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Ann Thorac Surg 2005;79:676-677
© 2005 The Society of Thoracic Surgeons

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New technology

INVITED COMMENTARY

Department of Surgery, University of South Alabama, 2451 Fillingim St, Mastin 719, Mobile, AL 33671-2293, USA

jlocicero{at}usouthal.edu

Tracheal replacement has a long and ignominious history. It has been the dream of thoracic surgeons since the early 1950s. At first, investigators fashioned prostheses out of materials such as Teflon, Marlex, and silicone elastomer tubing. The latter, the famed Neville prosthesis, introduced in 1970 hung around until the mid 1990s. Nearly all clinical applications failed owing to anastomotic disruption or infection. Despite this dismal result, much was learned about tracheal surgery.

Other observations concerning the dynamic nature of the trachea in promoting the removal of secretions and the lack of advancement of mucosa to line the foreign implant led some researchers to attempt other solutions. Tracheal transplantation seemed like a natural alternative. Attempts began in the mid 1960s showing that ciliated epithelia could survive, at least in the early period, but that ischemia of the cartilaginous rings resulted in tracheomalacia, thus rendering the grafts useless. Some researchers tried other autologous or allogeneic tissues such as the aorta, ileum, perichondrium, and a variety of nasal and auricular transfers for small defects—all with marginal results.

More recently, advances in tissue engineering opened a new door for researchers. Early attempts used polypropylene mesh that was coated with gelatin and lined with oral mucosa. Others seeded nasal and tracheal chondrocytes onto polyglycolic acid matrices that could duplicate the histology of the trachea. In the current communication, Shi and colleagues created a new prosthesis combining polypropylene, a relatively strong, nonabsorbable material with polylactic-coglycolic acid, a degradable scaffold, and coated the outside with polyurethane. When they combined this with collagen-hydroxyapatite composites, they produced a semirigid tube with pores ranging from 100 to 150 µm. This prosthesis has a more uniform pore size than previously produced constructs. That may provide a distinct advantage for fibrovascular ingrowth.

While this newly described prosthesis is a giant leap forward, major problems remain. The most significant problem is the migration of ciliated epithelium beyond just the ends of the tube. Solutions to this problem might include seeding the graft with epithelial cells before implant or impregnating the graft with growth factors. Or the solution may be as simple as increasing the pore size or making the polyurethane coating thinner.

Innovations by investigators Shi and coworkers open new vistas for stymied researchers to solve a problem we have been dreaming about for the past half-century. It demonstrates the need to be open to new technology in order to tackle issues in replacement therapy that up to now were thought impossible.

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by LoCicero, J. Search for Related Content PubMed Articles by LoCicero, J., III Related Collections Trachea and bronchi