The Stented Porcine Bioprosthesis: A 50-Year Journey Through Hopes and Realities.

The year 2018 marked the 50th anniversary of the first implant of a commercially manufactured stented porcine bioprosthesis. During the subsequent years considerable clinical and pathologic research was done to evaluate the overall performance of such devices and to identify the leading causes of failure. This brief review covers 5 decades, summarizing the initial hopes and the realities faced by surgeons who have believed from the start in these cardiac valve substitutes. From reported failures and long-term results a new generation of durable and reliable stented porcine bioprosthetic valves is currently available.

[Anomalous aortic origin of coronary arteries: a frequent and curable cause of sudden death]. / Les anomalies de naissance des artères coronaires à partir de l'aorte: une cause fréquente et évitable de mort subite.

Anomalous aortic origin of coronary arteries is a congenital heart defect in which one coronary artery arises from the opposite sinus (the left coronary artery from the right coronary sinus, or the right coronary artery from the left sinus). The initial segment of the abnormal artery courses between the great arteries and is usually located within the aortic wall. These anomalies are far from rare, affecting 0.1% to 0.3% of the population, and carry a high risk of sudden cardiac death. It is thought that the main mechanism of cardiac death is external compression of the abnormal coronary artery between the great arteries as they expand during strenuous exercise. The risk of sudden death is particularly high in patients with an anomalous left coronary artery or associated anatomic lesions (stenotic intramural segment, slit-like deformation of the ostium), and also in young athletes. A common presentation is sudden unexplained death. The diagnosis can be made by echocardiographic examination. Silent myocardial ischemia must be sought, with stress echocardiography and stress nuclear imaging. Various surgical techniques have been described. Our own technique involves the creation of a neo-ostium in the appropriate sinus. Surgical treatment is relatively safe and provides satisfactory results, most patients having no residual myocardial ischemia under stress. Surgery is recommended for all patients with an anomalous left coronary artery, regardless of symptom status, as well as for symptomatic patients with an anomalous right coronary artery (aborted sudden death, symptoms under stress, myocardial ischemia under stress). Because of the incidence and severity of these anomalies, careful echocardiographic evaluation should be performed routinely, at least in young athletes.

New biological solutions for hemodialysis access.

Since Scribner described the first prosthetic chronic dialysis shunt in 1961, the surgical techniques and strategies to maintain vascular access have improved dramatically. Today, hundreds of thousands of patients worldwide are treated with some combination of native vein fistula, synthetic vascular graft, or synthetic semipermanent catheter. Despite significantly lower efficacy compared with autologous fistulae, the basic materials used for synthetic shunts and catheters have evolved surprisingly slowly. The disparity between efficacy rates and concomitant maintenance costs has driven a strong campaign to decrease the use of synthetic grafts and catheters in favor of native fistulae. Whether arguing the benefits of Fistula First or "Catheter Last," the fact that clinicians are in need of an alternative to expanded polytetrafluoroethylene (ePTFE) is irrefutable. The poor performance of synthetic materials has a significant economic impact as well. End-stage renal disease (ESRD) accounts for approximately 6% of Medicare's overall budget, despite a prevalence of about 0.17%. Of that, 15%-25% is spent on access maintenance, making hemodialysis access a critical priority for Medicare. This clinical and economic situation has spawned an aggressive effort to improve clinical care strategies to reduce overall cost and complications. While the bulk of this effort has historically focused on developing new synthetic biomaterials, more recently, investigators have developed a variety of cell-based strategies to create tissue-engineered vascular grafts. In this article, we review the evolution of the field of cardiovascular tissue engineering. We also present an update on the Lifeline™ vascular graft, an autologous, biological, and tissue-engineered vascular graft, which was the first tissue-engineered graft to be used clinically in dialysis patients.

Beginning and development of surgery for acquired valvular heart disease in Japan.

