Infection Retardant Coatings Impact on Bacterial Presence in Penile Prosthesis Surgery: A Multicenter Study

OBJECTIVE

To investigate patients for positive culture rates with or without infection retardant coatings (IRC) penile prostheses (PPs) and to examine changes in culture positive isolates found in patients presenting overt clinical infection.

METHODS

Cultures were obtained from PPs immediately upon surgical exposure of the pump. 236 patients were broken down into 2 groups, with each further divided into 2 groups. The noninfected group included 208 patients: 133 with uncoated PPs and 75 with IRC implants. The infected group included 28 patients: 16 with uncoated PP and 12 with IRC inflatable penile prostheses (IPP). Additionally, sensitivity to the combination of tetracycline and rifampin were evaluated on all cultures.

RESULTS

In the noninfected group, culture positive isolates were found in 85 patients with uncoated PP's and in 32 patients with IRC implants [P value = 0.0003]. Cultures positive for Staphylococcus genus were found in 75 uncoated PP patients, while 20 patients with IRC implants had an isolate of this genus. In the infected group, culture positive isolates were found in 7 patients with uncoated PP and 6 patients with IRC IPPs [P value = 1.000]. Positive cultures for Staphylococcus genus were found in 6 patients with uncoated PP, while 3 patients with IRC IPP had an isolate of this genus. All bacterial isolates were sensitive to the combination of tetracycline and rifampin.

CONCLUSION

Positive bacterial cultures have been shown to be present on clinically uninfected IPPs at time of revision surgery. Culture isolates grown from patients with IRC IPPs reveal a nontraditional bacterial profile: fewer cultured isolates of Staphylococcus genus.

Impact of Baseline Total Testosterone Level on Successful Treatment of Sexual Dysfunction in Men Taking Once-Daily Tadalafil 5 mg for Lower Urinary Tract Symptoms and Benign Prostatic Hyperplasia: An Integrated Analysis of Three Randomized Controlled Trials

INTRODUCTION

Controversy exists as to whether erectile response to phosphodiesterase type 5 inhibitors is compromised in men with low total testosterone (TT) levels. This is amplified by reports of improved response to phosphodiesterase type 5 inhibitor therapy after coadministration of testosterone replacement therapy in hypogonadal men unresponsive to phosphodiesterase type 5 inhibitors.

AIM

To determine whether TT and luteinizing hormone levels influence efficacy of tadalafil for erectile dysfunction in men with concomitant lower urinary tract symptoms and benign prostatic hyperplasia.

METHODS

This integrated analysis included 1,075 men randomized to once-daily tadalafil 5 mg (n = 540) or placebo (n = 535) for 12 weeks in three prospective clinical trials who had not received concomitant testosterone replacement therapy. Subjects were categorized at baseline by low vs normal TT levels (n = 1,049; <300 vs ≥300 ng/dL) and normal vs high luteinizing hormone levels (n = 1,058; ≤9.4 vs >9.4 mIU/mL). Treatment-group differences in International Index of Erectile Function (IIEF) by hormone subgroups were assessed using analysis of covariance.

MAIN OUTCOME MEASURES

Changes in IIEF erectile function domain and other domain scores.

RESULTS

The overall study population was comprised primarily of white men (>86%) with a mean age range of 64 to 70 years. Median baseline TT level in the integrated population was 355 ng/dL; levels were lower than 300 ng/dL (cutoff for normal) in 32.4% of men. Men with low TT levels reported diabetes (21.8%), cardiovascular disease (54.1%), and hypertension (49.1%) numerically more often than men with normal TT levels (10.6%, 43.2%, and 36.7%, respectively). Low TT and high luteinizing hormone levels were associated with numerically, but not statistically significantly, lower 12-week IIEF domain scores compared with those with normal levels. Changes in most 12-week IIEF domain scores showed that tadalafil was significantly more effective than placebo (P < .02).

CONCLUSION

Low TT levels at baseline did not negatively influence response to tadalafil in men of advancing age with concomitant lower urinary tract symptoms and benign prostatic hyperplasia and erectile dysfunction.

Treatment satisfaction among men with concurrent benign prostatic hyperplasia and erectile dysfunction treated with tadalafil or other phosphodiesterase type-5 inhibitor combinations

OBJECTIVE

Erectile dysfunction (ED) and benign prostatic hyperplasia (BPH) frequently co-occur in men aged ≥40, along with lower urinary tract symptoms (LUTS) secondary to BPH. Given little real-world evidence on treatment use or satisfaction with treatment for concurrent BPH/LUTS and/or ED, this study examined medication regimens and differences in satisfaction and health-related quality of life (HRQoL) across regimens among men with concurrent BPH and ED.

METHODS

A cross-sectional study was conducted using an Internet survey of participants recruited through an online panel. Respondents (N=736) included men (aged ≥40) who self-reported a diagnosis of both ED and BPH with prescription treatment in the past 3 months for both conditions. Treatment satisfaction (eg, convenience and ease of planning) and HRQoL (eg, International Prostate Symptom Score, sleep quality) were self-reported. Generalized linear models examined the association of regimen with treatment satisfaction and HRQoL, adjusting for covariates (eg, age and comorbidities).

RESULTS

Final analyses included participants (N=507) using: tadalafil once-daily monotherapy (22%), tadalafil for ED with an alternate BPH therapy (36%), or another phosphodiesterase type-5 inhibitor (PDE5-I) combination (41%). These groups represented the major categories of treatment regimens found in the sample, excluded participants with ambiguous regimens, and were aligned with current standard of care for BPH and ED. Overall, patients reported moderate levels of BPH and a moderate-to-severe degree of ED. Tadalafil monotherapy patients had higher treatment satisfaction scores and greater reported ease of treatment planning and convenience than PDE5-I combination patients. No significant intergroup differences were found on HRQoL.

