Veterinary Surgery最新文献

Objective: To report a radical surgical technique for perianal melanomas involving the anal margin in standing horses.

Study design: Observational retrospective study.

Sample population: Twenty client-owned horses presented for surgical excision of extensive (≥4 cm) perianal melanomas.

Methods: Demographic data, surgical technique, intraoperative, immediate- and late-postoperative complications were reviewed.

Results: All horses (median age 15, Q1-Q3 12 to 17.3 years) were operated under standing sedation and epidural anesthesia. Median hospitalization period was 6.5 days (Q1-Q3 5 to 8.3 days). The anal margin was fully resected in 14 cases. A deep perirectal dissection was performed in 16 cases. Eight cases required additional local anesthetics. One case bled profusely during and after the procedure. One case became recumbent during the procedure, showed intense postoperative pain, and was eventually euthanized 6 weeks later because of ataxia. During hospitalization, one horse displayed colic signs and 10 others required manual evacuation of the rectum because of decreased fecal output. Complications after hospital discharge included mild colic signs (n = 4), partial wound dehiscence (n = 1) and hypergranulation of the wound (n = 2). All other cases healed without complications in 6 to 12 weeks. Median follow-up period was 11.8 months (Q1-Q3 6.3 to 27.2 months). Six horses developed new melanomas with only one in the perianal region.

Conclusion: This technique of surgical excision of extensive perianal melanomas was efficiently performed on standing horses with minimal local recurrence. This procedure led to high client satisfaction. Early postoperative pain was commonly encountered. Owners should be warned of the potentially large surgical wound that will be created.

Clinical significance: This technique allowed for removal of large perianal melanomas with limited recurrence during the long term follow up and may improve the quality of life of affected horses.

Objective: To describe fluid dispersal and retrieval patterns in an infusion-retrieval system across various configurations and locations in a cadaveric canine model.

Study design: Cadaveric study.

Animals: Four large breed canines.

Methods: Four full-thickness wounds (10 × 10 cm) were created bilaterally in four canine cadavers (shoulder, thorax, flank, and thigh). A wound infusion catheter and active suction drain were placed in four configurations (diagonal, opposite, parallel, and perpendicular) and the incisions were closed. Diluted methylene blue was instilled, allowed to dwell for 10 min, and quantified after retrieval. A 14 × 14 cm full-thickness skin segment, including the initial 10 × 10 cm wound, was removed. Images of the removed skin and cadaver wound bed were taken to calculate surface area (SA) and to evaluate fluid dispersion. A mixed-effects linear regression model was used for statistical analysis.

Results: Fluid retrieval did not differ by configuration (p = .92) or location (p = .32), although the perpendicular configuration resulted in the highest retrieval (11.35 ± 6.1 mL) (56.8 ± 30% volume instilled) and the flank location resulted in the lowest (7.2 ± 6.4 mL) (35.9 ± 32% volume instilled). Configuration influenced SA coverage of the wound bed (p < .01), whereas location did not (p = .10). The parallel configuration had the greatest SA coverage (83.4 ± 11.6%). No difference existed for leakage of methylene blue (MB) beyond the borders for configuration (p = .74) or location (p = .10).

Conclusion: The parallel configuration maximized the fluid dispersion within the cadaveric wound bed in comparison with other configurations (p < .01).

Clinical significance: An infusion-retrieval system could be considered during wound closure to administer topical solutions and remove excess free fluid.

Objective: To compare the efficiency and accuracy of freehand and three-dimensionally printed (3DP) guide-facilitated fluoroscopic-assisted Kirschner wire placement in the femoral capitis performed by novice and experienced surgeons.

Sample population: 3DP models of five skeletally immature dog femurs were replicated.

