Preliminary results of a new tool to evaluate cavernous body fibrosis following radical prostatectomy: penile elastography

Penile Elastography Versus Penile Duplex Ultrasonography in Diagnosing Non-Responders to Intracavernosal Injection: A Prospective Cohort Study

OBJECTIVES

The current study aims to investigate the value of penile elastography in assessing the fibrotic changes in the corpora cavernosa.

PATIENTS AND METHODS

Eighty participants were included in the study. These were divided into two equal groups: a study group (group 1) included patients with ED who did not respond to intracavernosal injection (ICI), and an age-matched control group (group 2) included age-matched subjects with normal erection. All subjects answered an International Index of Erectile Function-5 (IIEF-5) questionnaire. The first group was evaluated by two ICI trials of 1 mL Quadmix, each took place 1 week apart, followed by a color duplex/Doppler ultrasonography (CDDU) scan using also a 1 mL Quadmix. All the above was done a week before the penile shear wave elastography (SWE) scan. It comprised a 12-section scan of both corpora cavernosa. Each corpus was scanned in three different segments (proximal, mid-shaft, and distal), and in both longitudinal and transverse axes.

RESULTS

Comparisons of the laboratory data were non-significant, apart from the glycosylated hemoglobin which proved significant (P value <.001) in both groups. Also, the IIEF-5 scores were significantly lower in the study group (P value <.001). Significantly higher SWE readings (indicating higher fibrotic) were found in the study group compared with the control group in almost all of the scanned segments and their combinations (P value <.05).

CONCLUSION

SWE can effectively assess the fibrotic changes occurring in the corpora cavernosa. Hence, SWE could be utilized as a modality that helps diagnose patients with ED.

Factors affecting the shear wave elastic quantitative measurement of penile tissue in rats

Background

As a new ultrasound technology, 2-dimensional shear wave elastography (2D-SWE) can evaluate the elastic characteristics of penile tissue. However, no studies have reported the main factors affecting the shear wave elastic quantitative measurement (SWQ) in penile tissue.

Objectives

To analyze the main factors affecting the SWQ reflecting the elastic characteristics of penile tissue by 2D-SWE.

Methods

Twenty healthy male Sprague-Dawley rats (5-60 weeks old) were selected for this study. We performed the 2D-SWE examination on the penis using the Aixplorer ultrasound system, with SWQ as the measurement index. We performed penile immunohistochemistry analysis with the positive area proportion (PAP) of alpha-smooth muscle actin (PAPS) and type III collagen fiber (PAPC) as the outcomes. Then, we conducted multiple linear regression analysis to explore the correlation of SWQ with PAPS and PAPC and established the regression equation.

Results

The multiple linear regression analysis showed that the linear regression equation (SWQ = 10.376 - 0.05 PAPS - 0.07 PAPC) was statistically significant (F = 21.153, P < 0.001). The content of smooth muscle cells (SMCs) and collagen fibers was negatively correlated with SWQ, affecting 42.6% of the total variation in SWQ (R2 = 0.426).

Conclusions

SMCs and collagen fibers are the main factors affecting the SWQ value of penile tissue and the primary tissue components determining the SWQ when using 2D-SWE to quantitatively evaluate the elastic characteristics of penile tissue.

Use of penile shear wave elastosonography for the diagnosis of Peyronie's Disease: a prospective case-control study

BACKGROUND

To evaluate the stiffness of the tunica albuginea (TA), we used a new noninvasive diagnostic technique called shear wave elastography (SWE). We determined whether SWE values are correlated with the degree of penile curvature, the time of disease onset, and pain severity experienced by patients during erection. This study analyzed the elasticity of the TA of patients with Peyronie's disease compared to that of the control group. We also analyzed any correlations between the stiffness of the cavernous bodies and the degree of curvature, time from diagnosis to curvature onset, and erectile pain severity. This was a prospective case-control study involving 100 men enrolled from September 2020 to August 2021. Participants were divided into group A (case group, n = 50), which included men with PD, with or without pain, and with penile curvature, or group B (control group, n = 50), which included healthy patients older than 18 years who visited the urology clinic for reasons other than PD. The medical history was collected for all patients who also underwent objective examination, B-mode ultrasound evaluation, and SWE. The International Index of Erectile Function (IIEF-15) visual analog scale (VAS) questionnaire was administered to all participants.