CONCLUSION

A majority of patients (59%) took tadalafil alone or in combination for BPH/ED treatment. Tadalafil monotherapy patients reported greater treatment satisfaction than patients taking PDE5-I combination therapy. Higher satisfaction for both effectiveness and convenience of once-daily tadalafil may inform both patient and clinician decisions regarding pharmacotherapy regimens.

Time to onset of clinically meaningful improvement with tadalafil 5 mg once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: analysis of data pooled from 4 pivotal, double-blind, placebo controlled studies

PURPOSE

Tadalafil once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia consistently shows statistically significant I-PSS improvements. However, physicians and patients wish to know whether tadalafil provides rapid, clinically meaningful improvement in lower urinary tract symptoms. In this post hoc analysis we integrated results from 4 placebo controlled studies to determine the duration of tadalafil once daily required to achieve clinically meaningful improvement.

MATERIALS AND METHODS

We performed post hoc analysis of data integrated from 4 double-blind studies of tadalafil 5 mg and placebo once daily in 742 and 735 men, respectively, 45 years old or older with total I-PSS 13 or greater. Two clinically meaningful improvement categories were assessed, including 1) 3-point or greater baseline to end point total I-PSS improvement and 2) 25% or greater baseline to end point total I-PSS improvement. I-PSS was assessed at weeks 4, 8 and 12 in all studies, week 1 in 2 and week 2 in 1. Results in men treated with tadalafil who showed clinically meaningful improvement (responders) were further examined to determine the earliest time to clinically meaningful improvement.

RESULTS

Of 742 tadalafil treated patients 513 (69.1%) and 444 (59.8%) demonstrated category 1 and 2 clinically meaningful improvement, respectively, at the study end point. Of 234 category 1 responders with week 1 assessments 140 (59.8%) achieved clinically meaningful improvement by week 1 and 407 of the total of 513 category 1 responders (79.3%) showed it by week 4. Of the 205 category 2 responders with week 1 assessments 103 (50.2%) achieved clinically meaningful improvement by week 1 while 322 of the 444 category 2 responders (72.5%) did so by week 4.

CONCLUSIONS

Tadalafil 5 mg once daily led to clinically meaningful improvement in approximately two-thirds of men with lower urinary tract symptoms secondary to benign prostatic hyperplasia. More than half of this group of tadalafil treated responders achieved clinically meaningful improvement after 1 week of therapy and more than 70% did so within 4 weeks.

Sexual bother and function after radical prostatectomy: predictors of sexual bother recovery in men despite persistent post-operative sexual dysfunction

Changes in sexual bother (SB) following radical prostatectomy (RP) negatively affect health-related quality of life (HRQoL) of prostate cancer survivors. However, post-operative SB tends to be neglected whereas sexual function (SF) is thoroughly assessed in clinical practice and few studies have focused on and evaluated patients' SB. We retrospectively reviewed 2 345 consecutive patients who underwent RP between 2001 and 2009 at a single institution. SF and SB were assessed using Expanded Prostate Cancer Index Composite (EPIC) questionnaires. We stratified our cohort by SB recovery and post-operative SF status, including a subset of men who recovered SB despite persistent post-RP sexual dysfunction. Multivariable logistic regression analyses were conducted to identify factors for men who have SB recovery. Of 319 eligible patients, 133 (41.7%) recovered their SB at a mean of 20 months after RP. Among the 133 men who demonstrated SB recovery, 109 had post-operative sexual dysfunction. Patients with SB recovery despite post-RP sexual dysfunction were more likely to be old (p = 0.004), to have higher clinical T stage (p < 0.001), to have more non-nerve-sparing RP (p < 0.001), to have lower pre-operative EPIC-SF/SB scores (p < 0.001), to have more extracapsular extension (p = 0.031) and to be PDE5i non-users after surgery (p < 0.001). In multivariable analysis, predictors for this subset were lower comorbidity (OR 0.62, p = 0.043), higher clinical cancer stage (OR 2.35, p = 0.026), worse pre-operative SF (OR 0.98, p = 0.010), SB (OR 0.98, p < 0.010) and no PDE5i use (OR 0.37, p = 0.002); age was not related (OR 0.99, p = 0.555). As SB can influence patients' overall HRQoL, expectations of SB recovery should be provided to patients in the same way that SF recovery is presented. This study may help clinicians to discuss SB with patients and assess their potential for SB recovery following RP.

Role of oxidative stress in a rat model of radiation-induced erectile dysfunction

INTRODUCTION

Chronic oxidative stress is one of the major factors playing an important role in radiation-induced normal tissue injury. However, the role of oxidative stress in radiation-induced erectile dysfunction (ED) has not been fully investigated. Aims.  To investigate role of oxidative stress after prostate-confined irradiation in a rat model of radiation-induced ED.

METHODS

Fifty-four young adult male rats (10-12 weeks of age) were divided into age-matched sham radiotherapy (RT) and RT groups. Irradiated animals received prostate-confined radiation in a single 20 Gy fraction.

MAIN OUTCOME MEASURES

Intracavernous pressure (ICP) measurements with cavernous nerve electrical stimulation were conducted at 2, 4, and 9 weeks following RT. The protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunits (Nox4 and gp91(phox)), markers of oxidative DNA damage (8-hydroxy-2'-deoxyguanosine [8-OHdG]), lipid peroxidation (4-hydroxynonenal [4HNE]), and inflammatory response including inducible nitric oxide synthase, macrophage activation (ED-1), and nitrotyrosine, and endogenous antioxidant defense by nuclear factor erythroid 2-related factor (Nrf2) were evaluated in irradiated prostate tissue and corpora cavernosa (CC). In addition, we investigated the relationships between results of ICP/mean arterial pressure (MAP) ratios and expression level of oxidative stress markers.

