The correlation between penile tumescence measured by the erectometer and penile rigidity by the RigiScan

Nocturnal penile tumescence devices: past, present and future

Erectile function is an important part of men's health that can significantly impact quality of life. Naturally occurring nighttime erections experienced by men throughout their lifespan provides insight into penile health as well as overall health. Nocturnal penile tumescence (NPT) and nocturnal penile tumescence and rigidity (NPTR) devices that can non-invasively evaluate the presence and quality of erections can have valuable diagnostic and clinical utility. Early devices have several limitations that limit their current use. New, wearable devices have promising applications for the evaluation of erectile function over time. Continued advancements in this technology have the potential to render future generations of these devices as invaluable tools that are useful for both men and healthcare professionals.

How do Japanese patients really feel about losing potency after radical prostatectomy? (MAJI study)

OBJECTIVES

To investigate actual patients' feelings about losing erectile function because of treatment for prostate cancer.

METHODS

The study participants were 20 patients who were going to receive robot-assisted laparoscopic radical prostatectomy without nerve sparing. Before surgery, we interviewed them using an original questionnaire. The questionnaire included inquiries concerning their feelings about losing sexual function, whether they were sad or not, wanted to preserve sexual function, wanted to receive treatment if there were one that would restore sexual function and how much they would be willing to pay to recover their sexual function.

RESULTS

The median age of the participant was 67 years (range 60-73 years). Fourteen patients (70%) were sad about losing their sexual function and 17 (85%) wanted to preserve it if they could. Thirteen patients (65%) wanted to receive treatment that would restore their lost sexual function, and they thought that they would be willing to pay a median of 500 000 yen (range 0-1 000 000 yen) to recover it.

CONCLUSIONS

Most of the patients felt sad about losing their potency just before radical prostatectomy without nerve sparing. Although almost all patients wanted to preserve their sexual function if they could, they did not want to spend a great deal of money for it.

Penile Erection Morphometry: The Need for a Novel Approach

For many males, sexual function holds significant value in determining their quality of life. Despite the importance of male erectile function, no quantitative method to measure it accurately is currently available. Standardized assessment methods such as RigiScan™, International Index of Erectile Function (IIEF-5), and the stamp test are used to evaluate sexual function, but those methods cannot repetitively and quantitatively measure erectile function. Only direct measurement can quantitatively assess the shape of an erect penis. This paper presents the essential requirements for developing an ideal measurement method for penile erection. It also introduces current approaches for diagnosing male sexual function and reviews ongoing research to quantitatively measure erectile function. The paper further summarizes and analyzes the advantages and disadvantages of each method with respect to the essential requirements. Finally, the paper discusses the future direction toward the development of Penile Erection Morphometry.

Novel Concept Enabling an Old Idea: A Flexible Electrode Array to Treat Neurogenic Erectile Dysfunction

INTRODUCTION

Many studies have shown that electrostimulation of the cavernosal nerve can induce and maintain penile erection. Based on these discoveries, neurostimulation to activate the erectile response has been considered a potential solution to treat erectile dysfunction (ED). However, despite recognized potential, this technology has not been further developed. The barrier is the complex anatomy of the human cavernous nerve, which challenges the intraoperative identification of the cavernosal nerves for electrode placement.

AIM

To overcome this major barrier, we proposed a practical solution: a 2-dimensional flexible electrode array that can cover the entire plexus area, ensuring that at least 1 of the electrodes will be in optimal contact with the cavernosal nerve, without the need of intraoperative identification. The present study aims to evaluate this concept intraoperatively.

METHODS

24 patients enrolled for open radical prostatectomy were recruited. During the surgical procedures, the electrode array was positioned on the pelvic plexus (on the prostatic apex or pelvic wall) and electrical stimulation was applied to induce penile erection. Penile erectile response was assessed by (i) visual change of penile tumescence and (ii) by a penile plethysmograph system.

MAIN OUTCOME MEASURE

Ability and success rate of evoking penile response were measured by applying electrical stimulation using the developed electrode array.

RESULTS

Electrical stimulation produced immediate penile response in all cases when tested before (on prostatic apex) or after prostate removal (on pelvic wall). Clear visual penile engorgement was observed in 75% of the cases, whereas 25% showed minimal to moderate penile tumescence. As expected, patients with lower International Index of Erectile Function-5 score presented a reduced response, whereas stimulation before prostate removal showed greater response than following removal. Interestingly, erectile response was potentiated by bilateral stimulation (circumference increase [mm]: 2.7 ± 1.02 vs. 8.2 ± 1.9, P = .01).

CLINICAL IMPLICATIONS

These data bring sufficient proof of concept of a conceivable novel medical implant for the treatment of ED caused by mechanical nerve injury, such as prostatectomy and spinal cord injury.

