Template:Search infobox Steven C. Campbell, M.D., Ph.D.
Intersex surgery is one of several terms referring to surgery performed to correct birth defects or early injuries of the genitalia, primarily for the purposes of making the appearance more normal and to reduce the likelihood of future problems. The recent history of intersex surgery has been characterized by controversy after publicized reports that surgery failed to achieve the desired outcomes in many cases. Timing of surgery (infancy, adolescence or adult age) has also been controversial.
Intersex surgery is a form of genital reconstructive surgery, which also includes surgery performed for the purpose of transforming normal adult genitalia of one sex to that of the other (discussed elsewhere as sex reassignment surgery).
Purposes of genital reconstructive surgery
The goals of surgery vary with the type of abnormality but usually include one or more of the following:
- to improve the potential for fertility
- to provide an outlet for menstruation
- to prevent or reduce urinary tract infections or obstruction
- to reduce risk of cancer in abnormal gonads.
- to close open wounds or exposed internal organs
- to improve urinary or fecal continence.
- to alleviate parental distress over the atypical genital appearance.
- to make the appearance more normal for the person's sex of rearing
- to reduce effects of abnormal genitalia on psychosexual development and gender identity
- to improve the potential for adult sexual relationships
Types of surgery
Genital reconstructive surgery can be divided into masculinizing surgical procedures intended to make the genitalia more like those of normal males, and feminizing surgical procedures intended to make the genitalia more like those of normal females.
- There are several techniques or approaches for each procedure.
- Some of the variations of procedure are needed for varying degrees of severity of the abnormalities.
- Some of the different techniques have been devised to reduce complications associated with earlier techniques.
- Techniques and procedure have evolved over the last 60 years. Some have been considered obsolete for decades.
- Some children need a combination of procedures.
- For example, a severely undervirilized boy with a pseudovaginal perineoscrotal hypospadias may have midline urogenital closure, third degree hypospadias repair, chordee release and phalloplasty, and orchiopexy performed. A severely virilized girl with congenital adrenal hyperplasia (CAH) may undergo both a clitoral reduction and a vaginoplasty.
Masculinizing surgical procedures
Orchiopexy and hypospadias repair are the most common types of genital corrective surgery performed in infant boys, but most of these boys have no other abnormalities and are not considered to have an intersex condition. Undervirilized boys typically have at least one of these two procedures performed in addition to others described below.
Types of undervirization and malformation for which some type of masculinizing surgery has been performed most often in the last 50 years are:
- the configuration of ambiguous genitalia referred to as pseudovaginal perineoscrotal hypospadias (PPSH)
- the Reifenstein type of partial androgen insensitivity syndrome
- gonadal dysgenesis disorders such as mixed gonadal dysgenesis and testicular dysgenesis
- idiopathic (specific cause not determined)
- birth defects of male genitalia
- bladder exstrophy and epispadias spectrum
- chordee (simple or as part of undervirilization)
- concealed penis
The disorders above comprised over 90% of reported surgical series from North America and Europe. In a few parts of the world 5-alpha-reductase deficiency or defects of testosterone synthesis, or even rarer forms of intersex account for a significant portion of cases but these are rare in North America and Europe. Masculinizing surgery for completely virilized genetic females with CAH is even rarer.
Orchiopexy for repair of undescended testes (cryptorchidism) is the second most common surgery performed on infant male genitalia (after circumcision). The surgeon moves one or both testes, with blood vessels, from an abdominal or inguinal position to the scrotum. If the inguinal canal is open it must be closed to prevent hernia.
- Potential problems: Maintaining the blood supply is the major challenge. If vessels cannot be stretched into the scrotum, or are separated and cannot be reconnected, a testis will die and atrophy.
Hypospadias repair is a relatively simple single procedure if the hypospadias is first or second degree (urethral opening on glans or shaft respectively) and the penis is otherwise normal. Repair of a third degree hypospadias (urethral opening on perineum or in urogenital opening) is more challenging, may be done in stages, and has a significant rate of complications and unsatisfactory outcomes. (Glassberg, 1999)
- Potential problems: For severe hypospadias (3rd degree, on perineum) constructing a urethral tube the length of the phallus is not always successful, leaving an opening (a "fistula") proximal to the intended urethral opening. Sometimes a second operation is successful, but some boys and men have been left with chronic problems with fistulas, scarring and contractures that make urination or erections uncomfortable.