RESULTS

In the RT group, hemodynamic functional studies demonstrated a significant time-dependent decrease in ICP. Increased expression of Nox4, gp91(phox), 8-OHdG, and 4HNE were observed in the prostate and CC after RT. Similarly, expressions of inflammatory markers were significantly increased. There was a trend for increased Nrf2 after 4 weeks. ICP/MAP ratio negatively correlated with higher expression level of oxidative markers.

CONCLUSION

NADPH oxidase activation and chronic oxidative stress were observed in irradiated prostate tissue and CC, which correlated with lower ICP/MAP ratio. Persistent inflammatory responses were also found in both tissues after RT. These findings suggest that oxidative stress plays a crucial role in the development of radiation-induced ED.

An outcomes analysis of over 200 revision surgeries for penile prosthesis implantation: a multicenter study

INTRODUCTION

Inflatable penile prosthesis (IPP) implantation is a well-established treatment for medically refractory erectile dysfunction, with long-term reliability. Overall survival is 96% at 5 years and 60% at 15 years for primary (virgin) implantation.

AIM

The aim of this study was to explore factors associated with success and complications of IPP revision surgery in a multicenter study.

MAIN OUTCOME MEASURES

Reasons for revision including mechanical issues, patient dissatisfaction, corporal deformity, and supersonic transport (SST) deformity were recorded.

METHODS

At four institutions, 214 clinically uninfected IPP revisions were performed between November 2000 and November 2007. Data were incomplete for 28 cases (14%). Failure-free survival was estimated using Kaplan-Meier's Meier product limit method.

RESULTS

The majority of revisions were secondary to mechanical failure (N = 109; 65%) and combined erosion or infection (N = 17 + 15 = 32; 19%). Sixteen percent (N = 26) were carried out on functional uninfected prostheses secondary to patient dissatisfaction (N = 9), SST deformity (N = 10), scrotal hematoma (N = 2), or upsize revision because of corporal fibrosis (N = 5). Average age at revision was 66 years. Mean follow-up time was 55.7 months. In this study, 12 individuals required a secondary revision procedure or suffered a complication. Despite prior reports of high infection rates with revision surgery, only 5.7% of clinically uninfected and noneroded prostheses were complicated by infection or impending extrusion/erosion, following a revision washout protocol. Overall, 93% of cases were successfully revised, providing functioning IPPs.

CONCLUSIONS

For this study population, component exchange followed by revision washout showed a low incidence of infection and subsequent mechanical failure.

Radiation-induced erectile dysfunction using prostate-confined modern radiotherapy in a rat model

INTRODUCTION

The mechanisms of radiation-induced erectile dysfunction (ED) are unclear, as clinical studies are limited, and previous animal models were based on wide-field irradiation, which does not model current radiotherapy (RT) techniques.

AIMS

To perform functional and morphological analyses of erectile function (EF) utilizing image-guided stereotactic prostate-confined RT in a rat model.

METHODS

Sixty young adult male rats aged 10-12 weeks old were divided into age-matched sham and RT groups. A single 20-Gy fraction to the prostate was delivered to RT animals. Penile bulb, shaft, and testes were excluded from treatment fields.

MAIN OUTCOME MEASURES

Bioassay and intracavernous pressure (ICP) measurements were conducted at 2, 4, and 9 weeks following RT. Perfusion analysis of the corpora cavernosa (CC) was conducted using Hoechst injected prior to sacrifice. Penile shaft and cavernous nerve (CN) were evaluated by immunohistochemistry. Plasma testosterone level was analyzed using a testosterone enzyme-linked immunosorbent assay (ELISA) assay kit.

RESULTS

Irradiated animals demonstrated statistically significant time-dependent functional impairment of EF by bioassay and ICP measurement from 4 weeks. Neuronal nitric oxide synthase (NOS) expression was decreased in CN by 4 weeks. In CC, expression levels of anti-alpha smooth muscle actin and endothelial NOS were significantly decreased at 9 weeks. In penile dorsal vessels, smooth muscle/collagen ratio was significantly decreased at 4 and 9 weeks. Additionally, Hoechst perfusion showed time-dependent decrease in CC of RT animals, whereas CD31 expression was not affected. No toxicities were noted; testosterone levels were similar in both groups.

CONCLUSION

We demonstrated time-dependent ED following image-guided stereotactic RT. Our results imply that reduction of neuronal NOS expression in cavernous nerve could trigger consecutive reduction of smooth muscle content as well as blood perfusion in CC that resulted in corporal veno-occlusive dysfunction. Present study could be a cornerstone to future research that may bring comprehensive scientific understanding of radiation-induced ED.

Tadalafil administered once daily for lower urinary tract symptoms secondary to benign prostatic hyperplasia: a 1-year, open-label extension study

OBJECTIVE

• To evaluate the 1-year safety of 5 mg of tadalafil once daily in men with lower urinary tract symptoms secondary to benign prostatic hyperplasia (BPH-LUTS); efficacy measures were included to evaluate the maintenance of efficacy after an additional year of treatment.

PATIENTS AND METHODS

• In total, 427 men who completed a 12-week, placebo-controlled, dose- finding study assessing once-daily tadalafil (2.5, 5, 10 or 20 mg) or placebo elected to continue into the open-label extension period. Safety and efficacy parameters were assessed after 1 month and every 3 months.

