Transthoracic echocardiographic guidance of patent ductus arteriosus occlusion with an Amplatz® Canine Duct Occluder

Placement of an Amplatz Canine Duct Occluder (ACDO) is usually performed by fluoroscopy (Nguyenba and Tobias, 2007). The latter technical approach presents limitations, mostly due to radiation exposure, making this practice dangerous for the patient and operators. In this study, we describe the successful placement of an Amplatz Canine Duct Occluder device by using transthoracic echocardiographic (TTE) guidance, performed on an 11-month-old female mongrel dog with a grade VI/VI continuous heart murmur diagnosed with patent ductus arteriosus (PDA). The TTE is useful in eliminating exposure to radiation and is more versatile than fluoroscopy in conveying real-time detailed information concerning the position of the ACDO.     

Cardiovascular device infections in dogs: report of 8 cases and review of the literature

BACKGROUND: Infection is an infrequent but major complication of cardiovascular device implantation. HYPOTHESIS: Treatment of patients with cardiovascular implant infection with antibiotic therapy and removal of the device is superior to antibiotic therapy alone. METHODS: Medical records were reviewed for dogs that received a cardiovascular device from June 2001 to August 2006 at the University of Minnesota Veterinary Medical Center and the University of Missouri Veterinary Medical Teaching Hospital. RESULTS: Six of 63 (9.5%) pacemaker systems and 2 of 47 (4.3%) patent ductus arteriosus (PDA) occlusion devices became infected. Median time from procedure to diagnosis of implant infection was 62 days (range, 5 to 419). Median age of dogs with pacemaker infections was 8.5 years (range, 6.2 to 11.9). Pseudomonas aeruginosa and Staphylococcus spp were the most commonly cultured isolates. Four dogs were treated with antibiotics and pacemaker replacement. All 4 recovered completely from their infections. One was alive at the end of the study period, and 3 had been euthanized. However, the reasons for euthanasia were unrelated to pacemaker infection. In contrast, both dogs with infected pacemakers that were treated with antibiotics alone were euthanized because of complications attributable to infection. Infection of PDA occlusion devices occurred in puppies < 16 weeks of age, and Pasteurella spp were isolated from both. One was successfully treated with a combination of antibiotics and surgery, and the other was euthanized without treatment. CONCLUSIONS AND CLINICAL IMPORTANCE: Antibiotic therapy alone is associated with chronic complications in patients with cardiovascular implants and is unlikely to effect a cure.     

Use of transesophageal echocardiography for visualization of the patent ductus arteriosus during transcatheter coil embolization

Transesophageal echocardiography (TEE) enhances our ability to see the patent ductus arteriosus in the dog. The improved visualization may potentially improve our ability to perform transcatheter coil embolization in patients that are more likely to have a successful outcome. This report uses still and video images to detail the specifics of coil embolization as performed with the assistance of TEE and compares the images with those of angiography, surgery and postmortem examination.     

The valves of the cardiac outflow tract of the starry ray,Raja asterias (Chondrichthyes; Rajiformes): Anatomical,histological and evolutionary aspects

The cardiac outflow tract of chondrichthyans is composed of the myocardial conus arteriosus, equipped with valves at its luminal side, and the bulbus arteriosus devoid of myocardium. Knowledge of the histomorphology of the conal valves is scarce despite their importance in preventing blood backflow to the heart. Current information on the subject refers to a single shark species. The present report is the first to describe the structure of the conal valves of a batoid species, namely, Raja asterias. Hearts from seven starry rays were examined using scanning electron microscopy and histochemical techniques for light microscopy. In all hearts, the conus showed four transverse rows of three pocket‐like valves each. Each valve was composed of a leaflet and its supporting sinus. The leaflet had a stout central body, rich in glycosaminoglycans, which contained fibroblasts, collagen and elastin. The central body was surrounded by two thin fibrous layers, outer and inner, formed mainly by collagen. The valves of the anterior row, which were the largest of the valvular system, were attached proximally to the conus arteriosus and distally to the bulbus arteriosus, and not to the ventral aorta as previously reported for chondrichthyans. The arrangement of the anterior valves in the starry ray is an anatomical pattern that apparently has been preserved throughout the evolution of vertebrates.     

Chitosan hemostatic dressing for control of hemorrhage from femoral arterial puncture site in dogs

Removal of an introducer-sheath from a femoral artery after completing transarterial embolization of a patent ductus arteriosus can cause life-threatening hemorrhage in dogs. In the present study, the effectiveness of chitosan acetate dressing in 10 experimental dogs was tested. Under general anesthesia, an introducer-sheath was placed into the femoral artery with percutaneous puncture using Seldinger''s technique. The outer diameter of the introducer-sheaths varied from 3.0 to 4.0 mm with an introducer/artery ratio of 80 to 123%. The artery''s diameter was measured using ultrasonography. Following removal of the introducer-sheath, a chitosan acetate dressing was applied to the wound and held in place with manual compression for 10 min. Successful hemostasis was reached on 12 arteries. However, on two arteries, hemorrhage was uncontrollable and led to a hypovolemic shock during 10 min of manual compression. Possible causes of the negative outcome in two dogs were their old age and an introducer-sheath with a too large diameter. The chitosan acetate dressing was easy to use and the artery remained patent. Dogs could walk directly after recovery from anesthesia and their femoral arteries were saved. In conclusion, the outer diameter of the introducer-sheath should not exceed 3 mm or the inner diameter of the artery.     

