human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In a prospect i ve , placebo-controlled , one group crossover design study , we tested whether adding programmed intracavernous PGE1 injections ( IC-PGE1 ) can improve the effectiveness of sildenafil  in erectile dysfunction ( ED ) patients unresponsive to monotherapy with this drug . In all , 40 ED patients who had experienced unsatisfactory erections with both the 50 and 100 mg sildenafil doses were treated with four bi-weekly 20 μg IC-PGE1 injections given in the clinic and provided with either placebo or 50 mg sildenafil capsules for the next 4 weeks . Thereafter , they were crossed over to the other oral treatment for an additional 4-week period . The IIEF-Erectile Function domain score ( IIEF-EFS ) , the main outcome measure , was found considerably higher ( P<0.001 ) with the combined IC-PGE1–50 mg sildenafil treatment than with IC-PGE1–placebo or sildenafil alone ( 50 or 100 mg ) in a subset of 26 subjects ( 65 % ) . They thus shifted from the ‘ severe ’ or ‘ moderate ’ to the ‘ mild ’ grading of ED classification PURPOSE The exact process and time required for rehabilitation of erectile function after nerve sparing prostatectomy remain unclear to date . Different theories of the pathophysiology of postoperative erectile dysfunction are currently being discussed . In a prospect i ve study we performed recordings of nocturnal penile tumescence and rigidity during the acute phase after nerve sparing radical prostatectomy , ie in the first night after removal of the catheter , to assess the organic penile integrity . MATERIAL S AND METHODS In 27 patients with local prostate carcinoma who had been sexually active before the intervention , we performed unilateral or bilateral nerve sparing radical prostatectomy . Preoperative sexual function of all patients was evaluated by the International Index of Erectile Function-5 question naire . On the day of catheter removal ( postoperative day 7 to 14 ) an  NPTR recording  was performed on the following night with an erectometer ( RigiScan ) . RESULTS All patients had a preoperative IIEF score greater than 18 . After removal of the catheter 25 of 27 patients ( 93 % ) showed 1 to 5 nocturnal rigidity increases by greater than 70 % for at least 10 minutes . In a control group of 4 patients who underwent radical prostatectomy without nerve sparing , no nocturnal erections were recorded . CONCLUSIONS NPTR recording during the acute phase after nerve sparing radical prostatectomy showed residual erectile function as early as the first night after catheter removal . These results are significant for selecting adequate pharmacological treatment for optimal therapy and rehabilitation of satisfactory erections and sexual function . In cases of early nocturnal tumescence , application of a PDE5 inhibitor can support successive organ rehabilitation . However , if tumescence does not occur , penile injection therapy is recommended Four weeks after bilateral nerve-sparing radical retropubic prostatectomy , men with normal erectile function before surgery were r and omized to double-blind sildenafil ( 50 or 100 mg ) or placebo nightly for 36 weeks , followed by an 8-week drug-free period before assessment of erectile function . Enrollment was prematurely ceased and only 76 men completed because , assuming a placebo response rate similar to the published literature ( for example , 34 % in meta- analysis ) , the 25 % response at blinded interim review suggested a lack of treatment effect . On the contrary , spontaneous erectile function ( a combined score of ⩾8 for questions 3 and 4 of the International Index of Erectile Function and a positive response to ‘ Were erections good enough for satisfactory sexual activity ? ’ ) occurred in only 4 % of the placebo group ( n=1 of 25 ) versus 27 % ( n=14 of 51 , P=0.0156 , Fisher 's exact test ) of the sildenafil group . Nightly sildenafil administration for 36 weeks after surgery markedly increased the return of normal spontaneous erections OBJECTIVES To determine whether arbitrary minor variances in surgical technique can have a major impact on the recovery of sexual function  after radical retropubic prostatectomy . METHODS The surgical procedures of 62 potent men were videotaped prospect ively . Eighteen months after the study was initiated , the videotapes were review ed and specific steps in the surgical procedure correlated with patient-reported potency