Urogenital closure describes closure of any midline opening at the base of the penis. In severe undervirilization a boy may have a "pseudovaginal pouch" or a single urogenital opening in the midline of the perineum.
- Potential problems: The most complicated aspect of closure involves moving the urethra to the phallus if it is not already there (i.e., repairing a perineal hypospadias). Fistulas and scarring are the main risks.
Gonadectomy (also referred to as "orchiectomy") refers to removal of the gonads. This is done in three circumstances. (1) If the gonads are dysgenetic testes or streak gonads and at least some of the boy's cells have a Y chromosome, the gonads or streaks must be removed because they are nonfunctional but have a relatively high risk of developing gonadoblastoma. (2) In rare instances when an XX child with completely virilizing congenital adrenal hyperplasia (Prader stage 5) is being raised as a male, the ovaries must be removed before puberty to prevent breast development and/or menstruation. (3) Gonadectomy would be needed for the equally rare instance of a child with true hermaphrodite virilized enough to raise as male: any ovary or ovotestis would need to be removed. (Manuel, 1976)
- Potential problems: Gonadectomy involves little risk beyond that of any abdominal surgery.
Chordee release refers to cutting of ventral penile skin and connective tissue to free and straighten the penis. A mild chordee, manifest as a well-formed penis "bent" downward by subcutaneous connective tissue, may be an isolated birth defect easily repaired by releasing some of the inelastic connective tissue on the ventral side of the shaft. In a complete chordee the phallus is "tethered" downward to the perineum by skin. A more severe chordee is often accompanied by a hypospadias and sometimes by severe undervirilization: a perineal "pseudovaginal pouch" and bifid ("split") scrotum with an undersized penis. This combination, referred to as pseudovaginal perineoscrotal hypospadias, is in the spectrum of ambiguous genitalia due to a number of conditions.
- Potential problems: Scarring and contracture are occasional complications, but most unsatisfactory outcomes occur when a severe hypospadias needs to be repaired as well. Long-term complications can include fistulas between colon or upper rectum and skin or other cavities, or between urethra and perineum.
Cloacal repair is among the most complex of the surgeries described here. Bladder exstrophy or more severe cloacal exstrophy refers to a major birth defect involving inadequate closure and incomplete midline fusion of multiple pelvic and perineal organs as well as the front of the pelvis and lower abdominal wall. The penis and scrotum are often widely bifid (the two embryonic parts unjoined). The penis often cannot be salvaged, although the testes can be retained. Repair may involve closure of the bladder, closure of the anterior abdominal wall, colostomy (temporary or permanent) with reconstruction of the rectum. If the halves of the phallus cannot be joined, they may be removed. The smallest defect in this spectrum is an epispadias. Surgical repair for this is primarily a phalloplasty. (Schober, 2002)
- Potential problems: Surgery for the more severe degrees of cloacal exstrophy is extensive and usually multistage. A variety of potential problems and complications can occur, including need for long-term colostomy or vesicostomy. In many cases a functional penis cannot be created. Scarring is often extensive and the lower torso severely disfigured even with fairly good outcomes.
Phalloplasty is a general term for any reconstruction of the penis itself, especially for more unusual types of injuries, deformities, or birth defects. The principal difficulty is that erectile tissue is not easily constructed and this limits the surgeon's ability to make more than minor size changes. Construction of a narrow tube lined with mucosa (a urethra) is a similar challenge.
- Potential problems: Minor revisions of the skin are rarely followed by problems. More complicated reconstruction may result in scarring and contracture, which can distort the shape or curvature of the penis, or interfere with erections or make them painful.
Hysterectomy is removal of a uterus. It is rare that a uterus or mullerian duct derivatives would need to be removed from a child being raised as a boy. The most common scenario is accidental discovery of persistent mullerian derivatives or a small uterus during abdominal surgery of a normal boy for cryptorchidism, appendectomy, or bowel disease. Removal would not involve genital surgery. A rarer indication would be that of a completely virilized XX child with congenital adrenal hyperplasia (Prader stage 5) being raised as a male; ovaries and uterus must be removed to prevent breast development and menstruation by early adolescence.
- Potential problems: Risks are simply those of abdominal surgery.
