Axial twisting within an ending loop of a continuous suture pattern affects the biomechanical properties of knots of certain suture sizes and types.

OBJECTIVE: To determine whether axial twisting within an ending loop negatively impacts maximum load to failure and failure mode of suture knots. SAMPLES: 525 knots (15 samples each of 7 different suture types/sizes tested in 5 knot-twist configurations each). PROCEDURES: Each suture type (polydioxanone [PDO], Monoderm [polyglecaprone 25], and Nylon) and size (1, 0, 2-0, 3-0) were used to create a starting square knot, and each of the following ending square knot configurations: 0 twists, 1 twist, 4 twists, and 10 twists. Each suture was tested for failure using a universal testing machine (Instron, Instron Corp) with a 100 kg load cell at a speed of 100 mm/min. Each suture and knot was evaluated for a mode of failure using gross evaluation of the knots and video footage recorded during testing. Maximum load at failure (P-value set at .005) and failure mode (p-value set at 0.003) were recorded for each group. RESULTS: Maximum load at failure was decreased in knots tied within ending loops containing more twists for some types and sizes of the suture. With 4 twists, 0-PDO, 1 PDO, and 2-0 Nylon was more likely to fail at the knot than knots with 0 twists. All sutures containing 10 twists, except 3-0 Monoderm, were more likely to fail at the knot than knots with 0 twists. CLINICAL RELEVANCE: The number of twists within the ending loop may not increase the risk of failure at the knot; however, it can decrease the maximum load to failure at a knot, particularly as the suture size increases.

Students' Approaches to Learning during Pre-clinical and Clinical Phases of a Veterinary Curriculum, Their Motivations and Their Correlation with GPA.

This study was conducted to determine if veterinary students adopt a different approach to learning in the clinical compared to pre-clinical phase, and what factors motivate their approach. We also sought to determine if the learning approach adopted correlates with grade point average (GPA). Two questionnaires were administered to the same cohort of students (112 students) at the end of the pre-clinical and at the end of the clinical phase. A total of 87 students completed at least one questionnaire. The questionnaires included the Approaches and Study Skills Inventory for students, which was used to provide scores for three learning approaches: surface (focus on memorization), strategic (focus on optimum grades), and deep (focus on understanding). The questionnaires also included open-ended questions probing for motivations behind adopting learning approaches. Statistical analyses were performed on the data to detect correlations between variables. Students were more likely to adopt a surface approach in the pre-clinical phase than in the clinical phase, although other learning approaches were not different between phases. No strong correlations existed between learning approach and GPA. Students who adopted a deep approach were typically motivated by higher-level motivations than those who adopted a surface approach, especially in the clinical phase. Time constraints, the desire to get good grades, and passing classes were the main reasons for adopting the surface approach. The results of the study can be beneficial for students, by allowing them to identify those pressures that could prevent them from adopting a deeper approach earlier in the curriculum.

Blinded, randomized, placebo-controlled study of the efficacy of bupivacaine liposomal suspension using static bodyweight distribution and subjective pain scoring in dogs after tibial plateau leveling osteotomy surgery.

OBJECTIVE: To compare the analgesic effect of surgical wound infiltration with liposomal bupivacaine (LB) to saline placebo in dogs after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Blinded, randomized, placebo-controlled clinical prospective study. ANIMALS: Fifteen client-owned dogs receiving LB and 17 dogs receiving an equivalent volume of saline placebo, all with confirmed unilateral cranial cruciate ligament insufficiency. METHODS: Preoperatively and up to 48 h after surgery, Glasgow Composite Measure Short Form (CMPS-SF) pain scores were assigned and using a weight distribution platform, static bodyweight distribution (%BWdist ) to the operated limb was measured. Postoperatively, dogs also received carprofen 2.2 mg/kg subcutaneously every 12 h. Rescue analgesia was provided. Treatment success was defined as not requiring rescue analgesia over the 48-h postoperative period. RESULTS: There was no difference between treatment success, postoperative opioid consumption, CMPS-SF pain scores, or %BWdist in dogs that received surgical wound infiltration with LB compared with those receiving saline placebo, following TPLO. There was no linear correlation between CMPS-SF pain scores and %BWdist . CONCLUSION: For the population of dogs that underwent TPLO and received postoperative carprofen at our institution, LB did not provide an analgesic effect discernable by success/failure analysis, CMPS-SF pain scores, or %BWdist measurement using a weight distribution platform, compared with saline placebo. CLINICAL SIGNIFICANCE: LB may not provide detectable analgesia during the first 48 h for dogs recovering from TPLO and receiving only postoperative carprofen.

