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 .
Pilot study of changes in stretched penile length 3 months after radical retropubic prostatectomy.
OBJECTIVES To evaluate changes in stretched penile length after  radical retropubic prostatectomy ( RRP )  in a prospect i ve penile measurement study because an occasional complaint from patients after RRP is that their penis is shortened . METHODS Thirty-one patients undergoing RRP by one surgeon were enrolled . The same physician completed measurements with a paper ruler to the nearest 0.5 cm . The stretched penile length was measured from the tip of the glans to the pubopenile skin junction . The measurements were taken in the preoperative holding area before the patient received anesthetic medication for the RRP and again 3 months postoperatively . The reliability and reproducibility of this measurement were confirmed . RESULTS All 31 patients were measured at 3 months postoperatively . Of the 31 patients , 22 ( 71 % ) had a decrease in stretched penile length ( range 0.5 to 4.0 cm ) . Seven were shortened 0.5 cm , 11 were shortened 1.0 to 2.0 cm , and 4 were shortened more than 2.0 cm . Five patients had no change , and in four the penile length was longer ( range 0.5 to 1.0 cm ) . CONCLUSIONS The results of this pilot study appear to show that the stretched penile length decreases after RRP at 3 months of follow-up in most men ; 48 % ( 15 of 31 ) had considerable shortening greater than 1.0 cm . If confirmed by other investigators , the cause of this change needs to be eluci date
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 .