Spinal Decompression by Hemilaminectomy and Corpectomy-Wrong Side Surgery May Not Affect the Outcome: Preliminary Results

Thoracolumbar Intervertebral Disk Extrusion (IVDE) is a frequent and important cause of paraparesis, paraplegia and urinary incontinence in dogs. This study retrospectively compares the effect of approaching the correct or wrong side and the effect on the outcome. Financial constraints mean that not every surgeon has CT or MRI at their disposal and many owners cannot afford the fees for these advanced imaging techniques. Myelography is still used to make a diagnosis and localize the lesion but the weakness of using myelography is that the right versus left side cannot always be clarified. The wrong side was approached inadvertently in some cases based on the results of myelography due to the inaccuracy of myelography indicating the correct side to operate on. Two similar groups of chondrodystrophic dogs with acute clinical signs of thoracolumbar Intervertebral Disc Extrusion (IVDE) were treated with Hemilaminectomy (HL) for correct side and HL with Corpectomy (CP) for the wrong side. Combining HL with CP for surgical approach for wrong side is a new approach. Analysis was performed to compare the effect that approaching the correct or wrong side in the surgical procedure has on the outcome. An 83.3% successful outcome rate was obtained using the HL or HL/CP procedure irrespective of the side in which the surgery was approached. The biggest cause of poor outcome was the duration of symptoms, independently of the approaching side. The better results were obtained when the acute symptoms were treated before 24 hours. Operating on wrong side does not require a second opening from the correct side to achieve spinal decompression, although the degree of decompression was not analysed. Furthermore, the use of a more extensive decompressive technique produces similar results to HL procedure, even if it is approached from the wrong side.