Cutaneous blood supply of the penis

Twelve male cadaver specimens were injected with a latex solution to define the cutaneous blood supply of the penis. The cutaneous blood supply of the penile shaft is derived solely from a pair of axial arteries running in the dartos layer. Additional deep perforating arteries from the dorsal penile artery and corporal vessels supply the glans and subcoronal region. An understanding of this anatomy allows one to develop safely a variety of penile skin flaps for difficult reconstructive problems.     

Cardiovascular risk factors, erection disorders and endothelium dysfunction

Upon sexual stimulation, penile erection, occurring in response to the activation of pro-erectile autonomic pathways, is greatly dependent on adequate inflow of blood to the erectile tissue and requires coordinated arterial endothelium-dependent vasodilatation and sinusoidal endothelium-dependent corporal smooth muscle relaxation. Nitric oxide (NO) is the principal peripheral pro-erectile neurotransmitter which is released by both non-adrenergic, non-cholinergic neurons and the sinusoidal endothelium to relax corporal smooth muscle through the cGMP pathway. Any factors modifying the basal corporal tone, the arterial inflow of blood to the corpora, the synthesis/release of neurogenic or endothelial NO are prime suspects for being involved in the pathophysiology of erectile dysfunction (ED). In fact, conditions associated with altered endothelial function, such as ageing, hypertension, hypercholesterolemia and diabetes, may, by changing the balance between contractant and relaxant factors, cause circulatory and structural changes in penile tissues, resulting in arterial insufficiency and defect in smooth muscle relaxation and thus, ED. There is increasing evidence to suggest that ED is predominantly a vascular disease and may even be a marker for occult cardiovascular disease. Recent results illustrating the importance of endothelial dysfunction in the pathophysiology of different forms of experimental ED are discussed. These pathways may represent new potential treatment targets.     

La fracture de verge à Dakar. à propos de 25 cas

Objectives

To describe the epidemiological, clinical and therapeutic characteristics of penile fracture in the department of Urology-Andrology of h?pital général de Grand Yoff, Dakar, Sénégal.

Materials and methods

We reviewed the medical records of cases of penile fracture managed at the h?pital général de Grand Yoff from January 2001 to December 2011. The data of interest were: age at diagnosis, geographic origin, clinical presentation, surgical findings, treatment and outcomes.

Results

In ten years, 25 cases of penile fracture were found with an average of 2,5 cases per year and patients mean age of 36 years with 22 and 60 years as extremes. The circumstances of occurrence were mainly forced manipulation (52%) and coitus (32%). Pain associated with penile curvature, swelling localized to the penis or extending to the pubis or the perineum were the major clinical findings. A prompt emergency (mean time for providing care was 2 hours ranging from 45 minuts to 2 days) surgical explorationwith suture of the albuginea of the corpus cavernosum was the treatment in all cases.

Conclusion

Penile fracture is a relatively uncommon urological emergency in our setting. The diagnosis is easy, mostly based on clinical examination. A prompt and appropriate surgical management is the key to cosmetic and functional outcomes.     

The role of prostaglandins in penile erection

The balance of penile smooth muscle tone is finely controlled, with contractile factors acting in opposition to relaxant factors. The principal agents in this process are undoubtedly noradrenaline and nitric oxide. Prostaglandins probably have a crucial role in the 'fine tuning' of corporal smooth muscle tone. Their effects on control mechanisms in the healthy penis are more likely to be modulatory rather than direct.     

The biomechanics of erections: two- versus one-compartment pressurized vessel modeling of the penis

Previous biomechanical models of the penis simulated penile erections utilizing 2D geometry, simplified 3D geometry or made inaccurate assumptions altogether. These models designed the shaft of the penis as a one-compartment pressurized vessel fixed at one end when in reality it is a two-compartment pressurized vessel in which the compartments diverge as they enter the body and are fixed at two separate anatomic sites. This study utilizes the more anatomically correct two-compartment penile model to investigate erectile function. Simplified 2D and 3D models of the erect penis were developed using the finite element method with varying anatomical considerations for analyzing structural stresses, axial buckling, and lateral deformation. This study then validated the results by building and testing corresponding physical models. Finally, a more complex and anatomically accurate model of the penis was designed and analyzed. When subject to a lateral force of 0.5 N, the peak equivalent von Mises (EVM) stress in the two-compartment model increased by about 31.62%, while in the one-compartment model, the peak EVM stress increased by as high as 70.11%. The peak EVM stress was 149 kPa in the more complex and anatomically accurate penile model. When the perforated septum was removed, the peak EVM stress increased to 455 kPa. This study verified that there is significant difference between modeling the penis as a two- versus a one-compartment pressurized vessel. When subjected to external forces, a significant advantage was exhibited by two corporal based cavernosal bodies separated by a perforated septum as opposed to one corporal body. This is due to better structural integrity of the tunica albuginea when subjected to external forces.     

