Short-term clinical outcomes of 220 dogs with thoraco-lumbar disc disease treated by mini-hemilaminectomy.

Thoraco-lumbar intervertebral disc extrusion is a common condition seen in veterinary practice. Although there are different surgical techniques described for decompression, most of these techniques are based on the surgeon's preference or experience rather than clinical research. Our objective was to determine the clinical outcomes, using return to ambulation and micturition, as well as complication rates, in a large cohort of dogs by using a mini-hemilaminectomy for decompression of the thoraco-lumbar spinal cord with Hansen type I thoraco-lumbar intervertebral disc extrusions (IVDE). A retrospective study was performed on dogs presented for acute thoraco-lumbar IVDE undergoing surgical decompression. In total, 252 spinal decompression surgeries were performed. The recovery rates for patients graded with a modified Frankel score (MFS) of 5 to 0 were 100%, 99%, 100%, 96%, 86% and 64%, respectively. The mean days to micturition across all the MFS 5-0 were 1.5 (standard deviation [SD] ± 0.7), 1.8 (SD ± 1), 4.3 (SD ± 1.7), 6.4 (SD ± 2.2), 9.3 (SD 3) and 11.9 (SD ± 2.2), respectively. The mean days to ambulation across all the groups 5-0 were 2 (SD ± 0.7), 2.6 (SD ± 1), 7.6 (SD ± 4.4), 10.1 (SD ± 2.5), 16.1 (SD ± 2.9) and 19.3 (SD ± 2.6), respectively. Postoperative complications were seen in 32 of the surgeries, with a complication rate of 13%. Minor complications accounted for 38% of all complications, and major complications constituted 62% of all complications. In total, 15 dogs died or were euthanised as a direct result of thoraco-lumbar disc extrusion or the surgical procedure, with a mortality rate of 6% across all groups. A mini-hemilaminectomy provides similar clinical outcomes described in the literature for other methods of spinal cord decompressive surgery, and it also provides patients with similar short-term outcomes to other described decompressive surgical techniques in the dog, which have been described in the literature.

Hemilaminectomy for thoracolumbar Hansen Type I intervertebral disk disease in ambulatory dogs with or without neurologic deficits: 39 cases (2008-2010).

OBJECTIVE: To describe prognostic factors, outcome, and time to recovery among ambulatory dogs having hemilaminectomy for Hansen Type I intervertebral disk disease. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs (n = 38; 39 hemilaminectomies). METHODS: Medical records (January 2008-May 2010) on all dogs that had hemilaminectomy for Hansen Type I intervertebral disk disease were reviewed. Records for dogs that were ambulatory preoperatively were analyzed for signalment, duration and severity of signs, presence of neurologic deficits, and postoperative outcome. Dogs were categorized based on Frankel score and subcategorized by their level of conscious proprioceptive (CP) deficit. Postoperatively, time to ambulation and to regain normal CP responses was recorded. Results for each group were compared using a χ(2) test and considered significant when P < .05. Recovery times were analyzed using a Cox proportional hazards model. RESULTS: Seven dogs were categorized as modified Frankel grade I preoperatively and 32 dogs as grade II with varying levels of deficits (1 of these dogs had previously been operated as grade II and was reoperated again as grade II). Increasing degree of CP deficit preoperatively was significantly correlated with longer time to ambulation (P = .005) as well as longer time to CP normal (P = .01). Duration of signs was not significantly correlated with time to ambulation or neurologic recovery for either grade I or II dogs. CONCLUSIONS: Most dogs recovered well with surgical decompression. Increasing degree of deficits preoperatively is significantly correlated with longer recovery time.

Evaluation of topical epidural morphine for postoperative analgesia following hemilaminectomy in dogs.

A randomized prospective study was conducted in dogs undergoing hemi-laminectomy procedures for Hansen type I disk protrusion to compare postoperative analgesia achieved with topical spinal application of morphine versus saline. An absorbable gelatin sponge was placed in the defect next to the dura and soaked with either preservative-free morphine (0.1 mg/kg) or saline (0.1 ml/kg) just before wound closure. For 48 hours after surgery, dogs were monitored for pain using visual analog and numeric descriptive scales and given rescue analgesia according to study guidelines. A Kaplan-Meier survival analysis revealed that dogs in the morphine group had a longer (13.3 +/- 3.6 hours) duration of postoperative analgesia than those in the control saline group (5.3 +/- 1.8 hours), and dogs in the morphine group also required fewer doses of additional pain medication. Preservative-free morphine administered topically via an absorbable gelatin sponge appears to be a promising method to alleviate postoperative pain in dogs undergoing hemilaminectomy procedures.

