When Prevention Backfires: Nerve Root Compression After Prophylactic Disc Fenestration in a Dog

Lumbar nerve root compression resulting from extrusion of intervertebral disc material after prophylactic disc fenestration

F Harris, C Gordon, A Giles, L Wilson

Background

Thoracolumbar intervertebral disc disease (IVDD) is a common cause of neurological dysfunction in dogs, particularly chondrodystrophic breeds. Surgical decompression via hemilaminectomy is frequently combined with intervertebral disc fenestration to reduce the risk of recurrent disc extrusion, including prophylactic fenestration of adjacent degenerated discs. Although fenestration is generally considered safe, reported complications are rare. This case report describes a previously unreported complication in which prophylactic disc fenestration resulted in lateral extrusion of disc material causing lumbar nerve root compression.

Methods

A 5-year-old male neutered miniature dachshund presented with acute nonambulatory paraparesis and thoracolumbar spinal hyperpathia. Computed tomography (CT) identified a severe left-sided intervertebral disc extrusion at L2/3. A left-sided hemilaminectomy and disc fenestration were performed at L2/3, with additional prophylactic fenestration at L3/4 due to evidence of disc degeneration. Persistent and worsening spinal hyperpathia postoperatively prompted repeat CT imaging, followed by a second surgical intervention to address newly identified pathology.

Results

Initial surgery resulted in neurological improvement; however, marked spinal hyperpathia and kyphosis persisted postoperatively. Repeat CT revealed laterally extruded disc material from the prophylactically fenestrated L3/4 disc, causing compression of the left L3 nerve root without spinal canal involvement. A second surgery successfully removed the extraforaminal disc material, resulting in rapid resolution of pain and kyphosis. At 2-month follow-up, the dog was ambulatory with mild pelvic limb ataxia and no residual spinal pain.

Limitations

This report describes a single clinical case, limiting generalisability. Advanced imaging was not performed immediately postoperatively after the first surgery, which may have delayed recognition of the complication. As a case report, causal mechanisms underlying the complication cannot be definitively established.

Conclusions

This case documents a novel and clinically significant complication of prophylactic intervertebral disc fenestration, in which residual nucleus pulposus extruded laterally and caused lumbar nerve root compression. Persistent or atypical postoperative spinal pain should prompt repeat advanced imaging, even in the presence of improving neurological function. While fenestration remains a valuable preventive technique, this report highlights that it is not without risk and should be considered as a potential source of postoperative complications.

Disclaimer: The summary generated in this email was created by an AI large language model. Therefore errors may occur. Reading the article is the best way to understand the scholarly work. The figure presented here remains the property of the publisher or author and subject to the applicable copyright agreement. It is reproduced here as an educational work. If you have any questions or concerns about the work presented here, reply to this email.