Oh, MI!

Intervertebral disk disease, a common disabling condition in dogs, may necessitate surgical decompression for severe cases. Surgical approaches to the spine in dogs require extensive muscular dissection to access the vertebrae and spinal cord, especially in large-breed dogs in which degenerative lumbosacral stenosis is common. Comparatively, the approaches used by human neurosurgeons have evolved to a minimally invasive (MI) surgical strategy to reduce patient morbidity for similar conditions.

This study compared an MI approach to a traditional open approach for lumbosacral decompression in a canine cadaveric model (n = 8 per group). The MI approach used a human lumbar retractor. The incision length was reduced by >50% in the MI group (55 mm vs 116 mm), although the operative time was 25% greater than the open approach (18.5 minutes vs 14.6 minutes). The authors note that this small difference in surgical time would likely have little effect on overall surgical time in actual live patients with diseased spines. There was no difference in the size of the laminectomy or damage to the neurovascular structures. This study demonstrated the potential utility of an MI lumbar spinal retractor for lumbosacral decompression in dogs. Further studies are needed to confirm the success seen here in live clinical patients and to assess the proposed recovery benefits.

A parallel trend toward MI approaches has occurred in human and veterinary surgery for endoscopic, laparoscopic, and arthroscopic procedures, albeit delayed in the veterinary side. In human neurosurgery, there has been a similar evolution that remains to be explored in veterinary patients. Much of the evolution is driven by improved patient outcomes with reduced morbidity. This is facilitated by the use of an extensive armamentarium of scopes and retractors such as that used in this study. The practicality of such an approach appears feasible in larger patients, although (similar to other MI procedures) this may be limited by disproportionately large equipment vs small patient size.—Jason Bleedorn, DVM, DACVS