Influence of intervertebral disc fenestration at the herniation site in association with hemilaminectomy on recurrence in chondrodystrophic dogs with thoracolumbar disc disease: a prospective MRI study.

OBJECTIVE: To describe the influence of fenestration at the disc herniation site on recurrence in thoracolumbar disc disease of chondrodystrophoid dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Chondrodystrophic dogs (n=19). METHODS: Dogs were divided into 2 groups: group 1 (9 dogs) had thoracolumbar disc extrusion (Hansen type I) treated by hemilaminectomy and concomitant fenestration of the affected intervertebral disc and group 2 (10 dogs) had hemilaminectomy without fenestration. All dogs had 3 magnetic resonance imaging (MRI) examinations: preoperatively, immediately postoperatively to assess removal of herniated disc material, and again 6 weeks after surgery. RESULTS: There were 13 male and 6 female dogs; mean age, 7.1 years. Thoracolumbar disc herniation was confirmed with MRI. Immediate post surgical MRI revealed that the herniated disc removal was complete in all but 1 dog and that fenestration did not lead to complete removal of nucleus pulposus within the intervertebral disc space. On the 3rd MRI examination, none of the group 1 dogs had further disc material herniation at the fenestrated site. Six of the 10 group 2 dogs had a recurrence of herniation leading to clinical signs in 3 dogs (pain in 2 dogs, paresis in 1 dog). CONCLUSION: In thoracolumbar disc herniation, fenestration of the affected intervertebral disc space prevents further extrusion of disc material. CLINICAL RELEVANCE: Fenestration reduces the risk of early recurrence of disc herniation and associated postoperative complications.

The assessment of the usefulness of hemilaminectomy without fenestration in the treatment of thoracolumbar disc disease in chondrodystrophic dogs.

The aim of the publication is to assess the effectiveness of the treatment of type I disc extrusion according to Hansen by using the method of hemilaminectomy without fenestration. The evaluated clinical material comprised 36 chondrodystrophic dogs in which 38 surgical procedures were performed. All dogs were administered corticosteroid during the operation. Dachshunds made up to 79% of patients. In 34 cases grainy mass was extracted from the vertebral canal. In two cases it was plaster-like mass and in other two--granulo-chondral. Most often (12 cases) the prolapse of the nucleus pulposus was observed between the first and second lumbar vertebra. There was one case of the postoperative pyogenic infection of the wound. Recovery was observed in all dogs with 3rd grade clinical signs, 17 out of 18 dogs with 4th grade and 8 out of 13 dogs with 5th grade of dysfunction severity. The recovery time of the dog depended in the statistically significant way on the severity of symptoms and the grade of the present disease (p<0.00005). There did not appear to be any statistically significat relationship between the recovery time and the duration of symptoms pre operatively (p=0.42), the time of non-ambulatory status (p=0.27) and the breed of the dog (p=0.81).

Hemilaminectomy for the treatment of thoracolumbar disc disease in the dog: a follow-up study of 40 cases.

A study was made of dogs with Hansen type I thoracolumbar disc extrusions that had been treated by hemilaminectomy and fenestration of the affected disc. Follow-up information was available for 40 dogs undergoing treatment over a five-year period. The follow-up period ranged from 12 to 72 months (mean 34 months). The case details and the results of treatment of these 40 dogs are presented. All dogs were graded according to the degree of neurological dysfunction at the time of initial presentation and at the conclusion of the study period. Twenty-seven dogs (68 per cent) had no detectable signs of neurological dysfunction or thoracolumbar pain at the final assessment and a further eight dogs (20 per cent) had mild ambulatory paraparesis but were regarded by their owners as functional pets. Recurrence of neurological signs consistent with thoracolumbar disc disease was seen in five dogs (13 per cent) and was successfully resolved completely in one of three dogs that were treated.

Thoracolumbar intervertebral disk disease in large, nonchondrodystrophic dogs: a retrospective study.

Medical records of 62 large, nonchondrodystrophic dogs diagnosed with thoracolumbar intervertebral disk disease between March 1986 and February 1996 were reviewed. Fifty-seven (92%), primarily mixed-breed dogs (mean age, 6.6 years) had Hansen type I disease. Fifty-eight percent had acute onset. The interspace between the first (L1) and second (L2) lumbar vertebrae was affected most commonly. The outcomes of the 48 dogs available for follow-up after undergoing laminectomies were evaluated. Surgical success rate and mean time to walking for nonambulatory dogs with deep pain perception was 90% and seven weeks, respectively. Thirty-nine percent had residual deficits. Following surgery, 12% had recurrence of disk protrusion/extrusion at a different site.