Evaluation of phenylephrine and exercise with or without trocarization for treatment of suspected nephrosplenic entrapment in horses.

OBJECTIVE To report the outcomes of horses with suspected nephrosplenic entrapment (NSE) of the large colon treated by IV phenylephrine administration and exercise with and without trocarization (ie, medical management). DESIGN Retrospective, observational study. ANIMALS 134 horses. PROCEDURES Electronic medical records were searched to identify horses that underwent medical management for suspected NSE at a veterinary teaching hospital between 1995 and 2014. Demographic information, physical and ultrasonographic examination findings, treatment information (including the number of times the treatment was performed and patient response), surgical findings if applicable, complications, and patient outcome were recorded. Descriptive statistics were reported. RESULTS 72 horses had suspected NSE that resolved with medical treatment; 59 of 62 horses underwent laparotomy when medical management failed, and 3 were euthanized without surgery. Twenty-five of the 59 horses had confirmed NSE that was surgically corrected, and 34 had lesions other than or in addition to NSE. All horses that had surgically corrected NSE and 18 of 34 horses that had other lesions survived to hospital discharge. The odds of resolution of NSE with medical management were greater for horses that underwent ≤ 2 (vs > 2) treatments. The treatment success rate for horses that underwent trocarization was not greater than that for horses that did not have the procedure. CONCLUSIONS AND CLINICAL RELEVANCE Suspected NSE resolved with the described medical management for most horses. However, results indicated the potential for misdiagnosis was high. Timely surgical intervention is recommended for horses that fail to respond to medical treatment.

In Vitro Evaluation of the Aberdeen Knot for Continuous Suture Patterns with Large Gauge Suture.

OBJECTIVE: To evaluate the strength, size, and holding capacity of the Aberdeen knot compared to surgeon's and square knots using large gauge suture. STUDY DESIGN: In vitro mechanical study. STUDY POPULATION: Knotted suture. METHODS: Aberdeen, surgeon's, and square knots were tested using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone under linear tension on a universal testing machine. Mode of failure and knot holding capacity (KHC) were recorded and relative knot security (RKS) was calculated as a percentage of KHC. Knot volume and weight were quantified by a digital micrometer and balance, respectively. Strength between number of throws, suture, suture size, and knot type were compared by ANOVA and post hoc testing. P≤.05 was considered significant. RESULTS: Aberdeen knots had higher KHC and RKS than surgeon's or square knots for all suture types and number of throws (P<.001). For all suture materials, none of the Aberdeen knots unraveled, but a portion of square and surgeon's knots with <7 throws did unravel (P=.101). Aberdeen knots had a smaller volume and weight than both surgeon's and square knots with equal numbers of throws (P<.001). The knot with the combined highest RKS and smallest size and weight was an Aberdeen knot with 4 throws using 3 USP polyglactin 910. CONCLUSION: The Aberdeen knots were stronger, more secure, and smaller than surgeon's and square knots for ending a continuous suture pattern. Clinically, the Aberdeen knot may be a useful alternative for completion of continuous patterns using large gauge suture, without sacrificing knot integrity.

Meta-Analysis of the Effects of Adhesion Barriers on Adhesion Formation in the Horse.

OBJECTIVE: To determine the efficacy of adhesion barriers in horses using quantitative statistical analysis. STUDY DESIGN: Meta-analytical review. METHODS: A search using PubMed/MEDLINE and Google Scholar was performed, followed by secondary searches of veterinary trade journals, bibliographies of relevant articles, manufacturer websites, and technical reference guides. Randomized experimental trials in healthy horses were considered that included both a treatment and control group. The endpoint required was euthanasia or laparoscopy to identify adhesion formation. A meta-analysis was performed using a random effects model, with the effect size calculated as an odds ratio (OR) with 95% confidence intervals (CI). Statistical significance was set at P<.05. RESULTS: Out of 354 peer reviewed publications that met the search criteria, a total of 9 relevant studies were identified and investigated the use of sodium carboxymethylcellulose (CMC) solutions, sodium hyaluronate/carboxymethylcellulose (HA/CMC) membranes, hyaluronate (HA), and fucoidan solutions. The odds of adhesions in horses treated with an adhesion barrier were significantly lower than untreated controls (OR=0.102; 95% CI [0.041, 0.254]; P<.001). When analyzed as subsets for each type of barrier, horses treated with HA/CMC membranes and CMC solutions had significant OR for fewer adhesions (OR=0.061; 95% CI [0.013, 0.292]; OR=0.119; 95% CI [0.034, 0.415], respectively; P<.001). CONCLUSION: The meta-analysis demonstrated adhesion barriers provide a positive effect on the odds of adhesion formation. These results are tempered by the limitations of the study, including the small sample size and a bias towards publication of studies with only positive findings.

The fractal structure of equine articular cartilage.

The naturally occurring structure of articular cartilage has proven to be an effective means for the facilitation of motion and load support in equine and other animal joints. Cartilage has been found to be a complex and dynamic medium, which has led to an incomplete understanding of the nature and operating mechanisms acting within a joint. Although cartilage has biphasic and triphasic properties, it is believed that the performance of equine articular joints is influenced by the surface roughness of the joint cartilage (Ateshian et al., '98; Chan et al., 2011; Yao and Unsworth, '93). Various joint types with different motions and regimes of lubrication have altered demands on the articular surface that may affect cartilage surface properties. In research performed on freshly harvested samples, equine articular cartilage has been shown to possess a multiscale structure and a fractal dimension. It is thought that by determining the fractal dimension (D) of articular cartilage, a better understanding of the friction, wear, and lubrication mechanisms for biomechanic surfaces can eventually be reached. This study looks at the fractal dimensions of three different articular cartilage surfaces in the equine carpus: the radiocarpal, midcarpal, and carpometacarpal surfaces. The three surfaces provide an ideal comparison of fractal dimensions for a different range of motion, geometry, and loading. In each sample, identical treatment was performed during measurement by a stylus profilometer.