The influence of a tension band fixation as an adjunct for arthrodesis of the metacarpophalangeal joint in the horse.

OBJECTIVES: To determine the influence of a stainless-steel cable (SSC) tension band fixation as an adjunct to a locking compression plate (LCP) for arthrodesis of the equine metacarpophalangeal (MCP) joint. STUDY DESIGN: Experimental. An ex vivo biomechanical paired equine cadaver limb study. SAMPLE POPULATION: Five MCP joint pairs were collected from adult Thoroughbred horses, euthanized for reasons unrelated to orthopedic disease. METHODS: Each pair of MCP joints were randomly implanted with either a dorsally placed 5.5 mm LCP and a palmarly placed 2.0 mm SSC or a dorsally placed 5.5 mm LCP alone. Each construct was tested in cyclic loading followed by single cycle to failure in axial compression. Displacement at a target load of 1 kN over 3600 cycles at 1 Hz was recorded prior to single cycle to failure testing. RESULTS: In cyclic testing, displacement was not significantly different between the first and last 5% of testing cycles regardless of construct. Maximum displacement of each construct during cyclic testing was <1.1 mm. In single cycle testing, the observed yield point did not reveal any difference between LCP and LCP-SSC (p = .440). The maximum load at failure was significantly higher in LCP-SSC compared to constructs with the LCP alone (p = .046). CONCLUSION: The addition of the SSC to the LCP did not statistically affect construct displacement during cyclic loading or construct yield load during subsequent single cycle to failure. CLINICAL SIGNIFICANCE: This study provided much needed information regarding the necessity of a tension band SSC application in the arthrodesis of the MCP/MTP joint in horses.

Teaching veterinary surgical skills: Comparison of massed versus spaced instruction.

OBJECTIVE: To determine the effect of massed instruction (MI) versus spaced instruction (SI) of veterinary surgical skills on students' cognitive load and skill retention. STUDY DESIGN: Prospective randomized cohort study STUDY POPULATION: First-year veterinary students from Louisiana State University (LSU; n = 47) and Lincoln Memorial University (LMU; n = 101). METHODS: Students were randomized to MI (two skills in a single session of twice the duration) or SI (one skill per session on two consecutive days). Instructors, instructional ratio, and total educational time was equivalent. Following instruction, students completed a cognitive load questionnaire and underwent a structured assessment immediately after (LMU only), 1 day after, and 3-4 weeks after learning the second skill. Students completed two supervised practice sessions one and 2 weeks after the initial laboratory session(s). RESULTS: Overall cognitive load did not differ between groups (p > .05), although LMUs MI group reported higher physical and time demands, effort, and frustration. At initial assessment, SI students scored higher than MI students for the first skill at both LSU (mean checklist score = 27.7 vs. mean = 24; p = .004) and LMU (mean global rating score = 4.76 vs. mean = 4.55; p = .029). Differences between groups were no longer evident by 3-4 weeks after instruction. CONCLUSION: SI may lead to improved immediate performance; however, supervised practice was sufficient to overcome the initial disparity. CLINICAL SIGNIFICANCE: SI may be beneficial for initial skill performance. However, SI and MI students had similar performance after 3 weeks, suggesting the more convenient curricular design of MI may be sufficient as long as practice sessions are incorporated.

Hemodynamic optimization in high-risk mitral valve repairs as a key component in surgical readiness.

Ensuring optimal readiness for surgery using a preoperative checklist has been shown to reduce perioperative morbidity and mortality in both elective and urgent surgeries. We recently introduced hemodynamic optimization as part of our preoperative preparedness strategy for cardiothoracic surgery. Here we describe the case of a patient with severe mitral regurgitation and suboptimal hemodynamics that was optimized preoperatively with nesiritide to reduce pulmonary hypertension. Postoperatively, the patient had an improvement of his heart failure from New York Heart Association functional class 3 to class 1. Without hemodynamic optimization the patient may have been considered too high-risk to undergo mitral valve repair. This case report illustrates the importance of a systemic approach with high-risk surgery, and the use of strategies that optimize key patient factors, including hemodynamics, prior to all elective and urgent procedures.

