First reported long-term two- and three-dimensional echocardiographic follow-up with histopathological analysis of a transcatheter pulmonary valve implantation in a pet dog.

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.

Avaliação cirúrgica e laboratorial da utilização de pericárdio homólogo em lesões por abrasão em serosa de cólon maior (flexura pélvica) de equinos / Surgical evaluation and laboratory use of homologous pericardium in serous injuryby abrasion of large colon (pelvic flexure) of horses

Aderências intra-abdominais são complicações de cirurgias de equinos que podem resultar em processos obstrutivos e comprometer a sobrevida dos animais. O presente estudo utilizou dez equinos hígidos, machos, sem raça definida (SRD), com quatro a 15 anos de idade e peso vivo situado entre 300 e 400 quilogramas (kg). Os animais foram submetidos à laparotomia esquerda em estação com o objetivo de serem induzidas aderências, testar a utilização intestinal de membrana biológica de pericárdio como prevenção e avaliar as diferentes alterações sistêmicas e do líquido abdominal. Após sedação e analgesia local, foi utilizado o acesso cirúrgico em grade, na flexura pélvica foi criada uma área de abrasão que, no Grupo 1, foi coberta por pericárdio homólogo e no Grupo 2, lavada com solução fisiológica. Após reposicionamento foi realizada a sutura muscular, de subcutâneo e pele. O pós-operatório constou de avaliações clínicas, citologia do líquido abdominal, hematologia e bioquímica sérica nos momentos M0- pré-operatório e M7, M14, M21 e M28 dias de pós-operatório. Nova laparotomia foi realizada aos 30 dias para verificar aderências, aspecto e biópsia intestinal. A técnica cirúrgica possibilitou menor trauma e campo operatório restrito. A evolução clínica foi satisfatória e cicatriz fibrosa foi identificada entre os planos musculares. Aderências não foram observadas. As avaliações laboratoriais demonstraram aumento de bilirrubinas, hematócrito, monócito, ureia sanguíneos e de proteína, densidade e leucócitos segmentados no líquido peritoneal. Conclui-se que a abrasão foi insuficiente para promover aderências fibrosas. O implante, sem comprovada eficácia, é viável e possível, por não resultar em diferenças laboratoriais significativas ou alterações deletérias.

Intra-abdominal adhesions are equine surgery complications, which can result in obstructive processes and jeopardize the survival of these animals. The present study used 10 healthy, male mongrel horses (SRD), with four and 15 years of age and weighing between 300 and 400 kilograms (kg), who underwent laparotomy left station with the aim of inducing adhesions, test intestinal membrane using pericardium as prevention and evaluating the different systemic changes and the abdominal fluid. After sedation and local anesthesia, the surgical approach was used in grade; pelvic flexure was created in an area of abrasion that in Group 1 was covered by homologous pericardium and in Group 2, washed with saline. After repositioning muscle, the skin and subcutaneous tissue were sutured. Postoperative care consisted of clinical evaluation, abdominal fluid cytology, hematology and serum biochemistry in moments M0- preoperative, and M7, M14, M21 and M28 days postoperatively. New laparotomy was performed at 30 days from the surgery to verify adhesion, appearance and intestinal biopsy. The surgical technique allowed less trauma and restricted operative field. The clinical course was satisfactory, and fibrous scar was identified between the muscle planes. Adhesions were not observed. Laboratory evaluations showed increased bilirubin, hematocrit, monocyte, blood urea and protein density and segmented leukocyte peritoneal fluid. The present study concluded that the abrasion was insufficient to promote fibrous adhesions. The implant without proven efficacy is feasible and possible, and does not result in significant differences laboratory or deleterious changes.

Retrospective evaluation of urethral bovine cross-linked collagen implantation for treatment of urinary incontinence in female dogs.

