Association between anesthesia duration and outcome in dogs with surgically treated acute severe spinal cord injury caused by thoracolumbar intervertebral disk herniation

Exploring the Benefits of Stroboscopic Technology and Guided Visualization in Teaching Suturing Techniques to Veterinary Medicine Students

Suturing is widely regarded to be a core competency of veterinary education. With curricular requirements expanding, training interventions that improve students' suturing skills without added time would be valuable. This study evaluated the effects of stroboscopic visual resistance training, a technique using intermittent occlusion of vision, and guided visualization on suturing technique and speed. Students' anxiety levels were also assessed. Twenty-nine veterinary students with no prior surgical experience were divided into stroboscopic, visualization and control groups. Simple interrupted, simple continuous, and cruciate patterns were taught by an American College of Veterinary Surgeons (ACVS)-boarded veterinarian in week 1, and students also took an anxiety test at this time. One-hour-long tutored practice sessions were held for each group in weeks 2, 3, 4 and 6, and assessments were conducted in weeks 5 and 7. Assessments were conducted by a second ACVS-boarded veterinarian blinded to group assignments. Students in the stroboscopic training group had faster suturing times compared to students in the control group for the cruciate pattern at week 5 (p = 0.001) and week 7 (p = 0.006), and faster times compared to students in the visualization group at week 5 (p = 0.002). Students in the stroboscopic training group had faster suturing times than the control group (p = 0.005) for the simple continuous pattern at week 7. No significant differences were observed in anxiety. There was no significant difference in technique scores for any group with any pattern at any time point. Stroboscopic training may result in faster suturing times without deterioration of suturing technique.

Epidemiology of Canine Wei Syndrome and Its Hemorheology Characteristics

Canine paraplegia is a common condition in small animal medicine, referred to as Wei Syndrome (WS) in Traditional Chinese Veterinary Medicine (TCVM). Common clinical manifestations encompass hind limb paralysis, motor dysfunction, muscle atrophy, and the absence of pain perception. WS is considered a difficult-to-treat disease in small animal practice. The objective of this study was to investigate the epidemiology of canine WS and the characteristics of hemorheology. A total of 53 dogs with WS and 53 healthy dogs were included in this study. A retrospective case-controlled study design was employed. Data regarding the gender, season of WS occurrence, breed, and age of dogs with WS, as well as hemorheology from dogs with WS and healthy dogs, were collected and analyzed using SPSS 27.0. The study findings revealed that male dogs were more susceptible to WS (77.36%, 41/53). WS cases occurred more frequently in Winter (33.96%, 18/53), and were commonly found in Poodle breeds (43.40%, 23/53). The most affected age of WS was between 3 and 6 years old (54.72%, 29/53). Except for plasma viscosity and fibrinogen, the hemorheology indices of canine WS were significantly higher than those of healthy dogs (p < 0.05), especially in male dogs, Poodles and Bulldogs, those between 3 to 10 years, and in Autumn and Winter. This study provides evidence that male Poodles and Bulldogs aged 3 to 6 years are more prone to developing WS, with Winter being the season of high disease incidence. Abnormal hemorheology is a characteristic feature in dogs with WS, which should be considered during the treatment of WS.

Recovery of ambulation in small, nonbrachycephalic dogs after conservative management of acute thoracolumbar disk extrusion

BACKGROUND

Currently, low-level evidence suggests loss of ambulation associated with acute thoracolumbar disk extrusion is best treated by decompressive spinal surgery. Conservative management can be successful, but the proportion of dogs that recover and the fate of herniated material are uncertain.

OBJECTIVES

Determine the proportion of nonambulatory dogs with conservatively treated acute thoracolumbar disk extrusion that recover ambulation and measure the change in spinal cord compression during the first 12 weeks after presentation.

ANIMALS

Seventy-two client-owned nonambulatory dogs with acute thoracolumbar intervertebral disk extrusion.

METHODS

This is a prospective cohort study. Enrolled dogs underwent magnetic resonance imaging at presentation and owners were provided with conservative management recommendations. Imaging was repeated after 12 weeks. Recovery of ambulation was defined as 10 consecutive steps without falling. Spinal cord compression was determined from the cross-sectional area of the vertebral canal and extradural compressive material at the lesion epicenter. The association between recovery and change in compression over the 12-week observational period was examined.

