Experimental data support the concept of cavernosal damage and suggest a protective role for daily dosage of a PDE5-I ; however , similar data have not yet been replicated in humans .
Penile rehabilitation programs are common in clinical practice , but there is no definitive evidence to support their use or the best treatment strategy .
PDE5-Is are efficacious and safe in young patients with normal preoperative erectile function who have undergone bilateral nerve-sparing radical prostatectomy .
On-dem and use of a PDE5-I may be at least as efficacious as daily use .
PDE5-I use in penile rehabilitation programs is not supported by rigorous level 1 evidence -based medicine .
PDE5-Is are an efficacious and safe treatment for post-RP ED in properly selected patients .
The experimental results on the protective role of daily dosages of PDE5-Is , while robust , have not been replicated in humans .
CONTEXT  Erectile dysfunction ( ED ) after radical prostatectomy ( RP ) has a significant negative impact on a patient 's health-related quality of life .
Phosphodiesterase type 5 inhibitors ( PDE5-Is ) have recently been utilized not only as a treatment of ED in this population but also as a preventive strategy in penile rehabilitation programs .
OBJECTIVE To eluci date the pathophysiologic mechanisms of post-RP ED , to assess the need for rehabilitation following surgery , and to analyze the basic scientific evidence and clinical applications of PDE5-Is for the prevention and treatment of ED .
EVIDENCE SYNTHESIS Post-RP ED has many factors .
Cavernosal nerve injury induces pro-apoptotic factors ( ie , loss of smooth muscle ) and pro-fibrotic factors ( ie , an increase in collagen ) within the corpora cavernosa .
Factors predicting recovery of erections after radical prostatectomy.
PURPOSE Because preservation of functioning penile erections is a major concern for many patients considering treatment for localized prostate cancer , we analyzed various factors determined before and after radical retropubic prostatectomy to identify those significantly associated with recovery of erectile function . MATERIAL S AND METHODS Our prospect i ve data base of patients undergoing pelvic lymphadenectomy and radical retropubic prostatectomy  was used to determine factors predictive of erection recovery after radical prostatectomy . The study included 314 consecutive men with prostate cancer treated with radical retropubic prostatectomy between November 1993 and December 1996 . Preoperative potency satisfactory for intercourse and degree of neurovascular bundle preservation during the operation were documented . RESULTS Patient age , preoperative potency status and extent of neurovascular bundle preservation but not pathological stage were predictive of potency recovery after radical prostatectomy . At 3 years after the operation 76 % of men younger than age 60 years with full erections preoperatively who had bilateral neurovascular bundle preservation would be expected to regain erections sufficient for intercourse . Compared to the younger men , those 60 to 65 years old were only 56 % ( 95 % confidence interval [ CI ] 37 to 84 ) and those older than 65 years were 47 % ( 95 % CI 30 to 73 ) as likely to recover potency . Patients with recently diminished erections were only 63 % ( 95 % CI 38 to 100 ) as likely to recover potency as men with full erections preoperatively , and those with partial erections were only 47 % ( 95 % CI 23 to 96 ) as likely to recover potency . Resection of 1 neurovascular bundle reduced the chance of recovery to 25 % ( 95 % CI 10 to 61 ) compared to preserving both nerves . CONCLUSIONS Knowledge of preoperative erectile function and patient age before the operation and the degree of neurovascular bundle preservation afterward may aid in patient counseling regarding potency recovery after radical prostatectomy
Experimental data support the concept of cavernosal damage and suggest a protective role for daily dosage of a PDE5-I ; however , similar data have not yet been replicated in humans .
Penile rehabilitation programs are common in clinical practice , but there is no definitive evidence to support their use or the best treatment strategy .
PDE5-Is are efficacious and safe in young patients with normal preoperative erectile function who have undergone bilateral nerve-sparing radical prostatectomy .
On-dem and use of a PDE5-I may be at least as efficacious as daily use .
PDE5-I use in penile rehabilitation programs is not supported by rigorous level 1 evidence -based medicine .
PDE5-Is are an efficacious and safe treatment for post-RP ED in properly selected patients .
The experimental results on the protective role of daily dosages of PDE5-Is , while robust , have not been replicated in humans .
CONTEXT  Erectile dysfunction ( ED ) after radical prostatectomy ( RP ) has a significant negative impact on a patient 's health-related quality of life .
Phosphodiesterase type 5 inhibitors ( PDE5-Is ) have recently been utilized not only as a treatment of ED in this population but also as a preventive strategy in penile rehabilitation programs .
OBJECTIVE To eluci date the pathophysiologic mechanisms of post-RP ED , to assess the need for rehabilitation following surgery , and to analyze the basic scientific evidence and clinical applications of PDE5-Is for the prevention and treatment of ED .
EVIDENCE SYNTHESIS Post-RP ED has many factors .
Cavernosal nerve injury induces pro-apoptotic factors ( ie , loss of smooth muscle ) and pro-fibrotic factors ( ie , an increase in collagen ) within the corpora cavernosa .