rates . RESULTS Four steps were identified that appeared to correlate with the recovery of sexual function : over-sewing back-bleeders from the proximal dorsal vein on the anterior surface of the prostate , division of the striated sphincter when placing urethral sutures , division of the posterior striated sphincter , and hemostasis at the end of the case . CONCLUSIONS We believe that retrospective review of intraoperative videotapes has great promise . Because many surgeons use different techniques , it is likely that each individual may be able to identify other important arbitrary variations that may improve their patients ' outcomes . Similarly , for surgeons with less than optimal outcomes , the review of early successful cases may enable them to identify ways that modification of their surgical technique can improve the outcome of future patients . To the best of our knowledge , the use of retrospective review of intraoperative videotapes has not been commonly used in any other surgical field PURPOSE Erectile dysfunction continues to be a significant problem for men after radical retropubic prostatectomy  despite nerve sparing techniques . Sildenafil citrate ( Viagra ) has proved effective for erectile dysfunction in many men . We determine the efficacy of sildenafil in men with erectile dysfunction after radical retropubic prostatectomy  and examine variables that may impact the response to treatment . MATERIAL S AND METHODS A total of 84 men were prescribed sildenafil after radical retropubic prostatectomy  and asked to complete a series of question naires , including the International Index of Erectile Function ( IIEF ) , on erectile function before and after sildenafil administration . The importance of factors , such as patient age , time since surgery , degree of cavernous nerve sparing , preoperative prostate specific antigen , Gleason score , clinical and pathological stage , and baseline postoperative erectile function , was examined . RESULTS Of the 84 patients 45 ( 53 % ) had improved erections and 34 ( 40 % ) had improved ability for intercourse while taking sildenafil .  Mean IIEF score for the erectile function domain increased from 9 to 14 ( p < 0.001 ) . Orgasmic function ( p = 0.004 ) and intercourse satisfaction ( p = 0.009 ) also significantly improved . The degree of nerve sparing and baseline postoperative erectile dysfunction had a significant impact on the ability of sildenafil to improve erectile function ( p = 0.010 and p < 0.001 , respectively ) and total IIEF question naire responses ( p = 0.031 and p < 0.001 , respectively ) . Age and pathological stage also appeared to have a significant effect . CONCLUSIONS Sildenafil improved erectile function and the ability to have intercourse in more than half of men after radical retropubic prostatectomy . Baseline postoperative erectile function , which is dependent on the degree of nerve sparing technique , significantly impacts the likelihood that patients will respond to sildenafil PURPOSE This study was aim ed at assessing prospect ively the effect of postoperative intracavernous injections of alprostadil on the recovery of spontaneous erectile function after nerve-sparing radical retropubic prostatectomy . MATERIAL S AND METHODS A total of 30 potent patients with clinical ly localized prostate cancer ( clinical stage B1 or B2 , Gleason sum 7 or greater , prostatic specific antigen less than 20 ng./ml . ) underwent nerve-sparing radical retropubic prostatectomy  and was subsequently r and omized to alprostadil injections 3 times per week for 12 weeks ( group 1 , 15 patients ) or  observation without any erectogenic treatment ( group 2 , 15 patients ) . Patients were assessed at the 6-month followup by sexual history , physical examination , color Doppler sonography of the cavernous arteries and polisomnographic recording of nocturnal erections . RESULTS In group 1 , 12 patients ( 80 % ) completed the entire treatment schedule and were evaluated at the long-term followup . Eight patients in this group ( 67 % ) reported the recovery of spontaneous erection sufficient for satisfactory sexual intercourse , compared with 3 patients ( 20 % ) in group 2 . The difference between the 2 groups was statistically significant ( p < 0.01 ) . In group 1 , all but 1 patient reporting normal postoperative erections also showed normal erections at nocturnal testing , whereas color Doppler sonography demonstrated normal penile