Tunica albuginea allograft: a new model of LaPeyronie's disease with penile curvature and subtunical ossification

Injectable agents for the induction of Peyronie's disease in model rats: a comparative study

ABSTRACT

Peyronie's disease (PD) is a disorder characterized by fibrous plaque formation in the penile tissue that leads to curvature and complications in advanced stages. In this study, we aimed to compare four injectable induction agents for the establishment of a robust rat model of PD: transforming growth factor-β1 (TGF-β1), fibrin, sodium tetradecyl sulfate (STS) combined with TGF-β1, and polidocanol (POL) combined with TGF-β1. The results showed that injection of TGF-β1 or fibrin into the tunica albuginea induced pathological endpoints without causing penile curvature. The STS + TGF-β1 combination resulted in both histological and morphological alterations, but with a high incidence of localized necrosis that led to animal death. The POL + TGF-β1 combination produced pathological changes and curvature comparable to STS + TGF-β1 and led to fewer complications. In conclusion, fibrin, STS + TGF-β1, and POL + TGF-β1 all induced PD with a certain degree of penile curvature and histological fibrosis in rats. The POL + TGF-β1 combination offered comparatively greater safety and clinical relevance and may have the greatest potential for PD research using model rats.

A study of the histopathology of collagen fleece (TachoSil) patching of tunica albuginea in the rat penis and a literature review of penile graft materials in experimental animals

Background

A penile tunica defect may arise during surgery in patients with Peyronie's disease. Collagen fleece (TachoSil) has recently gained popularity in penile surgery to cover the tunica albuginea (TA) defect associated with clinical success. However, it is not known what the histological outcomes of these grafts are in the penis. We aimed to study the histopathology of the TachoSil graft in an experimental animal model for the regeneration of TA, inflammation, fibrosis, and the underlying cavernous tissue.

Methods

Six adult male Sprague Dawley rats were used. The penis was degloved through a circumferential subcoronal incision. A longitudinal 1 mm × 10 mm defect was created at the base of the lateral aspect of the penis. A TachoSil patch (Takeda, Japan) was applied to the defect. The penile skin covering was then restored. At 2 months, the rat penis was excised and examined with hematoxylin, eosin, and trichrome stains. We conducted a literature review of penile grafts in animals for comparison.

Results

Rats weighed 369.2 gm (standard deviation: 31.5). At 2 months, all rats showed normal-looking penis with complete healing, no scaring, tethering, or gross inflammatory features. Histopathology of the patch site showed fibrosis, chronic inflammation, and foreign body giant cell reaction. There was no generation of a new TA, or new vascularity. No inflammatory or pathological reaction affected the underlying corpus cavernous tissue. One rat died on the 6th postoperative day. Postmortem showed massive multiorgan hemorrhage consistent with disseminated intravascular coagulopathy (DIC). Unlike some other reported grafts, there is no TA regeneration.

Conclusions

TachoSil patching of penile TA defect forms a distinctive barrier against inflammation, protecting the underlying corpus cavernosum. However, no regeneration of the tunica defect is observed at 2 months. DIC is a potential complication of systemic absorption of TachoSil.

European Society of Sexual Medicine consensus statement on the use of animal models for studying Peyronie's disease

Introduction

Animal models are frequently used for translational research in Peyronie's disease (PD). However, due to lack of availability of guidelines, there is some heterogeneity in study design, data reporting, and outcome measures.

Aim

This European Society for Sexual Medicine consensus statement aims to provide guidance in utilization of animal models in PD research in a standardized and uniform fashion.

Methods

PubMed was searched for studies using animal models for PD. The following search terms were used: ("Peyronie's disease" OR "penile fibrosis" OR "penile curvature" OR "induration penis plastica" OR "erectile dysfunction") AND ("rodent" OR "mouse" OR "mice" OR "rat" OR "rabbit").

Outcomes

This European Society for Sexual Medicine statement describes best practice guidelines for utilization of animals in PD research: power calculation, details of available models, surgical procedures, and measurement techniques, while highlighting possible pitfalls and translational limitations of the models.

Results

In total, 2490 studies were retrieved and 2446 articles were excluded. A total of 44 studies were included, of which 40 studies used rats, 1 study used both rats and mice, 1 study used a genetic mouse model, and 2 studies used rabbits. A significant number of the studies (70.5%) used transforming growth factor β 1 for induction of fibrosis. Oxford 2011 Levels of Evidence criteria could not be applied due to the nature of the studies.

Conclusion

Despite certain limitations of PD animal models presented, we aimed to provide guidance for their appropriate use in translational research, with the purpose of improving study quality and reproducibility as well as facilitating interpretation of reported results and conclusions.