Pulmonary atresia and ventricular septal defect with aortopulmonary collaterals in an adult dog

Pulmonary atresia and ventricular septal defect (PA-VSD) was diagnosed in a 2-year-old castrated male Terrier mix. Transthoracic echocardiography identified a large ventricular septal defect, overriding aorta and severe right ventricular hypertrophy. A main pulmonary artery could not be identified, consistent with pulmonary atresia or persistent truncus arteriosus. Transesophageal echocardiography and angiography confirmed PA-VSD with aortopulmonary collateral circulation arising from the descending thoracic aorta. This case report describes the antemortem diagnosis of the rare congenital defect PA-VSD in an adult dog.     

二吡啶除草剂敌草快与肾上腺皮质激素引起胎鼠动脉管收缩的作用研究

本文研究了敌草快和肾上腺皮质激素对胎鼠动脉管的收缩作用。取妊娠19、20、21 d的大鼠,各随机分成2组。试验组皮下注射7 mg/kg敌草快,观察胎鼠动脉管收缩情况;取妊娠19 d大鼠,随机分成4组,试验1组未切除肾上腺,2、3组切除肾上腺。1、3组皮下注射7 mg/kg敌草快,第2组和对照组注射生理盐水,观察胎鼠动脉管收缩情况,并且测定母鼠血浆中肾上腺皮质激素的浓度;取妊娠19、20、21 d大鼠,各随机分成2组,试验组皮下注射40 mg/kg肾上腺皮质激素,观察胎鼠动脉管收缩情况,另用80 mg/kg肾上腺皮质激素,重复上述操作。结果表明:敌草快和肾上腺皮质激素对妊娠末期胎鼠动脉管具有收缩作用,且引起收缩的临界期均在胎龄19￣20 d。     

Peripheral pulmonary artery stenosis in three cats

Case 1 involved a 4-month-old intact male Somali cat in which peripheral pulmonary artery stenosis (PPS) was recognized after a cardiac murmur remained following patent ductus arteriosus ligation. Case 2, which involved a 1-year-old neutered male Norwegian Forest cat, and Case 3, which involved a 6-month-old intact female American Curl cat, were referred, because of cardiac murmurs. Grades III to IV/VI systolic heart murmurs were auscultated at the left heart base in all 3 cats. All cases showed bilateral pulmonary artery stenosis, although there were no associated clinical signs. In Cases 1 and 2, the pressure gradient through the stenosis decreased after treatment with atenolol.     

Infective endocarditis of the aortic valve in a Border collie dog with patent ductus arteriosus

Infective endocarditis (IE) in dogs with cardiac shunts has not been reported previously. However, we encountered a dog with concurrent patent ductus arteriosus (PDA) and IE. The dog was a 1-year-old, 13.9-kg female Border collie and presented with anorexia, weight loss, pyrexia (40.4°C) and lameness. A continuous murmur with maximal intensity over the left heart base (Levine 5/6) was detected on auscultation. Echocardiography revealed a PDA and severe aortic stenosis (AS) caused by aortic-valve vegetative lesions. Corynebacterium spp. and Bacillus subtilis were isolated from blood cultures. The dog responded to aggressive antibiotic therapy, and the PDA was subsequently surgically corrected. After a series of treatments, the dog showed long-term improvement in clinical status.     

Prospective evaluation of complications associated with transesophageal echocardiography in dogs with congenital heart disease

BackgroundTransesophageal echocardiography (TEE) is useful in the assessment and procedural monitoring of congenital heart disease (CHD) with a relatively low complication rate in humans.ObjectivesTo evaluate the safety of TEE and report complications in dogs.AnimalsForty client‐owned dogs with CHD.MethodsProspective observational study including gastroesophagoscopy before and after TEE imaging. TEE was planned with a GE 6VT‐D adult probe in dogs weighing ≥4 kg and a GE 10T‐D microprobe alternating with an intracardiac echocardiography probe placed in the esophagus in dogs <4 kg. Difficulties with probe placement, probe interference and TEE probe imaging times were recorded. Dogs were monitored in the recovery period after TEE using an established nausea scoring system.ResultsNew gastroesophageal abnormalities were identified after TEE in 4 dogs including 4 areas of mucosal damage involving <25% of the lower esophageal sphincter (n = 4) and 1 lesion at the heart base (n = 1) and were not attributed to longer imaging times or a specific probe. Lesions identified before TEE in 4 dogs remained unchanged after TEE. The 6VT‐D probe could not be placed in 1 dog with enlarged tonsils, and it obstructed fluoroscopic views in 3 dogs. The probes did not compress any structures in dogs in which fluoroscopy was performed (n = 20). Four dogs had evidence to suggest nausea after the procedure.Conclusions and Clinical ImportanceWhile major complications remain possible, complications in this study were mild and few in number. Dog size and probe characteristics are factors to consider when performing TEE.