RESULTS

Forty-nine of fifty-one (96%; 95% confidence interval [CI], 87%-99%) of deep pain-positive and 10/21 (48%; 95% CI, 28%-68%) of deep pain-negative dogs recovered ambulation within the 12-week period. The median time to ambulation was 11 and 25 days for deep pain-positive and -negative dogs, respectively. Reduction in spinal cord compression varied among individuals from minimal to complete and apparently was unrelated to the recovery of ambulation.

CONCLUSIONS AND CLINICAL IMPORTANCE

A high proportion of conservatively treated dogs recovered ambulation after conservative management of acute thoracolumbar disk herniation. Recovery was not dependent on the resolution of compression.

Outcome of the Use of Clinical Reasoning Alone in Dogs with Acute Thoracolumbar Myelopathy and/or Pain

Acute thoracolumbar myelopathy is a common neurological presentation in dogs. Although certain spinal conditions present with characteristic clinical pictures, managing such cases with clinical reasoning alone (i.e., without cross-sectional imaging) has never been explored. The aim of this study was to define the outcome of patients with suspected intervertebral disc extrusion (IVDE), ischaemic myelopathy (IM) or acute non-compressive nucleus pulposus extrusion (ANNPE) that were managed with clinical reasoning alone. The database of the Queen's Veterinary School Hospital (Cambridge) was searched for paraparetic or paraplegic dogs with suspected IVDE or IM/ANNPE that were initially managed medically without undergoing imaging. Clinical presentation and outcome were recorded. If cross-sectional imaging was subsequently performed, information about the final diagnosis was collected and compared with the initially suspected diagnosis. A total of 123 IVDE cases were collected: 81% had a successful outcome with no imaging performed; 16% had IVDE confirmed with imaging and successful outcome with surgery or medical management; and just 3% were found to have an alternative diagnosis or were euthanised without imaging. A total of 16 IM/ANNPE cases were collected: 94% had a successful outcome, and one dog was euthanised. Successful outcomes can be obtained by using clinical reasoning alone in most dogs with suspected IVDE or IM/ANNPE.

A case series of 37 surgically managed, paraplegic, deep pain negative French bulldogs, with thoracolumbar intervertebral disc extrusion, from two English referral centres

Background

Thoracolumbar intervertebral disc extrusions (TL-IVDEs) are a common spinal disorder in dogs, especially within chondrodystrophic breeds. Loss of deep pain perception is a well-documented negative prognostic indicator in dogs with TL-IVDE. The objectives of this study were to report the rate of return of deep pain perception and independent ambulation in surgically treated, paraplegic, deep pain perception negative French bulldogs with TL-IVDEs.

Methods

A retrospective case series of deep pain perception negative dogs with TL-IVDE presenting to two referral centres between 2015 and 2020 was conducted. Medical and MRI records were reviewed, including the following quantitative MRI changes: lesion length, extent of spinal cord swelling and severity of spinal cord compression.

Results

Thirty-seven French bulldogs met the inclusion criteria, with 14 of 37 (38%) regaining deep pain perception by the time of discharge (median hospitalisation 10.0 days [interquartile range 7.0-15.5 days]) with two dogs independently ambulatory (6%). Ten of the 37 dogs were euthanased during hospitalisation. Significantly fewer dogs (3/16, 19%) with L4-S3 lesions regained deep pain perception compared to 11 of 21 (52%) of dogs with T3-L3 lesions (p = 0.048). Quantitative MRI changes were not associated with the return of deep pain perception. After discharge, with a median 1-month follow-up period, an additional three dogs regained deep pain perception and five dogs became independently ambulatory (17/37 [46%] and 7/37 [19%], respectively).

Conclusions and clinical importance

This study adds support to the contention that the recovery of French bulldogs with TL-IVDE from surgery is poor compared with other breeds; further prospective, breed-controlled studies are indicated.

Does surgical timing affect the rapidity of recovery in deep pain-entire non-ambulatory dogs with thoracolumbar intervertebral disk extrusion?

OBJECTIVE

To investigate whether the delay between onset of neurological signs and spinal cord decompression affects the time to recovery in non-ambulatory paraparetic/paraplegic dogs with deep pain perception affected by thoracolumbar intervertebral disc extrusion.