RESULTS

• In total, 299 patients (69.9%) completed the 1-year, open-label extension period. Treatment-emergent adverse events (TEAEs) were reported by 57.6% of patients, with most TEAEs being mild (44%) or moderate (45%) in severity; the most common TEAEs (≥ 2%) were dyspepsia, gastro-oesophageal reflux disease, back pain, headache, sinusitis, hypertension and cough. Twenty-two patients (5.2%) discontinued as a result of AEs. During the open-label extension period, mean prostate-specific antigen increased from 1.6 ± 1.3 ng/mL to 1.8 ± 1.4 ng/mL. • Mean post-void residual volume was 61.1 ± 60.4 mL at study entry and 42.2 ± 64.1 mL after the open-label extension period. Changes in the total International Prostate Symptom Score (IPSS), IPSS irritative and obstructive subscores, IPSS health-related quality of life and BPH Impact Index were maintained after 1 year. In sexually-active patients with erectile dysfunction, improvements in the International Index of Erectile Function-Erectile Function domain were maintained after 1 year.

CONCLUSION

• In men with BPH-LUTS, 5 mg of tadalafil once daily during 1 year of treatment was well tolerated and efficacy changes were maintained.

Altered male physiologic function after surgery for prostate cancer: couple perspective

PURPOSE

Both the diagnosis of prostate cancer (PCa) and the physiologic outcomes of surgical treatment impact the male's psychological sphere. However, current research advocates a refocusing of outcomes directed to the PCa "couple". Herein we acquire insight into perspective and concordance regarding male physiological function from the standpoint of a couple recovering from PCa surgery.

MATERIALS AND METHODS

Couples whereby the male partner had undergone primary surgical treatment for PCa were mailed a Retrospective Sexual Survey (RSS) packet consisting of male and female partner questionnaires. RSS questions surveyed physiological changes in libido, foreplay, erection and arousal, orgasm and ejaculation in addition to perceived psychological impact. Patients' and partners' scores were evaluated to determine the concordance of both individual items as well as domain sums.

RESULTS

Twenty-eight couples completed the questionnaires. Only about 40% of men and women were happy with their levels of sexual interest with 82% concordance. Urine loss during orgasm was reported by 43% of men; the majority of participants were bothered by it. Ejaculation changes were observed by 96% of men (concordance 96%) with most reporting anejaculation. A change in orgasm experience was noted by 86% of men (and 36% of their female partners, p < 0.0001). Despite the change, the majority of men and women reported being satisfied with their ability to climax.

CONCLUSION

Our results indicate that patients and their female partners may interpret differently the same physiological outcomes of PCa surgery. This information could be useful to better counsel the PCa couple and help patients and partners adjust after surgery.

Prostate-specific antigen-based risk-adapted discontinuation of prostate cancer screening in elderly African American and Caucasian American men

OBJECTIVES

To evaluate the relationship between initial prostate-specific antigen (PSA) and prostate cancer (PCa) risk in elderly African American (AA) and Caucasian American (CA) men.

METHODS

A total of 408 AA and 1720 CA men whose initial PSA measurement was performed between 75 and 80 years of age were retrieved from Duke Prostate Center database. Patients were stratified by race and initial PSA value. The relative risk (RR) of PCa detection was estimated. The rates of high risk PCa, and death from PCa stratified by initial PSA groups were compared using the chi-square test.

RESULTS

The age-adjusted RR of PCa detection in CA men with PSA 3.0-5.9 ng/mL was 1.9-fold higher when compared with that of men with PSA 0.0-2.9 ng/mL (P < .001), but it did not change significantly in AA men (P = .270). PSA 6.0-9.9 ng/mL was associated with age-adjusted RR of PCa 9.3-fold in AA men and 4.1-fold in CA men (both P values < .001). A low rate of high-risk PCa and death from PCa was indicated with PSA < 6.0 ng/mL and < 3.0 ng/mL and follow-up of a maximum of 19.2 years and 17.6 years, respectively, in AA and CA men.

CONCLUSIONS

AA men with initial PSA < 6.0 ng/mL and CA men with initial PSA < 3.0 ng/mL between 75 and 80 years of age are unlikely to be diagnosed with high risk PCa or death from PCa. It may be safe to discontinue PSA screening in these men.

Efficacy and safety of tadalafil once daily: considerations for the practical application of a daily dosing option

OBJECTIVE

To provide clinically relevant information on tadalafil 2.5 or 5 mg once daily for the treatment of erectile dysfunction (ED), by reviewing safety and efficacy study findings. Findings from an integrated analysis of trials of tadalafil 10 and 20 mg as needed are presented to provide context for the daily dosing regime.

RESEARCH DESIGN AND METHODS

Of the three studies that included approved once-daily doses, two were conducted in the general ED population and one in a diabetic ED population. An integrated analysis was performed using 12-week efficacy and safety data from the studies conducted in the general ED population.

RESULTS

In the general ED population, the 12-week mean International Index of Erectile Function (IIEF) erectile function (EF) domain scores increased by 6.2 to an endpoint score of 19.2 and by 8.6 to 21.9 for 2.5 and 5 mg doses, respectively, versus an increase of 1.3 to 14.9 for placebo (p < 0.01). Mean successful intercourse attempts (SEP3) were 50% and 62% for tadalafil 2.5 and 5 mg once daily, respectively, versus 33% for placebo (p < 0.01). These findings were consistent with those for tadalafil as needed. In 1- and 2-year open label extensions of tadalafil 5 mg once daily, efficacy was maintained. In the diabetic ED population, 12-week mean IIEF EF scores increased by 4.8 to 18.3 and 4.5 to 17.2 with tadalafil 2.5 and 5 mg, respectively, versus an increase of 1.3 to 14.7 for placebo (p < 0.01). Mean successful intercourse attempts were more than 40% for each tadalafil dose, versus 28% for placebo (p < 0.01). The profile of treatment-emergent adverse events with tadalafil once daily was similar to that previously reported with as-needed treatment; the most common adverse events with tadalafil (dyspepsia, nasopharyngitis, headaches) were reported in <or=4% of participants.

