Background: Many men will undergo prostate or bladder cancer surgery or radiation to the pelvis. To the surprise of some patients, erection may be worsened at least temporarily by the procedure. Following surgery (called radical prostatectomy or radical cystectomy), or radiation in the pelvic area (called brachytherapy, “seeds”, or external beam radiation), there is manipulation, removal, or damage to at least some of the nerves (called cavernosal nerves) which run beneath the prostate toward the penis. There are 2 sets, one on the left and one on the right side of the pelvis. The penis relies on these nerves (in addition to blood flow) in order to produce an erection. While the number one goal of surgery is to safely remove all cancer, a secondary goal is to preserve the nerves responsible for erection during and after surgery.
Your age, health, and erection ability before surgery will help to predict your erection ability after surgery. In addition, if the surgeon needs to take extra tissue for cancer control, then the nerves may have to be sacrificed partially or completely on one or both sides. While many patients do not receive a regular medication program after pelvic surgery or radiation to maximize erectile function, research from Memorial Sloan Kettering Cancer Center in New York indicates that regular rigid erections in the postoperative period are extremely important to preserve and optimize erection for the future. Without regular erections, the penile tissue can become scarred and weakened (just like an arm muscle in a cast) except this damage can be irreversible.
Treatment: It is imperative that every patient planning for pelvic surgery or radiation visits a urologist to start a training program for the penis (called penile rehabilitation) 2 weeks prior to surgery or immediately following your surgery. It has been shown that starting penile rehabilitation early is better than starting it late. If you have no contraindications (your urologist will let you know), the best regimen should include daily medication (either Viagra™, Levitra™, or Cialis™, all of which are in the same drug family called phosphodiesterase-5 inhibitors or PDE5i). Your physician can recommend any one of these medications, and it should be taken each night at the lowest dose, for example Viagra 25mg for 5 nights of each week. Two times per week (it doesn’t matter which two nights), the patient would take a higher dose of Viagra (50mg or 100mg). The goal is to have the patient get at least 2 erections per week suitable for vaginal penetration (“hard enough” to have sexual intercourse). If erections are suitable for intercourse, then the patient continues this regimen (Viagra 25 mg 5 nights per week, and Viagra 100mg for the other 2 nights each week) for 1 year after surgery or 2 years after radiation therapy.
If your erections are not hard enough for intercourse with highest PDE5i dose, then penile injections (Trimix, a cocktail of three medications, is often used) would be prescribed to get 2 rigid erections per week. At this point, most men start grimacing, or turn pale white. In reality, there is no need to get to anxious about this penile injection therapy. Penile injections are performed at home by the patient with a tiny diabetic needle (like a mosquito bite). These injections are much less costly than the pills described above, and are used immediately prior to intercourse. As always with any of the above therapies, the early warning of a possible problem is any erection lasting more than an hour which could become a medical emergency.
Bottom line: The above regimen (taking low-dose PDE5i medication for 5 nights per week along with either higher dose PDE5i medication or penile injections 2 nights per week) should be done for 1 year following surgery or two years following radiation therapy to the pelvic area (typically for prostate cancer). While the described regimen is our sample recommendation, your urologist can decide the best course given your exact clinical circumstances. At the very least, you should ask your urologist about penile rehabilitation, and the benefits and the risks of such a program.
–Matthew Wosnitzer, M.D.
January 2, 2014