MATERIALS AND METHODS

Data on non-ambulatory dogs with preserved deep pain perception in both hindlimbs and surgically treated for thoracolumbar intervertebral disc extrusion were prospectively collected from three referral hospitals. Cox proportional hazards regression was used to explore the relationship of time until restoration of independent ambulation with age, weight, preoperative use of anti-inflammatory drugs, delay between onset of inability to walk and arrival at the clinic, time between presentation and spinal surgery and surgery time.

RESULTS

One hundred and fifty-one dogs were included. Median time from admission to surgery, including imaging, was 180 (interquartile range, 65.4 to 240) minutes. All dogs were operated within 72 hours. Follow-up was available for all 151 dogs and ranged from 1 to 21 months. All but three dogs, which were all grade IV at presentation, recovered the ability to ambulate. In both univariable and multivariable models, only duration of surgery and neurological (Frankel) grade at presentation were significantly associated with the rapidity of recovery of ambulation.

CLINICAL SIGNIFICANCE

Delay between onset of clinical signs and presentation and time between presentation and spinal surgery was not associated with the rapidity of recovery of ambulation in dogs surgically treated for thoracolumbar intervertebral disc extrusion. These results should be evaluated in the context of a limited range of delay since only 14.5% dogs had a delay ≥6.5 hours. Duration of surgery and neurological grade at presentation were significantly associated with rapidity of recovery of ambulation.

Intervertebral Disk Regeneration in a Rat Model via a Nanocomposite Collagen Hydrogel Loaded with Galanthus Extract: An In Vitro and In Vivo Study

In the current study, Galanthus extract was loaded into electrospun gelatin scaffolds using an electrospun method and then crushed. The resulting nanofibers were loaded into a collagen hydrogel to develop a filler material to treat nucleus pulposus injuries in the intervertebral disks. The nanocomposite hydrogel was studied regarding its biocompatibility, antiinflammatory activity, and swelling behavior. In Vivo study was performed in a rat model of intervertebral disk injury. Histopathological studies showed that the animals treated with the nanocomposite hydrogel restored its nucleus pulposus to a significantly higher extent than other experimental groups.

A 50-step walking test for analysis of recovery after decompressive surgery for thoracolumbar disc herniation in dogs

BACKGROUND

Despite its importance, there is no agreed definition of recovery of ambulation in dogs with spinal cord injury.

OBJECTIVES

To validate a new walking test in dogs recovering from thoracolumbar spinal cord injury.

ANIMALS

Two hundred twenty-four dogs weighing <20 kg: 120 normally ambulatory dogs, plus 104 dogs undergoing decompressive surgery for acute thoracolumbar intervertebral disc herniation.

METHODS

Prospective cohort studies. The distance each freely-ambulatory dog walked during 50 step cycles was regressed on ulna length. For each postsurgical dog, we recorded when the calculated 50-step distance was completed without falling, or their inability to complete this distance by 4 months or more after surgery. Bayesian analysis compared outcomes for presurgical neurologic categories; association of recovery with several preoperative variables was explored using logistic and time-to-event regression.

RESULTS

For control dogs, 50-step distance (m) = 1.384 × ulnar length (cm) + 2.773. In postsurgical dogs, the 50-step test provided decisive evidence that deep pain-negative dogs were less likely to recover ambulation than dogs with intact pain perception (12/29 recovered vs 71/75; Bayes factor [BF] = 5.9 × 106 ) and, if they did recover, it took much longer (median 91 days vs median 14 days; BF = 1.5 × 103 ). Exploratory analysis suggested that presurgical neurologic status (subhazard ratio [SHR] = 0.022; P < .001) and duration of presurgical anesthesia (SHR = 0.740; P = .04) were associated with rapidity of recovery.

CONCLUSIONS AND CLINICAL IMPORTANCE

This straightforward 50-step walking test provides robust data on ambulatory recovery well-suited to large scale pragmatic trials on treatment of thoracolumbar spinal cord injury in dogs.

Randomized clinical trial comparing outcomes after fentanyl or ketamine-dexmedetomidine analgesia in thoracolumbar spinal surgery in dogs

Background

Opioids are widely used for perioperative pain control in dogs undergoing spinal surgery, but alternatives may be required because data suggest that opioids exacerbate inflammation in the injured spinal cord and veterinary access to opioids may become more restricted in the future.