CONCLUSIONS

Findings from the three published studies support a favorable risk-benefit balance for tadalafil 2.5 or 5 mg once daily. Although no direct comparison studies were performed (no head-to-head trials), efficacy and safety findings were consistent with those with tadalafil as needed.

High cholesterol feeding in C57/Blc6 mice alters expression within the VEGF receptor-ligand family in corporal tissue

INTRODUCTION

Angiogenesis, the growth and proliferation of blood vessels from existing vascular structures, is mediated by many cytokine growth factors and receptors, among the most important are the vascular endothelial growth factor (VEGF) family.

AIM

Decreases in VEGF receptor signaling have been linked to abnormalities in vasoreactivity in corporal tissue, but it is unknown if alterations in the VEGF ligands and/or receptors contribute to this process.

MAIN OUTCOME MEASURES

We sought to determine changes in vasoreactivity and the expression of the family of VEGF ligands and receptors in corporal tissue with cholesterol feeding in C57BL6 mice. Methods. Twenty-four mice (N = 8/group) were fed a normal diet (Group 1) or a 1.25% high cholesterol diet for 4 (Group 2) or 12 (Group 3) weeks. Isometric tension studies were performed on corporal strips and dose response curves were generated to evaluate endothelium-dependent and endothelium-independent vasoreactivities. Levels of VEGF-A, B, C, D, VEGF receptors (VEGFRs) were detected by PCR (polymerase chain reaction) and/or western blot/enzyme-linked immunosorbent assay (ELISA). Endothelial and smooth muscle cell contents were determined by immunohistochemistry.

RESULTS

At 4 weeks there was a small but significant decrease in endothelium-dependent vasoreactivity. Both mRNA and protein levels of VEGFR-1 were decreased, while VEGF-B was increased in Group 2 vs. Group 1, with no change in VEGF-A or endothelial cell content. By 12 weeks, decreases in both endothelium-dependent and endothelium-independent vasoreactivity were evident with decrease in most VEGF ligands (except VEGF-B), receptors, and receptor signaling.

CONCLUSIONS

Cholesterol feeding in C57BL6 mice results in alterations in the VEGF receptor-ligand family that may initially serve to limit the degree of vascular injury but these adaptations fail with the continuation of cholesterol feeding.

Revision washout decreases implant capsule tissue culture positivity: a multicenter study

PURPOSE

Positive cultures, visible biofilm and confocal micrography confirm bacterial presence on clinically uninfected inflatable penile prostheses at revision surgery. Salvage irrigation has been proved to rescue patients with clinically infected inflatable penile prostheses. Similar washout at revision for noninfectious reasons significantly lowers subsequent infection rates. We investigated a larger series of patients for positive culture rates and evaluated implant capsule tissue culture rates before and after revision washout.

MATERIALS AND METHODS

At 4 institutions a total of 148 patients with inflatable penile prostheses underwent revision surgery for noninfectious reasons between June 2001 and September 2005. Swab cultures of the fluid around the pump and visible biofilm were obtained. Also, in 65 patients a wedge of tissue from the capsule that forms around the pump was cultured. After implant removal revision washout of the implant spaces was performed and a second wedge of tissue was cultured.

RESULTS

Of the 148 patients 97 (66%) had positive bacterial swab cultures of the fluid around the pump or biofilm. A total of 124 isolates were cultured. Of the 65 implant capsule tissue cultures obtained before washout 28 (43%) were positive for bacteria, while 16 (25%) obtained after revision washout were positive.

CONCLUSIONS

Positive cultures and visible bacterial biofilm are present on clinically uninfected inflatable penile prostheses at revision surgery in most patients. Revision washout appears to decrease the bacterial load on implant capsule tissue at revision surgery of inflatable penile prostheses for noninfectious reasons.

Mouse model of erectile dysfunction due to diet-induced diabetes mellitus

OBJECTIVES

To determine whether diet-induced diabetes mellitus (DM) in mice would reproduce the major features of human erectile dysfunction (ED) because DM is a significant risk factor in the development of ED.

METHODS

In total, 150 C57BL6 (bl6) mice were divided into six groups of 25 mice each. Of these 150 mice, 125 were fed a high-fat (45% of total calories) diet for the final 4 (group 2), 8 (group 3), 12 (group 4), 16 (group 5), or 22 (group 6) weeks. Group 1 was fed a normal diet. The mice were 22 to 25 weeks old at study termination. The corporal tissues were harvested and studied for endothelium-dependent and endothelium-independent vasoreactivity, endothelial and smooth muscle cell content by immunohistochemistry, nitric oxide synthase expression by nicotinamide adenine dinucleotide-diaphorase staining, and apoptosis by terminal deoxynucleotidyl transferase biotin-D-UTP nick-end labeling staining.

RESULTS

The blood glucose levels were greater in groups 2 to 6 compared with those in group 1. The vasoreactivity, endothelial cell content, and smooth muscle/collagen ratio were lower and apoptosis were greater in the DM mice (P = 0.0001, P = 0.10, P = 0.0002, P <0.001, and P <0.001, respectively). Significantly decreased nitric oxide synthase expression and significantly increased apoptosis (P <0.0001 each) was found in the high-fat diet mice.

CONCLUSIONS

Corporal tissue from mice with diet-induced DM demonstrated many of the major functional, structural, and biochemical changes found in humans with ED. This model should serve as a valuable tool for advancing our understanding of the role DM plays in the pathogenesis of ED.

A Mouse Model of Hypercholesterolemia-Induced Erectile Dysfunction

INTRODUCTION

Hypercholesterolemia is one of the most important risk factors for the development of erectile dysfunction (ED) in men.