RESULTS

There were no significant between-group differences regarding age, weight, and height (p > 0.05); however, there was a significant difference in the stiffness values (p < 0.05). An inverse correlation was observed between stiffness and the VAS score (p < 0.0001). A positive correlation was observed between the degree of curvature (p < 0.0001) and the time of curvature onset (p < 0.0001). The IIEF-15 scores were poorer in group A than in group B (p < 0.0001).

CONCLUSION

SWE is an inexpensive, noninvasive method that can be used to measure the stiffness of PD patients.

Elastography in the Urological Practice: Urinary and Male Genital Tract, Prostate Excluded—Review

The aim of this article is to review the utility of elastography in the day-to-day clinical practice of the urologist. An electronic database search was performed on PubMed and Cochrane Library with a date range between January 2000 and December 2021. The search yielded 94 articles that passed the inclusion and exclusion criteria. The articles were reviewed and discussed by organ, pathology and according to the physical principle underlying the elastographic method. Elastography was used in the study of normal organs, tumoral masses, chronic upper and lower urinary tract obstructive diseases, dysfunctions of the lower urinary tract and the male reproductive system, and as a pre- and post-treatment monitoring tool. Elastography has numerous applications in urology, but due to a lack of standardization in the methodology and equipment, further studies are required.

Curcumin slow-release membrane promotes erectile function and penile rehabilitation in a rat model of cavernous nerve injury

Male erectile dysfunction (ED) caused by cavernous nerve injury is a common complication of pelvic surgery, radiotherapy, transurethral surgery or other operations. However, clinical treatment for iatrogenic or traumatic male ED is difficult and not satisfactory. Many studies have shown that curcumin can promote the repair and regeneration of peripheral nerves; however, whether curcumin can rescue cavernous nerve injury is unknown, and the poor bioavailability of curcumin limits its application in vivo. Hence, the study was conducted. A curved slow-release membrane was produced, and the properties were examined. In addition, the effects of the curcumin slow-release membrane on cavernous nerve-injured SD rats were studied. We found that polylactic acid-glycolic acid-polyethylene glycol (PLGA-PEG) can be used as a good carrier material for curcumin, and curcumin-loaded PLGA-PEG membranes can effectively rescue the cavernous nerve in SD rats, restore the continuity of the cavernous nerve, and increase the expression of nNOS mRNA and proteins in penile tissue, which can improve the penile erectile function of injured SD rats, reduce the degree of penile tissue fibrosis, and effectively promote penis rehabilitation. The curcumin slow-release membrane is proposed to be a new therapeutic approach for penile rehabilitation of cavernous nerve injury.

Applications of artificial intelligence in the diagnosis and prediction of erectile dysfunction: a narrative review

Despite the high prevalence of erectile dysfunction, patients are reluctant to seek medical advice, which leads to low diagnostic rates in clinical practice. Artificial intelligence has been widely applied in the diagnosis of many diseases and may alleviate the situation. However, the applications of artificial intelligence in erectile dysfunction have not been reviewed to date. Therefore, the assistance from artificial intelligence needs to be summarized. In this review, 418 publications before January 10, 2021, regarding artificial intelligence applications in diagnosing and predicting erectile dysfunction, were retrieved from five databases, including PubMed, EMBASE, the Cochrane Library, and two Chinese databases (WANFANG and CNKI). In addition, the reference lists of the included studies or relevant reviews were checked to avoid bias. Finally, 30 articles were reviewed to summarize the current status, merits, and limitations of applying artificial intelligence in diagnosing and predicting erectile dysfunction. The results showed that artificial intelligence contributed to developing novel diagnostic questionnaires, equipment, expert systems, classifiers by images and predictive models. However, most of the included studies were not subjected to external validations, resulting in doubt on the generalizability. In the future, more rigorously designed studies with high-quality datasets for erectile dysfunction are required.