Long-acting injectable methadone (methadone-fluconazole) provides safe and effective postoperative analgesia in a randomized clinical trial for dogs undergoing soft tissue surgery.

OBJECTIVE: To assess the pharmacokinetics, clinical efficacy, and adverse effects of injectable methadone with the pharmacokinetic enhancer fluconazole (methadone-fluconazole), compared with the standard formulation of injectable methadone, in dogs after ovariohysterectomy. We hypothesized that 2 doses of methadone-fluconazole would provide 24 hours of postoperative analgesia. ANIMALS: 3 purpose-bred dogs (pharmacokinetic preliminary study) and 42 female dogs from local shelters (clinical trial) were included. PROCEDURES: Pharmacokinetics were preliminarily determined. Clinical trial client-owned dogs were blocked by body weight into treatment groups: standard methadone group (methadone standard formulation, 0.5 mg/kg, SC, q 4 h; n = 20) or methadone-fluconazole group (0.5 mg/kg methadone with 2.5 mg/kg fluconazole, SC, repeated once at 6 h; n = 22). All dogs also received acepromazine, propofol, and isoflurane. Surgeries were performed by experienced surgeons, and dogs were monitored perioperatively using the Glasgow Composite Measure Pain Scale-Short Form (CMPS-SF) and sedation scales. Evaluators were masked to treatment. RESULTS: Findings from pharmacokinetic preliminary studies supported that 2 doses of methadone-fluconazole provide 24 hours of drug exposure. The clinical trial had no significant differences in treatment failures or postoperative CMPS-SF scores between treatments. One dog (methadone-fluconazole group) had CMPS-SF > 6 and received rescue analgesia. All dogs had moderate sedation or less by 1 hour (methadone-fluconazole group) or 4 hours (standard methadone group) postoperatively. Sedation was completely resolved in all dogs the day after surgery. CLINICAL RELEVANCE: Methadone-fluconazole with twice-daily administration was well tolerated and provided effective postoperative analgesia for dogs undergoing ovariohysterectomy. Clinical compliance and postoperative pain control may improve with an effective twice-daily formulation.

Dogs ≥ five years of age at the time of congenital extrahepatic portosystemic shunt diagnosis have better long-term outcomes with surgical attenuation than with medical management alone.

OBJECTIVE: To determine the outcome in dogs diagnosed with congenital extrahepatic portosystemic shunts (EHPSS) at ≥ 5 years of age treated with medical management only (M) or with surgical attenuation (S). The hypothesis was that dogs undergoing surgical attenuation would have a longer survival time than dogs undergoing medical management only. ANIMALS: 351 dogs definitively diagnosed with EHPSS at ≥ 5 years of age. PROCEDURES: Medical records from 2009 to 2019 at 16 veterinary teaching hospitals were evaluated. Data collected included signalment, clinical signs at diagnosis, clinicopathologic data, surgical and medical treatments, shunt morphology, clinical signs and medical treatments at 6 to 12 months after diagnosis, and survival time. RESULTS: 351 dogs (M, 119 [33.9%]; S, 232 [66.1%]) were included in the study. Survival time was longer with surgery than medical management (hazard ratio, 4.2; M, 3.4 years; S, 10.9 years). Continued clinical signs at 6 to 12 months after diagnosis were more common with medical management (M, 40% [33/88]; S, 14% [21/155]). Continued medical treatments at 6 to 12 months after diagnosis were more common in the medical management group (M, 78% [69/88]; S, 34% [53/155]). Perioperative mortality rate was 7.3%. CLINICAL RELEVANCE: Dogs diagnosed at ≥ 5 years of age with EHPSS have significantly better survival times and fewer clinical signs with surgical attenuation, compared with medical management. Older dogs have similar surgical mortality rates to dogs of all ages after surgical EHPSS attenuation.