Percutaneous closure of patent foramen ovale: a case series and literature review.

Patent foramen ovale (PFO) is an anatomical variant of the interatrial septum with an overall prevalence of 27% in autopsy studies. PFOs have a potential role in causation of stroke, platypneaorthodeoxia, decompression sickness, right to left shunt and migraine headaches. Data regarding percutaneous closure of PFO in low volume tertiary care centers is lacking. Retrospective review of 14 percutaneous PFO closures done in our facility from March 2005 to August 2006 was performed for efficacy of procedure and safety. All patients received clopidogrel for a period of 3 months, and aspirin and subacute bacterial endocarditis prophylaxis for 6 months. Mean age of the study population was 54 years. Fifty percent (7 of 14) of patients experienced an atrial septal aneurysm and 14% (2 patients) exhibited a hypercoagulable state. The indication for closure in 13 patients was transient ischemic attacks or strokes, while one patient had persistent hypoxia due to a severe right to left shunt at PFO. Patients received either a CardioSEAL or Amplatzer device. Deployment rate was 100%. All patients completed a minimum of 6 months of follow-up, with a mean follow-up time of 14.9 +/- 7.6 months. No immediate or late bleeding complication occurred in any patient. One patient developed paroxysmal atrial fibrillation and one patient developed thrombotic complications at 7 months post-procedure secondary to the progression of her anal carcinoma and subsequently died. Pending the results of the four large randomized trials that are enrolling patients, percutaneous closure of PFO for cryptogenic strokes is an attractive alternative to lifelong anticoagulation with relatively few complications, even in low volume centers. There are many challenges in the management of this subset of patients, the foremost being the selection of a target patient population. Role of PFO in migraines is less clear.

The Marshfield Youth Health Study: design, objectives and cohort characteristics.

PROBLEM: The Marshfield Youth (MY) Health Study was designed to identify parental and infant factors associated with childhood and adolescent overweight. METHODS: The study examined 867 children (age 5-17 years) from the Marshfield Public Schools. Heights and weights were measured by standard methods. Age- and gender-specific body mass index (BMI) percentiles and z-scores were determined. Definitions of overweight from the Centers for Disease Control and Prevention were applied. Family characteristics were self-reported by questionnaire and included parents' BMI, employment, education, smoking, physical activity; and child's daycare attendance, and television/computer use. Maternal and child medical records were reviewed. RESULTS: The MY Health cohort included 361 families. The mean +/- SD age of the children was 12.1 +/- 3.0 yrs; 511 (59%) were born in Marshfield, Wis. Of the children studied, 70% had a healthy body weight (BMI >5th and <85th percentile); 14.4% were at risk of overweight (BMI > or = 85th and <95th percentile) and 13% were overweight (BMI > or = 95th percentile). There were no differences in gender or weight status between the study cohort and all Marshfield school children (n=2782). CONCLUSIONS: Children in the MY Health Study are representative of all school-age children in Marshfield. This cohort will be studied to identify factors associated with overweight among children.

Surgical management of mycotic aneurysm of the left anterior descending artery.

Mycotic aneurysms of the coronary artery with underlying infective endocarditis are rare. The present report discusses the case of a 53-year-old woman with acute ST elevation myocardial infarction in the setting of native aortic valve endocarditis. Percutaneous transluminal coronary angioplasty was performed. Approximately four weeks after hospital admission, the patient had systemic embolization to the extremities with resulting cyanosis of the left toes. She was evaluated for replacement of the aortic valve and underwent a repeat angiogram, which demonstrated a mycotic aneurysm at the site of the angioplasty. She subsequently underwent successful excision of the aneurysm with coronary artery bypass grafting and replacement of the aortic valve with a 21 mm St Jude aortic valve prosthesis. The remaining hospital course was unremarkable.

An update on the epidemiology, pathogenesis and management of infective endocarditis with emphasis on Staphylococcus aureus.

