Effect of durotomy on functional outcome of dogs with type I thoracolumbar disc extrusion and absent deep pain perception

Summary

Spinal cord durotomy is performed as a diagnostic aid in determining spinal cord structural integrity, and this may be useful as an indicator of prognosis in cases with loss of deep pain perception (DPP). It has been suggested that a durotomy may relieve intramedullary compression but there is some debate about the therapeutic value. The purpose of this study was to compare ambulatory outcome of dogs that had loss of DPP treated with hemilaminectomy with durotomy versus hemilaminectomy without durotomy. Medical records of 81 dogs diagnosed with type I thoracolumbar IVD were reviewed. Dogs were included in the study if DPP was absent upon initial neurological examination and surgical decompression via hemilaminectomy was performed. Of the 81 cases, 48 were included in this study. The number of dogs that recovered ambulatory function were compared between durotomy and nondurotomy groups with a chi-squared test (p<0.05). No differences were found. The findings of this study suggest that durotomy is useful as a diagnostic modality and that performing a durotomy does not significantly affect post-operative recovery of voluntary motor function.

Keywords

Durotomy - deep pain perception - hemilaminectomy - thoracolumbar

• References

• 1 Jerram RM. et al. Acute thoracolumbar disk extrusion in dogs-part I. Compend Cont Educ 1999; 21 (10) 922-30.
• 2 Jerram RM. et al. Acute thoracolumbar disc extrusion in dogs-part II. Compend Cont Educ 1999; 21 (11) 1037-47.
• 3 Seim III HB. Surgery of the Thoracolumbar Spine. Fossum TW. In: Small Animal Surgery. St. Louis: Mosby Inc; 2002: 1269-301.
• 4 Toombs JP. et al. Intervertebral disc disease. Slatter D. In: Textbook of Small Animal Surgery. Philadelphia: WB Saunders Co; 1993: 1080-6.
• 5 Toombs JP. et al. Intervertebral disc disease. Slatter D. In: Textbook of Small Animal Surgery. Philadelphia: WB Saunders Co; 2003: 1193-209.
• 6 Scott HW. et al. Laminectomy for 34 dogs with thoracolumbar intervertebral disc disease and loss ofdeeppainperception. J Small Anim Pract 1999; 40: 417-22.
• 7 Thomas WB. et al. Performing the neurological examination. Dewey CW. In: A practical guide to canine and feline neurology. Ames: Iowa State Press; 2003: 31-55.
• 8 Davis GJ. et al. Prognostic indicators for time to ambulation after surgical decompression in non-ambulatory dogs with acute thoracolumbar disk extrusions: 112 cases. Vet Surg 2002; 31 (6) 513-8.
• 9 Cudia SP. et al. Thoracolumbar intervertebral disk disease in large, nonchondrodystrophic dogs: A retrospective study. J Am Anim Hosp Assoc 1997; 33: 456-60.
• 10 Duval J. et al. Spinal cord swelling as a myelographic indicator of prognosis: a retrospective study in dogs with intervertebral disc disease and loss of deep pain perception. Vet Surg 1996; 25: 6-12.
• 11 Scott HW. et al. Hemilaminectomy for the treatment of thoracolumbar disc disease in the dog: A follow-up study of 40 cases. J Small Anim Pract 1997; 38: 488-94.
• 12 Kornegay JN. et al. Intervertebral disk disease: Treatment guidelines. Kirk RW, Bonagura JD. In: Kirk's Current Veterinary Therapy XI: Small Animal Practice. Philadelphia: WB Saunders Co 1992; 1013-8.
• 13 Hill TP. et al. Lumbar spine stability following hemilaminectomy, pediculectomy, and fenestration. Vet Comp Orthop Traumatol 2000; 13: 165-71.
• 14 Shires PK. et al. A biomechanical study of rotational instability in unaltered and surgically altered canine thoracolumbar vertebral motion units. ProgVet Neurol 1991; 2: 6-14.
• 15 Smith GK. et al. Spinal decompressive procedures and dorsal compartment injuries: Comparative biomechanical study in canine cadavers. Am JVet Res 1988; 49 (2) 266-73.
• 16 Seim III HB. Hemilaminectomy for T-L disk disease. Canine Pract 1996; 21 (3) 25-9.
• 17 Bagley RS. et al. Lateral and foraminal disk extrusion in dogs. Compend Cont Educ 1996; 18 (7) 795-804.
• 18 Coates JR. Intervertebral disk disease. Vet Clinics of North America: Small Animal Practice: Common Neurological Problems 2000; 30 (1) 77-104.
• 19 Parker AJ. Durotomy and saline perfusion in spinal cord trauma. JAmAnimHosp Assoc 1975; 11: 412-3.
• 20 Trotter EJ. Canine intervertebral disk disease. Kirk RW. Current Veterinary Therapy VI: Small Animal Practice. Philadelphia: WB Saunders Co; 1977: 841-8.
• 21 Parker AJ. et al. Functional recovery from spinal cord trauma following delayed incision of spinal meninges in dogs. Res Vet Sci 1975; 18 (1) 110-2.
• 22 Amsellem PM. et al. Loss of deep pain sensation following thoracolumbar intervertebral disk herniation in dogs: treatment and prognosis. Compend Cont Educ 2003; 25 (4) 266-74.
• 23 Fingeroth JM. Treatment of canine intervertebral disc disease: recommendations and controversies. Bonagura JD, Kirk RW. In: Kirk's Current Veterinary Therapy XII: Small Animal Practice. Philadelphia: WB Saunders Co; 1995: 1146-53.
• 24 Dewey CW. Myelopathies: Disorders of the spinal cord. Dewey CW. In: A practical guide to canine and feline neurology. Ames: Iowa State Press; 2003: 277-336.
• 25 Amsellem PM. et al. Loss of deep pain sensation following thoracolumbar intervertebral disk herniation in dogs: pathophysiology. Compend Cont Educ 2003; 25 (4) 256-64.
• 26 Olby N. et al. Long-term functional outcome of dogs with severe injuries of the thoracolumbar spinal cord: 87 cases (1996-2001). JAmVet Med Assoc 2003; 222 (6) 762-9.
• 27 Trevor PB. et al. Healing characteristics of free and pedicle fat grafts after dorsal laminectomy and durotomy in dogs. Vet Surg 1991; 30: 282-90.
• 28 Olby N. Current concepts in the management of acute spinal cord injury. J Vet Intern Med 1999; 13: 399-407.
• 29 Bergman R. et al. Acute spinal cord trauma: mechanisms and clinical syndromes. Vet Med Nov 2000; 846-9.
• 30 Ducote JM. et al. Neurodiagnostics. Dewey CW. In: A practical guide to canine and feline neurology. Ames: Iowa State Press; 2003: 57-98.