Does diabetes mellitus affect the progress of tolerance to isosorbide dinitrate (ISDN) in corporal tissue?

For erection to take place, the penile arteries and sinusoids have to dilate, thereby increasing the blood flow into the penis. There is increasing evidence that release of l-arginine derived nitric oxide (NO) from nonadrenergic-noncholinergic (NANC) nerves and from the sinusoidal endothelium is a major event in penile smooth muscle relaxation and promotes the endogenous formation of cyclic guanosine monophosphate (cGMP). Nitrovasodilators can be attributed to the activation of soluble guanylate cyclase, resulting in an increase in intracellular level of cyclic guanosine monophosphate, but prolonged exposure to high levels of nitroglycerine and other organic nitroesters induces tolerance against the cardiovascular effect. In this study, the aim was to determine the effect of diabetes on the corporal smooth muscle relaxant effect of ISDN and the effect of diabetes on the process of tolerance to the drug. For this purpose, alloxan-induced diabetic rabbits were used to form diabetes group. The responses of the corpus cavernous strips obtained from control and alloxan-induced diabetic rabbit were studied in organ chamber. In conclusion, prolonged in vitro exposure of corpus cavernosum strips obtained from control and diabetic groups to high concentrations of ISDN caused significant desensitization to the relaxant effect the drug. So, prolonged exposure of corporal tissue to the agents like nitroglycerine, used for treatment of impotence, may render ineffective the therapy in diabetic erectile impotence. However, intolerance to nitric oxide provides a rationale for the concept of using nitro oxide agents (like SNP) in the treatment of diabetic erectile dysfunction.     

Les lésions de l’urètre associées à une fracture des corps caverneux. A propos d’une série de 4 cas et revue de la littérature

Introduction

Urethral injury associated with corpora cavernosa fracture is a relatively uncommon form of urological trauma. Early diagnosis and immediate surgical repair are essential.

Patients and methods

Between January 1990 and December 2004, a total of 4 male patients with urethral injury associated with fracture of the corpora cavernosa were retrospectively studied from a series of 96 cases of penile fracture.

Results

The mean age of the patients was 36.5 years (range: 27–45 years). Urethral bleeding was noted in all patients. Immediate surgical repair via a penile circular subcoronal incision was performed in all cases. Two partial urethral injuries associated with a unilateral corpus cavernosum lesion were identified. In the other cases, total urethral injury was associated with bilateral rupture of the corpora cavernosa. The tunica albuginea defect was closed and the urethral laceration repaired over a urethral catheter. With a mean follow-up of 2.5 years, 2 short urethral strictures were observed and were managed non-operatively with good outcome.

Comments

Secondary urethral lesions associated with corpora cavernosa fracture most frequently affect young adults. In North African countries, forced self-manipulation of an erect penis is the most frequent cause, but the associated urethral lesion is usually related to vaginal intercourse. The diagnosis can generally be made on the basis of history and physical examination alone. Blood at the meatus or haematuria or voiding difficulties suggest associated trauma to the urethra [4]. Additional imaging examinations are rarely required. The standard treatment is prompt surgical exploration, evacuation of haematoma, and primary repair of the urethral and corpora cavernosa defects. Late complications after surgical repair are penile curvature and pain during coitus. They are usually attributable to a residual fibrotic area.

Conclusion

Urethral injury associated with corpora cavernosa fracture usually has typical signs. The mechanism of trauma is very suggestive. Early surgical treatment is the only guarantee of a satisfactory functional result.     

Penile revascularization in the treatment of vasculogenic impotence

Arterial insufficiency is the most common organic cause of impotence. The diagnosis can be established on a clinical basis through the use of Doppler probe evaluation of the penile pulses, penile blood pressure measuring, and nocturnal penile tumescence monitoring. The diagnosis may be confirmed by internal pudendal arteriography. Through microsurgical arterial revascularization, a 60 percent long-term success rate has been achieved. Two early and two late failures suggest the need for improved patient selection and confirm the progressive nature of the arteriosclerotic process.     

Cancer du pénis au Sénégal : aspects cliniques et thérapeutiques

Objective

Describe the clinical and therapeutic aspects of penile cancer in Senegal.

Patients and methods

We conducted a retrospective study that looked at records of patients followed for penile cancer in the urology service of the Aristide Le Dantec hospital between January 2000 and December 2011.