Objectives

To compare recovery of ambulation and other functions between spinal cord‐injured dogs receiving peri‐operative fentanyl and those receiving a ketamine‐dexmedetomidine combination.

Animals

A total of 102 client‐owned dogs undergoing decompressive surgery for thoracolumbar intervertebral disc herniation.

Methods

Randomized clinical trial. Dogs were randomized 1:1 to fentanyl or a ketamine‐dexmedetomidine combination for intra and postoperative analgesia. Primary outcome was time to recovery of ambulation; secondary outcomes were the postoperative Colorado Acute Pain Scale, the short‐form Glasgow Composite Measure Pain Scale, time to recovery of voluntary urination and time to unassisted eating.

Results

No difference was found in time to recovery of ambulation between groups (adjusted sub‐hazard ratio, 0.83; 95% confidence interval [CI], 0.55‐1.24; P = .36) or in pain scores (Colorado: χ² = 14.74; P = .32; Glasgow: χ² = 6.61; P = .76). Differences in time to recovery of eating and urination were small but favored ketamine‐dexmedetomidine (adjusted odds ratios, 3.31; 95% CI, 1.53‐7.16; P = .002 and 2.43; 95% CI, 1.00‐5.96; P = .05, respectively).

Conclusions and Clinical Importance

There was no evidence that, at the doses used, fentanyl impaired ambulatory outcome after surgery for thoracolumbar intervertebral disc herniation in dogs. Pain control appeared similar between groups. Secondary outcomes suggested minor benefits associated with ketamine‐dexmedetomidine. The ketamine‐dexmedetomidine combination appears to be a reasonable alternative to peri‐operative opioids.

ACVIM consensus statement on diagnosis and management of acute canine thoracolumbar intervertebral disc extrusion

Background

Thoracolumbar intervertebral disc extrusion (TL‐IVDE) is the most common cause of acute paraparesis and paraplegia in dogs; however, guidelines on management of the condition are lacking.

Objectives

To summarize the current literature as it relates to diagnosis and management of acute TL‐IVDE in dogs, and to formulate clinically relevant evidence‐based recommendations.

Animals

None.

Methods

A panel of 8 experts was convened to assess and summarize evidence from the peer‐reviewed literature in order to develop consensus clinical recommendations. Level of evidence available to support each recommendation was assessed and reported.

Results

The majority of available literature described observational studies. Most recommendations made by the panel were supported by a low or moderate level of evidence, and several areas of high need for further study were identified. These include better understanding of the ideal timing for surgical decompression, expected surgical vs medical outcomes for more mildly affected dogs, impact of durotomy on locomotor outcome and development of progressive myelomalacia, and refining of postoperative care, and genetic and preventative care studies.

Conclusions and Clinical Importance

Future efforts should build on current recommendations by conducting prospective studies and randomized controlled trials, where possible, to address identified gaps in knowledge and to develop cost effectiveness and number needed to treat studies supporting various aspects of diagnosis and treatment of TL‐IVDE.

Influence of Spinal Shock on the Neurorehabilitation of ANNPE Dogs

Acute noncompressive nucleus pulposus extrusion (ANNPE) is related to contusive spinal cord injuries, and dogs usually appear to be exercising vigorously at the time of onset. ANNPE has a characteristic peracute onset of clinical signs during exercise or following trauma, with non-progressive signs during the first 24 h and possibly signs of spinal shock. The main aim was to assess if the presence of spinal shock affects the neurorehabilitation outcomes of ANNPE dogs. This prospective controlled cohort clinical study was conducted at the Arrábida Rehabilitation Center. All of the dogs had T3−L3 injuries and were paraplegic/monoplegic with/without nociception, the study group (n = 14) included dogs with ANNPE spinal shock dogs, and the control group (n = 19) included ANNPE dogs without spinal shock. The study group was also evaluated using a new scale—the Spinal Shock Scale (SSS)—and both groups were under the same intensive neurorehabilitation protocol. Spinal shock was a negative factor for a successful outcome within less time. SSS scores > 4 required additional hospitalization days. The protocol was safe, tolerable, and feasible and accomplished 32% ambulation within 7 days, 29% in 14 days, and 29% in 30 days. The results were better than those obtained in previous studies—94% at 60 days—and 75% of the dogs without nociception recovered ambulation. Long-term follows-ups carried out 4 years later revealed a positive evolution.