A Consistent Lack of Consistency in Defining the Acute and Chronic Phases of Peyronie's Disease: A Review of the Contemporary Literature

INTRODUCTION

Treatment recommendations for Peyronie's Disease (PD) differ based on whether a patient is in the acute/active versus chronic/stable phase of the disease, yet there are no agreed upon criteria for defining these clinical entities.

OBJECTIVES

To review the criteria used to define acute and chronic phase PD in modern PD intervention studies.

METHODS

We performed a search engine review to identify indexed publications for PD intervention studies and review articles / meta-analyses from the year 2011-2020. Outcomes results were catalogued and summarized across articles. As a result of the substantial heterogeneity of outcome measures and follow-up intervals, meta-analytic techniques were not applied to the data analysis.

RESULTS

We identified a total of 104 studies that met inclusion criteria and had available information for review (n = 79 primary intervention studies; n = 25 review articles/meta-analyses/guidelines). Among the queried studies, we were unable to identify a consensus with respect to the criteria used to define acute and chronic phases of PD. 33% of primary intervention studies did not specifically define their criteria for acute and chronic phase PD, despite referencing these populations as part of the inclusion criteria in many instances. Studies used heterogenous criteria including total symptom duration, duration of "stable" symptoms, and presence/absence of pain.

CONCLUSION

Due to varying definitions across the literature, we were unable to create a standardized definition of acute and chronic phase Peyronie's in terms of time. Our findings emphasize the need for greater consensus in defining the treatment cohorts with future studies that assess treatment for men with PD.

Peyronie's disease: is it genetic or not?

Peyronie's disease (PD) is a devastating disease that affects up to 13% of adult men. While trauma to the erect penis is common prior to onset, it is clear that trauma alone is not sufficient to cause PD. Over the past 40 years, multiple lines of evidence have pointed to a genetic factor that predisposes some men to develop PD. Despite dramatic technological advances in the field of genetics, we have made little progress in identifying the genetic contributors to the disease. This review will critically evaluate the literature concerning the genetics of PD published to date. Particular focus will be placed on study design as much of the data are contradictory yet may still give some insight into the etiology of PD. The challenges in identifying the genetic underpinnings of PD will be discussed along with the potential mechanisms that can overcome these challenges.

Physicochemical and biochemical spatiotemporal maps of a mouse penis

Spatiotemporal mechanobiology resulting in penile pathologies continues to be investigated using small scale animals models such as mice. However, species-dependent functional biomechanics of a mouse penis, is not known. In this study, spatial mapping of a mechanosensitive transcription factor, scleraxis (Scx), at ages 4, 5, 6 weeks, and 1 year were generated to identify mechanoactive regions within penile tissues. Reconstructed volumes of baculum collected using micro X-ray computed tomography illustrated significantly increased baculum length with decreased porosity, and increased mineral density (p < 0.05) with age. The bony-baculum was held centrally in the Scx positive corpus cavernosum glandis (CCG), indicating mechanoactivity within the struts in a 6 week old mouse. The struts also were stained positive for fibrillar proteins including collagen and elastin, and globular proteins including protein gene product 9.5, and α-smooth muscle actin. The corpus cavernosum penis (CCP) contained significantly (p < 0.05) more collagen than CCG within the same penis, and both regions contained blood vessels with equivalent innervation at any given age. Comparison of volumes of flaccid and erect penile forms revealed functional characteristics of the CCP. Results of this study provided insights into biomechanical function of the CCG; in that, it is a high-pressure chamber that stiffens the penis and is similar to the human corpus cavernosum.

Cavernosopatía traumática crónica. Un nuevo síndrome de fibrosis peneana

Introdución La llamada genéricamente «enfermedad de Peyronie» es un diagnóstico que explica un porcentaje de ciertos estados de fibrosis peneana grave, pero se queda corta para abarcar la amplia gama de grises de la fibrosis peneana secundaria a microtrauma sexual repetido.

Objectivo Describir un nuevo síndrome por trauma repetido en el pene al que se propone denominar «cavernosopatía traumática crónica» (CTC), con 4 componentes: fibrosis (leve, moderada o grave), disfunción eréctil, curvatura y fugas venosas peneanas.

Materiales y métodos Se realizó un estudio de corte transversal en una base de datos de 128 pacientes que tenían al menos una ecografía de pene con vasoactivo y en los que se había detectado algún grado de fibrosis cavernosa según la clasificación de Levine. Se evaluó la presencia de disfunción eréctil, curvas y fugas venosas según el grado de fibrosis. El estudio contó con la aprobación del Comité de Ética en Investigación.