hemodynamics in all of them . In these patients , failures were the result of cavernous veno-occlusive dysfunction ( 2 cases , 17 % ) and cavernous nerve injury ( 2 cases , 17 % ) . In group 2 , patients with normal erections showed both normal nocturnal testing and penile hemodynamics , whereas failures were the result of cavernous veno-occlusive dysfunction ( 8 cases , 53 % ) , cavernous arterial insufficiency ( 2 cases , 13 % ) or cavernous nerve injury ( 3 cases , 20 % ) . Complications in patients treated with alprostadil injections accounted for 2 cases ( 13 % ) of a penile nodule and 1 further case ( 6 % ) of prolonged penile erection . Complications were not seen in group 2 patients . CONCLUSIONS Early postoperative administration of alprostadil injections significantly increases the recovery rate of spontaneous erections after nerve-sparing radical retropubic prostatectomy . It is our belief that programmed vasoactive injections improve cavernous oxygenation , thereby limiting the development of hypoxia-induced tissue damage . The potential complications related to the use of intracavernous injections must be clearly explained to patients Early pharmacological prophylaxis has been reported to increase the return of spontaneous erections following radical prostatectomy ( RP ) . In this study , we evaluated the role of intracavernosal alprostadil ( PGE1 ) combined with sildenafil in stimulating early recovery of spontaneous erections following RP . In this prospect i ve study , we included 22 patients who underwent bilateral nerve-sparing RP after October 2004 .  Sildenafil dose of 50 mg/day was started at the time of hospital discharge . Of 22 patients , 18 started on PGE1–4 μg ( 1–8 ) and four started on low-dose Trimix ( 20 U ) 2–3 times/week . These patients are followed up at regular intervals ( 3 , 6 , 9 and 12 months ) with abridged version of the International Index for Erectile Function-5 question naire . Patient compliance , return of sexual activity and return of natural erection , adverse effects and reasons for discontinuation were recorded . Penile doppler studies were performed during followup visits to assess the vascular status . After a mean followup of 6 months ( 3–8 months ) , 11/22 ( 50 % ) patients had return of spontaneous partial erections . Of the 18 PGE1 users , six continued 4 μg PGE1 , four increased the dose to 8 μg , six decreased the dose to 2 μg and two patients further reduced the dose to 1 μg . Of four low-dose Trimix users , three increased the dose to 30 U and one reduced the dose to 15 U. Of 22 patients , 21 were sexually active : 12/21 ( 57 % ) with the injections alone and 9/21 ( 42.9 % ) with combination therapy ( injections ( PGE1 ) and sildenafil ) . Penile doppler studies revealed arterial insufficiency in 77 % ( 17/22 ) patients and venous insufficiency in one patient . Early intracavernosal injections following RP facilitated early sexual intercourse , patient satisfaction and potentially earlier return of natural erections . Early combination therapy with sildenafil allowed a lower dose of intracavernous injections , minimizing the penile discomfort PURPOSE It has been suggested that postradical prostatectomy ( RP ) erectile function outcomes are improved by early use of erectogenic medications . This analysis was design ed to assess the ability of a post-RP vasoactive drug program to improve long-term spontaneous erectile function . METHODS Men with functional preoperative erections who underwent RP were challenged early postoperatively with oral sildenafil . Nonresponders were switched to intracavernosal injection therapy ( ICI ) . Patients were instructed to inject three times a week . Only patients who presented within 6 months post RP , who completed the International Index of Erectile Function ( IIEF ) question naire on at least three separate occasions after surgery , and who had been followed for at least 18 months were included . Data from men who were committed to rehabilitation were compared with those of men who did not follow the protocol but continued to be followed serially following RP . RESULTS There were 58 patients in the rehabilitation ( R ) group and 74 in the nonrehabilitation ( NR ) group . No differences existed in mean patient age , comorbidity profile , intraoperative nerve sparing status , or postoperative erectile hemodynamics between the two groups . At 18 months post R 
    Output:
    
agent
