Tracheal replacements: part 1

In this review, we summarize the history of tracheal reconstruction and replacement as well as progress in current tracheal substitutes. In Part 1, we cover the historical highlights of grafts, flaps, tube construction, and tissue transplants and address the progress made in tracheal stenting as a means of temporary tracheal support. This is followed in Part 2 by an analysis of solid and porous tracheal prostheses in experimental and clinical trials. We conclude Part 2 with a summary of recent efforts toward generating a bioengineered trachea. Finally, we provide an algorithm on the spectrum of options available for tracheal replacement.

1992: Parodi, Montefiore, and the First Abdominal Aortic Aneurysm Stent Graft in the United States

In 1990 Juan C. Parodi performed the first endovascular abdominal aortic aneurysm (AAA) repair in Buenos Aires. Two years later, in 1992, Parodi and Claudio Schonholz visited Montefiore Medical Center in New York to perform with us the first endovascular AAA repair to be done in the United States. Since then the Montefiore/Einstein vascular group has performed 1522 endovascular grafts in 674 patients for many types of vascular lesions using a variety of both surgeon-made and industry-made devices. The purpose of the present article is to describe the events that surrounded the performance of the first seminal endovascular AAA repair at our institution on November 23, 1992.

Historical overview on the development and characteristics of stents and future outlooks

The history and development of endovascular stents is described beginning with the Maass double helix spiral prosthesis, the first stent used in human clinical trials in the early 80s. This is followed by a description of the three main groups of stent techniques: the shape memory alloy stents, the balloon-expandable stents, and the self-expanding stainless steel stents. Requirements and new trends for improving clinical results in the future complete this text.

The future of biomedical materials

The purpose of this communication is to present the author's perspectives on the future of biomedical materials that were presented at the Larry L. Hench Retirement Symposium held at Imperial College, London, in late September 2005. The author has taken a broad view of the future of biomedical materials and has presented key ideas, concepts, and perspectives necessary for the future research and development of biomedical polymers and their future role as an enabling technology for the continuing progress of tissue engineering, regenerative medicine, prostheses, and medical devices. This communication, based on the oral presentation, is meant to be provocative and generate discussion. In addition, it is targeted for students and young scientists who will play an ever-increasing role in the future of biomedical materials.

The origin of the word Stent

In 1856, the English dentist Charles Stent developed a thermoplastic-like material for taking impressions of toothless mouths. This "Stent mass" was later used as a device or mould for keeping a skin graft in place; it was also used to provide support for anastomosis. A hundred years after the inventor's death in 1885, the word stent has been adopted all over the world in interventional radiology but today it is understood to mean percutaneous tubular structures that induce or maintain lumen patency. The true origin of the word stent is not found in many dictionaries. In most references, the wrong dentist is given credit for the discovery. Dictionaries also refer to the obsolete English and Scottish words stent and stint which mean, among other things, "to extend". The true origin of the word is therefore somewhat unclear.

Stent thrombosis: historical perspectives and current trends

Coronary stents are now implanted in more than 70% of percutaneous coronary revascularization procedures. Early enthusiasm for improved acute angiographic results and limited restenosis was dampened initially by a high rate of stent thrombosis and later by the increased bleeding complications of aggressive and complex anticoagulation protocols designed to lower the stent thrombosis risk. More recently, routine high-pressure deployment strategies and anti-platelet drug regimens have lowered the incidence of stent thrombosis to approximately 1% without an increased bleeding risk. The timing of stent thrombosis has also changed from a median of 4-5 days to a median of 1 day after the stent procedure. Risk factors in earlier studies included stenting for threatened or abrupt closure, smaller vessels, longer lesions, and possibly left anterior descending artery lesion location. Modern studies have shown a slightly increased risk for multiple stent use, residual dissection, and smaller final lumen. Optimal therapy for stent thrombosis includes emergent revascularization and anti-thrombotic treatment, although the clinical consequences remain dire despite successful reperfusion. The use of platelet glycoprotein IIb/IIIa inhibitors, especially in high-risk situations may further reduce the incidence of stent thrombosis.

[Microsurgery: History of instrumental vascular anastomoses, our experience with eversion-stapling using VCS forceps]

One century, after Carrel in 1906, technics of vascular surgery are the same. After two world wars, peace surgery has been improved by war surgery. Microscopy surgery gave a new way for vascular surgery which became microsurgery with specific instrumentation. We have move from the developing period of microsurgery in the 1970s, to the fully matured period of microsurgery in the 1980s and the the development of clinical free flaps. The 1990s must be the turning point from autogenous tissue transplantation to allogenic transplantation. Ethic comity keeps keys of future! About microvascular anastomoses, many instrumental technics are explored but no-one is better than the classic manual suture. For us, the best instrumental technic is the anastomose with titanium clips VCS((R)) but we only use it in good situation without difficulties.

What is a stent and where can you get one

The development of the word stent as we use it today refers to a material to hold tissues in position or to make tissues patent. Dr. Charles Thomas Stent, a 19th century London dentist, created a compound for dental impressions that was used to hold skin grafts in place by later plastic surgeons, presaging its present usage.