Laminotomy of the Axis for Surgical Access to the Cervical Spinal Cord A Case Report

Abstract

A cranially hinged laminotomy of vertebra C2 was used to expose the cervical spinal cord of a dog with a meningioma in the region of the atlantoaxial articulation. By preserving the dorsal atlantoaxial ligament, the technique seemed to result in greater and more physiologic stability between the atlas and axis than dorsal laminectomy and prosthetic replacement of the dorsal atlantoaxial ligament. The procedure allowed a dorsal approach, avoiding injury to the vertebral arteries and limited exposure, which are potential problems with hemilaminectomy of C1-C2. Further investigation is needed to evaluate long-term consequences of this procedure.

Canine Intraspinal Meningiomas: Imaging Features, Histopathologic Classification, and Long‐Term Outcome in 34 Dogs

“…A tentative diagnosis of intraspinal tumor may be made after advanced imaging and cerebrospinal fluid (CSF) analysis, but histologic evaluation of tumor type is essential for definitive diagnosis. Results of CSF analysis usually are within normal limits, 7,8,13 but mild to moderately increased protein concentration with or without pleocytosis also has been reported 9,11,13,15,16 . On myelography, spinal cord meningiomas usually are discrete extramedullary intradural masses 5−8,10–18 .…”

“…Results of CSF analysis usually are within normal limits, 7,8,13 but mild to moderately increased protein concentration with or without pleocytosis also has been reported 9,11,13,15,16 . On myelography, spinal cord meningiomas usually are discrete extramedullary intradural masses 5−8,10–18 . Reports of computed tomography (CT) imaging are scarce, but contrast‐enhancing mass lesions have been described 14,17 .…”

“…A recent review of 112 intracranial canine meningiomas has applied the human WHO classification and grading system to these tumors and clearly outlines the advantages of and purpose for using this system compared with the current WHO system for dogs 22 . Reported treatments for canine intraspinal meningiomas consist of medical management and cytoreductive surgery with or without radiation therapy 2,5,9–19,35,36 . After surgery, survival times vary from 4 to 47 months 2,5,9–19 .…”

“…Reported treatments for canine intraspinal meningiomas consist of medical management and cytoreductive surgery with or without radiation therapy 2,5,9–19,35,36 . After surgery, survival times vary from 4 to 47 months 2,5,9–19 . The effect of adjunctive radiation therapy on survival time is unclear, because there are few reports describing its use 10,17–19 …”

Neoplasia

“…Preoperative vertebral body collapse in humans also has a negative effect on outcome after laminectomy (Findlay, 1987;Santen et al, 1991;Chauvet et al, 1999) (12.11). Laminotomy has been used in children instead of laminectomy to avoid late deformity due to instability and may be warranted in certain situations for animals (Fingeroth and Smeak, 1989;Cristante and Herrmann, 1994;Gilson, 2003). Implant failure may occur due to inadequate fixation (Brasmer and Lumb, 1972;Yturraspe and Lumb, 1973;Onimus et al, 1996;Miller et al, 2000).…”