Penile Epithesis: Preliminary Study

Abstract

Sir: The principle of osseointegration is accepted and used in different disciplines: ceramic teeth, silicone ears and noses, joints and fingers, and upper and lower extremity epitheses that can be fixed with various titanium screws.1 A possible ultimate application can be represented by penile reconstruction. Particularly for female-to-male transsexuals, the ultimate goal is to create, in a one-stage procedure, an aesthetically appearing neophallus, with erogenous and tactile sensation, provided with a competent neourethra, to allow for voiding while standing, and rigidity to allow for sexual intercourse. Minimal scarring and no functional loss in the donor area are further requirements.2 No ideal technique has been described yet.3 Previously, Hage and Bouman4 described a silicone genital prosthesis for female-to-male transsexuals. Different from Hage and Bouman's “prosthesis,” our “epithesis” would be osseointegrated, allowing for sexual intercourse, transmission of vibration with possible stimulation of the clitoris, and eventually voiding through the device. In this preliminary study, we present our experimental surgery on explanted bones and on two cadavers (one male and one female cadaver) to fix a penile epithesis to the pubic bones, using Branemark screws. We analyzed anatomy of the pubic bone, implant fixation, and soft-tissue coverage. On the two cadavers, a U-shaped incision was positioned on the lower part of the pubic area: this pubic flap needed major defatting. Alternatively, complete tissue excision and full-thickness skin grafting are possible. A hole 2 mm in diameter was performed bilaterally to the pubic symphysis, on the lowest and anterior part of the pubic bones (depth, 12 to 15 mm). Holes were enlarged using a Branemark Integration AB drill kit. For clinical cases, we recommend 5-mm-wide, 20-mm-long implants. We propose three different types of epitheses (Table 1): type I (no urinary channel), to be possibly used for female-to-male transsexuals without previous surgery; type II, in which the epithesis incorporates an internal catheter, to be inserted in an urethrostomy, indicated after penile avulsion (trauma/excision after cancer), congenital anomalies, or in combination with urethrostomy/clitoris displacement in female-to-male transsexuals; and type III, in which the epithesis incorporates an internal pocket, for insertion of a possible congenital or post metoidioplasty micropenis (Fig. 1).Table 1: Different Types of Penile EpithesesFig. 1.: Prototype of a type III penile epithesis. An internal pouch in the epithesis is accommodating a congenital, or postmetoidoioplasty, micropenis. Eventually, the internal channel can drain urine up to the tip of the epithesis.Apart from the simplicity of the surgical technique, an epithesis would avoid completely donor-site disfigurement,3 as occurs following conventional flap surgery.3 The urethra/clitoris transposition in female-to-male transsexuals might enhance the chance for orgasm during sexual intercourse, as it is normally performed with other flap techniques.5 The penile epithesis can be a versatile surgical method, not precluding flaps in case it will not work clinically as a first-choice technique, or it can be used after flap failure. Our anaplastologists proposed different variations of the penile epithesis such as a silicone malleable type, and a telescopic type than can be enlarged when the patient is planning sexual intercourse. Clinical pilot cases should be started by experienced gender reassignment surgery centers, for selected groups of patients. ACKNOWLEDGMENTS The authors gratefully thank the European Society of Plastic and Reconstructive Surgery (EURAPS), because this work started under the EURAPS Fellowship (winner, Gennaro Selvaggi, M.D.; sponsor, Prof. S. Monstrey; receiving institution/tutor, Sahlgrenska University Hospital, Gothenburg University Hospital, Prof. Holmstrom). The authors thank Professor Johansson for help in the cadaver laboratory; Kerstin Bergström and Stewe Jönsson, anaplastologists, for their contribution in developing the penile epithesis; and John Brooks for the artwork preparation. DISCLOSURE Gennaro Selvaggi, M.D., has filed a temporary application, entitled “Penile Epithesis,” with the U.S. Patent and Trademark Office. The other authors have no financial interest to declare in relation to the content of this article. Gennaro Selvaggi, M.D. Anna Elander, M.D., Ph.D. Department of Plastic Surgery Rickard Branemark, M.D., Ph.D. Department of Orthopedics Sahlgrenska University Hospital Gothenburg, Sweden