Methods: Virtual surgical planning was done to position three parallel, virtual Kirschner wires inserted from the lateral subtrochanteric surface of the femur, coursing proximomedially through the femoral neck to engage the central capitis without penetrating the subchondral bone. Patient-specific guides were designed and 3DP to facilitate optimal Kirschner wire placement in each femoral model. Four faculty surgeons and four surgery residents performed freehand fluoroscopic-assisted wire placement in the femoral models. Wire placement was repeated ≥1 month later using the 3DP guides. Surgical time, number of times wires were redirected, number of fluoroscopy images acquired and Likert scores from the participants were recorded. Post-procedural CTs of the femur models were used to assess wire placement by 3D analysis.

Results: The number of fluoroscopy images was greater (p < .001) and procedure time was longer (p < .001) for freehand applications, while Likert scores were greater (p < .001) for 3DP-guide applications. Wire placement was more accurate with 3DP guides. Subchondral bone penetration occurred more frequently during freehand applications (p < .01).

Conclusion: 3DP patient-specific guides resulted in faster, simpler, and more accurate Kirschner wire placement than freehand placement for both novice and experienced surgeons. Further cadaveric and clinical studies are warranted to evaluate the utility of 3DP patient-specific guides to facilitate minimally invasive fluoroscopic-assisted femoral capital physeal fracture stabilization in dogs.

Objective: To assess the effect of screw thread direction on rotational resistance in canine sacroiliac (SI) luxation models using left- and right-handed screws.

Study design: Controlled laboratory study.

Sample population: Twenty-four adult canine pelves with proximal femora were examined.

Methods: Four groups (n = 6 each) were established: right-handed screw/right SI luxation (RhRSI), right-handed screw/left SI luxation (RhLSI), left-handed screw/left SI luxation (LhLSI), and left-handed screw/right SI luxation (LhRSI). Under fluoroscopy, 2.4 mm cortical screws were placed into the SI joint in a lag fashion. An acute failure test measured force and torque at yield and peak points, with the ilium and femur positioned at a 108° angle and displacement at 0.099 cm/s. Torque (N cm) was calculated from force (N) and the moment arm (cm).

Results: Differences in median torque were found at yield and peak points. RhRSI gave 50.08 N cm versus 16.01 N cm for RhLSI (p < .01), and LhLSI showed 39.42 N cm versus 19.93 N cm for LhRSI (p < .03). At peak, RhRSI recorded 67.55 N cm compared to 28.14 N cm for RhLSI (p < .01), and LhLSI reached 51.79 N cm versus 28.28 N cm for LhRSI (p < .05). All samples failed by rotation without screw breakage or fractures.

Conclusion: Right-handed screws provided greater rotational resistance in right-sided luxation, and left-handed screws in left-sided luxation, which demonstrated that screw thread direction influenced fixation stability in SI luxation.

Clinical significance: The findings suggest that selecting screw thread direction can enhance biomechanical stability in SI luxation repair, improving surgical outcomes for affected dogs.

Objective: To report demographics, clinical signs, physical examination, diagnostic test results, surgical findings, and prognostic factors for in-hospital postoperative mortality following biliary peritonitis surgery in dogs.

Study design: Retrospective, multi-institutional cohort study.

Animals: Thirty-three client-owned dogs.

Methods: The medical records of dogs that underwent surgery for biliary peritonitis between 2015 and 2021 were reviewed. Dogs were included if they had a definitive diagnosis of biliary peritonitis and a surgery report. Information on demographics, clinical signs and duration, physical examination findings, laboratory and diagnostic imaging results, surgery, perioperative medical treatment, and complications for each patient was obtained. Statistical analyses were performed to identify risk factors that affected survival.

Results: Cholecystectomy was the procedure most frequently performed (31/33, 94%). The overall mortality rate was 36% (12/33). Survival was affected negatively by hyperbilirubinemia (p = .049), administration of vasopressors (p = .002), renal dysfunction (p = .008), and number of postoperative complications (p = .005). A mortality rate of 50% was observed in dogs with a total bilirubin level greater than 60.5 μmol/L. There was no difference in mortality rate between septic and nonseptic biliary effusions.

Conclusion: New prognostic factors associated with in-hospital postoperative mortality in dogs treated surgically for biliary peritonitis were identified, while others that had been reported previously were confirmed. A preoperative bilirubin threshold value associated with a 50% mortality was identified.