Evaluation of outcomes following subtotal colectomy for the treatment of idiopathic megacolon in cats.

OBJECTIVE: To evaluate outcomes in cats undergoing subtotal colectomy for the treatment of idiopathic megacolon and to determine whether removal versus nonremoval of the ileocecocolic junction (ICJ) was associated with differences in outcome. ANIMALS: 166 client-owned cats. PROCEDURES: For this retrospective cohort study, medical records databases of 18 participating veterinary hospitals were searched to identify records of cats with idiopathic megacolon treated by subtotal colectomy from January 2000 to December 2018. Data collection included perioperative and surgical variables, complications, outcome, and owner perception of the procedure. Data were analyzed for associations with outcomes of interest, and Kaplan-Meier survival time analysis was performed. RESULTS: Major perioperative complications occurred in 9.9% (15/151) of cats, and 14% (12/87) of cats died as a direct result of treatment or complications of megacolon. The median survival time was not reached. Cats with (vs without) a body condition score < 4/9 (hazard ratio [HR], 5.97), preexisting heart disease (HR, 3.21), major perioperative complications (HR, 27.8), or long-term postoperative liquid feces (HR, 10.4) had greater hazard of shorter survival time. Constipation recurrence occurred in 32% (24/74) of cats at a median time of 344 days and was not associated with retention versus removal of the ICJ; however, ICJ removal was associated with long-term liquid feces (OR, 3.45), and a fair or poor outcome on owner assessment (OR, 3.6). CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that subtotal colectomy was associated with long survival times and a high rate of owner satisfaction. Removal of the ICJ was associated with less favorable outcomes in cats of the present study.

A survey of attributes of surgical resident applicants deemed important to American College of Veterinary Surgeons board-certified surgeons involved in resident selection and methods used to evaluate these attributes.

OBJECTIVE: To determine which attributes of residency applicants were most commonly assessed by large and small animal American College of Veterinary Surgeons diplomates and to determine which evaluation methods were perceived to assess those attributes. STUDY DESIGN: Online survey. SAMPLE POPULATION: American College of Veterinary Surgeons board-certified surgeons as of March 2019. METHODS: An online survey was sent to eligible individuals. Respondents rated the importance of 23 attributes assessed by the Veterinary Internship and Residency Matching Program (VIRMP) application as well the usefulness of interviews, conversations with people knowledgeable with the applicants, and review of the VIRMP packet for evaluating each of these attributes. Responses were compared between large and small animal practitioners and between individuals involved in residency selection (supervisors) and individuals not involved in residency selection (nonsupervisors). RESULTS: Surveys were completed by 221 individuals (14.6% response rate). Seventeen of the 23 attributes were considered important by most respondents. Grade point average (GPA) and class rank were used as screening tools by 73% and 65% of supervisors, respectively. Letters of reference (LOR) were ranked as the most important part of the VIRMP packet. Conversations with people knowledgeable with the applicant was the only method judged by most respondents to be appropriate to evaluate all 23 attributes. Responses were similar between large and small animal supervisors and nonsupervisors. CONCLUSION: Respondents considered conversations with people knowledgeable with the applicant to be the most useful methods for assessing a resident applicant, but LOR, GPA, and class rank were also important. IMPACT: Resident applicants and mentors can use this information to strengthen applications.

Perioperative analgesia associated with oral administration of a novel methadone-fluconazole-naltrexone formulation in dogs undergoing routine ovariohysterectomy.

