The objective of this prospective pilot study is to assess the feasibility of a minimally invasive, integrated endoscopic hemilaminectomy in chondrodystrophic dogs with clinically relevant Hansen type 1 intervertebral disc extrusion (IVDE). Study subjects included five client-owned chondrodystrophic dogs under 15kg with an acute, single site IVDE between T10 and L5 of less than 90 days duration and no loss of deep pain perception. The extent of the extrusion could not exceed 2/3 the diameter of the cannula to be used as defined by magnetic resonance imaging (MRI). A postoperative MRI was performed to assess remaining spinal cord compression. If significant compression remained, patients returned to surgery for a standard, open hemilaminectomy. Only the first dog required conversion to an open approach which resulted in adequate decompression. The same dog had a significant surgical complication of iatrogenic damage to the spinal cord during the minimally invasive approach. The other 4 dogs had no complications and achieved adequate spinal cord decompression. Three dogs eventually returned to normal neurologic status and another was improved compared to presentation. One dog was euthanized for reasons unrelated to IVDE. The authors conclude that a minimally invasive, integrated endoscopic hemilaminectomy is a feasible approach and can allow for adequate decompression of the spinal cord secondary to acute, single-site extrusion. Endoscopic approaches have a steep learning curve and extra care is required in the learning phase to avoid complications. Further studies are warranted to compare the safety and efficacy of this technique to a standard approach. / Master of Science / Acute intervertebral disc extrusion, or "slipped disc", is a common spinal emergency in dogs, particularly in small, chondrodystrophic breeds like dachshunds. Surgery is aimed at removing the disc material causing spinal cord compression. The traditional approach, known as a hemilaminectomy, involves elevating the muscles along the spine over multiple vertebrae, followed by creating a window in the bone with a surgical burr. Minimally invasive spinal surgery that minimizes the elevation of muscles, has the potential to decrease postoperative pain, surgical time, hospital stay, intraoperative blood loss and recovery time. This study was designed to assess the use of a minimally invasive, integrated endoscopic approach to a hemilaminectomy in clinical patients. Five dogs were enrolled with an acute, single site intervertebral disc extrusion between T10 and L5 that was no more than 2/3 the diameter of the cannula to be used in surgery. Study subjects were chondrodystrophic breeds under 15kg. All dogs had intact deep pain perception. Spinal cord compression was assessed by magnetic resonance imaging (MRI) both before and after a minimally invasive approach. If significant acute compression remained, a standard, open approach was immediately performed. Spinal cord decompression was adequate in all but one dog which required a second procedure to remove the remaining material. This same dog had accidental damage to the spinal cord during the minimally invasive approach. Three dogs eventually returned to normal neurologic status and the dog that required a second, traditional approach surgery eventually improved compared to his preoperative status. One dog was improving but euthanized eight days later due to chronic disease unrelated to IVDE. This approach is feasible for decompressing the spinal cord after a single site, acute intervertebral disc extrusion in a chondrodystrophic dog. However, like any endoscopic surgery, previous experience is of great benefit and errors are more likely to happen during the learning phase.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/112642 |
| Date | 24 May 2021 |
| Creators | Drury, Adam Gardner |
| Contributors | Biomedical and Veterinary Sciences, Lanz, Otto I., Pancotto, Theresa Elizabeth, Sawyere Hansford, Dominique M., Bolton, Timothy |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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