The initiation and development of surgery for acquired valvular heart disease in Japan was reviewed. The first series of attempts at closed valvular surgery were performed in 1951-1952 by collaboration between the brothers Tohru and Shigeru Sakakibara in patients with pulmonary or mitral stenosis. During the popularization of closed valvular surgery, open heart surgery under direct vision was successfully performed by Shigeru Sakakibara with cooling of the body in 1954 and by using cardiopulmonary bypass (CPB) in 1956. With the development of CPB and artificial heart valves, closed valvular heart surgery was replaced by open surgery, which expanded rapidly during the 1960s and 1970s. Along with the serial introduction and improvement of mechanical vales thereafter, bioprosthetic valves were also introduced and were adopted for certain patients. Use of bioprosthetic valves in the aortic position exceeded 50% in 2005, along with the increase of elderly patients. Although trials of mitral valve plasty for mitral regurgitation were first done during the 1950s to 1960s in Japan, interest in valve plasty only increased during the late 1970s. Considering the patient's quality of life and the long-term results, mitral valve plasty became the major procedure (exceeding valve replacement) from 2004. In 2002, the Guideline for Surgical and Interventional Treatment of Valvular Heart Disease was published by a joint committee of the relevant academic societies, and it has made an important contribution to improving surgical outcomes.

Blood vessel replacement: 50 years of development and tissue engineering paradigms in vascular surgery.

The gold standard material in bypass surgery of blood vessels remains the patient's own artery or vein. However, this material may be unavailable, or may suffer vein graft disease. Currently available vascular prostheses, namely polyethylene terephthalate (PET, Dacron) and expanded polytetrafluoroethylene (ePTFE), perform well as large-caliber replacements, but their long-term patency is discouraging in small-caliber applications (<6 mm), such as in coronary, crural or microvessel surgery. This failure is mainly a result of an unfavorable healing process with surface thrombogenicity, due to lack of endothelial cells and anastomotic intimal hyperplasia caused by hemodynamic disturbances. An ideal small-diameter vascular graft has become a major focus of research. Novel biomaterials have been manufactured, and tissue-biomaterial interactions have been optimized. Tissue engineering technology has proven that the concept of partially or totally living blood vessels is feasible. The purpose of this review is to outline the vascular graft materials that are currently being implanted, taking into account cell-biomaterial physiology, tissue engineering approaches and the collective achievements of the authors.

The early history of tubulation in nerve repair.

The first experiments for bridging peripheral nerve gaps using nerve tubulation emerged in the 19th century. Because Gluck (1853-1942) is said to have performed the first animal experiment of nerve tubulation in 1880, it is interesting to explore the background and veracity of this claim. The original documents on nerve tubulation in the 19th century were studied. We conclude that the conduit that was initially used for nerve tubulation was derived from a resorbable decalcified bone tube developed for wound drainage by Neuber (1850-1932) in 1879. Gluck proposed the use of the bone tube as a guided conduit for regenerating nerves in 1881 but stated briefly that his experiments failed because of scar formation. Vanlair (1839-1914) documented the first successful application of nerve tubulation using a bone tube to bridge a 3 cm sciatic nerve defect in a dog in 1882.

Lasker Award to heart valve pioneers.

This year, the Lasker Foundation recognizes Albert Starr and Alain Carpentier for their development of effective treatments for valvular heart disease. Their innovative work is a model of interdisciplinary basic and clinical research and has benefited millions of people.

Technology insight: the evolution of tissue-engineered vascular grafts--from research to clinical practice.

There is a considerable clinical need for alternatives to the autologous vein and artery tissues used for vascular reconstructive surgeries such as CABG, lower limb bypass, arteriovenous shunts and repair of congenital defects to the pulmonary outflow tract. So far, synthetic materials have not matched the efficacy of native tissues, particularly in small diameter applications. The development of cardiovascular tissue engineering introduced the possibility of a living, biological graft that might mimic the functional properties of native vessels. While academic research in the field of tissue engineering in general has been active, as yet there has been no clear example of clinical and commercial success. The recent transition of cell-based therapies from experimental to clinical use has, however, reinvigorated the field of cardiovascular tissue engineering. Here, we discuss the most promising approaches specific to tissue-engineered blood vessels and briefly introduce our recent clinical results. The unique regulatory, reimbursement and production challenges facing personalized medicine are also discussed.

[Historical evolution of prosthetic heart valves]. / Evolución histórica de las prótesis valvulares cardíacas.