AIM

We employed an established mouse model of hypercholesterolemia.

MAIN OUTCOME MEASURES

We test for abnormalities in vasoreactivity in corporal tissue and temporally correlated changes in vasoreactivity with alterations in histology and protein expression.

METHODS

A total of 150 mice were studied. A total of 100 apolipoprotein-E knockout (ApoE(-/-)) mice were fed a 1.25% cholesterol diet for 2, 4, 8, and 12 weeks (N = 25/group), while a group of ApoE(-/-) and wild-type Bl-6 mice were fed a normal diet. The study was terminated, and all mice were harvested at 22 weeks of age for vasoreactivity, histology, and protein studies from corporal tissues. Dose-response curves were generated to evaluate endothelium-dependent and endothelium-independent vasoreactivity, ex vivo. The contents of endothelial cells, smooth muscle cells, and smooth muscle/collagen ratio were assessed by immunohistochemistry staining or Masson staining. Level of cyclic guanosine monophosphate (cGMP) was detected by enzyme immunoassay assay. Levels of phosphorylated endothelial nitric oxide synthase (p-eNOS)/total eNOS, neuronal nitric oxide synthase (nNOS), and cyclic GMP-dependent kinase (cGK-1) protein were assessed by Western analysis.

RESULTS

Abnormalities in endothelium-dependent and endothelium-independent vasoreactivities, endothelial content, smooth muscle/collagen ratio, p-eNOS phosphorylation at Ser1177 only, nNOS, cGMP, and cGK-1 changed with the different durations of the high-cholesterol diet.

CONCLUSIONS

These data demonstrate that this mouse model is suitable for investigating aspects of hypercholesterolemic ED.

Recovery of sexual function after prostate cancer treatment

PURPOSE OF REVIEW

The estimated disease-free survival rates are approximately equivalent across standard treatments for localized prostate cancer. We aim to review the efforts being made to reduce posttreatment erectile dysfunction, a major morbidity of these therapies.

RECENT FINDINGS

Potency as an important factor in a patient's decision about choosing a form of therapy has been demonstrated in the literature. For nerve-sparing surgery, though some proponents of laparoscopic radical prostatectomy believe it may confer an advantage over the open surgical techniques, the published data is scarce and has yet to demonstrate a true difference. Enthusiasm has declined for sural nerve grafting because of the associated complexity of the procedure and inconsistent results. Concurrent implantation of a penile prosthesis is an option for certain patients who already have some baseline erectile dysfunction or are not candidates for nerve-sparing surgery. Agents such as phosphodiesterase inhibitors, immunophilin ligands, and recombinant human erythropoietin have demonstrated potential benefits in early reports of both in-vitro and ongoing clinical trials.

SUMMARY

Currently, no standard treatment or prophylaxis exists for posttreatment erectile dysfunction. Neuro-protective and regenerative therapies, including the immunophilin ligands, hold promise to reduce the morbidity of localized prostate cancer therapy.

Use of negative-pressure dressings and split-thickness skin grafts following penile shaft reduction and reduction scrotoplasty in the management of penoscrotal elephantiasis

From 1988 to 2005, 8 men who presented with penoscrotal elephantiasis underwent penile shaft degloving and reduction scrotoplasty, followed by transplantation of a split-thickness skin graft (STSG) to the penile shaft. The etiology of elephantiasis in these patients included self-injection of viscous fluid and postsurgical obstructive lymphedema. In the 6 most recent cases, negative-pressure dressings were applied over the STSG to promote graft take, and STSG take rate was 100%. The results of our series corroborate those of a previous report, which showed circumferential negative-pressure dressings to be safe and efficacious in bolstering STSGs to the penile shaft. Furthermore, these results suggest that the use of negative-pressure dressings may improve graft take in this patient population.

Biofilm formation on clinically noninfected penile prostheses

PURPOSE

Biofilms are matrix enclosed bacterial populations that adhere to each other and/or to surfaces of implanted medical devices. Biofilm formation has consistently been demonstrated in association with infected penile prosthetic material. Clinically noninfected patients undergoing revision for mechanical malfunction have a surprisingly high rate of positive intraoperative cultures. After revision replacement prostheses have a higher rate of postoperative infection than first time implants. We characterized biofilm formation on penile prostheses in clinically noninfected patients undergoing revision surgery.

MATERIALS AND METHODS

Ten patients undergoing revision or removal of inflatable penile prosthetic devices due to mechanical malfunction were included. Specimens from the corporeal cylinders, scrotal pump and reservoir were analyzed. Bacterial biofilm coverage was detected and characterized using confocal scanning laser microscopy.

RESULTS

Bacterial biofilm formation associated with multiple microorganisms was demonstrated on 8 of 10 prostheses. Biofilms consisted of gram-positive rods, cocci and fungal elements.

CONCLUSIONS

The degree of biofilm formation on these prosthetic devices suggests that most patients have bacterial coverage on the implant. Host mechanisms to control infection may lead to a homeostatic balance that enables biofilms to exist on the surface of the prosthesis without generating clinical infection. A critical threshold of biofilm extent may exist beyond which clinical infection may occur. These results justify further evaluation of biofilms and penile prosthesis infections. Furthermore, the findings help to explain why strategies such as mini salvage procedures to eliminate subclinical biofilms may decrease the postoperative infection risk in patients undergoing repair or replacement of penile prostheses.

Etiology of ejaculation and pathophysiology of premature ejaculation

INTRODUCTION

Ejaculation is comprised of three stages of the male sexual response cycle, namely emission, ejection, and orgasm; however, in comparison with erection, which is a well-understood component of male sexual response, the pathophysiology of ejaculation has yet to be fully delineated. Premature ejaculation (PE), the most common sexual disorder in men, while believed to have a multifactorial etiology, is even less well understood.