Testicular prostheses are saline-filled plastic ovoids implanted in the scrotum. They have no function except to provide the appearance and feel of testes. Several sizes are available, but most are implanted in adolescence to avoid repeated procedures to implant larger sizes at puberty. Prostheses made of silastic are no longer available due to safety and perception-of-safety concerns.
- Potential problems: Foreign body reactions, rarely with infection or erosion of scrotal skin, are minimal but constitute the most significant complication.
Penile augmentation surgery is surgery intended to enlarge a small penis. Early attempts in the 1950s and 1960s involved constructing a tube of non-erectile flesh extending a small penis but the penis did not function. In recent years a small number of urologists have been offering an augmenation procedure that involves moving outward some of the buried components of the corpora so that the penis protrudes more. The girth is augmented with transplantation of the patient's fat. This procedure is designed to preserve erectile and sexual function without surgically altering the urethra. This type of surgery is not performed on children and primarily produces a small increase in the size of a normal penis, but would be less likely to produce a major functional change in a severe micropenis.
- Potential problems: Reabsorption of the fat is common. Scarring resulting in interference with erectile function is less likely but more damaging.
Concealed penis is the term used to describe a normal penis buried in suprapubic fat. In most cases, when the fat is depressed with the fingers, the penis is seen to be of normal size. This is common in overweight boys before the penile growth of puberty. Surgical techniques have been devised to improve it. (Casale, 1999)
- Potential problems: The most common difficulty is recurrence with further weight gain. Scarring can occur.
Feminizing surgical procedures
In the last 50 years, the following procedures were most commonly performed for the following intersex conditions and birth defects in order to make the genitalia more like those of normal females:
- virilization due to congenital adrenal hyperplasia
- malformations of genitalia in genetic females
- urogenital sinus malformation
- cloacal exstrophy
- conditions involving severe undervirilization or malformations of genetic males, or infants with mixed genetic sex, to be assigned and raised as girls
- gonadal dysgenesis (various forms)
- partial and complete androgen insensitivity syndrome
- cloacal and bladder exstrophy
There are rarer causes of virilization of genetic females or undervirililizaton of genetic males (see intersex for a fuller list), as well as some less easily categorized types of intersex conditions or other malformations of the genitalia. In the last decade, feminizing surgery to support reassignment of genetic males with non-ambiguous micropenis has been largely discontinued, and surgical reassignment of genetic males with exstrophy or other severe malformations or injuries is diminishing. See history of intersex surgery.
Clitorectomy describes amputation or removal of most of the clitoris, including glans, erectile tissue, and nerves. This procedure was the most common clitoral surgery performed prior to 1970, but was largely abandoned by 1980 because it usually resulted in loss of clitoral sensation.
- Potential problems: The primary effect of this surgery, not surprisingly, is a drastic reduction in ability to experience orgasm. The appearance is not very normal. Regrowth of unwanted erectile tissue has sometimes presented problems.
Clitoroplasty, like phalloplasty, is a term that encompasses any surgical reconstruction of the clitoris, such as removal of the corpora. Clitoral recession and reduction can both be referred to as clitoroplasty.
- Potential problems: Major complications can include scarring, contractures, loss of sensation, loss of capacity for orgasm, and unsatisfactory appearance.
Clitoral recession involves the repositioning of the erectile body and glans of the clitoris farther back under the symphysis pubis and/or skin of the preputium and mons. This was commonly done from the 1970s through the 1980s to reduce protrusion without sacrificing sensation. Outcomes were often unsatisfactory, and it fell into disfavor in the last 15 years. (Rangecroft, 2001)
- Potential problems:Unfortunately the subsequent sensations were not always pleasant, and erection could be painful. Adults who had a clitoral recession in early childhood often report reduced capacity for enjoyment of sexual intercourse, though similar women who had not had surgery also report a high rate of sexual dysfunction. (Minto, 2003)
Clitoral reduction was developed in the 1980s to reduce size without reducing function. Lateral wedges of the erectile tissue of the clitoris are removed to reduce the size and protrusion. The neurovascular tissue is carefully spared to preserve function and sensation. Nerve stimulation and sensory responses are now often performed during the surgery to confirm function of the sensory nerves. (Chase, 1996; Rangecroft, 2001))
- Potential problems: The degree to which the goal of preserving sexual sensations is attained is a subject of controversy. Many of the children who have had the newer versions of this procedure have not yet become adults.