BACKGROUND: Transurethral collagen injections are an alternative treatment for canine urinary incontinence. There is controversy regarding the long-term effectiveness of collagen and the impact urethral coaptation and injection site have on outcome. HYPOTHESIS/OBJECTIVES: To evaluate outcome and client satisfaction after urethral collagen injections, and correlation between degree of urethral coaptation and collagen placement with outcome. ANIMALS: Thirty-six procedures on 31 dogs, 10 with ureteral ectopia. METHODS: Retrospective review of records and video evaluation of injection procedures. Follow-up communication with owners was performed between 1 and 56 months after bovine cross-linked collagen implantation to evaluate duration of continence, need for additional medical therapy, and owner satisfaction. Continence score was evaluated before and after the procedure, and after additional medical therapy, if needed. Injection location and degree of urethral coaptation was assessed with respect to duration of continence. RESULTS: Dogs had a significant increase in continence score after the procedure. Mean (SD) duration of continence in dogs without addition of medication was 16.4 (15.2) months, and 5.2 (4.3) months in dogs needing additional medical therapy. No significant difference was found with respect to degree of coaptation. Median client satisfaction with the procedure was 100%. CONCLUSIONS AND CLINICAL IMPORTANCE: Transurethral collagen implantation may be a viable option for treatment of female dogs with urethral sphincter mechanism incompetence, particularly after medical failure. Duration and degree of improvement are variable. Client satisfaction was excellent despite lack of complete continence in some dogs, and highlights the importance of discussing outcome expectations with owners.

Bioprosthesis valve replacement in dogs with congenital tricuspid valve dysplasia: technique and outcome.

OBJECTIVE: To describe the surgical technique and report outcome of dogs undergoing bioprosthesis valve replacement for severe tricuspid regurgitation (TR) secondary to congenital tricuspid valve dysplasia (TVD). ANIMALS, MATERIALS AND METHODS: Twelve client-owned dogs (19-43 kg) with TVD underwent tricuspid valve replacement with a bovine pericardial or porcine aortic bioprosthesis with the aid of cardiopulmonary bypass. Anticoagulation with warfarin was maintained for 3 months after surgery and then discontinued. RESULTS: Ten of 12 (83.3%) dogs survived surgery and were discharged from the hospital. Seven dogs were alive with complete resolution of TR for a median period of 48 months (range 1-66 months) after surgery. Two dogs underwent euthanasia because of bioprosthesis failure due to inflammatory pannus at 10 and 13 months after surgery. Two dogs experienced valve thrombosis that was resolved by tissue plasminogen activator. One dog developed suspected endocarditis after surgery that was resolved with antibiotics. Serious cardiac complications included atrial fibrillation and flutter, right-to-left shunt through an uncorrected patent foramen ovale, complete atrioventricular block, and sudden cardiac arrest. Postoperative atrial fibrillation or flutter did not occur in 7 dogs treated prophylactically with oral amiodarone before surgery. CONCLUSIONS: Curative intermediate-term outcomes are possible in dogs undergoing open tricuspid valve replacement with a bioprosthesis. Prosthesis-related complications include inflammatory pannus, thrombosis, and endocarditis. Postoperative atrial fibrillation or flutter can be reduced or prevented by prophylactic preoperative treatment with amiodarone. Several identified complications are avoidable or can be reduced with increased awareness and experience with these techniques.

Design of a miniature tissue culture system to culture mouse heart valves.

Valvular heart disease is a leading cause of morbidity and mortality in adults but little is known about the underlying etiology. A better understanding of the genetic and hemodynamic mechanisms involved in growth and remodeling of heart valves during physiological and pathological conditions is needed for a better understanding of valvular heart disease. Here, we report the design of a miniature tissue culture system (MTCS) that allows the culture of mitral valves from perinatal to adult mice. The design of the MTCS is novel in that fine positioning and cannulation can be conducted with hearts of different sizes (perinatal to adult). Perfusion of the heart and hence, culture of the mitral valve in its natural position, occurs in a hydraulically sealed culture bath environment. Using the MTCS, we successfully cultured the mitral valve of adult mouse hearts for 3 days. Histological analysis indicated that the cultured valves remained viable and their extracellular matrix organization was similar to age-matched native valves. Gene expression could also be modified in cultured valves by perfusion with medium containing beta-galactosidase-expressing adenovirus. Thus, the MTCS is a new tool to study the genetic and hemodynamic mechanisms underlying the three-dimensional organization of the heart valves, which could provide insights in the pathology of valvular heart disease and be used in animal models for the development of tissue-engineered heart valves.

