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Transcatheter pulmonary valve implantation (TPVI) is indicated for use in the management of failing pulmonary valves in humans. We report here the long-term follow-up of the first documented transcatheter pulmonary valve implanted in a client-owned dog. A one-year-old Beagle dog with severe congenital type A valvular pulmonic stenosis first underwent percutaneous balloon pulmonary valvuloplasty, leading two years later to severe pulmonary regurgitation. A TPVI using a Melody™ bioprosthetic valve was then successfully performed, with normalization of the right heart cavities. Repeated two- and three-dimensional transthoracic echocardiographic examinations combined with Doppler modes confirmed the appropriate position and function of the valve for four years. Mitral myxomatous valvular degeneration led to refractory left-sided congestive heart failure, and the dog was humanely euthanized. After postmortem examination, X-ray imaging and histopathological evaluation of the stent and the valve were performed. Ex-vivo imaging of the implanted valve using a Faxitron® Path radiography system and microscopic evaluation of the implanted stent and bioprosthetic leaflets did not show any relevant leaflet or stent alterations. This case provides a proof of concept in interventional veterinary cardiology, showing that TPVI can be performed in dogs with subsequent long-term maintaining normal pulmonary valve function. [ABSTRACT FROM AUTHOR]

This report describes five cases of double outlet right ventricle (DORV) in four dogs (aged 3–18 months, two males and two females) and a domestic shorthair cat (aged 6 months, female) who presented with various clinical signs including tachypnea (n = 5), exercise intolerance (n = 5), mucous cyanosis (n = 3), delayed growth (n = 2), and/or lethargy (n = 2). The represented canine breeds were poodle, Yorkshire terrier, Samoyed, and Shetland sheepdog. For all animals, echocardiography revealed marked aortic dextroposition with both arterial trunks totally arising from the right ventricle, associated with a ventricular septal defect and various other congenital abnormalities, including subvalvular aortic stenosis (n = 2), minor aortic insufficiency (n = 5), subvalvular pulmonic stenosis with pulmonary trunk hypoplasia (n = 1), patent ductus arteriosus (n = 1), minor mitral and/or tricuspid dysplasia (n = 3). Subsequent cardiac remodeling was characterized by marked right ventricular hypertrophy for all patients, associated with right ventricular and right atrial dilation for most of them (4/5). Two dogs died soon after the initial DORV diagnosis (i.e. after 24 h and two months). A surgical correction attempted for another dog confirmed the presence of a DORV associated with patent ductus arteriosus, but the animal died during the procedure from sudden cardiac arrest. The fourth dog underwent a contrast-enhanced retrospective electrocardiogram-gated multidetector computed tomography angiography under general anesthesia, which confirmed the conotruncal malformation. Despite episodes of exercise intolerance, this dog is still alive, at the age of 53 months, as is the cat at the age of 21 months. [ABSTRACT FROM AUTHOR]

Transcatheter pulmonary valve (TPV) implantation is a therapeutic approach approved by the United States Food and Drug Administration for human patients with failing pulmonary conduits in 2010 and for failing bioprosthetic surgical pulmonary valves in 2017. We report here the first successful transcatheter implantation of a stented valve in a pulmonary position in a dog with congenital pulmonary valve disease. A 3-year-old, 10.9 kg, client-owned Beagle dog was referred for a follow-up visit after a percutaneous balloon valvuloplasty performed 22 months before for treatment of a severe type A valvular pulmonary stenosis. The Doppler-derived peak pressure gradient was 348 mmHg before the procedure and 66 mmHg 24 h after. The dog was lethargic. Echocardiography revealed a mild pulmonary stenosis (pressure gradient—43 mmHg), severe pulmonary regurgitation, and secondary severe right ventricular and right atrial dilation. Worsening of right heart dilation was observed 2 months later despite medical therapy. A TPV implantation was performed using a prestented Melody bovine jugular bioprosthetic valve. The dog recovered uneventfully and was discharged 10 days after the procedure. Right heart dilation resolved within 15 days. The dog was doing well 7 months after valve implantation. This case demonstrates that TPV implantation with a stented valve is technically feasible in dogs with severe pulmonary valve disease. Stringent postoperative care, with particular attention to thrombosis and infectious endocarditis, and appropriate sizing and positioning of the valve stent are keys to the success of this procedure. [ABSTRACT FROM AUTHOR]

Abstract Transcatheter occlusion of patent ductus arteriosus (PDA) using an Amplatz® Canine Duct Occluder (ACDO) is routinely performed in dogs. Pulmonary embolization of the device is a rarely reported complication of this procedure. We report here the first two cases of successful transcatheter retrieval of an embolized ACDO. An 8-month-old, 21-kg, German shepherd (case 1) was referred for pulmonary edema secondary to a large PDA with left-to-right shunting. After medical stabilization, an emergency procedure for PDA closure was recommended. An 8-mm ACDO was deployed under general anesthesia. The device was released after confirming its stability with a gentle tug test but migrated into the pulmonary trunk. A 10-mm ACDO was subsequently successfully deployed and released. Vascular access was then obtained from the right jugular vein so that a vascular snare could be used to capture the ACDO waist and pull it back toward the right ventricle and then the right atrium. It was then removed through the jugular vein. The dog recovered uneventfully and was discharged after confirmation of complete ductal occlusion. The same complication occurred in a second case (case 2, asymptomatic 6-month-old, 7.9-kg, cocker spaniel), and a similar procedure was used to successfully retrieve the embolized device. Both dogs are still doing well 9 and 21 months, respectively, after the procedure. These cases illustrate that transcatheter retrieval of ACDO devices embolized in the pulmonary artery using vascular snares is technically feasible in the dog. [ABSTRACT FROM AUTHOR]