Vaginoplasty, the construction or reconstruction of a vagina, can be fairly simple or quite complex, depending on the initial anatomy. If a normal internal uterus, cervix and upper vagina (the mullerian derivatives) exist, and the outer virilization is modest, surgery involves separating the fused labia and widening the vaginal introitus. With greater degrees of virilization, the major challenge of the procedure is to provide a passage connecting the outer vaginal opening to the cervix which will stay wide enough to allow coitus. XY girls or women with partial androgen insensitivity syndrome will have a blind vaginal pouch of varying degrees of depth. Sometimes this can be dilated to a usable depth. Sometimes surgery is performed to deepen it.
The most challenging surgery with the highest complication rate is construction of an entirely new vagina (a "neovagina"). The most common instance of this is when a child will be assigned and raised as a female despite complete virilization, as with Prader 5 CAH, or (in the past) when a genetic male infant with a severely defective penis was reassigned as a female. One method is to use a segment of colon, which provides a lubricated mucosal surface as a substitute for the vaginal mucosa. Another is to line the new vagina with a skin graft. (Creighton, 2001; Rink, 1998; Schnitzer, 2001)
- Potential problems: Stenosis (narrowing) of the constructed vagina is the most common long-term complication and the chief reason that a revision may be required when a girl is older. When a neovagina is made from a segment of bowel, it tends to leak mucus; when made with a skin graft, lubrication is necessary. Less common complications include fistulas, uncomfortable scarring, and problems with urinary continence. (Alizai, 1999; Lobe, 1987; Minto, 2003)
Gonadectomy refers to removal of the gonads. If the gonads are dysgenetic testes or streak gonads and at least some of the cells have a Y chromosome, the gonads or streaks must be removed because they are nonfunctional but have a relatively high risk of developing gonadoblastoma. If the gonads are relatively "normal" testes, but the child is to be assigned and raised as female, (e.g., for intersex conditions with severe undervirilization, or major malformations involving an absent or unsalvageable penis) they must be removed before puberty to prevent virilization from rising testosterone. Testes in androgen insensitivity are a special case: if there is any degree of responsiveness to testosterone, they should be removed before puberty. On the other hand, if androgen insensitivity is complete, the testes may be left to produce estradiol (via testosterone) to induce breast development, but there is a slowly increasing risk of cancer in adult life. Streak gonads without a Y chromosome cell line need not be removed but will not function. Finally, the gonads in true hermaphroditism must be directly examined; abnormal gonads with Y line or potential testicular function should be removed but in rare instances a surgeon may try to preserve the ovarian part of an ovotestis. (Manuel, 1976)
- Potential problems: Gonadectomy involves little risk beyond that of any abdominal surgery.
Cloacal exstrophy and bladder exstrophy repair is needed regardless of the sex of assignment or rearing. Simple bladder exstrophy in a genetic female does not usually involve the vagina. Cloacal exstrophy in a genetic female usually requires major surgical reconstruction of the entire perineum, including bladder, clitoris, symphysis pubis, and both the vaginal introitus and urethra. However, the uterus and ovaries are normally formed. Severe bladder exstrophy or cloacal exstrophy in genetic males often renders the phallus widely split, small, and unsalvageable. The scrotum is also widely split, though testes themselves are usually normal. From the 1960s until the last decade, many of these infants were assigned and raised as females, with fashioning of a vagina and gonadectomy as part of the perineal reconstruction. (Schober, 2002)
- Potential problems:Surgery for the more severe degrees of cloacal exstrophy is extensive and usually multistage. A variety of potential problems and complications can occur, including need for long-term colostomy or vesicostomy. Creating a functional urethra is difficult and poor healing, with scarring, stricture, or fistula can require a vesicostomy to prevent urinary incontinence. Construction of a functional anal sphincter can be equally difficult when this has been disrupted as well. Functional problems can warrant a temporary or long-term colostomy. The added challenge for the most severely affected genetic females, and for genetic males who are being raised as females, is construction of a neovagina. Scarring is extensive and the lower torso disfigured even with the best outcomes. Finally, it has become apparent in recent years that some genetic males (without intersex conditions) who are reassigned and raised as females have not developed a female gender identity and have sought reassignment back to male. (Reiner, 2004)
Controversies and unsettled questions
Management practices for several types of intersex conditions and other abnormalities and injuries of the genitalia have evolved over the last 50 years. In the last decade several of the surgical practices have become the subject of public and professional controversy. See History of intersex surgery for more detail.
