Takeshi Aikawa

Long-term neurologic outcome of hemilaminectomy and disk fenestration for treatment of dogs with thoracolumbar intervertebral disk herniation: 831 cases (2000–2007)

OBJECTIVE To determine the proportion of dogs with thoracolumbar intervertebral disk herniation (IVDH) that successfully recovered following hemilaminectomy and fenestration, the time to ambulation (TTA) in affected dogs after surgery, and the frequency of urinary and fecal incontinence in recovered dogs and to document long-term complications. DESIGN Retrospective case series. ANIMALS 831 dogs with thoracolumbar IVDH treated by hemilaminectomy and concomitant disk fenestration by the same surgeon. PROCEDURES For all dogs, neurologic deficits before surgery had been assessed with a modified grading system. Dogs were reexamined after surgery over a period of 3 to 6 months, and follow-up evaluation was performed at > 12 months. The proportion of dogs that neurologically improved after surgery, TTA, and incidence of fecal or urinary incontinence in recovered dogs were compared among dogs with various grades of neurologic dysfunction before surgery. RESULTS Of 831 dogs, 122 had unsuccessful outcomes and 709 had successful outcomes. Of 620 dogs with intact deep nociception before surgery, 606 (97.7%) were ambulatory after surgery. Despite maintaining the ability to walk, 7 dogs were judged to have an unsuccessful outcome because the severity of ataxia did not improve. Of 211 paraplegic dogs with loss of deep nociception, 110 (52.1%) dogs became ambulatory after surgery. Long-term complications included incontinence, permanent neurologic deterioration, and self-mutilation. Dogs with paraplegia before surgery had a higher frequency of urinary or fecal incontinence, compared with dogs that were ambulatory. CONCLUSIONS AND CLINICAL RELEVANCE Prognosis for dogs with thoracolumbar IVDH that retain deep nociception in at least 1 of the pelvic limbs or tail before surgery was good.

Recurrent thoracolumbar intervertebral disc extrusion after hemilaminectomy and concomitant prophylactic fenestration in 662 chondrodystrophic dogs.

OBJECTIVES To determine the prevalence and location of recurrent thoracolumbar intervertebral disc extrusion (T-L IVDE) after hemilaminectomy with prophylactic fenestration (PF) and to document PF-related complications. STUDY DESIGN Retrospective case series. SAMPLE POPULATION Chondrodystrophic dogs (n = 793). METHODS In 662 successfully recovered dogs (>1 year follow-up), the prevalence of dogs with recurrent T-L IVDE that required a 2nd surgery and dogs with clinical signs that improved without surgery was evaluated. Prevalence of second disc extrusions (SDEs) within T11-L4 intervertebral discs was compared between PF discs and non-PF discs. RESULTS T-L SDEs were intraoperatively confirmed in 15 dogs (2.3%), 2-61 months after initial surgery and 66 dogs (10.0%) had signs of T-L IVDE recurrence that improved without surgery (mean follow-up, 44.7 months). No dog had further extrusion at the initial T-L site. SDE occurred at a PF disc (n = 1), adjacent to PF discs (8), or at distant discs (6). Prevalence of SDE in non-PF discs was 26.2 times higher than PF discs (95% CI: 3.4, 203.4; P < .001). Major PF-related complications included iatrogenic introduction of the disc material into the spinal canal (n = 1), and vertebral subluxation/instability (3) at 1-88 months postoperatively. CONCLUSION SDE is more likely to occur at non-PF discs than PF discs when PF is performed at spaces predisposed to disc extrusion. PF is a safe and effective treatment to prevent SDE in chondrodystrophic dogs.

Modified Ventral Stabilization Using Positively Threaded Profile Pins and Polymethylmethacrylate for Atlantoaxial Instability in 49 Dogs