AIM

This article reviews the physiology of ejaculation, and the multifactorial pathophysiology of PE.

METHODS

The Sexual Medicine Society of North America hosted a State of the Art Conference on Premature Ejaculation on June 24-26, 2005 in collaboration with the University of South Florida. The purpose was to have an open exchange of contemporary research and clinical information on PE. There were 16 invited presenters and discussants; the group focused on several educational objectives.

MAIN OUTCOME MEASURE

Data were obtained by extensive examination of published peer-reviewed literature.

RESULTS

Evidence supports that biologic mechanisms associated with neurotransmitters such as norepinephrine, serotonin, oxytocin, Gamma-amino-butyric acid, and nitric oxide (NO) as well as the hormone estrogen play central roles in ejaculation, and subsequently may mediate PE. There is also emerging evidence to show that hyperthyroidism may be a causal factor in PE. Recent data also suggest that psychogenic factors include high level of any experience by some men with PE.

CONCLUSIONS

The pathophysiology of both lifelong and acquired PE appears to be both neurobiogenic and psychogenic. While psychogenic factors appear to be contributory to PE, pharmacologic intervention of PE can modify intravaginal ejaculatory latency time (IELT), which suggests that IELT is a biological variable, and is likely biologically dependent upon neurotransmitters and hormones.

Timing and patterns of recurrences and deaths from prostate cancer following adjuvant pelvic radiotherapy for pathologic stage T3/4 adenocarcinoma of the prostate

To determine the timing and patterns of late recurrence after radical prostatectomy (RP) alone or RP plus adjuvant radiotherapy (RT). Between 1970 and 1983, 159 patients underwent RP for newly diagnosed adenocarcinoma of the prostate and were found to have positive surgical margins, extracapsular extension and/or seminal vesicle invasion. Of these, 46 received adjuvant RT and 113 did not. The RT group generally received 45-50 Gy to the whole pelvis, then a boost to the prostate bed (total dose of 55-65 Gy). In the RP group, 62% received neoadjuvant/adjuvant androgen deprivation vs 17% in the RT group. Patients were analyzed with respect to timing and patterns of failure. Only one patient was lost to follow-up. The median follow-up for surviving patients was nearly 20 years. The median time to failure in the surgery group was 7.5 vs 14.7 years in the RT group (P=0.1). Late recurrences were less common in the surgery group than the RT group (9 and 1% at 10 and 15 years, respectively vs 17 and 9%). In contrast to recurrences, nearly half of deaths from prostate cancer occurred more than 10 years after treatment. Deaths from prostate cancer represented 55% of all deaths in these patients. Recurrences beyond 10 years after RP in this group of patients were relatively uncommon. Despite its long natural history, death from prostate cancer was the most common cause of mortality in this population with locally advanced tumors, reflecting the need for more effective therapy.

Efficacy of Tadalafil in Men with Erectile Dysfunction Naïve to Phosphodiesterase 5 Inhibitor Therapy Compared with Prior Responders to Sildenafil Citrate

INTRODUCTION

Tadalafil, an inhibitor of phosphodiesterase 5 (PDE5), is indicated for treatment of erectile dysfunction. Most tadalafil clinical trials excluded patients with unsuccessful prior treatment with sildenafil citrate (sildenafil).

AIM

This retrospective analysis of pooled data from 14 tadalafil clinical trials examines the effect of this exclusion by comparing efficacy results in 1,349 patients without prior sildenafil use (naïve, presumably a mixture of potential responders and nonresponders) with efficacy results in 1,440 patients previously responsive to sildenafil (prior responders).

MAIN OUTCOME MEASURES

Efficacy measures included the International Index of Erectile Function (IIEF) erectile function (EF) domain, overall satisfaction (OS), and intercourse satisfaction (IS) domain scores; Sexual Encounter Profile (SEP) diary questions 2 through 5 (SEP2 [successful penetration], SEP3 [successful intercourse], SEP4 (satisfaction with hardness of erection), and SEP5 [overall satisfaction with the sexual experience]); and a Global Assessment Question (GAQ1) (13/14 trials) about erection improvement. Efficacy was compared using analysis of covariance (IIEF and SEP) and logistic regression (GAQ1) models.

METHODS

After a 4-week, treatment-free, run-in period, patients in 14 double-blind, placebo-controlled, parallel-group trials were treated with tadalafil 10 mg, tadalafil 20 mg, or placebo for 12 weeks (dosed as needed before sexual activity, no more than once daily).

RESULTS

Tadalafil improved erectile function compared with placebo (P < 0.001) in naïve patients and sildenafil prior responders for all efficacy measures. For most efficacy outcomes, responses in the naïve group (probable mix of responders and nonresponders) were not statistically different from responses in the prior-responder group (P >or= 0.10).

CONCLUSIONS

The similar responses of these two patient groups observed in this post hoc analysis suggest, but do not confirm, that exclusion of sildenafil nonresponders in previously reported tadalafil clinical trials may not have substantially affected efficacy outcomes. Tadalafil improved erectile function in patients naïve to PDE5 inhibitor therapy and in patients who previously responded to sildenafil therapy.

ORIGINAL RESEARCH—BASIC SCIENCE: Intracavernosal Basic Fibroblast Growth Factor Improves Vasoreactivity in the Hypercholesterolemic Rabbit

PURPOSE

We determined the effects of intracavernosal injection (ICI) of recombinant basic fibroblast growth factor (rbFGF) on corporal tissue in hypercholesterolemic rabbits.