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 .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: In a prospect i ve , placebo-controlled , one group crossover design study , we tested whether adding programmed intracavernous PGE1 injections ( IC-PGE1 ) can improve the effectiveness of sildenafil  in erectile dysfunction ( ED ) patients unresponsive to monotherapy with this drug . In all , 40 ED patients who had experienced unsatisfactory erections with both the 50 and 100 mg sildenafil doses were treated with four bi-weekly 20 μg IC-PGE1 injections given in the clinic and provided with either placebo or 50 mg sildenafil capsules for the next 4 weeks . Thereafter , they were crossed over to the other oral treatment for an additional 4-week period . The IIEF-Erectile Function domain score ( IIEF-EFS ) , the main outcome measure , was found considerably higher ( P<0.001 ) with the combined IC-PGE1–50 mg sildenafil treatment than with IC-PGE1–placebo or sildenafil alone ( 50 or 100 mg ) in a subset of 26 subjects ( 65 % ) . They thus shifted from the ‘ severe ’ or ‘ moderate ’ to the ‘ mild ’ grading of ED classification PURPOSE The exact process and time required for rehabilitation of erectile function after nerve sparing prostatectomy remain unclear to date . Different theories of the pathophysiology of postoperative erectile dysfunction are currently being discussed . In a prospect i ve study we performed recordings of nocturnal penile tumescence and rigidity during the acute phase after nerve sparing radical prostatectomy , ie in the first night after removal of the catheter , to assess the organic penile integrity . MATERIAL S AND METHODS In 27 patients with local prostate carcinoma who had been sexually active before the intervention , we performed unilateral or bilateral nerve sparing radical prostatectomy . Preoperative sexual function of all patients was evaluated by the International Index of Erectile Function-5 question naire . On the day of catheter removal ( postoperative day 7 to 14 ) an  NPTR recording  was performed on the following night with an erectometer ( RigiScan ) . RESULTS All patients had a preoperative IIEF score greater than 18 . After removal of the catheter 25 of 27 patients ( 93 % ) showed 1 to 5 nocturnal rigidity increases by greater than 70 % for at least 10 minutes . In a control group of 4 patients who underwent radical prostatectomy without nerve sparing , no nocturnal erections were recorded . CONCLUSIONS NPTR recording during the acute phase after nerve sparing radical prostatectomy showed residual erectile function as early as the first night after catheter removal . These results are significant for selecting adequate pharmacological treatment for optimal therapy and rehabilitation of satisfactory erections and sexual function . In cases of early nocturnal tumescence , application of a PDE5 inhibitor can support successive organ rehabilitation . However , if tumescence does not occur , penile injection therapy is recommended Four weeks after bilateral nerve-sparing radical retropubic prostatectomy , men with normal erectile function before surgery were r and omized to double-blind sildenafil ( 50 or 100 mg ) or placebo nightly for 36 weeks , followed by an 8-week drug-free period before assessment of erectile function . Enrollment was prematurely ceased and only 76 men completed because , assuming a placebo response rate similar to the published literature ( for example , 34 % in meta- analysis ) , the 25 % response at blinded interim review suggested a lack of treatment effect . On the contrary , spontaneous erectile function ( a combined score of ⩾8 for questions 3 and 4 of the International Index of Erectile Function and a positive response to ‘ Were erections good enough for satisfactory sexual activity ? ’ ) occurred in only 4 % of the placebo group ( n=1 of 25 ) versus 27 % ( n=14 of 51 , P=0.0156 , Fisher 's exact test ) of the sildenafil group . Nightly sildenafil administration for 36 weeks after surgery markedly increased the return of normal spontaneous erections OBJECTIVES To determine whether arbitrary minor variances in surgical technique can have a major impact on the recovery of sexual function  after radical retropubic prostatectomy . METHODS The surgical procedures of 62 potent men were videotaped prospect ively . Eighteen months after the study was initiated , the videotapes were review ed and specific steps in the surgical procedure correlated