OBJECTIVE: To determine perioperative analgesia associated with oral administration of a novel methadone-fluconazole-naltrexone formulation in dogs undergoing routine ovariohysterectomy. ANIMALS: 43 healthy female dogs. PROCEDURES: Dogs were randomly assigned to receive the methadone-fluconazole-naltrexone formulation at 1 of 2 dosages (0.5 mg/kg, 2.5 mg/kg, and 0.125 mg/kg, respectively, or 1.0 mg/kg, 5.0 mg/kg, and 0.25 mg/kg, respectively, PO, q 12 h, starting the evening before surgery; n = 15 each) or methadone alone (0.5 mg/kg, SC, q 4 h starting the morning of surgery; 13). Dogs were sedated with acepromazine, and anesthesia was induced with propofol and maintained with isoflurane. A standard ovariohysterectomy was performed by experienced surgeons. Sedation and pain severity (determined with the Glasgow Composite Pain Scale-short form [GCPS-SF]) were scored for 48 hours after surgery. Rescue analgesia was to be provided if the GCPS-SF score was > 6. Dogs also received carprofen starting the day after surgery. RESULTS: None of the dogs required rescue analgesia. The highest recorded GCPS-SF score was 4. A significant difference in GCPS-SF score among groups was identified at 6:30 am the day after surgery, but not at any other time. The most common adverse effect was perioperative vomiting, which occurred in 11 of the 43 dogs. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of a methadone-fluconazole-naltrexone formulation at either of 2 dosages every 12 hours (3 total doses) was as effective as SC administration of methadone alone every 4 hours (4 total doses) in dogs undergoing routine ovariohysterectomy. Incorporation of naltrexone in the novel formulation may provide a deterrent to human opioid abuse or misuse.

Effect of Duration and Onset of Clinical Signs on Short-Term Outcome of Dogs with Hansen Type I Thoracolumbar Intervertebral Disc Extrusion.

OBJECTIVE: The aim of this study was to determine if either the rate of onset of clinical signs or duration from initial clinical signs to surgical decompression affected the overall quality or duration of recovery in dogs with intervertebral disc extrusion. STUDY DESIGN: This was a retrospective case series of 131 client owned dogs. Medical records of dogs surgically treated with hemilaminectomy for intervertebral disc extrusion between January 2016 and December 2017 were reviewed for signalment, neurological grade at presentation, rate of onset and duration of clinical signs and surgical variables. These variables were analysed to determine their effect on return of pain sensation, urinary continence and ambulation. RESULTS: Duration of clinical signs prior to surgery and rate of onset of signs did not correlate with return of pain sensation, urinary continence or ambulation. Preoperative neurological grade was the main variable that was found to be associated with outcome. CONCLUSIONS: Delay from initial clinical signs of intervertebral disc extrusion to surgery is unlikely to affect the ultimate outcome or the length of time for a dog to regain pain sensation, urinary continence or ambulation. The rate of onset of signs likewise does not influence these outcomes.

Assessment of time to completion, number of errors, and knot-holding capacity of square knots and Aberdeen knots tied by veterinary students and student perceptions of knot security and knot-tying difficulty.

OBJECTIVE: To assess the time to completion, number of errors, and knot-holding capacity (KHC) for starting and ending square knots (SSKs and ESKs) of a continuous pattern and Aberdeen knots tied by veterinary students and to investigate student perceptions of knot security and knot-tying difficulty for the 3 knot types. SAMPLE: 16 second-year veterinary students. PROCEDURES: Students created 3 (4-throw) SSKs, 3 (5-throw) ESKs, and 3 (3 + 1 configuration) Aberdeen knots with 2-0 polydioxanone on a custom test apparatus. Time to complete each knot, the number of errors in each knot, and student ratings of knot-tying difficulty and confidence in knot security were recorded. Each knot was tested to failure on a uniaxial tensiometer to determine KHC and mode of failure. Variables of interest were compared by repeated-measures ANOVA or the Friedman test with post hoc pairwise comparisons. RESULTS: Mean knot completion time for Aberdeen knots was significantly less than mean completion time for SSKs or ESKs. Mean KHC was significantly lower for ESKs than for SSKs; KHC for Aberdeen knots was not compared with these values because of methodological differences. Median error rate was higher for ESKs than for other knot types. Mean difficulty rating for Aberdeen knots was lower than that for ESKs. Most tested knots failed by breakage at the knot. CONCLUSIONS AND CLINICAL RELEVANCE: Aberdeen knots appeared to be easy for veterinary students to learn and were completed more rapidly and with fewer errors than ESKs. Including this type of knot in surgical skills curriculum for novices may be beneficial.