Outcome of thoracolumbar surgical feline intervertebral disc disease

OBJECTIVES

The aim of this study was to evaluate the outcome and prognosis of thoracolumbar feline intervertebral disc disease (IVDD) treated by surgical decompression.

METHODS

This was a multi-institutional retrospective study evaluating the age, breed, sex, body weight, presenting complaint, neuroanatomic diagnosis at presentation, diagnostic imaging results, surgery performed and the overall outcome at discharge and at recheck. Bivariable associations between variables were assessed using the Kruskal-Wallis test (age and grade of IVDD at presentation) and Fisher's exact test (grade of IVDD at presentation and outcome).

RESULTS

A total of 35 cats met the inclusion criteria for the study. The most frequently reported clinical sign was difficulty walking (54.2%). The majority of cats presented with an L4-S3 localization (57%). The most common site of intervertebral disc herniation (IVDH) was at L6-L7 (34%). The majority of feline patients that received surgery had a positive outcome at the time of discharge (62.5%; n = 20/32) and at the time of the 2-week recheck (91.3%; n = 21/23). No association was identified between the age of the patient and the grade of IVDD. No association was identified between the presenting grade of IVDD and the clinical outcome at the time of discharge or at the time of recheck evaluation.

CONCLUSIONS AND RELEVANCE

Cats undergoing spinal decompressive surgery for thoracolumbar IVDH appear to have a favorable prognosis independent of the initial presenting grade of IVDD. A larger sample size and a longer length of follow-up is necessary to obtain statistical associations between the presenting grade of IVDD and overall clinical outcome.

Prevalence and clinical features of thoracolumbar intervertebral disc-associated epidural hemorrhage in dogs

Background

Intervertebral disc‐associated epidural hemorrhage (EH) in dogs is a poorly understood neurological condition.

Objective

To compare the clinical presentation, magnetic resonance imaging (MRI) changes, and clinical outcome of dogs with acute thoracolumbar intervertebral disc herniation (TL‐IVDH) with and without EH.

Animals

One hundred sixty client‐owned dogs that underwent MRI and hemilaminectomy for acute TL‐IVDH at a private practice in Colorado, including 63 dogs with EH and 97 dogs without EH.

Methods

Retrospective review of medical record data from 160 dogs presenting sequentially to a single practice with acute TL‐IVDH that underwent MRI and hemilaminectomy surgery.

Results

Sixty‐three of 160 (39%) dogs had confirmed EH. French Bulldogs were significantly overrepresented (23/63; odds ratio [OR]: 4.1; 95% confidence interval [CI]: 1.8‐9.0; P < .001) of the EH cases. Dogs with EH were more likely to present with clinical signs less than 48 hours than were dogs without EH (24‐48 vs 48‐72 hours; OR: 2.4; 95% CI: 1.2‐4.6; P = .02) and were more likely to be nonambulatory on presentation (OR: 2.1; 95% CI: 1.0‐4.1; P = .04). Dogs with EH were more likely to have <50% cross‐sectional spinal cord compression than dogs without EH (OR: 2.3 vs. 0.4; 95% CI: 1.2‐4.4 and 0.2‐0.9, respectively), longer longitudinal spinal cord compression (3 spaces vs 1 space, P < .001), and greater intrinsic spinal cord change (grade 3/severe vs grade 1/mild; P < .001) based on MRI. The location of the intervertebral disc herniation in French Bulldogs with EH was more likely to be thoracolumbar (OR: 10.8; 95% CI: 2.1‐55.7; P = .03).

Conclusions and Clinical Importance

French Bulldogs have a high prevalence of intervertebral disc‐associated EH. Dogs with EH have a shorter clinical course and are more likely to be nonambulatory on initial presentation.

Late onset recurrence of clinical signs after surgery for intervertebral disc extrusion in French bulldogs

OBJECTIVES

To identify the prevalence of recurrence of clinical signs after initial successful decompressive surgery for intervertebral disc extrusion in French bulldogs.