Is functional outcome better when surgery is performed in infancy, in adolescence, or adulthood, for vaginoplasty for markedly virilized females (e.g., from congenital adrenal hyperplasia, mixed gonadal dysgenesis, or partial androgen insensitivity)?
- Argued or putative advantages of infant surgery
- Tissue is more elastic and heals better according to many surgeons.
- Genital surgery performed before the age of memory is less emotionally traumatic.
- Surgery in infancy avoids asking adolescent to make a decision that is stressful and difficult even for adults.
- Assuming infant surgery is successful, there is no barrier to engaging in normal sexual activities, and less distortion of psychosexual identity.
- Argued or putative advantages of surgery in adolescence or later
- If outcome is less than satisfactory, early surgery leaves a person wondering if she would have been better off without it.
- Any surgery not absolutely necessary for physical health should be postponed until the person is old enough to give informed consent; parents should not be empowered to make medical decisions for their children.
- Genital surgery should be handled differently than other birth defect surgery; this is the one type of surgery that parents should not be empowered to make decisions about because they will be under social pressure to make "bad" decisions.
- By mid-adolescence or later, a woman may decide that her abnormal genitalia do not need to be changed.
- Infant vaginoplasties should not be done because most women who have had them performed report some degree of difficulty with sexual function; even though we have no evidence that adult sexual function will be better if surgery is deferred, the outcomes couldn't be worse than they currently are after infant surgery.
Do any advantages of infant clitoral reduction surgery outweigh the potential disadvantages of reduced or distorted sexual sensation? Clitoral reduction is rarely done except in combination with vaginoplasty when substantial virilization is present.
- How much weight should be given to the cosmetic argument that there is value in making it more normal looking? See for example the letters following Melton, 2001.
Should parents have the same ethical and legal right to consent on behalf of their child to genital surgery as to consent to other reconstructive surgery (e.g., cleft lip repair or birth mark removal) for largely psychosocial purposes?
- The high court in Colombia has ruled no , and some advocacy groups in the US and elsewhere agree (, comparing this type of surgery to genital mutilation (intactivism).
How can we minimize gender identity problems? Is it valid to assume in cases of ambiguous genitalia that the magnitude of the "innate" tendency to develop a specific gender identity is usually similar to the degree of genital virilization? Should we abandon completely the idea that an unambiguous XY child with an irreparably defective penis might be better off raised as a girl?
- Medical professionals have traditionally considered the worst outcomes after genital reconstruction in infancy to occur when the person develops a gender identity discordant with the sex assigned as an infant. Most of the cases in which a child or adult has voluntarily changed sex and rejected sex of assignment and rearing have occurred in partially or completely virilized genetic males who were reassigned and raised as females. This is the management practice that has been most thoroughly undermined in the last decade, as a result of a small number of spontaneous self-reassignments back to male in a number of genetic males who had been raised as female because of birth defects of the penis which did not involve undervirilization (e.g., exstrophy or traumatic loss).
- Reducing the likelihood of a gender "mismatch" is also a claimed advantage of deferring reconstructive surgery until the patient is old enough to assess gender identity with confidence.
- However, support groups tend to identify intense feelings of shame and betrayal as the worst outcomes of a philosophy of management that focuses on normalizing the child's anatomy. Many individuals who have developed a discordant gender identity and rejected the sex assigned during infancy have done quite well after transition (Reiner 2004, Consortium 2006, ). Gender identity may not be the most important variable to consider in caring for children with intersex conditions.
Within the last decade, some people have raised the question of whether surgery to correct abnormal genitalia should be done at all, especially for purposes of changing appearance. Opponents of all "corrective surgery" on abnormal genitalia suggest we should be attempting to change social opinion regarding the desirability of having genitalia that look more average, rather than performing surgery to try to make them more like other peoples'.
Historical background, supporting arguments, and changing practice standards are treated in more detail in History of intersex surgery, and in some of the following references (Creighton, 2001).