Long-term clinical evaluation of mitral valve replacement with porcine bioprosthetic valves in dogs.

This study evaluated the long-term clinical performance of newly developed porcine bioprosthetic valves cross-linked with glutaraldehyde and polyepoxy compound for mitral valve replacement (MVR) in dogs. Five beagle dogs underwent MVR using the porcine bioprosthetic valves during cardiopulmonary bypass. Antithrombotic drugs were administered only for one month after MVR. Six months after MVR, transvalvular regurgitation was not observed in all dogs, paravalvular leakage was seen only in one dog. Twelve months after MVR, mild transvalvular regurgitations were observed in two dogs. Although diastolic atrioventricular pressure gradient was increased gradually, no significant differences were observed. Pressure half-time and valve area were within normal ranges as the bioprosthetic value. There was no clinical symptom of the thrombosis and the thrombogenesis was not observed in the porcine bioprosthetic valve and the annulus in all dogs for twelve months after MVR. The clinical findings suggest that antithrombogenicity of the valves were maintained, though the duability might not be enough in the long-term period.

Short-term performance of mitral valve replacement with porcine bioprosthetic valves in dogs.

Porcine bioprosthetic valves cross-linked with glutaraldehyde and polyepoxy compound were newly developed for mitral valve replacement (MVR) in dogs. Five beagle dogs were performed a left thoracotomy and underwent MVR using the porcine bioprosthetic valves during cardiopulmonary bypass (CPB). A vein catheter inserted into right atrium and a vent catheter inserted into the right ventricle to drain. The hemodynamic conditions of CPB were excellent during surgery. The left atrial pressure was measured before and after MVR; there was no significant difference and it was normal. Thrombosis and the prosthetic valve regurgitation were not observed one week after MVR. Pressure half time (PHT) prolonged significantly (P<0.05) from 31.40 +/- 4.0 msec presurgery to 99.20 +/- 19.4 msec at seven days after MVR, although it indicated the normal range as the bioprosthetic valve. The symptom of the prosthetic valve failure was not observed. This study indicated that the MVR using porcine bioprosthetic valves under CPB might have been effective in dogs as a short-term evaluation.

Beating heart mitral valve replacement with a bovine pericardial bioprosthesis for treatment of mitral valve dysplasia in a Bull Terrier.

OBJECTIVES: To describe an open, beating heart surgical technique and use of a bovine pericardial prosthetic valve for mitral valve replacement (MVR) in the dog. STUDY DESIGN: Clinical case report. ANIMALS: Male Bull Terrier (17-month-old, 26 kg) with mitral valve dysplasia and severe regurgitation. METHODS: A bovine pericardial bioprosthesis was used to replace the mitral valve using an open beating heart surgical technique and cardiopulmonary bypass. RESULTS: Successful MVR was achieved using a beating heart technique. Mitral regurgitation resolved and cardiac performances improved (left ventricular end-diastolic diameter decreased from 57.6 to 48.7 mm, and left atrium/aorta ratio returned to almost normal, from 1.62 to 1.19). Cardiopulmonary by-pass time and total surgical duration were decreased compared with standard cardioplegic techniques. Surgical recovery was uneventful and on echocardiography 6 months later valve function was excellent. CONCLUSION: Considering the technique advantages (no cardiac arrest, ischemic reperfusion injury, and hypothermia, or the need for aortic dissection and cannulation for administration of cardioplegic solution), short-term mortality and morbidity may be reduced compared with standard cardioplegic techniques. CLINICAL RELEVANCE: Based on experience in this dog, beating heart mitral valvular replacement is a seemingly safe and viable option for the dog and bovine pericardial prosthesis may provide better long-term survival than mechanical prostheses.