Results

Eight patients of mean age of 51.5, with extremes of 27 and 77 have been identified. They were all circumcised in childhood. Clinical examination had highlighted ulcerated and burgeoning tumor affecting glans and a part of the penis in five cases; in two cases, it concerned the entire penis, while one case was limited to the glans. Patients were thus classified according cT3 (three cases) and cT1 (one case). The histological type of the tumour was, in all patients, squamous cell carcinoma. There was no secondary location in the thoracic-flow-pelvic scanner. Therapeutically, a partial penectomy was conducted in five cases, a total penectomy with ganglionic flushing in one case. Two patients refused surgical treatment. There was no recurrence in five patients who underwent a partial amputation of the penis. Overall survival was therefore of 83.3 for surgical patients.

Conclusion

cancer of the penis is rare in Senegal. The support is delicate because of late diagnosis associated with advanced lesions, hence the importance of awareness of the population.     

Penile curvatures

Penile curvatures are common. They are caused by tethering inelastic tissues that can be from the skin externally, from the congenital fibrous tissue of hypospadias and epispadias, and from inelastic tunica albuginea as in fractures, trauma, or Peyronie's disease. At the present time, with sexual organs exposed in photographs, human sexuality talked about with more freedom, and sexual experiences more open, a great deal of mental stress and anxiety can be produced by penile curvatures. Adjunct to this are impotency and other sexual problems. Surgical treatment is generally curative with grafts, flaps, excision of tunica albuginea, or repositioning and coaptation of the corporal bodies. Also, the use of a sex therapist can offer additional aid to the physician and realistic acceptance by the patient. More attention should be given to the patient with this problem. It is not well recognized by most physicians, and therefore, patients may suffer needlessly in silence without adequate help.     

An epidermal cyst of the penis after distal hypospadias surgery: a case report

Background

Epidermoid cyst is a benign tumor that can occur anywhere in the body but is rarely seen in the penis. Congenital and previous penile surgeries have been reported to be involved in the etiology of the disease, which is usually asymptomatic. Here we describe a case of a patient with a penile epidermoid cyst, which occurred in the circumcision line on the left side of his penis, and urethral dehiscence following hypospadias surgery.

Case summary

A 3-year-old white boy who underwent primary distal hypospadias surgery 1.5?years ago presented with a slowly growing mass in the left ventrolateral portion of the penile circumcision line and urethral dehiscence. The histology of the excised mass revealed an epidermal inclusion cyst. Since then, he has remained healthy.

Conclusions

Epidermal inclusion cyst as a complication of hypospadias surgery is a very rare situation. The diagnosis is made histologically and surgical excision is sufficient for treatment.

     

Doctors in the decent society: torture, ill-treatment and civic duty

How should physicians act when faced with corporal punishment, such as amputation, or torture? In most cases, the answer is clear: international law, UN resolutions and universal codes of medical ethics absolutely forbid physicians from countenancing torture and corporal punishment in any form. An acute problem arises, however, in decent societies, but not necessarily liberal states, that are, nonetheless, welcome in the world community. The decent society is often governed, in whole or in part, by religious laws, and while these states abridge various human rights they are peace loving, generally tolerant, and offer their citizens wide avenues for political participation. Under these circumstances the prohibition against corporal punishment and torture weakens, often compelling physicians to participate. This is true in two cases. In Rawls’ hypothetical nation of Kazanistan, Islamic law is the order of the day, and amputations and corporal punishment play an integral part in the execution of traditional Islamic justice. In Israel, torture is sometimes used to elicit the information needed to thwart impending terror attacks. In each case, a physician's participation is essential. In light of the near universal condemnation that accompanies torture and corporal punishment, physicians can only appeal to norms anchored in collective well‐being and concern for life that override respect for human dignity in these societies. Western societies have consistently rejected this reasoning, but it is part and parcel of life in the decent society.     

The "cricket bat" flap: a one-stage free forearm flap phalloplasty

Total and subtotal penile reconstruction represents a major surgical challenge. We present a new method and two illustrative cases using a modified design of the radial forearm free-tissue transfer: the "cricket bat" flap.     

Scanning electron microscopy of celluloid replicas of the penile spines of the domestic cat

Using scanning electron microscopy of celluloid impressions the feline penile spines in the adult and after castration were studied. A solution of celluloid in a mixture of amyl acetate was placed on the glans. The replica thus obtained was coated with gold in an ion-spatter coater, and observed under a scanning electron microscope (JSM-1). The structure of the penile spines and fine arrangement of superficial cells of the epidermis could be observed three-dimensionally. Since the penile spines are the only known external indicators of the level of male hormone in cats, and since their fine structure can be observed without excising the penile skin, this simple method can be applied for diagnosis of fertility of the male cat.     