Role of shear wave elastography (SWE) in erectile dysfunction patients for evaluation of daily tadalafil treatment outcome

The purpose of this study was to evaluate and anticipate the outcome of daily use of tadalafil in patients with erectile dysfunction using elastography. 183 volunteers and 183 patients with erectile dysfunction were included. Pretreatment SWE readings for our patients were calculated with a linear probe. IIEF score Q was measured once at the start of the study for volunteers and twice for patients, one prior to the start of tadalafil administration and the other on one year of 5 mg daily tadalafil after the second post-washout (one month post-treatment stopped). There was no significant difference between patients and volunteers in mean age or risk factors except in SWE values as mean SWE of volunteers was 14.03 ± 1.54 kpasc, while mean SWE of patients was 21.278 ± 8.228 kpasc. The presence of comorbid diabetes, severe disease and pre-SWE ≥23.635 was significantly associated with poor outcome. We conclude that penile SWE could be useful to select probable good responders for a continuous tadalafil use, thus avoiding the unnecessary cost and time in non-responders.

Pathophysiology and Grayscale Ultrasonography of Penile Corporal Fibrosis

INTRODUCTION

Penile corporal fibrosis may occur secondary to explantation of an infected penile prosthesis, severe penile trauma, refractory low-flow priapism, Peyronie's disease, or chronic intra-cavernous injection of vasoactive drugs. Other etiologies of corporal fibrosis, presenting primarily with erectile dysfunction, can develop in chronic smokers, hypertensive patients, alcoholics, diabetics, and after radical prostatectomy. Corporal erectile tissue fibrosis is a significant pathophysiologic component of erectile dysfunction; however, current ultrasound-based penile imaging protocols do not directly assess it.

OBJECTIVE

To determine if grayscale ultrasonography (US) is a suitable imaging modality to identify and assess penile corporal erectile tissue fibrosis.

METHODS

A PubMed literature review was performed for studies that detailed ultrasonographic methods and findings of pathologies causing penile corporal fibrosis. Our main outcome measure was the ultrasonographic findings of pathologies causing penile corporal fibrosis.

RESULTS

Grayscale US demonstrates the capability to detect and localize the fibrotic changes of the corpora cavernosa. Ultrasonographic findings capture penile corporal tissue heterogeneity including diffuse, circumscribed, or localized patterns.

CONCLUSION

Overall, grayscale US may be a useful and convenient imaging modality to assess penile corporal fibrosis secondary to explantation of an infected penile prosthesis, priapism, penile trauma, chronic intra-cavernous injection of vasoactive drugs, diabetes, Peyronie's disease, and vascular disease. While limited by the skill and knowledge of the US operator, the combined knowledge of pathophysiology and US may help clinicians identify and manage the underlying etiology of penile corporal fibrosis. Kim J, Drury R, Morenas R et al. Pathophysiology and Grayscale Ultrasonography of Penile Corporal Fibrosis. Sex Med Rev 2022;10:99-107.

Evaluation of Arterial Erectile Dysfunction Using Shear Wave Elastography: A Feasibility Study

OBJECTIVES

To explore the feasibility of shear wave elastography (SWE) in the evaluation of arterial erectile dysfunction (ED).

METHODS

From November 2018 to November 2019, 26 patients with arterial ED and 30 patients with non-vascular ED were prospectively included. SWE values of corpus cavernosum penis (CCP) and the flow velocity of cavernous artery for all patients in both before intracavernous injection (ICI) (flaccid state) and after ICI (erectile state) were measured. Performance of SWE value in assessing arterial ED was studied. Correlation between SWE value of CCP and the age of patients was also investigated.