Clinical significance: Additional information that could help to predict survival in dogs with biliary peritonitis has been provided. However, further research is warranted.

Objective: To compare three measurement methods for acetabular sizing and evaluate the influence of osteoarthritis (OA) on the accuracy of measurements.

Study design: Observational study.

Sample: Radiographic images of 73 hip joints from 60 dogs with cementless cups.

Methods: Radiographs were anonymized and measured independently by three observers. One observer measured 12 sets of radiographs three times. A best-fit acetabular circle (AC) and cranial-caudal acetabular line (AL) were measured on ventral-dorsal (VD) radiographic view and open leg lateral (OLL) view. A best-fit femoral head circle (FHC) was measured on VD, OLL, and craniocaudal horizontal beam (CCHB) views. Two observers scored the OA in each hip joint. Intra- and interobserver consistency and repeatability and bias relative to implanted cup size were calculated and analyzed.

Results: Intraobserver consistency and repeatability were excellent for all measurements. Interobserver consistency was excellent (ICC > 0.9) for AC_VD and AC_OLL and was good (0.75 < ICC ≤ 0.9) for all other methods. Bias was small for AC and AL measurements (range, -0.46 to 0.45 mm) and large for FHC measurements (-3.58 to -2.42 mm). OA score significantly influenced bias for all acetabular measurement methods (p < 0.05).

Conclusion: All acetabular measurement methods were highly consistent within an observer. Interobserver consistency was highest for AC_VD and AC_OLL. FHC measurements underestimated cup size. Higher OA scores decreased the accuracy of all acetabular measurement methods.

Clinical significance: Superimposing a circle on the acetabulum seen on VD radiographic view accurately measures the acetabulum before cementless cup placement.

Objective: To report the use of intraoperative sentinel lymph node (SLN) mapping with indocyanine green (ICG) and near-infrared (NIR) imaging in a dog with a primary pulmonary carcinoma that underwent lung lobectomy via a video-assisted thoracoscopic approach.

Study design: Case report.

Animals: A 9-year-old female spayed Labrador retriever.

Methods: A solitary, 6.5 cm diameter, right caudal pulmonary mass was identified on contrast-enhanced thoracic and abdominal computed tomography, with no overt metastatic disease or other primary neoplastic diseases. The dog underwent video-assisted thoracoscopic surgery. A right-sided thoracoscopic approach was initially performed for right caudal pulmonary ligament transection and image-guided peritumoral (intrapulmonary) ICG injection. Due to the large size of the mass, a wound retractor was then placed in the right 6th intercostal space for right caudal lung lobectomy. Sentinel lymph node mapping was performed via NIR imaging, and the SLN was extirpated for histologic assessment.

Results: The right tracheobronchial lymph node was identified as sentinel via NIR fluorescence following peritumoral ICG injection. Right caudal lung lobectomy and right tracheobronchial lymph node extirpation were performed without complication, and histologic evaluation revealed a grade 1 pulmonary adenocarcinoma with pneumonia and a reactive lymph node.

Conclusion: Peritumoral ICG administration with NIR imaging appears to be an effective method for intraoperative SLN mapping in dogs with primary pulmonary tumors. The technique utilized in this report can be applied to open or minimally invasive procedures. Large-scale studies with SLN mapping are needed to determine an accurate incidence of nodal metastatic disease and any effect of extirpation of early metastatic disease via SLN mapping techniques on oncologic outcomes in dogs with primary pulmonary carcinoma.

Objective: The objectives of the study were to describe a standing percutaneous adhesion induction model in the digital flexor tendon sheath (DFTS) of horses and to evaluate the effect of intrathecal administration of the angiotensin-converting enzyme (ACE) inhibitor enalapril on tendon healing and adhesion formation.

Study design: Randomized, blinded, controlled experimental study.

Animals: Eight healthy horses.