Estudo da resposta tissular à endoprótese recoberta de jugular bovina em veia cava inferior de suínos / Bovine jugular covered stent-grafit implanted in swine inferior vena cava - a study of tissue response

Objetivo: avaliar a resposta tissular a uma endoprótese, com cobertura biológica, implantada em veia cava inferior de suínos. Métodos: Desenvolvemos uma endoprótese auto-expansível, revestida com um segmento de jugular bovina, conservada por processo L-hydro e saturada em um stent de aço inoxidável 316L. O dispositivo introdutor utilizado foi a bainha de liberação da endoprótese aórtica Taheri-Leonhardt (Flórida, EUA). Foram implantadas endopróteses em 10 suínos, todas na veia cava infra-renal. Os animais foram submetidos à flebografia peroperatória. À necropsia, após 2 meses, cada endoprótese foi retirada em bloco e analisada macroscopicamente, visando a avaliação da perviedade, aderência aos tecidos vizinhos e incorporação à parede venosa; e, histopatologicamente, visando a resposta histológica ao enxerto. Resultados: Na análise macroscópica, todas as endopróteses encontravam-se pérvias e totalmente incorporadas à parede venosa, porém seis apresentavam trabeculações grosseiras no seu interior e quatro algum grau de fibros perivascular. Três animais desenvolveram linfocele, uma retroperitonial e as outras na parede abdominal...

An experimental study of apico-aortic valved conduit (AAVC) for surgical treatment of aortic stenosis in dogs.

A new valved conduit was developed using a canine aortic valve. The bioprosthetic valve was fixed with glutaraldehyde and epoxy compound (Denacol-EX313/810). A vascular graft composed of ultra-fine polyester fiber (10 mm in diameter, 200 mm in length) was used. Four dogs underwent apico-aortic valved conduit (AAVC) implantation and aortic banding (bypass group, BG), while another 4 dogs underwent aortic banding without AAVC implantation (control group, CG). Cardiac catheterization and angiocardiography were performed for assessment of hemodynamics 2 weeks and 6 months after surgery. Left ventricular systolic pressure, left ventricular end-diastolic pressure and the left ventricular-aortic pressure gradient differed significantly (P<0.01) between the BG and CG dogs. Left ventricular angiocardiography showed patency of the valved conduit in all the BG dogs. Echocardiography was performed before and 2, 4 and 6 months after surgery, and showed that while pressure overload caused concentric myocardial hypertrophy in the CG dogs, the left ventricle dilated eccentrically in the BG dogs. Furthermore, relief of left ventricular pressure overload by AAVC was maintained.

Successful prosthetic mitral valve implantation in pigs.

Clotting mechanisms, the coagulation cascade, platelet function, and platelet-leukocyte-endothelial cell interactions are all very similar in humans and pigs. Because of these similarities, the authors concluded that the pig would be an ideal model for the study of thromboembolism resulting from prosthetic heart valves. To date, they have successfully recovered a total of 11 pigs (52.9 +/- 8.1 kg), 3 with bioprosthetic valves and 8 with mechanical valves, all in the mitral position (25 mm od). The normal presence of high numbers of pulmonary endothelial macrophages and other unique aspects of porcine cardiovascular and pulmonary function dictate somewhat different surgical protocols than those normally used for human patients and ruminant species. Some of these special procedures include 1) crystalloid prime without the use of plasma volume expanders, especially those with a starch base; 2) pharmacologic protection against arrhythmias (lidocaine, 4 mg/kg); 3) special attention to adequate hypothermic cardioprotection during the time of cross-clamp; 4) the use of shock doses of corticosteroid (prednisolone sodium succinate, 0.5 mg/kg) before removal of the aortic cross-clamp; and 5) positive inotropic support (dopamine, 0.008 mg/kg) while weaning from cardiopulmonary bypass. Gamma camera images of 111In tagged autologous platelets 24 hours after surgery show most thrombi located on the sewing ring with fewer on the pledgets and anchor sutures. The latter observations were confirmed by quantification of platelet deposition using a gamma counter.