METHODS

Twenty New Zealand White rabbits were fed a 1% cholesterol diet for 6 weeks and were randomly divided into four groups. Group 1 (N = 5) received an ICI of phosphate buffered saline solution (PBS) once and again 3 weeks later. Group 2 (N = 4) received an ICI of 2.5 microg rbFGF once and PBS 3 weeks later. Group 3 (N = 6) received an ICI of 2.5 microg rbFGF once and again 3 weeks later. Group 4 (N = 5) received an ICI of 2.5 microg rbFGF once. All animals were maintained on the high cholesterol diet until sacrifice, 3 weeks after last injection. Strips of corporal tissue were submaximally contracted with norepinephrine, and dose-response curves were generated to evaluate endothelial-dependent (acetylcholine, ACH) and endothelial-independent (sodium nitroprusside, SNP) vasoreactivity. Protein levels of bFGF and vascular endothelial growth factor (VEGF) were assessed by enzyme-linked immunosorbent assay. Neuronal nitric oxide synthase (nNOS) protein and mRNA were detected by Western blot and semi-quantitative polymerase chain reaction, respectively.

RESULTS

Vasoreactivity was improved by bFGF treatment as shown by higher ED50[-log(M)] of ACH and SNP in Groups 2, 3, and 4. The expression of bFGF protein, VEGF protein, nNOS protein, and mRNA were all increased after bFGF treatment.

CONCLUSIONS

ICI of bFGF improved vasoreactivity in hypercholesterolemic rabbit corporal tissue, offering a new direction to explore for the treatment of erectile dysfunction.

Cholesterol Feeding Reduces Vascular Endothelial Growth Factor Signaling in Rabbit Corporal Tissues

PURPOSE

Hypercholesterolemia is a major risk factor for erectile dysfunction (ED), but the mechanisms are not completely understood. Vascular endothelial growth factor (VEGF) is reduced in rabbit corporal tissue with cholesterol feeding. VEGF signaling leads to the phosphorylation of Akt and endothelial nitric oxide synthase (p-Akt and p-eNOS).

MATERIAL AND METHODS

New Zealand White rabbits (n = 50) were fed a 1% cholesterol (n = 8, 8, 8, 4) or normal (n = 6, 6, 6, 4) diet for 2, 4.5, 7.5, and 12 weeks. Akt, p-Akt, and p-Akt/Akt were measured by enzyme-linked immunosorbent assay. Levels of eNOS, p-eNOS, and neuronal and inducible nitric oxide synthase (nNOS and iNOS) mRNA and protein were assessed by polymerase chain reaction and Western analysis.

RESULTS

Cholesterol feeding was associated with a significant decrease in p-Akt/Akt 2.16-fold (P < 0.05), 3.28-fold (P < 0.02), and 3.42-fold (P < 0.02) at 4.5, 7.5, and 12 weeks, respectively. The reduction in p-Akt/Akt with the cholesterol diet at 2 weeks was not significantly different, but the correlation between the duration of cholesterol feeding and the reduction in p-Akt/Akt was high (r( 2) = 0.858). eNOS protein or mRNA did not change with cholesterol feeding, but p-eNOS was significantly decreased at 4.5 weeks and all subsequent time points. nNOS mRNA and protein levels were decreased at 4.5 weeks and all subsequent time points, while iNOS was not different between groups.

CONCLUSIONS

Hypercholesterolemia results in decreased VEGF signaling and decreased levels of the active form of eNOS in corporal tissue. Levels of nNOS were reduced by a different mechanism. VEGF signaling may provide a target to modulate ED.

The Prepuce as a Donor Site for Reconstruction of an Extravasation Injury to the Foot in a Newborn

Extravasation injury is a common event in pediatric intensive-care units. This is the first report of successful utilization of the prepuce as a skin graft to reconstruct a full thickness skin necrosis due to a phenobarbital extravasation to the forefoot of a newborn.

DECREASES IN CORPOREAL VASCULAR ENDOTHELIAL GROWTH FACTOR EXPRESSION PRECEDE VASOREACTIVITY CHANGES IN CHOLESTEROL FED RABBITS

PURPOSE

We determined temporal changes in vasoreactivity and angiogenic growth factor levels in corporeal tissue at varying time points after the induction of hypercholesterolemia in rabbits.

MATERIALS AND METHODS

A total of 42 New Zealand White rabbits were fed a 1% cholesterol (8 per group) or normal (6 per group) diet for 2, 4.5 or 7.5 weeks. Vascular endothelial growth factor (VEGF) mRNA expression in corpus cavernosum was assessed by real-time polymerase chain reaction analyses for the 3 isoforms VEGF121, VEGF165 and VEGF189. Isometric tension studies were performed and dose response curves were generated to evaluate endothelial dependent and endothelial independent vasoreactivity.

RESULTS

Real-time polymerase chain reaction analysis showed 2.2 to 2.5 and 1.5 to 2.7-fold decreases in VEGF121 and VEGF165, respectively, in the corporeal tissues of the high cholesterol group vs the normal diet group at the 2 week time point. At 2 weeks VEGF189 was unchanged but it was decreased 1.5 to 2-fold at 4.5 weeks. Acetylcholine isometric tension studies revealed no difference in mean ED50 (-log [M]) +/- SD until 7.5 weeks of high cholesterol diet (5.10 +/- 0.64 vs 3.95 +/- 1.35, p = 0.0269). The response to sodium nitroprusside was not statistically different at any time point. Endothelial cell and smooth muscle content were decreased for the high cholesterol vs normal diet at 4.5 weeks (endothelial only) and 7.5 weeks (each cell).

CONCLUSIONS

Alterations in corporeal tissue levels of VEGF occur before abnormalities in vasoreactivity. The results suggest that VEGF has a role in normal vasoreactivity in corporeal tissue and, thereby, in normal erectile function.