MATERIALS AND METHODS

A medical record search was performed to identify French bulldogs that experienced an initial successful outcome after surgery for thoracolumbar or cervical intervertebral disc extrusion. Collected information included signalment, neurological examination findings, intervertebral disc extrusion location, presence of vertebral malformations, kyphosis, type and extent of surgery. Decompressive surgery was not followed by extensive prophylactic fenestrations. Follow-up information was retrieved from medical records and telephone interviews with referring veterinary surgeons.

RESULTS

Eighty-four French bulldogs with thoracolumbar (n=55) or cervical (n=29) intervertebral disc extrusion were included. Forty-three (51%) dogs that had decompressive surgery for thoracolumbar (n=29) or cervical (n=14) intervertebral disc extrusion suffered recurrence of signs. The median time between decompressive surgery and recurrence of clinical signs was 9 months and 21 days. Of the 29 dogs suffering recurrence of clinical signs following surgery for thoracolumbar intervertebral disc extrusion, 24 returned for recurrence of clinical signs localised to the thoracolumbar segments, while five returned for recurrence of signs localised to the cervical region. Of the 14 dogs who suffered recurrence of signs following surgery for cervical intervertebral disc extrusion, nine returned for signs localised to the cervical region, while five returned for clinical signs localised to the thoracolumbar region.

CLINICAL SIGNIFICANCE

This study suggests a high rate of late onset recurrence of clinical signs after decompressive surgery for intervertebral disc extrusion in French bulldogs. This information can aid in the management of owner expectations.

A comparative study between high-definition volumetric imaging computed tomography and multi-slice computed tomography in the detection of acute thoraco-lumbar disc extrusions in dogs

Computed tomography (CT) is commonly used to image intervertebral disc extrusion (IVDE) in dogs. The current gold standard for CT imaging is the use of multi-slice CT (MS CT) units. Smaller high-definition volumetric imaging (HDVI) mobile CT has been marketed for veterinary practice. This unit is described as an advanced flat panel. The goal of this manuscript was to evaluate the ability of the HDVI CT in detecting IVDE without the need for CT myelography, compared with the detection of acute disc extrusions with a MS CT without the need for MS CT myelogram. Retrospective blinded analyses of 219 dogs presented for thoraco-lumbar IVDE that had a HDVI CT (n = 123) or MS CT (n = 96) were performed at a single referral hospital. A total of 123 cases had HDVI CT scans with surgically confirmed IVDE. The IVDE was identified in 88/123 (72%) dogs on pre-contrast HDVI CT. The remaining 35/128 (28%) cases required a HDVI CT myelogram to identify the IVDE. Ninety-six cases had MS CT scans with surgically confirmed IVDE. The IVDE was identified in 78/96 (81%) dogs on the pre-contrast MS CT. The remaining 18/96 (19%) cases had a MS CT myelogram to identify the IVDE. Multi-slice CT detected IVDE significantly more than HDVI CT (p = 0.032). This study showed that the ability of HDVI CT for detecting IVDE is lower than that of MS CT. The HDVI CT system may be useful in smaller referral practices, with a lower case load where space is limited.

Outcomes and prognostic indicators in 59 paraplegic medium to large breed dogs with extensive epidural hemorrhage secondary to thoracolumbar disc extrusion

OBJECTIVE

To evaluate outcomes and prognostic factors after decompressive hemilaminectomy in paraplegic medium to large breed dogs with extensive epidural hemorrhage (DEEH) and thoracolumbar intervertebral disc extrusion (TL-IVDE).

STUDY DESIGN

Retrospective, cohort, descriptive study.

ANIMALS

Fifty-nine client-owned dogs.

METHODS

Medical records and advanced imaging were reviewed for paraplegic dogs with DEEH. Ambulatory status 6 months after surgery and postoperative complications were recorded. Multiple logistic regression models were constructed to explore prognostic factors.