with patient-reported potency rates . RESULTS Four steps were identified that appeared to correlate with the recovery of sexual function : over-sewing back-bleeders from the proximal dorsal vein on the anterior surface of the prostate , division of the striated sphincter when placing urethral sutures , division of the posterior striated sphincter , and hemostasis at the end of the case . CONCLUSIONS We believe that retrospective review of intraoperative videotapes has great promise . Because many surgeons use different techniques , it is likely that each individual may be able to identify other important arbitrary variations that may improve their patients ' outcomes . Similarly , for surgeons with less than optimal outcomes , the review of early successful cases may enable them to identify ways that modification of their surgical technique can improve the outcome of future patients . To the best of our knowledge , the use of retrospective review of intraoperative videotapes has not been commonly used in any other surgical field PURPOSE Erectile dysfunction continues to be a significant problem for men after radical retropubic prostatectomy  despite nerve sparing techniques . Sildenafil citrate ( Viagra ) has proved effective for erectile dysfunction in many men . We determine the efficacy of sildenafil in men with erectile dysfunction after radical retropubic prostatectomy  and examine variables that may impact the response to treatment . MATERIAL S AND METHODS A total of 84 men were prescribed sildenafil after radical retropubic prostatectomy  and asked to complete a series of question naires , including the International Index of Erectile Function ( IIEF ) , on erectile function before and after sildenafil administration . The importance of factors , such as patient age , time since surgery , degree of cavernous nerve sparing , preoperative prostate specific antigen , Gleason score , clinical and pathological stage , and baseline postoperative erectile function , was examined . RESULTS Of the 84 patients 45 ( 53 % ) had improved erections and 34 ( 40 % ) had improved ability for intercourse while taking sildenafil .  Mean IIEF score for the erectile function domain increased from 9 to 14 ( p < 0.001 ) . Orgasmic function ( p = 0.004 ) and intercourse satisfaction ( p = 0.009 ) also significantly improved . The degree of nerve sparing and baseline postoperative erectile dysfunction had a significant impact on the ability of sildenafil to improve erectile function ( p = 0.010 and p < 0.001 , respectively ) and total IIEF question naire responses ( p = 0.031 and p < 0.001 , respectively ) . Age and pathological stage also appeared to have a significant effect . CONCLUSIONS Sildenafil improved erectile function and the ability to have intercourse in more than half of men after radical retropubic prostatectomy . Baseline postoperative erectile function , which is dependent on the degree of nerve sparing technique , significantly impacts the likelihood that patients will respond to sildenafil PURPOSE This study was aim ed at assessing prospect ively the effect of postoperative intracavernous injections of alprostadil on the recovery of spontaneous erectile function after nerve-sparing radical retropubic prostatectomy . MATERIAL S AND METHODS A total of 30 potent patients with clinical ly localized prostate cancer ( clinical stage B1 or B2 , Gleason sum 7 or greater , prostatic specific antigen less than 20 ng./ml . ) underwent nerve-sparing radical retropubic prostatectomy  and was subsequently r and omized to alprostadil injections 3 times per week for 12 weeks ( group 1 , 15 patients ) or  observation without any erectogenic treatment ( group 2 , 15 patients ) . Patients were assessed at the 6-month followup by sexual history , physical examination , color Doppler sonography of the cavernous arteries and polisomnographic recording of nocturnal erections . RESULTS In group 1 , 12 patients ( 80 % ) completed the entire treatment schedule and were evaluated at the long-term followup . Eight patients in this group ( 67 % ) reported the recovery of spontaneous erection sufficient for satisfactory sexual intercourse , compared with 3 patients ( 20 % ) in group 2 . The difference between the 2 groups was statistically significant ( p < 0.01 ) . In group 1 , all but 1 patient reporting normal postoperative erections also showed normal erections at nocturnal testing , whereas color Doppler sonography