STRENGTH & LIMITATIONS

This is the first approach that can ensure the optimal site stimulation of the erectogenic neuronal path within the lower pelvic area and overcome the major barrier of individual anatomic variability. However, because this study was performed intraoperatively in an acute scenario, further studies are needed to evaluate its chronic efficacy for clinical practice.

CONCLUSION

The flexible electrode array concept can ensure the electrostimulation of erectogenic neuronal path when positioned on the prostate apex or pelvic floor. Skoufias S, Sturny M, Fraga-Silva R, et al. Novel concept enabling an old idea: A flexible electrode array to treat neurogenic erectile dysfunction. J Sex Med 2018;15:1558-1569.

Relation Between Erectile Dysfunction and Silent Myocardial Ischemia in Diabetic Patients: A Multidetector Computed Tomographic Coronary Angiographic Study

INTRODUCTION

Erectile dysfunction (ED) can precede coronary artery disease. In addition, silent myocardial ischemia (SMI) is more common in diabetic patients and is a strong predictor of cardiac events and death.

AIM

To evaluate the presence of SMI in patients with diabetes and ED using multidetector computed tomographic coronary angiography (MDCT-CA).

METHODS

This study evaluated patients with diabetes and ED without any history of cardiac symptoms or signs. Erectile function was evaluated with the Sexual Health Inventory for Men score, erection hardness score (EHS), and maximal penile circumferential change by an erectometer. MDCT-CA was used for the detection of coronary artery stenosis.

MAIN OUTCOME MEASURES

Sexual Health Inventory for Men score, EHS, maximal penile circumferential change, and coronary artery stenosis by MDCT-CA.

RESULTS

Of 20 patients (mean age = 61.45 ± 10.7 years), MDCT-CA showed coronary artery stenosis in 13 (65%) in the form of one-vessel disease (n = 6, 30%), two-vessel disease (n = 2, 10%), and three-vessel disease (n = 5, 25%). Fifty percent of patients showed at least 50% vessel lumen obstruction of the left anterior descending coronary artery, which was the most commonly affected vessel (55%). Fifteen percent (3 of 20) of patients had greater than 90% stenosis, and two of them underwent an immediate coronary angioplasty with stenting to prevent myocardial infarction. Maximum coronary artery stenosis was positively correlated with age (P = 0.016, r = 0.529) and negatively correlated with EHS (P = .046, r = -0.449). Multivariate regression analysis using age and EHS showed that age was the only independent predictor of SMI (P = .04).

CONCLUSION

MDCT-CA can be a useful tool to identify SMI in diabetic patients with ED, especially in those of advanced age and/or with severe ED.

Correlation between erection hardness score and nocturnal penile tumescence measurement

INTRODUCTION

The Erection Hardness Score (EHS) and the Sexual Health Inventory for men (SHIM) are patient-reported outcome scoring systems for erectile function. It is unclear which is more reliable for predicting the objective erectile function.

AIM

The aim of this study was to evaluate whether the EHS could predict objective erectile function by measuring the maximal penile circumferential change (MPCC) with an erectometer.

METHODS

The study included 98 patients who visited our clinic from 2005 to 2010. The erectile function was evaluated using the SHIM, EHS, and MPCC. The MPCC was measured with the largest circumferential change of three consecutive occurrences of nocturnal penile tumescence (NPT) determined using the erectometer.

MAIN OUTCOME MEASURES

We defined erectile dysfunction (ED) as MPCC < 20 mm and carried out multivariate analysis using logistic regression analysis to clarify the predictors for ED, with the variables including age, the SHIM score, and the EHS. We compared the tendency for MPCC ≥ 20 mm when EHS was 3 or more with that when EHS was 2 or less.

RESULTS

The median age of the patients was 59.5 years (range 18-83). In logistic regression analysis, the EHS was the only predictor for ED with MPCC < 20 mm. The mean EHS in the MPCC < 20 mm group was 1.64 ± 0.20 (mean ± SEM) and that in the MPCC ≥ 20 mm group was 2.46 ± 0.13 (P = 0.0018). There was a correlation between the EHS and the MPCC (correlation coefficient = 0.33). In comparison with the group having an EHS of 2 or less, that with an EHS of 3 or more tended to have MPCC ≥ 20 mm (P = 0.013).

CONCLUSIONS

The EHS was correlated with the MPCC. The EHS represents the objective erectile function shown by the measurement of NPT.

Impact of visceral fat ratio on sleep-related erection: a retrospective study of elderly patients

OBJECTIVES

To investigate the impact of visceral fat accumulation on the preoperative erectile function of elderly patients undergoing radical prostatectomy.

METHODS

A total of 83 patients who underwent radical prostatectomy from August 2005 through August 2013 were included in the present study. Findings at preoperative computed tomography scanning and sleep-related erection were used to determine the objective erectile function. Sleep-related erection was measured with an erectometer during at least three nights, and we assessed the maximum penile circumferential change. The visceral fat ratio was calculated as the ratio of the visceral fat area to the total subcutaneous fat area on computed tomography images, and the influence of these parameters on preoperative erectile function was assessed.

