A 66-year-man is reviewed in clinic for prostate-specific antigen (PSA) follow-up after radical prostatectomy. His radical prostatectomy was 16 months ago with unrecordable PSA (i.e. <0.01). Overall, he was feeling well and getting better. His incontinence had improved and was not using any pads with stable lower urinary tract symptoms. His main issue was no improvement in erectile dysfunction (ED) despite initial trial of phosphodiesterase type 5 (PDE5) inhibitors postoperatively. Evaluation includes sexual function history, general medical history, psychosocial history, medication history, physical examination and appropriate laboratory tests. On examination the abdomen was soft, external genitalia were normal and no prostate or recurrence was palpable on rectal examination. Routine bloods include FBC, U&E, LH/FSH and testosterone were normal.
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1. What are the causes of ED post RP?
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Various factors are considered as responsible for ED in patients with prostate cancer. Psychological impact of cancer has potential role in ED. Intraoperative neurapraxia and nerve injury has an important role in ED even in patients with unilateral or bilateral nerve-sparing prostatectomy. There is little evidence of arterial injury on such a large scale after radical prostatectomy. Over time, natural recovery starts with the nocturnal activity that corresponds with increase in natural erectile function.
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2. What are the initial management options?
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Proper explanation and reassurance is very important. It should be explained that with time the neuropraxia can improve but it can take 18–24 months. As neuropraxia improves, the penis becomes increasingly more responsive to PDE5 inhibitors such as sildenafil. Even in patients who did not respond to initial PDE5 inhibitor therapy, later response may be noticed after 18 months and should be tried. Different PDE5 inhibitors should be tried before the patient is labelled as a non-responder.
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3. What intermediate options are available?
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The intermediate options for non-responses to PDE5 inhibitors include injection therapy, intra-urethral prostaglandin and vacuum erection devices. Medicated Urethral System for Erection (MUSE) is tried as the next option on its own or in combination with sildenafil.
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4. What is the treatment of last resort?
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When ED is unlikely to improve naturally or with medical treatments, a penile implant is used. These devices are either malleable or inflatable. The simplest type of prosthesis is malleable rods surgically implanted. With this type of implant the penis is always semi-rigid and merely needs to be lifted or adjusted for sexual activity. More recently, the preferred choice is a three-piece inflatable prosthesis where erection can be achieved on demand. Satisfaction rates are very high in both patient and partner (90–95%).
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5. What are the complications associated with penile implants?
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Penile implants can be associated with complications such as infection (<2%), erosion, mechanical failure and auto-inflation. However, the efficacy and reliability of these implants are now very good.