OBJECTIVE To describe diagnostic findings, complications, and long-term outcome of dogs with atlantoaxial instability (AAI) that had modified ventral stabilization with positively threaded profile pins and polymethylmethacrylate by 1 surgeon and to evaluate the potential prognostic indicators. STUDY DESIGN Retrospective case series. ANIMALS Dogs (n = 49) with AAI. METHODS Medical records (2000-2010) of dogs with AAI that had modified ventral stabilization were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, and outcomes were retrieved. Age, neurologic grade, duration of clinical abnormalities, dens abnormalities, and MRI findings were evaluated as the potential predictors for recovery. Age and cancellous bone grafting were evaluated as the potential predictors of postoperative pin breakage. RESULTS Two dogs died during the perioperative period. In 47 dogs with follow up (median: 29 months; range, 4-110 months), 46 dogs (94%) improved neurologically after surgery, but 1 dog did not become ambulatory. There were no long term complications that resulted in serious neurologic deterioration or that required additional surgery. Partial pin breakage (1-5 pins) occurred in 16 dogs at 1-27.5 months (median, 5 months) without neurologic deterioration. Only the nonambulatory preoperative grade was significantly (P = .002) associated with non/incomplete recovery compared with ambulatory dogs. CONCLUSIONS Adequate stabilization of the vertebrae and improved neurologic status were achieved in most dogs with AAI using a modified ventral stabilization technique with positively threaded profile pins and polymethylmethacrylate.

Epidural idiopathic sterile pyogranulomatous inflammation causing spinal cord compressive injury in five Miniature Dachshunds.

OBJECTIVE To characterize the clinical signs, diagnostic and surgical findings, and outcome of dogs with idiopathic sterile pyogranulomatous inflammation (ISP) of epidural fat causing spinal cord compression. STUDY DESIGN Retrospective study. ANIMALS Dogs (n=5). METHODS Dogs with epidural ISP (2002-2006) were identified retrospectively. Inclusion criteria were neurologic examination, myelography, and definitive diagnosis of ISP confirmed by surgery and histopathologic examination of epidural spinal cord compressive tissue. RESULTS The most common clinical sign was paraparesis/paraplegia. No abnormalities were detected by laboratory testing or survey spine radiographs. On myelography, extradural spinal cord compressions were focal (dogs 1, 3, and 5) or multifocal (dogs 2 and 4). Surgical decompression of the spinal cord was completed by hemilaminectomy. Epidural fat collected surgically had pyogranulomatous inflammation of unknown cause and was histologically similar to subcutaneous ISP. All dogs had good long-term neurologic outcome (10-45 months follow-up). Some dogs had episodes of ISP at other sites before or after surgical treatment of epidural ISP, suggesting there may be a systemic form of ISP. CONCLUSION Epidural ISP may cause a spinal cord compressive lesion in Miniature Dachshunds, which can be treated by surgical decompression of the spinal cord with or without administration of adjunctive steroids. CLINICAL RELEVANCE Epidural ISP should be considered as a possible cause of thoracolumbar myelopathy for Miniature Dachshunds.

Hemilaminectomy and vertebral stabilization for thoracolumbar intervertebral disc associated dynamic compression in 11 dogs

OBJECTIVE To describe the diagnostic findings, surgical technique and outcome in dogs with thoracolumbar intervertebral disc-associated dynamic compression. STUDY DESIGN Retrospective case series. ANIMALS Client owned dogs (n = 11). METHODS Medical records (2005-2010) of dogs with a stress myelographic diagnosis of spinal cord injury due to thoracolumbar intervertebral disc-associated dynamic compression with inconclusive compression in the neutral myelographic views that had hemilaminectomy and vertebral stabilization were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, surgical techniques and outcomes were retrieved. Follow-up clinical and radiographic evaluations were performed immediately, and at approximately one, two, and six months postoperatively as well as at annual follow-up examinations. RESULTS The stress myelography demonstrated distinct ventral dynamic compression due to bulging of the disc and additional dorsal compression due to infolding of the ligamentum flavum in some cases. The median percentage of post-stress reduction in spinal cord height on the lateral view was 18.0% (9.8-27.2%). All dogs recovered after surgery and at follow-up examinations were still ambulatory (median: 45 months, range: 7 to 94 months). CONCLUSIONS AND CLINICAL RELEVANCE Thoracolumbar intervertebral disc degeneration may result in disc-associated dynamic compression. Stress myelography was an effective means of diagnosing this condition and hemilaminectomy with vertebral stabilization was an effective treatment resulting in long-term neurological improvement in all dogs.