Resultados Se estudió a 128 pacientes con fibrosis, con 51,3 años de edad promedio (DE = 13). El grado de fibrosis fue leve (Levine 1) en 30 (23,43%), moderado (Levine 2) en 23 (17,96%) y grave (Levine 3) en 75 (58,6%). Se demostró que, a mayor fibrosis, mayor disfunción eréctil, 66,6; 83,6 y 96% para Levine 1, 2 y 3, respectivamente (p ≤ 0,0001). La frecuencia de curvatura secundaria (n = 71) fue de 0; 4,2 y 95,7% para Levine 1, 2 y 3, respectivamente (p ≤ 0,0001). La frecuencia en los 44 pacientes con fugas cavernosas fue de 9; 20,4 y 70,4% (p = 0,0060) y en los 15 de fugas dorsales fue de 80; 13,3 y 6,6% (p < 0,0001) para Levine 1, 2 y 3 respectivamente. El grupo de 79 pacientes (64,03%) con mayor posibilidad de CTC, con presencia de 3 o 4 criterios que incluyeran curvatura secundaria y fuga cavernosa, tuvo un promedio de edad de 59,2 años (DE = 8,7), comparado con 41,7 años (DE = 11,7) en el grupo de menor posibilidad, diferencia estadísticamente significativa (p ≤ 0,0001).

Conclusiones Proponemos que existe un síndrome de microtrauma repetido en el pene, que puede denominarse CTC, análogo a la encefalopatía traumática crónica, con 4 componentes: fibrosis cavernosa, disfunción eréctil, curvatura peneana y fugas venosas. La fibrosis es un continuum que el paciente recorre por fases leves y moderadas, a menudo inapreciables para los clínicos. Las curvaturas secundarias y las fugas cavernosas están relacionadas directamente con el grado de fibrosis y con mayor riesgo de disfunción eréctil. La edad empeora algunos factores de la CTC.

Microsurgical tunica albuginea transplantation in an animal model

Several andrological diseases require surgical repair or reconstruction of tunica albuginea, which envelops the corpora cavernosa penis. Despite intense research efforts involving a variety of biological materials, such as skin, muscle aponeurosis, human dura mater, tunica vaginalis, and pericardium, engineered tunica albuginea suitable for graft use is yet to be obtained. The study investigates microsurgical tunica albuginea allotransplantation in an animal model with the purpose of creation of an organ-specific tissue bank to store penile tissue, from cadaveric donors and male-to-female trans-sexual surgery, for allogeneic transplantation. Materials were tunica albuginea tissue explanted from 15 donor rats, cryopreserved at -80°C, gamma-irradiated, and implanted in 15 recipient rats, of which three rats were used as controls. Penile grafts were explanted at different time intervals; after macroscopic evaluation of the organ, the grafts were processed to morphological, histochemical, and immunohistochemical examinations by light microscopy. Detection of pro-inflammatory cytokines was also performed. Examination of the tunica albuginea allografts collected 1, 3, or 6 months after surgery and of control tunica albuginea fragments showed that tunica albuginea implants achieved biointegration with adjacent tissue at all-time points. The integration of cryopreserved rat tunica albuginea allografts, documented by our study, encourages the exploration of tunica albuginea allotransplantation in humans. In conclusion, the effectiveness and reliability of the tunica albuginea conditioning protocol described here suggest the feasibility of setting up a tunica albuginea bank as a further tissue bank.

Peyronie's disease and autoimmunity—a real-life clinical study and comprehensive review

INTRODUCTION

Although heavily investigated over the last decades, Peyronie's disease (PD) pathogenesis remains unclear.

AIM

We sought to investigate the association between PD and autoimmune diseases (ADs) in men seeking medical help for sexual dysfunction in the real-life setting.

METHODS

Complete sociodemographic and clinical data from a homogenous cohort of 1,140 consecutive Caucasian-European men were analyzed. Health-significant comorbidities were scored with the Charlson Comorbidity Index and ADs were stratified according to International Classification of Diseases, Ninth Revision classification.

MAIN OUTCOME MEASURES

Descriptive statistics and multivariate logistic regression models tested the association between ADs and PD.

RESULTS

PD was diagnosed in 148 (13%) of the 1,140 men; of PD patients, 14 (9.5%) had a comorbid AD; conversely, the rate of ADs in non-PD patients was significantly lower (χ(2) = 24.7; P < 0.01). Both patient age and AD comorbidity achieved multivariable independent predictor status for PD (odds ratio [OR]: 1.05; P < 0.01 and OR: 4.90; P < 0.01, respectively).

CONCLUSIONS

Our observational findings showed that ADs are highly comorbid with PD in a large cohort of same-race individuals seeking medical help for sexual dysfunction in the real-life setting.