Amount of skin shrinkage affecting tumor versus grossly normal marginal skin of dogs for cutaneous mast cell tumors excised with curative intent.

OBJECTIVE To assess differences in skin shrinkage between grossly visible tumor and grossly normal marginal skin of dogs for cutaneous mast cell tumors (MCTs) excised with curative intent and to determine an equation to estimate postexcisional gross tumor margins from preexcisional measurements and vice versa. SAMPLE 19 cytologically confirmed and surgically excised cutaneous MCTs obtained from dogs. PROCEDURES Tumors were measured in craniocaudal and dorsoventral directions before excision, immediately after excision, and after fixation in formalin. Both grossly visible tumor and surrounding grossly normal skin that comprised the surgical margin were measured at each time point. Percentage of shrinkage was compared among time points and between the tumor and surrounding grossly normal skin. Patient and histopathologic variables were correlated to skin shrinkage. RESULTS Overall shrinkage was 17.70%. The amount of shrinkage within the grossly visible tumor (4.45%) was less than that within the surrounding grossly normal skin (24.42%). Most of the shrinkage occurred immediately after excision. There was no effect of age, sex, completeness of excision, or degree of edema. Accuracy of an equation to estimate postexcisional margins from preexcisional measurements was only 18.4%. CONCLUSIONS AND CLINICAL RELEVANCE Grossly evident MCTs of dogs shrunk less than did the grossly normal surrounding skin. Although an equation to estimate postexcisional margins from preexcisional measurements could be derived, it likely would need to contain additional variables not included in the study reported here. Until such an equation exists, care must be used when extrapolating surgical margins from histologic margins and vice versa.

Comparison of tensile strength and time to closure between an intermittent Aberdeen suture pattern and conventional methods of closure for the body wall of dogs.

OBJECTIVE To compare tensile strength and time to completion of body wall closure among 3 suture patterns. SAMPLE Eighteen 5 × 5-cm leather specimens and sixty-eight 5 × 5-cm full-thickness tissue specimens from the ventral portion of the abdominal body wall of 17 canine cadavers. PROCEDURES During experiment 1 of a 2-experiment study, each leather specimen was cut in half and sutured with a simple interrupted or simple continuous pattern or continuous pattern with intermittent Aberdeen knots (intermittent Aberdeen pattern). During experiment 2, 4 tissue specimens were obtained from each cadaver; the linea alba of 3 specimens was incised and closed with 1 of the 3 suture patterns evaluated in experiment 1, and the fourth specimen was left intact as a control. All leather and tissue specimens underwent mechanical testing. Time to completion, mode of failure, and maximum force at failure (Fmax) were compared among the suture patterns. RESULTS In experiment 1, the mean Fmax for the simple continuous and intermittent Aberdeen patterns was significantly greater than that for the simple interrupted pattern. In experiment 2, the mean Fmax for specimens obtained cranial to the umbilicus was greater than that for specimens obtained caudal to the umbilicus, and the mean time to completion for both continuous suture patterns was significantly less than that for the simple interrupted pattern. Most (34/51) sutured tissue specimens failed because the suture cut through the tissue at the suture-tissue interface. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the intermittent Aberdeen pattern may be an alternative for body wall closure in dogs.

Effects of administration of adipose-derived stromal vascular fraction and platelet-rich plasma to dogs with osteoarthritis of the hip joints.