RESULTS

Records of 22 dogs with and 37 dogs without pelvic limb pain perception at presentation were included. Median age of dogs was 5 years (interquartile range, 4-7), and mean weight was 26.9 kg (SD, ±9.71). Labradors and Labrador mixes were most common (17/59 [28.8%]). Recovery of ambulation occurred in 17 of 22 (77.3%) dogs with and in 14 of 37 (37.8%) dogs without pain perception prior to surgery. Progressive myelomalacia was recorded in three of 59 (5.1%) dogs, one with pain perception and two without pain perception at presentation. Postoperative complications (14/59 [23.7%]) were common. Factors independently associated with outcome included clinical severity (odds ratio [OR] 0.179, P = .005), number of vertebrae with signal interruption in half Fourier single-shot turbo spin-echo sequences (HASTEi; OR, 0.738; P = .035), and ratio of vertebral sites decompressed to HASTEi (OR, 53.79; P = .03).

CONCLUSION

Paraplegic medium to large breed dogs with DEEH have a less favorable outcome after surgical decompression than paraplegic dogs with TL-IVDE.

CLINICAL SIGNIFICANCE

Dogs with DEEH can have severe postoperative complications. Loss of pain perception and increased HASTEi are associated with a poor outcome, while more extensive decompression improves outcome.

Outcomes of extensive hemilaminectomy with durotomy on dogs with presumptive progressive myelomalacia: a retrospective study on 34 cases

Background

Progressive myelomalacia (PMM) is a fatal complication of progressive ascending and descending necrosis of the spinal cord after acute spinal cord injury. A recent study suggested that extensive hemilaminectomy with durotomy (EHLD) at the intramedullary T2-hyperintense region which performed immediately after magnetic resonance imaging (MRI) improved the survival rate in dogs with presumptive PMM. The objective of this retrospective study was to evaluate the effects of EHLD on halting the progression of PMM in dogs presumptively diagnosed with PMM which had the interval between MRI and surgery.

Results

Thirty-four dogs with presumptive PMM which had undergone EHLD with the delay following MRI examination (range, 0 to 3 days) were included. The cranial side of EHLD was set depending on the delay time after MRI, MRI findings, neurological examination and intraoperative macroscopic appearance. Two weeks after surgery, the perioperative survival rate was 97% (33/34). During follow-up with a median time period of 82.5 weeks (range, 0-290 weeks), the postoperative survival rate was 91% (31/34). At the end of the follow-up period, 31 out of 34 dogs were alive without severe postoperative complications while the remaining 2 dogs died from causes not directly attributable to the surgery. There was no improvement in the pelvic limb function of all dogs.

Conclusions

EHLD appears to be effective in halting the progression of presumptive PMM and preventing morbidity even in dogs which had the interval between MRI and EHLD. Our algorithm of determining the range of EHLD may enable to set the appropriate ranges of EHLD in the cases which develop signs consistent with PMM after MRI examination.

Association between anesthesia duration and outcome in dogs with surgically treated acute severe spinal cord injury caused by thoracolumbar intervertebral disk herniation

Background

Retrospective research recently identified a possible relationship between duration of surgery and outcome in severely affected dogs treated surgically for acute thoracolumbar intervertebral disk herniation (TL‐IVDH).

Hypothesis

That increased duration of surgery is associated with poorer outcome in dogs with absent pain perception treated surgically for TL‐IVDH.

Animals

Two hundred ninety‐seven paraplegic dogs with absent pain perception surgically treated for acute TL‐IVDH.

Methods

Retrospective cohort study. Medical records of 5 institutions were reviewed. Inclusion criteria were paraplegia with absence of pain perception, surgical treatment of TL‐IVDH, and 1‐year postoperative outcome (ambulatory: yes or no). Canine data, outcome, and surgery and total anesthesia duration were retrieved.

Results

In this study, 183/297 (61.6%) dogs were ambulatory within 1 year, 114 (38.4%) dogs failed to recover, including 74 dogs (24.9%) euthanized because of progressive myelomalacia. Median anesthesia duration in dogs that regained ambulation within 1 year of surgery (4.0 hours, interquartile range [IQR] 3.2‐5.1) was significantly shorter than those that did not (4.5 hours, IQR 3.7‐5.6, P = .01). Multivariable logistic regression demonstrated a significant negative association between both duration of surgery and total anesthesia time and ambulation at 1 year when controlling for body weight and number of disk spaces operated on.

Conclusions and Clinical Importance

Findings support a negative association between increased duration of anesthesia and outcome in this group of dogs. However, the retrospective nature of the data does not imply a causal relationship.