Anatomical studies of the fetal genitalia: surgical reconstructive implications

Timing of androgen receptor disruption and estrogen exposure underlies a spectrum of congenital penile anomalies

Congenital penile anomalies (CPAs) are among the most common human birth defects. Reports of CPAs, which include hypospadias, chordee, micropenis, and ambiguous genitalia, have risen sharply in recent decades, but the causes of these malformations are rarely identified. Both genetic anomalies and environmental factors, such as antiandrogenic and estrogenic endocrine disrupting chemicals (EDCs), are suspected to cause CPAs; however, little is known about the temporal window(s) of sensitivity to EDCs, or the tissue-specific roles and downstream targets of the androgen receptor (AR) in external genitalia. Here, we show that the full spectrum of CPAs can be produced by disrupting AR at different developmental stages and in specific cell types in the mouse genital tubercle. Inactivation of AR during a narrow window of prenatal development results in hypospadias and chordee, whereas earlier disruptions cause ambiguous genitalia and later disruptions cause micropenis. The neonatal phase of penile development is controlled by the balance of AR to estrogen receptor α (ERα) activity; either inhibition of androgen or augmentation of estrogen signaling can induce micropenis. AR and ERα have opposite effects on cell division, apoptosis, and regulation of Hedgehog, fibroblast growth factor, bone morphogenetic protein, and Wnt signaling in the genital tubercle. We identify Indian hedgehog (Ihh) as a novel downstream target of AR in external genitalia and show that conditional deletion of Ihh inhibits penile masculinization. These studies reveal previously unidentified cellular and molecular mechanisms by which antiandrogenic and estrogenic signals induce penile malformations and demonstrate that the timing of endocrine disruption can determine the type of CPA.

Sexualmedizinische Aspekte bei Intersexsyndromen

Disorders of somatosexual development that lead to ambiguous genitalia occur in one from 3,000-5,000 newborns. Parents and health care professionals are confronted with a number of crucial questions: to what sex should the child be assigned, what is the appropriate treatment in terms of hormonal and surgical interventions, when and how should these take place, and what impact do they have on the development of gender identity (GI), psychosexual well-being and fertility? This paper reviews the etiology, treatment and outcome in terms of GI and sexual health for the following syndromes: congenital adrenal hyperplasia (CAH), complete and partial androgen insensitivity (cAIS, pAIS), and pure and mixed gonadal dysgenesis (pGD, mGD). Emphasis is focussed on the current discussion involving the timing and extent of genital surgery. Finally, a procedure is introduced that covers the sexual-medical needs of patients, parents and health care professionals.

Minimal surgical intervention in the management of intersex conditions

The surgical correction of ambiguous genitalia has been a significant part of treatment for intersex conditions for the last 50 years, based on the belief that the child will be psychologically damaged by the uncorrected appearance. Despite widespread adoption of this policy, there is no evidence in the literature to support this approach. More commonly, the primary indication appears to be for the relief of parental anxiety. However, patients are increasingly expressing dissatisfaction with previous management, arguing that surgery should only be performed for strictly defined medical indications. Surgery may comprise treatment for the absent or shortened vagina, or for the correction of virilised external genitalia. The timing of such surgery is controversial, with many surgeons believing that a 'one-stage' procedure in infancy is appropriate. However, given that the vast majority of patients require further surgery at adolescence, others argue that deferral of vaginal surgery until after puberty is more appropriate. The role of clitoral surgery is contentious with many questioning the necessity of any operation in childhood for cosmesis which may impair subsequent sexual function. Despite claims that newer surgical techniques lead to a better result than previously, there remains little information in the literature regarding long-term functional outcomes following clitoral reduction procedures. Alternatives to vaginal and clitoral surgery are considered in this article. Vaginal operations should almost always take place at adolescence, given the poor outcomes of early surgery. When clitoral operations are performed, this should be for severely virilised individuals, with surgery best avoided for those with only mild or moderate virilisation.

Hypospadias surgery: when, what and by whom?

Hypospadias is repaired by paediatric surgeons, paediatric urologists, adult reconstructive urologists and plastic surgeons. This review is unique in representing all four specialities, to provide a unified policy on the management of hypospadias. The surgeon of whichever speciality should have a dedicated interest in this challenging work, ideally having an annual volume of at least 40-50 cases. The ideal time for primary repair is at 6-12 months old, although when this is not practicable there is another opportunity at 3-4 years old. A surgical protocol is presented which emphasises both functional and cosmetic refinement. Using a logical progression of a very few related procedures allows the reliable correction of almost any hypospadias deformity. A one-stage repair is used when the urethral plate does not require transection and its axial integrity can be maintained. Occasionally, when the plate is of adequate width and depth, it can be tubularized directly using the second stage of the two-stage repair. When (usually) the urethral plate is not adequately developed and requires augmentation before it can be tubularized, then that second-stage procedure is modified by adding a dorsal releasing incision +/- a graft (alias Snodgrass and 'Snodgraft' procedures). The two-stage repair offers the most reliable and refined solution for those patients who require transection of the urethral plate and a full circumferential substitution urethroplasty. From available evidence this protocol combines excellent function and cosmesis with optimum reliability. Nevertheless, it would be complacent to assume that these gratifying results will be maintained into adult life. We therefore recommend that there is still a need for active follow-up through to genital maturity.