Introduction of Disc Material into the Vertebral Canal by Fenestration of Thoracolumbar Discs Following Decompressive Surgery

Abstract

Objective Intervertebral disc extrusion is a common disease affecting chondrodystrophic dogs. It has been reported that fenestration of thoracolumbar intervertebral discs reduces recurrence of disc extrusion and is associated with a low complication rate. One complication reported is iatrogenic introduction of disc material into the canal directly following fenestration. This study aimed to ascertain if, and at what frequency, additional disc material may be introduced into the vertebral canal by fenestration of the affected disc following decompressive surgery.

Study Design Twenty-one dogs that underwent hemilaminectomy and disc fenestration for the treatment of thoracolumbar intervertebral disc extrusion had intraoperative assessment of the vertebral canal before and after fenestration. The spinal cord was first decompressed by hemilaminectomy and removal of all visible extruded disc material within the vertebral canal. Once no further material was visible, manual fenestration of the affected disc was performed. The vertebral canal was re-inspected, and the presence or absence of additional material was noted and included in the surgery report.

Results Seven dogs showed the presence of new disc material in the vertebral canal post fenestration.

This preliminary study shows that additional disc material can be forced into the vertebral canal by fenestration following decompressive surgery, with a frequency of 7/21.

Conclusion This illustrates the importance of checking the vertebral canal after fenestration of an extruded intervertebral disc.

Keywords

fenestration - intervertebral - disc - vertebral canal - dog

Authors’ Contributions

Georgina Harris contributed to conception of study, study design, acquisition of data, and data analysis and interpretation. Paul Freeman contributed to conception of study, study design, acquisition of data and data analysis and interpretation. Both the authors drafted, revised and approved the submitted manuscript.

• References

• 1 Freeman P, Jeffery ND. Re-opening the window on fenestration as a treatment for acute thoracolumbar intervertebral disc herniation in dogs. J Small Anim Pract 2017; 58 (04) 199-204
• 2 Brisson BA. Intervertebral disc disease in dogs. Vet Clin North Am Small Anim Pract 2010; 40 (05) 829-858
• 3 Brisson BA, Moffatt SL, Swayne SL, Parent JM. Recurrence of thoracolumbar intervertebral disk extrusion in chondrodystrophic dogs after surgical decompression with or without prophylactic fenestration: 265 cases (1995-1999). J Am Vet Med Assoc 2004; 224 (11) 1808-1814
• 4 Brisson BA, Holmberg DL, Parent J, Sears WC, Wick SE. Comparison of the effect of single-site and multiple-site disk fenestration on the rate of recurrence of thoracolumbar intervertebral disk herniation in dogs. J Am Vet Med Assoc 2011; 238 (12) 1593-1600
• 5 Aikawa T, Fujita H, Shibata M, Takahashi T. Recurrent thoracolumbar intervertebral disc extrusion after hemilaminectomy and concomitant prophylactic fenestration in 662 chondrodystrophic dogs. Vet Surg 2012; 41 (03) 381-390
• 6 Tomlinson J. Tetraparesis following cervical disk fenestration in two dogs. J Am Vet Med Assoc 1985; 187 (01) 76-77
• 7 Bartels KE, Higbee RG, Bahr RJ, Galloway DS, Healey TS, Arnold C. Outcome of and complications associated with prophylactic percutaneous laser disk ablation in dogs with thoracolumbar disk disease: 277 cases (1992-2001). J Am Vet Med Assoc 2003; 222 (12) 1733-1739
• 8 Roach WJ, Thomas M, Weh JM, Bleedorn J, Wells K. Residual herniated disc material following hemilaminectomy in chondrodystrophic dogs with thoracolumbar intervertebral disc disease. Vet Comp Orthop Traumatol 2012; 25 (02) 109-115
• 9 Forterre F, Gorgas D, Dickomeit M, Jaggy A, Lang J, Spreng D. Incidence of spinal compressive lesions in chondrodystrophic dogs with abnormal recovery after hemilaminectomy for treatment of thoracolumbar disc disease: a prospective magnetic resonance imaging study. Vet Surg 2010; 39 (02) 165-172
• 10 Holmberg DL, Palmer NC, VanPelt D, Willan AR. A comparison of manual and power-assisted thoracolumbar disc fenestration in dogs. Vet Surg 1990; 19 (05) 323-327