The incidence of infective endocarditis (IE) is thought to be around 4/100,000 person years in the general population, and 15/100,000 over the age of 50 years. The risk of acquiring IE is higher among patients with valvular heart disease (e.g., rheumatic valves, bicuspid aortic valves, myxomatous degeneration, etc.), congenital heart disease (e.g., coarctation, patent ductus arteriosus, ventricular septal defect, etc.), prosthetic cardiac valves, and among intravenous drug abusers. Staphylococcus aureus is one of the most common infective agents of IE, and most commonly originates from nosocomial sources, e.g., intravenous and arterial catheters, pacemaker leads, and prosthetic valves. Endocarditis caused by S aureus has a mortality rate of approximately 20% to 40%. In up to 40% of patients, IE caused by S aureus is associated with embolic complications. The risk of death increases with the development of complications. The epidemiology and microbiology of S aureus are changing rapidly, and resistance to antibiotics, especially methicillin, is becoming more widespread. In this review we will focus on the epidemiology, microbiology, and pathogenesis of S aureus IE, and also summarize the current guidelines for diagnosis, treatment, and prophylaxis of this clinical condition.

Percutaneous tube cystostomy and vesicular irrigation for treatment of obstructive urolithiasis in a goat.

Treatment of a 3-month-old male goat with obstructive urolithiasis by means of percutaneous tube cystostomy and vesicular irrigation with a chemolysis solution is described. The cystostomy tube was inserted percutaneously with ultrasonographic guidance. Patency of the urethra was reestablished with no clinical evidence of urethral stricture or recurrence of obstruction during the following 12 months. Results in this goat suggest that percutaneous tube cystostomy may be an economical alternative to surgical cystostomy tube placement. Chemical dissolution of calcium phosphate uroliths with a commercially available compound appears to be feasible in goats.

Second case of infective endocarditis caused by Gemella sanguinis.

BACKGROUND: A 69-year-old man presented with a history of spiking fevers and symptoms of transient expressive aphasia and a left hemispheric cerebrovascular accident. A transthoracic echocardiogram revealed thickened mitral leaflets. A subsequent transesophageal echocardiogram demonstrated vegetations on both mitral leaflets and severe mitral regurgitation by color flow imaging. A gram-positive coccus was isolated from the blood culture of this patient. METHODS: The bacterium was identified by polymerase chain reaction (PCR) amplification of its 16S rRNA gene with the broad range eubacterial primers, FD1 and RD1, followed by sequencing of the PCR product. The obtained sequence was compared to all sequences deposited in GenBank and the ribosomal database project II. A phylogenetic tree was created to determine the relatedness of this bacterium to other bacterial species. RESULTS: The phylogenetic tree created from the 1389 bp 16S rDNA sequence indicated that the endocarditis was due to Gemella sanguinis, a member of the normal oral flora and a rare cause of bacteremia. CONCLUSION: This report describes the second case of endocarditis caused by G. sanguinis. A history of periodontal disease and tooth abscess in this patient suggests that the oropharynx was the probable origin of the Gemella bacteremia. We propose that G. sanguinis should be added to the list of Gemella species that can cause endocarditis.

Use of a carbon dioxide laser for surgical management of cutaneous masses in horses: 32 cases (1993-2000).

OBJECTIVE: To determine outcome of horses in which cutaneous masses were removed with a carbon dioxide laser. DESIGN: Retrospective study. ANIMALS: 32 horses. PROCEDURE: Medical records of horses with 1 or more cutaneous masses treated with a carbon dioxide laser were examined. Follow-up information was obtained through telephone interviews with owners and referring veterinarians. RESULTS: Cutaneous masses were classified as sarcoids (15 horses), neoplastic masses other than sarcoids (squamous cell carcinoma [91; fibroma [1]; and melanoma [1]), and nonneoplastic masses (6). Minimum follow-up time was 6 months. Five sarcoids and 2 squamous cell carcinomas recurred. Seven (21%) horses had complications associated with dehiscence of wounds that had been closed primarily or failure of wound healing because of recurrence of the mass. Twenty-six (81%) owners were satisfied with the cosmetic appearance following surgery. CONCLUSION AND CLINICAL RELEVANCE: Results suggest that a carbon dioxide laser may be effective for treatment of cutaneous masses in horses.