RESULTS

In simple linear regression analysis there was a strong correlation between the waist circumference and visceral fat ratio (P < 0.01). A visceral fat ratio of 55% was equivalent to a waist circumference of 85 cm, which is the standard value for central obesity in Japan. Furthermore, the factor that most negatively affected maximum penile circumferential change was the visceral fat ratio. In addition, only a visceral fat ratio of 55% or greater was a significant independent risk factor for declining maximum penile circumferential change in both univariate and multivariate analyses (P = 0.04 and 0.02, respectively).

CONCLUSIONS

The present study is the first to show the utility of the visceral fat ratio as an index of central obesity and the relationship with sleep-related erection in elderly men.

Outcome analysis of sildenafil citrate for erectile dysfunction of Japanese patients

The approved maximal dose of sildenafil is only 50 mg in Japan, but the impact of dose regulation on treatment outcomes has not been established. Moreover, the contributors to the efficacy in patients having an intact peripheral nervous system have not been fully elucidated. We assessed in Japanese patients the treatment outcomes of sildenafil for erectile dysfunction (ED) under regulation of the approved dose and identified factors contributing to its efficacy among those with various etiologies other than pelvic surgery. We retrospectively reviewed 196 ED patients treated with sildenafil. The overall efficacy was 70.9% (139/196), and patients with psychological problems and concomitant cardiovascular disease showed high response rates (82.4 and 87.0%, respectively). Of the 139 responders, 89.9% achieved efficacy with a dose of 25 or 50 mg. Logistic regression analysis revealed concomitant cardiovascular disease and a favorable nocturnal penile tumescence result to be independent contributors to the efficacy.

Erectile dysfunction following nerve-sparing radical retropubic prostatectomy and its treatment with sildenafil

BACKGROUND

We retrospectively evaluated the erectile function after nerve-sparing radical retropubic prostatectomy (RRP) and the efficacy of sildenafil for erectile dysfunction (ED) following RRP according to the preoperative erectile function.

METHODS

We evaluated 48 Japanese patients who underwent nerve-sparing RRP at the Sapporo Medical University School of Medicine, Sapporo, Japan, between January 1996 and December 2001. Erectile function following nerve-sparing RRP was assessed by a simple mailed questionnaire that was constructed for the study.

RESULTS

Of the 48 patients, 36 had normal erectile function preoperatively, but for 12, function was not sufficient to penetrate. The overall estimated recovery rates of any degree of erection were 50.6% at 36 months and 94.3% at 60 months. However, that of erection sufficient to penetrate was only 17.7% at 36 months and was only seen in bilateral nerve-sparing patients. Sildenafil was effective in 9 of 13 ED patients (69.2%) in both nerve-sparing groups. When patients were divided according to preoperative erectile function, no difference was found in the efficacy rate between patients with normal function and those with ED.

CONCLUSIONS

Even bilateral nerve-sparing RRP can not always guarantee a sufficient erection. However, sildenafil is effective for ED following nerve-sparing RRP regardless of the nerve-sparing procedure or preoperative erectile function. Thus, preoperative function alone, although depending on its severity, may not necessarily be a reason for exclusion from receiving nerve-sparing RRP if patients want to have the operation.

Investigations in erectile dysfunction

PURPOSE OF REVIEW

This is an update of recent developments in the investigation of erectile dysfunction in the period since March 2002.

RECENT FINDINGS

Three developments in the field of medical sexology redirected the approach towards the investigation of erectile dysfunction. First, the emergence of oral pharmacological therapy; second, the notion that sexual relationship issues have an important impact on the successful outcome of pharmacological therapy; and finally, the concept that erectile dysfunction is often a sequel or even a sentinel of cardiovascular disease. Consequently, the current evaluation of men with erectile dysfunction may be divided into two steps: a basic diagnostic evaluation for the majority of men, and specific diagnostic procedures for a small minority. The basic evaluation is aimed at the identification of the underlying pathological condition and erectile dysfunction-associated risk factors. Such screening may diagnose reversible causes of erectile dysfunction and also unmask medical and psychological conditions that manifest with erectile dysfunction. The basic evaluation consists of a comprehensive medical, sexual and psychosocial history and a physical examination. Patients who have failed first-line treatment or complicated cases qualify for specific diagnostic procedures, traditionally performed by urologists.

SUMMARY

Current research into the investigation of erectile dysfunction emphasizes the notion that erectile dysfunction is often a result of an interplay between medical and psychosexual conditions. Recognition of the underlying conditions and an estimation of their relative contribution to the patient's and his partner's sexual problem are key issues in the current evaluation of the man with erectile dysfunction.