RESULTS

ICI significantly reduced SWE values in both arterial and non-vascular group (from 19.57 ± 6.33 KPa to 12.17 ± 3.64 KPa in the first, and from 19.91 ± 6.69 KPa to 8.04 ± 3.13 KPa in the former, both P < .001). SWE values of CCP after ICI in arterial ED were significantly larger than that in non-vascular ED (P < .001). SWE values of CCP before ICI negatively correlated with age of patients in arterial ED (r = - 0.601, P < .001). With a cutoff value of 7.75 KPa, the area under curve, specificity, sensitivity, PPV, and NPV of SWE values of CCP after ICI in distinguishing arterial ED from non-vascular ED were 0.810, 63.3%, 96.2%, 96.2%, and 70%, respectively.

CONCLUSIONS

SWE was expected to be a potential technique for the noninvasive, simply operated, repeatable and quantitative evaluation of arterial ED.

Assessment of changes in penile sensation by electrophysiological study after radical prostatectomy: A pilot study

Background:

To evaluate the changes in penile sensation by electrophysiological tests in patients who underwent radical prostatectomy (RP) and to demonstrate the role of dorsal penile nerve injury in postoperative erectile dysfunction.

Materials and methods:

Twenty-six volunteer patients who were eligible for RP were included in the study. Preoperative penile sensory electromyography and the International Index of Erectile Function-5 (IIEF-5) questionnaire were done for each patient. Erectile function assessment and electrophysiological evaluation of penile sensation were repeated at postoperative 3rd and 6th months.

Results:

Postoperative IIEF-5 scores and electromyography values were significantly lower than preoperative findings (p < 0.05). The IIEF-5 scores in the nerve sparing-RP (NS-RP) group were significantly higher than the non-nerve sparing-RP (NNS-RP) group in the postoperative period. Nerve conduction velocity values in the NS-RP group were also higher than the NNS-RP group at the postoperative 3rd and 6th months. However, these changes were not statistically significant (p > 0.05).

Conclusions:

Patients who underwent RP have decreased penile sensation due to cavernous nerve damage and a possible dorsal penile nerve injury. The decrease of penile sensation may be associated with postoperative erectile dysfunction.

Shear wave elastography as a new, non-invasive diagnostic modality for the diagnosis of penile elasticity: a prospective multicenter study

Objective:

Shear wave elastosonography (SWE) could be used to evaluate the elasticity of penile tissue. Few studies in the literature, however, have investigated its use in patients with erectile dysfunction (ED) or have attempted to correlate findings with International Index of Erectile Function (IIEF-5) scores. The primary aim of this study was to evaluate the characteristics of erectile tissue using SWE and to determine possible relationships with IIEF-5 and Erection Hardness Scale (EHS) scores. The secondary aim was to establish a cut-off SWE examination value over which cavernous tissue stiffness could contribute to a subsequent organic alteration.

Methods:

This prospective study included male patients 18−80 years of age who attended two general andrology clinics and underwent SWE. Subjects were divided into groups according to IIEF-5 score, and correlations between SWE and IIEF-5 and EHS questionnaire scores were explored.

Results:

A total of 270 subjects (mean age 46.7 ± 16.9 years) were included. ED was reflected by low IIEF-5 and EHS scores and a decrease in the mean elasticity of the corpora cavernosa according to SWE, although the difference between the left and right corpora cavernosa was not statistically significant. No statistically significant correlation was found between measurements of the corpora cavernosa (in kPa) and age. The optimal cut-off identified was 24.75 kPa.

Conclusion:

Results demonstrated that the mean elasticity of the corpora cavernosa according to SWE was correlated with IIEF-5 score and EHS score.

Sonography of the penis/erectile dysfunction

Erectile dysfunction (ED) is defined as the persistent inability to achieve and/or maintain an erection for a satisfactory sexual activity. It is secondary to several organic, psychogenic, and combined causes, and represents a serious health dilemma affecting both men and their partners. The diagnostic approach to erectile dysfunction has significantly changed in the last years with the advent of phosphodiesterase-5 (PDE5) inhibitors, and with the recognition that surgical treatment of both arterial insufficiency and penile venous leak have poor long-term clinical outcomes. Although imaging modalities have diminished in importance, differentiating among causes of erectile dysfunction remains mandatory in good medical practice, and ultrasound (US) still remains the cornerstone of the diagnostic workup. US provides an objective, minimally invasive evaluation of penile hemodynamics. Moreover, it provides an excellent depiction of the penile anatomy and of its changes in pathological conditions such as in patients with Peyronie's disease, priapism, and posttraumatic erectile dysfunction.