OBJECTIVE To evaluate effects of simultaneous intra-articular and IV injection of autologous adipose-derived stromal vascular fraction (SVF) and platelet-rich plasma (PRP) to dogs with osteoarthritis of the hip joints. ANIMALS 22 client-owned dogs (12 placebo-treated [control] dogs and 10 treated dogs). PROCEDURES Dogs with osteoarthritis of the hip joints that caused signs of lameness or discomfort were characterized on the basis of results of orthopedic examination, goniometry, lameness score, the Canine Brief Pain Inventory (CBPI), a visual analogue scale, and results obtained by use of a pressure-sensing walkway at week 0 (baseline). Dogs received a simultaneous intraarticular and IV injection of SVF and PRP or a placebo. Dogs were examined again 4, 8, 12, and 24 weeks after injection. RESULTS CBPI scores were significantly lower for the treatment group at week 24, compared with scores for the control group. Mean visual analogue scale score for the treatment group was significantly higher at week 0 than at weeks 4, 8, or 24. Dogs with baseline peak vertical force (PVF) in the lowest 25th percentile were compared, and the treatment group had a significantly higher PVF than did the control group. After the SVF-PRP injection, fewer dogs in the treated group than in the control group had lameness confirmed during examination. CONCLUSIONS AND CLINICAL RELEVANCE For dogs with osteoarthritis of the hip joints treated with SVF and PRP, improvements in CBPI and PVF were evident at some time points, compared with results for the control group.

Effects of sample site and size, skin tension lines, surgeon, and formalin fixation on shrinkage of skin samples excised from canine cadavers.

OBJECTIVE: To assess the effects of sample size and location, skin tension lines, surgeon, and formalin fixation on the extent of shrinkage that occurs in excised canine skin samples. ANIMALS: Cadavers of 4 adult purpose-bred mixed-breed hound dogs with grossly normal skin. PROCEDURES: 54 circular areas of skin (2-, 4-, and 6-cm-diameter samples from each of 9 body regions on each side) were excised by 1 of 2 surgeons from each cadaver. The diameter of each sample was measured in 4 orientations (parallel to previously reported tension lines, perpendicular to tension lines, in a dorsoventral orientation, and in a craniocaudal [or rostrocaudal] orientation) at 3 time points (before and immediately after excision and after 24 hours of formalin fixation). RESULTS: 216 samples were measured in all 4 orientations at all 3 time points. For all samples, mean ± SE decrease in diameter after fixation, compared with pre-excision findings, was 6.2 ± 0.7 mm. No significant correlations were found between percentage of skin shrinkage and surgeon, body side or region, or measurement orientation in relation to skin tension lines. The mean sample diameter immediately after excision differed significantly from that before excision (mean diameter decrease, 5.5 ± 0.7 mm). Overall, sample diameter immediately after excision and after formalin fixation did not differ. CONCLUSIONS AND CLINICAL RELEVANCE: The extent of shrinkage of skin samples from hound cadavers that occurred immediately after excision was notable. A better understanding of the effectors of excised skin sample shrinkage is needed, especially when histopathologic findings provide guidelines for surgical margins.

A highly conserved His-His motif present in alpha1-->3/4fucosyltransferases is required for optimal activity and functions in acceptor binding.

Alpha1-->3/4fucosyltransferases (FucTs) from several species contain a highly conserved His-His motif adjacent to an enzyme region correlating with the ability to catalyze fucose transfer to type 1 chain acceptors. Site-directed mutagenesis has been employed to analyze structure-function relationships of this His-His motif in human FucT-IV. The results indicate that most changes of His(113) and His(114) and nearby residues of FucT-IV reduced the specific activity of the enzymes. Analysis of acceptor properties demonstrated close similarity of most mutants with wild-type FucT-IV, whereas an apparent preference for the H-type II acceptor was observed for the His(114) mutants. Kinetic studies demonstrated that mutants of His(114) had a substantially increased K(m) for acceptor compared to other enzymes tested. The dramatic increase in acceptor K(m) for the His(114) mutants, particularly for the nonfucosylated acceptor, suggests that this His-His motif is involved in acceptor binding and perhaps interacts with GlcNAc residues of type 2 acceptors. The presence of fucose in acceptor substrates may promote more efficient substrate binding and presumably partially overcomes the weaker interaction with GlcNAc caused by the mutation.