, Knecht (Figure 1.6) reported results for hemilaminectomies in 99 dogs with thoracolumbar disk extrusions [59].
The location and anatomical peculiarities of L7 present unique challenges to the neurosurgeon; consequently, unique surgical techniques have been suggested to repair fractures or dislocations that occur at L7. In 1966, Northway [60] published a technique for para‐anal insertion of an intramedullary pin through the bodies of the sacrum and L7 to L4. In 1975, Slocum and Rudy [61] published a report using a transilial intramedullary pin for stabilizing L7 dislocations. Dulisch and Nichols at Michigan State University [62] modified the transilial technique by combining plastic plates affixed to the spinous processes rostral to the fracture‐dislocation with two transilial pins that pass through holes in the plates. To mitigate pin migration, Ullman and Boudrieau [63] at Tufts University used crossed transilial Steinmann pins connected by double Kirschner clamps. McAnulty et al. [64] at the University of Pennsylvania proposed a modified segmental spinal instrumentation technique utilizing multiple Steinmann pins on either side of the spinous processes. The pins were initially advanced through the ilial wing and then bent 90° and wired to the articular processes and dorsal spinous processes rostral to the fracture site. Shores et al. [65] at Michigan State University combined Kirschner‐Ehmer external fixator apparatus with internal dorsal spinal plate fixation for the repair of caudal lumbar fractures. This technique provided rigid fixation of the fracture site, allowed decompression procedure, and could be used in dogs with fractures of the spinous and articular processes.
Figure 1.6 Dr Charles (pictured here in 1984 at Auburn University) reported on 99 cases of thoracolumbar IVD extrusions in dogs in 1972.
Source: Photo courtesy of The Auburn Speculum – 1984.
Compared to the thoracolumbar spine, the lumbosacral (LS) region has other unique pathologic distinctions. The L7–S1 disk space must accommodate the biomechanical forces attendant to the relative mobile L7 vertebra and the nearly immobile sacral vertebra. These forces typically converge at the intervertebral disk, the diarthrodial joint, and associated soft tissues. Over time, these forces can result in degenerative changes in the disk, joint capsule, ligamentum flavum, and diarthrodial joint producing stenosis that compresses the associated neural elements. Before the advent of CT and MRI, clinicians could only confirm LS pathology with plain film radiographs, myelography, epidurography, or interosseous venography; regrettably, radiographic findings in these cases were usually inconclusive. Consequently, most of the early surgical procedures were devised as all‐purpose procedures designed to decompress the nervous tissues and to stabilize the LS joint. In 1978, Oliver et al. at the University of Georgia [66] proposed that the LS region pathology was akin to the malarticulation‐malformation pathology noted in the caudal cervical region of Doberman Pinschers and described a dorsal laminectomy for decompression of the cauda equine and removal of disk prolapse and attendant fibrous adhesions. A foraminotomy was prescribed for L7 nerve root entrapment. Tarvin and Prata [67] at the AMCNY endorsed a dorsal laminectomy and bilateral facetectomies/foraminotomies for LS stenosis. Slocum and Devine [68]