Intracardiac echocardiography (ICE) is used in humans for percutaneous interventional procedures, such as transcatheter device closures. Intracardiac echocardiography provides high-resolution imaging of cardiac structures with two-dimensional, M-mode, Doppler, and also three-dimensional modalities. The present report describes application of ICE during transcatheter occlusion of patent ductus arteriosus using a canine ductal occluder in a dog for which transesophageal echocardiography could not provide an optimal acoustic window. [ABSTRACT FROM AUTHOR]

Sheep are a good model for cardiopathy and surgery training in medical studies because organ volumes are similar to humans. Grafting of stem cells collected from skeletal muscles is a major area of research into treatments for heart failure. To establish an efficient protocol it is first necessary to follow the fate of grafted cells in an animal model. The aim of the project was to obtain 2 cloned sheep of the same genetic background, 1 conventional and 1 expressing green fluorescent protein (GFP), to be used for graft experiments. First, chimeric transgenic fetuses were generated by transduction of 8-cell stage embryos with a lentivirus expressing GFP under the EF1a human ubiquitous promoter. A large dilution of the lentivirus solution was used so that only some cells were transduced. Chimeric transgenic embryos were examined for GFP expression and transferred to recipients at the blastocyst stage. At 50 days of pregnancy, 8 fetuses were obtained. Three showed stable but mosaic expression of GFP in some tissues, as expected. The proportion of green cells ranged from 20 to 80% between fetuses. To make sure that low-level expression was not overlooked in GFP-negative fetuses, skin cells from each of the 8 fetuses were cultured for 10 days to isolate green from white cell colonies. This step confirmed the negative signal in 5 fetuses, but also led to the elimination of 1 positive fetus whose cells tended to switch off the GFP signal. Only 1 fetus yielded a good enough ratio of white to green cell colonies to enable the freezing of cells, which were subsequently used in 4 NT experiments. In total, 42 blastocysts were transferred to 20 recipients, of which 4 reached late pregnancy. A GFP-positive cloned fetus was delivered by C-section 4 days before term and required no intensive care. This animal is now over 6 months old and clinically normal. Expression of GFP in skin is stable and readily visualised with specialised GFP glasses. Global expression of GFP in all tissues will be followed in an F1generation to avoid risk of contamination after biopsies in this first precious animal. Weekly ultrasound examination revealed the onset of fetal suffering (abdominal fluid accumulation, reduced heart rate, and fetal movements) in the last week before term in 3 other fetuses. These did not survive despite emergency C-section and intensive neonatal care. Fetal anomalies were similar to those observed in bovine NT. Gross placental abnormalities, however, were not present. None of the postmortem observations could be attributed to lentivirus integration as they were similar to those seen in nontransgenic cloned animals. Experiments are now proceeding to generate a normal white cloned sheep by NT using frozen nontransgenic cells from the same fetus. This will allow generation of sheep with the same genetic background that can be used to develop muscle stem cell grafting protocols. The authors thank M. Bonneau, CRII, for help in C-section, and J. P. Albert, J. Massoneau, and S. Rotg for animal care. [ABSTRACT FROM AUTHOR]

Objectives: The goal of this study was to develop a device for percutaneous replacement of the tricuspid valve in animals.Background: Percutaneous valve replacement has recently been introduced, and early clinical experience has been reported. To date, this technique is limited to the replacement of pulmonary and aortic valves in selected patients.Methods: A newly designed nitinol stent, forming two large disks separated by a cylinder with a diameter of 18 mm, was specially designed for the purpose of this study. An 18-mm bovine valve was mounted in the central part of the stent, and a polytetrafluoroethylene membrane was sutured onto the ventricular disk. Eight ewes were equally divided into two groups (group 1, acute study; group 2, killed at one month).Results: Seven of eight devices were successfully delivered in the desired position. In one animal, the device was trapped in tricuspid cordae, leading to its incomplete opening. A significant paravalvular leak was noticed in one animal of group 2. Mean right atrial pressure increased from 5 to 7 mm Hg and did not change during the follow-up. At autopsy, examination confirmed the good position of devices in successfully implanted animals.Conclusions: Implantation of a semi-lunar valve in the tricuspid position is possible in ewes through a transcatheter approach. A disk-based nitinol stent is needed to allow valve implantation in the atrioventricular position. These studies open new perspectives into tricuspid as well as mitral valve replacement. [ABSTRACT FROM AUTHOR]