Penile Implant

A 58-year-old heterosexual man was referred to our clinic for control visit. He had previously undergone penile implant surgery at 2000, for erectile dysfunction because of arterial vascularisation failure which had developed after transurethral prostatectomy in 1999, and which was unresponsive to medical therapy. He and his partner were satisfied with the penile implant. However, he had begun using home-made herbal remedies in February 2003 to obtain normal physiological erection because he felt himself sentenced to artificial erection evoked by the implant. After 2 months, he perceived that spontaneous full, rigid erections upon sexual arousal, without activation of the implant were adequate for vaginal penetration and satisfying sexual intercourse. He stated that since then, he had been activating the implant only once per month to prevent malfunction of the implant and had been regularly achieving sexual intercourse with spontaneous erection without activation of the implant.

We wanted to confirm radiologically this urological entity by magnetic resonance imaging technique. The images of flaccid penis and artificial erection evoked by the implant were obtained. On the following day, 50 mg sildenafil was given orally to the patient with the inactivated implant, for achievement of penile erection to demonstrate whether the penis still contains erectile tissue. One hour later, rigid penile erection was obtained. The glans and corpus spongiosum are also involved.

However, erection was not resolved spontaneously and semirigid erection persisted with minimal pain. The erection lasted for 6 h and, resolved with oral terbutaline, the application of ice pack to the genitalia and intermittent activation of the implant until detumescence. We did not attempt to stick a needle into cavernous body for diagnostic or therapeutic purposes during prolonged erection, because of the presence of an intracavernous implant. Routine haematological, biochemical and urine tests were normal.

Although the latest pharmacological developments have revolutionised the management of erectile dysfunction, penile implant surgery remains one of the most effective treatments for all types of erectile dysfunction. Nevertheless, it is a common belief that erectile tissue is destroyed utterly during dilatation of corporeal space in penile implant surgery and the penis thus loses its erectile function permanently. Even special penile implants (soft or fenestrated) have been developed with the aim at avoiding this adverse event and the fact remains that spontaneous tumescence or even erection was achieved with these devices in accordance with the expectations. Regular spontaneous tumescence is not surprising in men with specially designed implants, because these devices restore erectile function by the initiation of a new haemodynamic status in the corpora cavernosa which are dilated lesser than that of standard procedure.

The remaining functional cavernous tissue between the cylinder of implant and the tunica albuginea plays a pivotal role in men who experienced spontaneous tumescence, with this special penile implant. However, the same condition was not expected theoretically in men with three-piece hydraulic implants. Surprisingly, Manning et al. reported spontaneous tumescence without activation of the device in 50% of patients with three-piece inflatable device in their retrospective study including 32 patients.

More interestingly, one patient had claimed regular, full, rigid spontaneous erections that were adequate for sexual intercourse in their study. The authors finally stated that the destruction of cavernous tissue during dilatation was incomplete and tumescence, even with three-piece hydraulic implants, was not completely prevented.

Our report includes the complete case history of a penile implant patient who is regularly achieving sexual intercourse with spontaneous erection upon sexual arousal without activation of the three-piece implant. This extremely rare condition becomes more interesting with the occurrence of prolonged drug-induced erection in the patient with penile implant because of arteriogenic erectile dysfunction. The same has not yet been reported in terms of the presence of both spontaneous and prolonged drug-induced erection.

The most important question that needs to be answered in this subject is, how the penis which was unresponsive to medical therapy before penile implant surgery, spontaneously achieves an erection after penile implant. Several hypotheses were proposed to explain the phenomenal aspect. Our case, particularly with the occurrence of prolonged drug-induced erection supports the hypothesis proposed by Goldstein et al. They stated that elevated pre-load of likely compressed rather than destructed cavernous tissue and easier venous compression is the underlying mechanism of spontaneous tumescence with penile implants.

In addition, the herbal remedies used by the patient may have played a role in occurrence of this interesting phenomenon because some naturopathic remedies have significant hormonal content, even though this issue has not yet been clearly elucidated.