The Tunica Vaginalis Dorsal Graft Urethroplasty: Initial Experience (Editorial Comment)
International Braz J Urol 2007; 33: 523-531.
The use of tunica vaginalis in reconstructive urethral surgery was mainly suggested by pediatric urologists in hypospadias repair. The objective was to provide vascular and mechanical support to the reconstructed urethra in order to avoid fistula formation. For our best knowledge, the authors of this manuscript reported, by the first, the use of tunica vaginalis graft in adult bulbar urethroplasty. The authors honestly emphasized the weaknesses and the drawbacks of their study, including a very short followup. It can be speculated that the success rate of this new kind of urethroplasty will probably decrease with extended follow-up; it is a “natural evolution” of any kind of urethroplasty apart from the substitute graft material. History of reconstructive urethral surgery is full of new and different substitute materials for urethral reconstruction, but, unfortunately, the final, long term follow-up outcome of any kind of urethroplasty is probably influenced more by the original urethral pathology than by the substitute material used for the repair. Surgical treatment of urethral stricture diseases is a continually evolving process, and urologists have changed over time the substitute material. In the ‘90s, skin grafts were the preferred substitute material for urethroplasty, but at present, many of us have left the use of skins graft. Up-to-date, buccal mucosa has become the most preferred substitute material in the treatment of urethral strictures as it is readily available in all patients and easily harvested from the inner cheek or lower lip and guarantees a concealed donor site scar and low oral morbidity. Buccal mucosa is hairless and has a thick elastin-rich epithelium, which makes it tough yet easy to handle, and a thin and highly vascular lamina propria, which facilitates inosculation and imbibition. These statements are now supported by literature evidence (1). In our experience, when we convey this message to the patients, they always appreciate it. Patients do not like to be considered as an experimental animal. For this reason, we are publishing all the results of our urethroplasties in an open and no-profit dedicate website (www.urethralcenter.it), to convey to the patients that the surgical technique we have selected for him is worldwide used in the urological community and the results of this technique are fully at his disposal. In the near future, every patient with a urethral stricture will be able to manage dedicated nomograms, which will predict his success and complication rate after surgery accurately on the basis of his age, of the site, of the length and the etiology of stricture. This article is important for another reason. One of the basic principles in urethral reconstruction consists in the formation of an epithelialized tube from a buried strip of skin. In 1880, Duplay described a method for urethral construction in hypospadias, which was based on that principle, and reported the method that is usually associated with his name (2). In 1949, Denis Browne described a similar method for construction of the urethra in hypospadias (3). His method differs from Duplay’s in a few essential respects. Over time, the Duplay’s and Denis Browne’s principles, according to which the buried strip of intact epithelium becomes an epithelialized tube, is widely exploited in reconstructive urology. In 1980, Monseur described the first dorsal urethroplasty and fully quoted the Duplay’s principle: “…En premier lieu, l’urètre c’est un tube natural. Si une bandelette de peu ou de muqueuse enfouie, selon le principe de Duplay, tend spontanément à se tubuliser, combine plus facilement le tube urètral transfromé en bandelette par une incision longitudinal reprendera-t-il sa forme préalabe! Elargir le canal ne suffit pas, il faut en fixer les bords” (4). In 1996 (reference 2 in the text), we have fully exploited the Duplay’s-Denis Browne’s-Monseur’s principles. The authors of this article showed in the experimental model and in humans that a buried strip of tunica vaginalis becomes an epithelialized tube. One hundred-twenty-seven years later, these authors confirm and expand the ingenious Duplay’s principle: each strip of autologus epithelial tissue has the potential to be used for urethral regeneration. This is an important message for people involved in tissue engineering studies. This new surgical technique should be now included in the armamentarium of the reconstructive urethral surgeon. The reconstruction of urethral channel is a challenging problem, for instance, sometimes, in our daily surgical practice, we might ask ourselves what kind of repair we are going to do in a particularly unusual and complex case. The replay should be “let us use the tunica vaginalis graft as suggested in the International Braz J Urol in 2007!”