Ca2+-activated Cl- channels in corpus cavernosum smooth muscle: a novel mechanism for control of penile erection.

Little is known of the excitatory mechanisms that contribute to the tonic contraction of the corpus cavernosum smooth muscle in the flaccid state. We used patch-clamp electrophysiology to investigate a previously unidentified inward current in freshly isolated rat and human corporal myocytes. Phenylephrine (PE) contracted cells and activated whole cell currents. Outward current was identified as large-conductance Ca(2+)-activated K(+) current. The inward current elicited by PE was dependent on the Cl(-) gradient and was inhibited by niflumic acid, indicative of a Ca(2+)-activated Cl(-) (Cl(Ca)) current. Furthermore, spontaneous transient outward and inward currents (STOCs and STICs, respectively) were identified in both rat and human corporal myocytes and derived from large-conductance Ca(2+)-activated K(+) and Cl(Ca) channel activity. STICs and STOCs were inhibited by PE and A-23187, and combined 8-bromoadenosine cAMP and 8-bromoadenosine cGMP decreased their frequency. When studied in vivo, chloride channel blockers transiently increased intracavernosal pressure and prolonged nerve-evoked erections. This report reveals for the first time Cl(Ca) current in rat and human corpus cavernosum smooth muscle cells and demonstrates its key functional role in the regulation of penile erection.     

Carcinoma in situ of the urinary bladder. Clinical presentation, cytologic pattern and stromal changes

The clinical presentation, cytologic pattern and stromal changes in the cystectomy specimen were studied in a group of 26 patients with carcinoma in situ of the urinary bladder who underwent cystectomy. Only cases in which the nuclear area of the carcinoma in situ cells was over 80 sq micron (large-cell type) were included in this study. The results indicate that the cells from large-cell carcinoma in situ of the bladder exfoliate easily, resulting in a cytologic pattern of predominantly single, highly abnormal cancer cells. Due to the increased exfoliation of the affected epithelium, the bladder stroma is focally denuded; therefore, while cytology may be strongly positive for malignancy in these cases, the histologic diagnosis can be falsely negative when only denuded stroma is biopsied. The edematous stroma causes complaints of "cystitis." The neoplastic urothelium may involve contiguously related epithelial surfaces. When the lesion extends into the prostatic ducts, the patient can have "pseudoprostatitis" complaints. Urethral extension may give penile voiding pain. In one female patient, involvement of the vagina and vulva was found. Carcinoma in situ may develop in patients with papillary low-grade bladder carcinoma during follow-up, with a concomitant shift in the cytologic and clinical patterns; this deserves the consideration and attention of the cytologist and the clinician due to its serious clinical implications.     

Secondary penile tumours revisited

Objective

To highlight the salient features of metastatic malignancies involving the penis, with special reference to the primary tumour sites, metastatic mechanisms, clinical features, differential diagnosis, treatment and prognosis.

Methods

A comprehensive search of the literature was performed using MEDLINE and EMBASE, using the keywords 'penis', 'secondary malignancy', 'metastasis' and 'malignant priapism' to identify reviews and case reports of secondary penile malignancy. A case of rare clinical presentation of metastatic penile lesion is presented along with the review of the literature.

Conclusion

Secondary malignancy of the penis is a rare clinical entity, despite the rich vascularisation of this organ. The majority of metastatic lesions take their origin from the neighbouring genito-urinary organs, mainly prostate and bladder. These lesions are often associated with disseminated malignancy and hence have a poor outcome. Nodular or ulcerative lesions involving the corpora cavernosa or priapism are the main modes of clinical presentation. In most cases, only palliative or supportive therapy is indicated.

     

Soft tissue tumors of the penis: a review

Penile soft tissue tumors comprise 5% of tumors at this site and most have been reported as isolated case reports. The purpose of this review is to aid the practicing surgical pathologist in distinguishing penile soft tissue tumors, such as sarcomatoid squamous cell carcinoma, from other prognostically and therapeutically important entities in the differential diagnosis. Clinical presentation, management, prognosis and factors influencing behavior are reviewed. The immunohistochemical profiles and salient morphologic clues that may help distinguish penile spindle cell tumors from sarcomatoid carcinomas are evaluated. Soft tissue tumors of the penis may be classified as benign or malignant, as superficial or deep and in terms of age at presentation. All are rare. The most common benign soft tissue tumors that affect the penis are vascular neoplasms, followed by tumors of neural, myoid and fibrous origin. Among reported cases, the most frequent malignant penile soft tissue tumors are Kaposi sarcoma and leiomyosarcoma. Correctly diagnosing penile soft tissue tumors is imperative, because the biologic behavior and the clinical management of these neoplasms vary considerably. Distinguishing sarcomas from sarcomatoid carcinoma and melanoma is particularly important. Accurate diagnosis is best facilitated by consideration of all available aspects of the case, including clinical information, histopathologic findings and immunohistochemical results.     