Surgical management of subvalvular aortic stenosis and mitral dysplasia in a golden retriever.

A 12-month-old neutered male golden retriever was presented with a history of lethargy and exercise intolerance. Clinical examination, electrocardiography, radiography and echocardiography supported a diagnosis of fixed subvalvular aortic stenosis with a Doppler pressure gradient of 77.5 mmHg. Surgical inspection also revealed gross structural abnormalities of the mitral valve consistent with mitral dysplasia. Intervention consisted of resection of the dysplastic mitral valve and the subvalvular aortic stenosis. The mitral valve was replaced with a bioprosthetic valve. Total cardiopulmonary bypass time was 65 minutes and aortic cross-clamp time was 55 minutes. A full recovery was made and 11 months postoperatively the aortic transvalvular gradient was 30 mmHg. At the time of writing, 12 months after surgery, the dog was clinically normal and requires no medication.

Uso do pericárdio de eqüino conservado em glicerina como enxerto penetrante da córnea de cäes. Estudo experimental / Use of horse pericardium preserved in glycerin as corneal graft in dogs. Experimental study

Com o objetivo de estudar o emprego do pericárdio de eqüino, conservado em glicerina, na reparaçäo experimental de defeitos penetrantes da córnea de cäes utilizaram-se 15 animais; mestiços, machos e fêmeas, pesando entre 8 e 10 kg. Uma lesäo penetrante da córnea de 5 x 4 mm foi provocada e fragmento de pericárdio, de igual dimensäo, foi suturado em pontos simples separados com Prolene 7-0. Os animais foram sacrificados nos tempos 2, 7, 15, 30 e 70 dias de pós-operatório. Os resultados obtidos, quando analisados, tanto do ponto de vista clínico quanto histológico, mostraram que o pericárdio de eqüino conservado apresentou-se como meio satisfatório de reparaçäo penetrante de lesöes da córnea de cäes

Mitral valve replacement for the treatment of congenital mitral dysplasia in a bull terrier.

A 10-month-old entire male bull terrier was presented with a history of collapse on exercise. Clinical examination, electrocardiography, radiography and echocardiography all supported a diagnosis of mitral valve dysplasia. There was no evidence of congestive heart failure. Surgical intervention consisted of open resection of the dysplastic mitral valve and its replacement with a bioprosthetic valve. The procedure was performed through a median sternotomy and the dog was placed on to full cardiopulmonary bypass. Total cardiopulmonary bypass time was 70 minutes. A full recovery was made and at the time of writing (17 months postoperatively) the dog is clincally normal requiring no medication.

Embolia calcificada a la arteria coronaria por degeneración de bioprótesis en posición aórtica / Calcified embolism of the coronary artery by degeneration of bioprothesis in aortic position

Se presenta un caso de embolia arterial coronaria por material calcificado de una bioprótesis de pericardio bovino del INC en posición aórtica 8 años después de su implantación. Se realizaron estudios de ecordiograma y cateterismo con coronariografía, que demostraron disfunción protésica aórtica y coronarias normales. Antes de internarse al hospital, el paciente refería angor y disnea. Durante la coronariografía hubo un aumento de la sintomatología, acompañado de cambios electrocardiográficos y horas después con elevación enzimática. El paciente fue llevado de urgencia a cirugía donde se efectuó un recambio protésico mitroaórtico con prótesis mecánica. Como hallazgos quirúrgicos: ausencia de una valva de la prótesis en posición aórtica, con calcio libre fragmentado en la región perianular y las dos valvas restantes completamente calcificadas, la prótesis en posición mitral de apariencia normal. Concluimos que la isquemia o el infarto de miocardio en presencia de coronarias normales en pacientes con bioprótesis de pericardio bovino en posición aórtica puede ser secundaria a embolia por calcio, originada por el proceso de mineralización de una bioprótesis degenerada años después de su implantación