The historical evolution of the prosthetic heart valves is resumed, quoting the first experimental steps, the conditions that a prosthesis has to fulfil, and the first clinical attempts with the Hufnagel's valve in the treatment of the aortic insufficiency (September 11, 1952) and with the Chesterman's in the pathology of the mitral valve (July 22, 1955) till the Starr Edwards' ball valve (Agoust 12, 1960). The characteristics of the different types of ball valve are described (Harken, Smeloff, etc), disc valves (Kay-Shiley, Beall, Lillehei-Nakib etc.), tilting disc valves (Bjork-Shiley, Hall-Kaster, Omniscience etc), bileaflet valves ( St. Jude and others) and biological valves, using autologous tisues (diaphragm, fascia lata, pericardium) homologous (aortic and mitral valves, duramater) and heterologous (porcine and bovine valves, Carpentier-Edwards, Hancock, Ionescu's valve of bovine pericardium), to conclude with the new trends with valves made from autologous cells, the valves made with polymers, those based on the concept of flexible tubes and finally with those used by percutaneous transcatheter implantation (Boudjemline y Bonhoeffer. Cribier.).

Bioprótese valvar de pericárdio bovino St Jude Medical-Biocor: sobrevida tardia / St Jude Medical-Biocor bovine pericardial bioprosthesis: long-term survival

OBJETIVO: Nosso objetivo é apresentar resultados a longo prazo da subsituicão valvar por bioprótese de pericárdio bovino SJM-BiocorTM. MÉTODO: Entre 1992 e 2000, tiveram alta hospitalar, após substituicão valvar por bioprótese de pericárdio bovino SJM-BiocorTM 304 pacientes. Idades eram de 15 a 83 anos (média: 60,6n14,3), sendo 50,3 por cento do sexo masculino. Pacientes tiveram situacão clínica atualizada e análise atuarial foi empregada no cálculo da sobrevida simples e livre de eventos. RESULTADOS: Em um seguimento total de 931,0 pacientes-ano, ocorreram 28 (9,2 por cento) óbitos tardios, sendo cinco (1,6 por cento) relacionados à bioprótese, sete (2,3 por cento) cardíacos, quatro (1,3 por cento) não-cardíacos e 12 (3,9 por cento) de causa desconhecida. Eventos de bioprótese foram: endocardite: 18 (5,9 por cento), degeneracão fibrocálcica: 15 (4,9 por cento), tromboembolismo: três (1,0 por cento), hemólise: um (0,3 por cento). Disfuncão de bioprótese resultou em 16 (5,2 por cento) reoperacões, por degeneracão fibrocálcica (nove), endocardite (seis) e tromboembolismo (um). Probabilidade de sobrevida foi 86,3n3,4 por cento, no 5º, e 69,3n9,0 por cento, no 10º ano pós-operatório. Idade jovem (<40 anos, n= 35) mostrou maior sobrevida em relacão à mais idosa (>60 anos, n=187): 82,0n13,3 por cento vs 58,8n13,6 por cento, no 9º ano. Sobrevida livre de eventos foi 77,5n3,7 por cento, no 5º, e 40,2n9,0 por cento, no 10º ano. Probabilidade de falência estrutural de bioprótese foi 5 por cento, no 5º ano, e 20 por cento, no 10º; em aórticos, zero e 8 por cento, respectivamente. A classe funcional (NYHA) atual é I para 88,5 por cento, II para 9,1 por cento e III para 2,4 por cento dos pacientes. CONCLUSAO: Implante de bioprótese de pericárdio bovino SJM-BiocorTM resulta em satisfatória perspectiva de sobrevida dos pacientes com doenca valvar e apresenta baixa prevalência de disfuncão de prótese.

The evolution of mitral valve surgery: 1902-2002.

The evolution of the surgical therapy of mitral valve disease emanates from original statements by British cardiologists in 1902 and anecdotal individual surgical cases in 1923 and 1925. Considerable amounts of experimental investigation during these years and after World War II in 1948 finally resulted in the widespread use of closed mitral commissurotomy, a successful therapy for noncalcified mitral stenosis. The history of mitral valve surgery then rapidly progressed with a variety of prosthetic and bioprosthetic valve devices, ultimately, to a considerable number of successful valve repair operations with prosthetic ring annuloplasty. The authors conclude with a discussion of the current status of minimally invasive mitral valve surgery, both by direct vision and robotic assistance. The entire evolution of thought and technique of mitral valve surgery is summarized in this paper from 1902-2002.