Penile Doppler ultrasonography and elastography evaluation in patients with erectile dysfunction

Purpose

To evaluate the relationship between erection grade, erectile function score, Doppler ultrasonography (US) indexes, and elasticity score (ES) according to Doppler US diagnosis in patients with erectile dysfunction (ED).

Material and methods

Real-time strain type penile elastography was performed during penile Doppler US examination for 88 patients with ED. The diagnosis according to Doppler US was determined. Erection score according to the Erection Hardness Grading Scale was evaluated. A scoring for erectile function was performed with the International Index of Erectile Function (IIEF-5), and the Sexual Health Inventory for Men (SHIM) was defined. The relationships, according to Doppler diagnosis, of ES, IIEF-5 score, SHIM scale, and erection score were evaluated.

Results

Among the patients, 50 (57%) had abnormal penile Doppler US findings. According to Doppler US findings, patients were classified as normal (n = 38), borderline for arterial insufficiency (n = 4), arterial insufficiency (n = 5), and venous insufficiency (n = 41). The lowest erection hardness grades and IIEF-5 scores were detected in patients with arterial failure. When compared to the normal group, in terms of ES, the arterial failure borderline group and venous failure group had lower scores, and the arterial failure group had a higher score. However, the only significant difference was obtained in the left cavernous body of the venous failure group.

Conclusions

Sonoelastography seems to add additional value for determination of stiffness of the penile cavernous body in routine evaluation of ED.

Strategies to improve nerve regeneration after radical prostatectomy: a narrative review

Peripheral nerves are complex organs that spread throughout the entire human body. They are frequently affected by lesions not only as a result of trauma but also following radical tumor resection. In fact, despite the advancement in surgical techniques, such as nerve-sparing robot assisted radical prostatectomy, some degree of nerve injury may occur resulting in erectile dysfunction with significant impairment of the quality of life. The aim of this review was to provide an overview on the mechanisms of the regeneration of injured peripheral nerves and to describe the potential strategies to improve the regeneration process and the functional recovery. Yet, the recent advances in bio-engineering strategies to promote nerve regeneration in the urological field are outlined with a view on the possible future regenerative therapies which might ameliorate the functional outcome after radical prostatectomy.

The Impact of Immediate Salvage Surgery on Corporeal Length Preservation in Patients Presenting with Penile Implant Infections

PURPOSE

Removal of an infected penile implant often results in corporeal fibrosis, irreversible penile shortening and dissatisfaction with future implant surgery. Salvage surgery may avoid these problems but to our knowledge no study to date has evaluated these specific end points. We evaluated patients who presented to our center with an infected implant to determine the impact of salvage surgery on penile length.

MATERIALS AND METHODS

We evaluated consecutive patients undergoing removal of an infected penile prosthesis with immediate salvage or delayed reimplantation using a comprehensive, prospective database. Total corporeal length prior to and following immediate salvage or delayed reimplantation were compared. The impact of patient age, comorbidities, bacterial species, initial penile length and time to reimplantation on subsequent total corporeal length was evaluated.

RESULTS

The cohort consisted of 40 patients. Overall 81% of salvaged cases were successful, resulting in a mean 0.6 cm (95% CI 0.20 to 1.1) reduction in total corporeal length. Delayed reimplantation resulted in a mean 3.7 cm (95% CI 2.9-4.5) total corporeal length loss. In patients who underwent delayed reimplantation the total corporeal length reduction was directly proportionate to the initial penis size of the patient. No statistically significant impact on penile length was attributable to patient age, diabetes, bacterial species or time to reimplantation.

CONCLUSIONS

When possible, salvage surgery should be offered to patients with an infected penile implant. Our data confirmed that successful salvage surgery preserves penile length. When a device is explanted and replaced at a later date, patients can expect to lose 15% to 30% of penile length irrespective of age, diabetes, type of infecting organism and time to reimplantation.