Methods: A collagenase-induced adhesion model was implemented in the deep digital flexor tendon (DDFT) of both forelimbs under standing ultrasonographic guidance. Daily intrathecal injections of 5 mg enalapril (the treatment condition) were administered to a randomly assigned forelimb for 5 days, with the contralateral limb receiving an equivalent volume of 0.9% NaCl (the control). Lameness and limb circumference were recorded weekly. Horses were euthanized after 8 weeks and evaluated for gross digital flexor tendon sheath (DFTS) adhesions. Tendons were collected for histopathologic scoring of DDFT healing. Paired data were analyzed using a one-sided alternative sign test and longitudinal regression.

Results: Multiple DFTS adhesions were formed in control limbs of all horses. The median number of gross DFTS adhesions in treated limbs was less than in control limbs (p = .0039). The average reduction in limb circumference and lameness scores over time occurred faster in treated versus control limbs (p < .025). There were no differences in DDFT histopathologic scores between groups.

Conclusion: The standing percutaneous DFTS adhesion induction model demonstrated that intrathecal enalapril reduced DFTS adhesion formation, lameness scores, and limb circumference over time.

Clinical significance: Intrathecal enalapril administration may reduce morbidity in horses with naturally occurring tendon injuries.

Objective: To describe the use of virtual surgical planning (VSP) and three-dimensionally (3D) printed surgical guides for corrective osteotomies stabilized with an interlocking nail in a dog with a multiplanar femoral deformity.

Study design: Case report.

Animals: An 8-year-old male neutered mixed breed dog weighing 44 kg.

Methods: A dog was presented for a right grade 3 lateral patellar luxation secondary to a multiplanar femoral deformity due to a suspected femoral malunion. A computed tomography (CT) scan was obtained to create virtual femoral models. Corrective osteotomies were simulated with VSP. Custom osteotomy guides and reaming guides were designed to facilitate the correction and the placement of an interlocking nail. The preoperative femoral model, virtually aligned femoral model, custom osteotomy guides, and reaming guides were 3D printed, sterilized, and utilized intraoperatively. A CT scan was performed postoperatively to assess femoral length and alignment.

Results: Custom osteotomy and reaming guides were used as intended by the VSP. Postoperative femoral length as well as frontal, sagittal, and axial plane alignment were within 0.7 mm, 2.2°, 0.5°, and 1.6°, respectively, of the virtually planned femoral model. Two months postoperatively, the dog was sound on visual gait examination, and the patella tracked in the trochlear groove throughout stifle range of motion and was unable to be manually luxated. Radiographs obtained 2 months postoperatively revealed static femoral alignment and implants. Both osteotomies were discernable with callus bridging.

Conclusion: Virtual surgical planning and custom osteotomy and reaming guides facilitated complex femoral corrective osteotomies and interlocking nail placement.

Objective: The aim of the study was to describe the surgical technique and outcome of a combined forequarter amputation and hemilaminectomy (FAHL) for excision of canine peripheral nerve sheath tumors (PNSTs) of the brachial plexus extending into the vertebral canal.

Study design: Retrospective case series.

Animals: Nine client-owned dogs.

Methods: Dogs which underwent FAHL for resection of a brachial plexus PNST extending into the vertebral canal were included. Data from medical records including signalment, clinical findings, MRI data, histopathology reports, interval between appearance of the clinical signs and surgical intervention, affected spinal nerves and nerve roots, time to ambulate postoperatively, survival time, tumor grade and completeness of surgical margins were collected.

Results: In seven of nine cases the PNST affected the eighth cervical nerve root. Five of the nine cases were ambulatory within the first 3 days postoperatively and in one case unassisted ambulation was delayed and achieved 28 days postoperatively. The median survival time was calculated to be 317 days and the mean 522 days (range 120-1620 days). Four of nine dogs were euthanized 120, 270, 306 and 317 days postoperatively, because of suspected tumor recurrence. In one of those four cases the histological margins were reported as complete.

Conclusion: FAHL appeared to be a reliable technique for excision of PNSTs of the brachial plexus invading the spinal canal, with similar outcomes to previously reported for PNSTs not extending into the vertebral canal.