Axis Dorsal Laminotomy for Excision of a Meningioma in a Dog
DOI:
https://doi.org/10.22456/1679-9216.102660Abstract
Background: Surgical access to the spinal cord at the level of C2 vertebra presents technical limitations, due to anatomical particularities in this region. The ventral slot technique does not allow space for the removal of dorsolateral masses. The axis hemilaminectomy technique provides limited access to the dorsal aspect of spinal cord and there is a risk of damaging the vertebral arteries. The axis dorsal laminotomy technique allows good access to spinal cord and preserves the atlantoaxial and nuchal ligaments, however few papers describe this technique. The objective of this paper is to report the axis dorsal laminotomy performed in a dog with a meningioma at this level.
Case: An 11-year-old male, Maltese dog, was presented with a 15-day history of progressive weakness, intense cervical pain and difficulty in locomotion of the four limbs. He was being treated with painkillers without improvement. On clinical examination, the physiological parameters were normal. Neurological examination showed tetraparesis with the syndrome localized in the cranial cervical region. The main differential diagnoses were intervertebral disc disease, neoplasia, inflammatory or infectious disease. Computed tomography was performed and the evaluation of images allowed the visualization of an intradural-extramedullary neoplastic process, promoting important spinal compression, with approximate dimensions of the lesion 0.70 cm high x 0.67 cm wide x 0.78 cm long, with apparent involvement of the meninges, with a more lateralized location on the left, with meningioma being the main differential diagnosis. Thus, exploratory surgery, through the technique of dorsal laminotomy of the axis was performed. After the removal of the mass, the spinous process was repositioned in its anatomical location and fixed with 0.6 mm steel cerclage wire that was passed through the holes made in the dorsal lamina of the axis. After the surgery a neck brace was kept for 45 days. According to the histological changes observed, the neoplasm was classified as grade one meningothelial meningioma. The patient showed gradual improvement and started walking again 4 days after the surgery, staying well and without pain for 5 months, when there was a recurrence of the neoplasia.
Discussion: Surgical access to the cervical region in question is limited due to the presence of complex ligamentous structures, vascular network and the anatomical features of the first and second cervical vertebrae. Thus, the dorsal axis laminotomy technique was used. The approach allowed good visualization of the spinal canal as well as the preservation of the atlantoaxial ligament, maintaining atlantoaxial stability. Through histopathological analysis, the neoplasm was classified as grade I meningothelial, which is considered a benign meningioma, but its behavior is considered malignant due to the compression of the spinal cord and the impossibility of removal with surgical margins, as recommended for oncological surgeries. The patient's survival after surgical treatment is in accordance with that described by other authors which varies from 2.2 to 47 months. Radiotherapy seems to improve the prognosis, but this therapeutic modality is not easily available in the country. There is also insufficient information on the use of chemotherapy for this type of neoplasia, or on the relationship between tumor graduation and survival. The surgery was proposed in order to confirm the suspicion, decompress the spinal cord and collect material for biopsy; the technique performed is feasible and no intraoperative complications have occurred.
Downloads
References
Adamo, P.F., Forrest L. & Dubielzig R. 2004. Canine and Feline Meningiomas: Diagnosis, Treatment, and Prognosis. Compendium on Continuing Education Practicing Veterinarian. 26: 951-966.
Bagley R.S. 2010. Spinal Neoplasms in Small Animals. The Veterinary Clinics of North America. Small Animal Practice. 40(5): 915-927.
Barker A.D., Palus V., Eminaga S. & Cherubini B. G. 2018. Axis dorsal laminotomy in dogs: a retrospective analysis of 10 cases. Veterinary Records Case Reports. 6: e000574.
Barnhart K.F., Wojcieszyn J. & Storts R.W. 2002. Immunohistochemical staining patterns of canine meningiomas and correlation with published immunophenotypes. Veterinary Pathology. 39: 311-321.
Fingeroth J.M. & Smeak D.D. 1989. Laminotomy of the Axis for Surgical Access to the Cervical Spinal Cord A Case Report. Veterinary Surgery. 18: 123-129.
Fingeroth J.M. 2017. Dorsal Cervical Decompression (Laminectomy/Hemilaminectomy and Laminotomy). In: Shores A. & Brisson B.A. (Eds). Current Techniques in Canine and Feline Neurosurgery. Ames: Willey-Blackwell, pp.149-156.
Lacassagne K., Hearon K., Berg J., Séguin B., Hoyt L., Byer B. & Selmic L.E. 2018. Canine spinal meningiomas and nerve sheath tumours in 34 dogs (2008-2016): Distribution and long-term outcome based upon histopathology and treatment modality. Veterinary and Comparative Oncology. 16(3): 344-351.
Lopez J., Fuente C., Pumarola M. & Añor S. 2013. Spinal meningiomas in dogs: Description of 8 cases including a novel radiological and histopathological presentation. Canadian Veterinary Journal. 54: 948-954.
Montoliu P., Añor S., Vidal E. & Pumarola M. 2006. Histological and Immunohistochemical Study of 30 Cases of Canine Meningioma. Journal of Comparative Pathology. 135(4): 200-207.
Patnaik A.K., Kay W.J. & Hurvitz A.I. 1986. Intracranial Meningioma: A Comparative Pathologic Study of 28 Dogs. Veterinary Pathology. 23(4): 369-373.
Petersen S.A., Sturges B.K., Dickinson P.J., Pollard R.E., Kass P.H., Kent M.S., Vernau K. & Lecouteur R.A. & Robert Higgins R. 2008. Canine intraspinal meningiomas: Imaging features, histopathologic classification, and long-term outcome in 34 dogs. Journal of Veterinary Internal Medicine. 22: 946-953.
Santos R.P., Fighera R.A., Beckmann D.V., Brum J.S., Ripplinger A., P. Neto D., Baumhardt R. & Mazzanti A. 2012. Neoplasmas envolvendo o sistema nervoso central de cães: 26 casos (2003-2011). Pesquisa Veterinária Brasileira. 32(2): 153-158.
Valentim L.G., Marcasso R.A., Bracarense A.P.F.L. & Bahr Arias M.V. 2016. Spinal Neoplasm in Dogs. Acta Scientiae Veterinariae. 44(1): 1-10.
Published
How to Cite
Issue
Section
License
This journal provides open access to all of its content on the principle that making research freely available to the public supports a greater global exchange of knowledge. Such access is associated with increased readership and increased citation of an author's work. For more information on this approach, see the Public Knowledge Project and Directory of Open Access Journals.
We define open access journals as journals that use a funding model that does not charge readers or their institutions for access. From the BOAI definition of "open access" we take the right of users to "read, download, copy, distribute, print, search, or link to the full texts of these articles" as mandatory for a journal to be included in the directory.
La Red y Portal Iberoamericano de Revistas Científicas de Veterinaria de Libre Acceso reúne a las principales publicaciones científicas editadas en España, Portugal, Latino América y otros países del ámbito latino