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- Author or Editor: David A. Upchurch x
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Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
Abstract
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.