Urogenital system of the spotted hyena (Crocuta crocuta Erxleben): a functional histological study

The unique urogenital anatomy and histology of female spotted hyenas (Crocuta crocuta Erxleben) was reexamined to identify adaptations of "structure" that enable/facilitate urination, mating, and parturition through the clitoris. Unusual features of penile anatomy required for meeting ceremonies and successful mating through a clitoral point of insertion were also examined. As reported previously, the upper urogenital tract of the female spotted hyena is typical of other carnivores and consists of the oviducts, uterine horns, uterine body, and vagina. An anatomically defined cervix is absent, even though a histologically defined transition zone between the uterine body and vagina was demonstrated. Adaptive features of the upper genital tract were a helical-shaped uterine cavity, extensive smooth muscle in the uterus and vagina, and a newly discovered submucosal mucous urogenital gland (SMUG) located immediately caudal to the vagina. The extensive smooth muscle facilitates the expulsion of the large pups at parturition through the recurved birth canal. Secretions of the SMUG provide lubrication and protection for the urogenital mucosa during mating and parturition. Two types of "erections" are suggested by behavioral observations: the common hemodynamic erection required for insertion and thrusting by the male, and phallic "flipping" that commonly occurs earlier in the mating sequence and is sometimes seen during meeting ceremonies. Phallic "flipping" appears to be accomplished by the coordinated contractions of the large ischiocavernosus and retractor muscles acting on the semirigid organ. The extremely thick tunica albuginea and interstitial collagen of the common corporal body of the penis and clitoris gives the flaccid phallus some degree of rigidity even in the resting state in males and nulliparous females. Phallic "flipping" implies a hinge region in which flexibility is the key feature. Such a proximal hinge region of the male and female phallus was defined and was notable for its diminished collagen content. The urogenital sinus traversing the clitoris was specialized for distensibility, thus facilitating receipt of the penis during mating and for passage of the infant to the tip of the glans clitoris, where it emerges at parturition. The morphology of the glans penis is notable for the tapered common corporal body that extends to the distal tip of the glans. This adaptation is suggested to be required for a clitoral (as opposed to a vaginal) point of insertion during mating. Finally, additional segments of erectile tissue devoid of a thick collagenous capsule were demonstrated in the glans penis and glans clitoris, which appear to account for the "partially-locking" of the male into the female during the late stages of a mating sequence. Taken together, it is evident that the unusual sexual behaviors of the male and female spotted hyenas are facilitated by unique structural modifications of the relevant organs.     

Mesenchymal stem cells alone or ex vivo gene modified with endothelial nitric oxide synthase reverse age-associated erectile dysfunction

Mesenchymal stem cells (MSCs) can be used in adult stem cell-based gene therapy for vascular diseases. To test the hypothesis that MSCs alone or endothelial nitric oxide synthase (eNOS)-modified MSCs can be used for treatment of erectile dysfunction (ED), syngeneic rat MSCs (rMSCs) were isolated, ex vivo expanded, transduced with adenovirus containing eNOS, and injected into the penis of aged rats. Histological analysis demonstrated that rMSCs survived for at least 21 days in corporal tissue after intracavernous injection, and an inflammatory response was not induced. Intracavernous administration of eNOS-modified rMSCs improved the erectile response in aged rats at 7 and 21 days after injection. The increase in erectile function was associated with increased eNOS protein, NOS activity, and cGMP levels. rMSCs alone increased erectile function of aged rats at day 21, but not at day 7, with the transplanted cells exhibiting positive immunostaining for several endothelial and smooth muscle cell markers. This change in rMSC phenotype was accompanied by upregulation of penile eNOS protein expression/activity and elevated cGMP levels. These findings demonstrate that an adenovirus can be used to transduce ex vivo expanded rMSCs to express eNOS and that eNOS-modified rMSCs improve erectile function in the aged rat. Intracavernous injection of unmodified wildtype rMSCs improved erectile function 21 days after injection through mechanisms involving improved endothelium-derived NO/cGMP signaling and rMSC differentiation into penile cells expressing endothelial and smooth muscle markers. These data highlight the potential clinical use of adult stem cell-based therapy for the treatment of ED.