demonstrated normal penile hemodynamics in all of them . In these patients , failures were the result of cavernous veno-occlusive dysfunction ( 2 cases , 17 % ) and cavernous nerve injury ( 2 cases , 17 % ) . In group 2 , patients with normal erections showed both normal nocturnal testing and penile hemodynamics , whereas failures were the result of cavernous veno-occlusive dysfunction ( 8 cases , 53 % ) , cavernous arterial insufficiency ( 2 cases , 13 % ) or cavernous nerve injury ( 3 cases , 20 % ) . Complications in patients treated with alprostadil injections accounted for 2 cases ( 13 % ) of a penile nodule and 1 further case ( 6 % ) of prolonged penile erection . Complications were not seen in group 2 patients . CONCLUSIONS Early postoperative administration of alprostadil injections significantly increases the recovery rate of spontaneous erections after nerve-sparing radical retropubic prostatectomy . It is our belief that programmed vasoactive injections improve cavernous oxygenation , thereby limiting the development of hypoxia-induced tissue damage . The potential complications related to the use of intracavernous injections must be clearly explained to patients Early pharmacological prophylaxis has been reported to increase the return of spontaneous erections following radical prostatectomy ( RP ) . In this study , we evaluated the role of intracavernosal alprostadil ( PGE1 ) combined with sildenafil in stimulating early recovery of spontaneous erections following RP . In this prospect i ve study , we included 22 patients who underwent bilateral nerve-sparing RP after October 2004 .  Sildenafil dose of 50 mg/day was started at the time of hospital discharge . Of 22 patients , 18 started on PGE1–4 μg ( 1–8 ) and four started on low-dose Trimix ( 20 U ) 2–3 times/week . These patients are followed up at regular intervals ( 3 , 6 , 9 and 12 months ) with abridged version of the International Index for Erectile Function-5 question naire . Patient compliance , return of sexual activity and return of natural erection , adverse effects and reasons for discontinuation were recorded . Penile doppler studies were performed during followup visits to assess the vascular status . After a mean followup of 6 months ( 3–8 months ) , 11/22 ( 50 % ) patients had return of spontaneous partial erections . Of the 18 PGE1 users , six continued 4 μg PGE1 , four increased the dose to 8 μg , six decreased the dose to 2 μg and two patients further reduced the dose to 1 μg . Of four low-dose Trimix users , three increased the dose to 30 U and one reduced the dose to 15 U. Of 22 patients , 21 were sexually active : 12/21 ( 57 % ) with the injections alone and 9/21 ( 42.9 % ) with combination therapy ( injections ( PGE1 ) and sildenafil ) . Penile doppler studies revealed arterial insufficiency in 77 % ( 17/22 ) patients and venous insufficiency in one patient . Early intracavernosal injections following RP facilitated early sexual intercourse , patient satisfaction and potentially earlier return of natural erections . Early combination therapy with sildenafil allowed a lower dose of intracavernous injections , minimizing the penile discomfort PURPOSE It has been suggested that postradical prostatectomy ( RP ) erectile function outcomes are improved by early use of erectogenic medications . This analysis was design ed to assess the ability of a post-RP vasoactive drug program to improve long-term spontaneous erectile function . METHODS Men with functional preoperative erections who underwent RP were challenged early postoperatively with oral sildenafil . Nonresponders were switched to intracavernosal injection therapy ( ICI ) . Patients were instructed to inject three times a week . Only patients who presented within 6 months post RP , who completed the International Index of Erectile Function ( IIEF ) question naire on at least three separate occasions after surgery , and who had been followed for at least 18 months were included . Data from men who were committed to rehabilitation were compared with those of men who did not follow the protocol but continued to be followed serially following RP . RESULTS There were 58 patients in the rehabilitation ( R ) group and 74 in the nonrehabilitation ( NR ) group . No differences existed in mean patient age , comorbidity profile , intraoperative nerve sparing status , or postoperative erectile hemodynamics between the two groups . At 18 months post R 
    Output:
    