Clinical Outcomes and Complications after Open Reduction and Internal Fixation Utilizing Conventional Plates in 65 Distal Radial and Ulnar Fractures of Miniature- and Toy-Breed Dogs

OBJECTIVE  This article aims to evaluate clinical outcomes and complications of distal radial and ulnar fractures in miniature- and toy-breed dogs treated with conventional bone plate fixation. METHODS  Medical records (2001-2010) of miniature- and toy-breed dogs with distal radial and ulnar fractures repaired with open reduction and internal fixation utilizing conventional plates were reviewed. The inclusion criteria were body weight of <7 kg, fracture located in the distal antebrachium (distal-to-total radial length ratio < 0.4) and follow-up radiographs available. RESULTS  All 65 fractures healed without developing non-union, and had a successful return to normal function (median follow-up: 73 months; range: 2-149 months). Minor complication in seven fractures and major complication in four fractures were identified. CLINICAL SIGNIFICANCE  Open reduction and conventional plate fixation of distal radial and ulnar fractures in miniature- and toy-breed dogs are effective means of fixation that result in normal functional outcome without developing non-union.

Use of skin stretchers for single-stage bilateral mastectomies in a dog and a cat

OBJECTIVE To describe the application of skin stretchers for closure of single-stage bilateral mastectomies in a dog and a cat. STUDY DESIGN Clinical case report. ANIMALS A 12-year-old intact female Miniature Dachshund and a 13-year-old spayed female domestic short-hair cat. METHODS Skin stretchers were applied to the site of the skin adjacent to mammary glands for 2-4 days before surgery. Cable tension was adjusted every 6-8 hours to elongate the skin and to achieve primary closure of single-stage bilateral mastectomy without tension. RESULTS Wound closure after single-stage bilateral mastectomy was achieved without tension or major complication in both animals. CONCLUSION Use of skin stretchers allows primary closure of single-stage bilateral mastectomy in dogs and cats.

Ganglion cyst arising from the composite occipito-atlanto-axial joint cavity in a cat

A four-year-old, female spayed Domestic Longhaired cat was referred for evaluation with a two month history of initial inability to jump progressing to ambulatory tetraparesis. Magnetic resonance imaging studies demonstrated a cystic lesion arising from the composite occipito-atlanto-axial joint cavity and extending to the region of the occipital bone and the axis. The lesion surrounded the spinal canal, causing moderate dorsal spinal cord compression at the atlanto-occipital joint. A dynamic myelographic study demonstrated attenuation of the dorsal contrast column at the atlanto-occipital joint when the cervical spine was positioned in extension. Partial excision of the cyst capsule by a ventral approach resulted in long-term (64 months) resolution of clinical signs. Histological evaluation was consistent with a ganglion cyst. An intra-spinal ganglion cyst arising from the composite occipito-atlanto-axial joint cavity may be considered as an uncommon differential diagnosis for cats with cervical myelopathy.

Recurrent Thoracolumbar Intervertebral Disc Extrusion after Hemilaminectomy and Concomitant Prophylactic Fenestration in 662 Chondrodystrophic Dogs: Recurrent T-L IVDE after Hemilaminectomy and PF

OBJECTIVES To determine the prevalence and location of recurrent thoracolumbar intervertebral disc extrusion (T-L IVDE) after hemilaminectomy with prophylactic fenestration (PF) and to document PF-related complications. STUDY DESIGN Retrospective case series. SAMPLE POPULATION Chondrodystrophic dogs (n = 793). METHODS In 662 successfully recovered dogs (>1 year follow-up), the prevalence of dogs with recurrent T-L IVDE that required a 2nd surgery and dogs with clinical signs that improved without surgery was evaluated. Prevalence of second disc extrusions (SDEs) within T11-L4 intervertebral discs was compared between PF discs and non-PF discs. RESULTS T-L SDEs were intraoperatively confirmed in 15 dogs (2.3%), 2-61 months after initial surgery and 66 dogs (10.0%) had signs of T-L IVDE recurrence that improved without surgery (mean follow-up, 44.7 months). No dog had further extrusion at the initial T-L site. SDE occurred at a PF disc (n = 1), adjacent to PF discs (8), or at distant discs (6). Prevalence of SDE in non-PF discs was 26.2 times higher than PF discs (95% CI: 3.4, 203.4; P < .001). Major PF-related complications included iatrogenic introduction of the disc material into the spinal canal (n = 1), and vertebral subluxation/instability (3) at 1-88 months postoperatively. CONCLUSION SDE is more likely to occur at non-PF discs than PF discs when PF is performed at spaces predisposed to disc extrusion. PF is a safe and effective treatment to prevent SDE in chondrodystrophic dogs.