- Alizai NK, Thomas DFM, Lilford RJ, Batchelor AGG, Johnson N. Feminizing genitoplasty for congenital adrenal hyperplasia: what happens at puberty? J Urol 161:1588-91, 1999. One of several studies documenting disappointing sexual function after early childhood vaginoplasty.
- Casale AJ, Beck SD, Cain MP, Adams MC, Rink RC. Concealed penis in childhood: a spectrum of etiology and treatment. J Urol 162:1165-8, 1999. Overview of types of concealed penis, surgical repair, complications, outcomes.
- Chase C. Re: Measurement of pudendal evoked potentials during feminizing genitoplasty: technique and applications (letter). J Urol 156:1139-40, 1996. Cheryl Chase represents ISNA and cautions that even documentation of clitoral nerve function during surgery does not ensure normal sexual function later.
- Consortium on the Management of Disorders of Sex Differentiation. 2006. Clinical Guidelines for the Management of Disorders of Sex Development in Childhood. Rohnert Park: Intersex Society of North America.  2006. Handbook for Parents. Rohnert Park: Intersex Society of North America. 
- Creighton S. Surgery for intersex. J Royal Soc Med 94:218-20, 2001. Excellent, brief, recent overview of history and current controversies.
- Glassberg KI. Editorial: gender assignment and the pediatric urologist. J Urol 161:1308-10, 1999. Defense of infant assignment and surgery. Good overview of hypospadias issues not addressed by some of the other articles.
- Lobe TE, Woodall DL, Richards GE, Cavallo A, Meyer WJ. The complications of surgery for intersex: changing patterns over two decades. J Pediatr Surg 1987, 22:651-2. Overview of complications of older techniques.
- Manuel M, Katayama PK, Jones HW Jr. The age of occurrence of gonadal tumors in intersex patients with a Y chromosome. Am J Obstet Gynecol 124:293-300, 1976. Why and when it's sometimes safer to remove nonfunctional gonads.
- Melton L. New perspectives on the management of intersex. Lancet 357:2110, 2001. A recent journalist’s summary of the controversies. Letters exchanged in response demonstrate arguments from professionals on both sides of the arguments and complexity of some of the issues. E.g., in response to argument against clitoral reduction surgery, a girl who will not swim at school because her clitoris is visibly prominent is described.
- Minto CL, Liao L-M, Woodhouse CRJ, Ransley PG, Creighton SM. The effect of clitoral surgery on sexual outcome in individuals who have intersex conditions with ambiguous genitalia: a cross-sectional study. Lancet 361:1252-7, 2003. Recent outcomes are disappointing but unoperated women with similar conditions have high rate of sexual dysfunction as well.
- Passerini-Glazel G. Editorial: feminizing genitoplasty. J Urol 161:1592-3, 1999. This commentary on Alizai's "What happens at puberty?" report defends infant genitoplasty.
- Rangecroft L, Brain C, Creighton S, Di Ceglie D, Ogilvy-Stuart A, Malone P, Turnock R.  Statement of the British Association of Pediatric Surgeons Working Party on the Surgical Management of Children Born with Ambiguous Genitalia. July 2001. Excellent brief summary of many of the surgical procedures, plus good discussion of the timing of repair controversy.
- Reiner WG, Gearhart JP. Discordant sexual identity in some genetic males with cloacal exstrophy assigned to female sex after birth. New Engl J Med 350:333-41, 2004. Eight of 14 genetic males with cloacal exstrophy raised as females after feminizing genitoplasty requested reassignment as males as they grew up.
- Rink RC, Adams MC. Feminizing genitoplasty: state of the art. World J Urol 16:212-218, 1998. Recent review that concentrates on method and complication reduction. Brief history of changing surgical techniques as well.
- Schnitzer JJ, Donahoe PK. Surgical treatment of congenital adrenal hyperplasia. Endocrinol Metab Clin N Am 30:137-54, 2001. Recent description and advocacy of genital reconstruction of intersex infants. Focus is on feminizing vaginoplasty and clitoral reduction for CAH, but brief descriptions of surgical treatments for several other forms of intersex are provided. Good overview of the steps of surgery for non-surgeons. Patricia Donahoe is Chief of Pediatric Surgery at Massachusetts General Hospital.
- Schober JM, Carmichael PA, Hines M, Ransley PG. The ultimate challenge of cloacal exstrophy. J Urol 167:300-4, 2002. Discusses the surgical and outcome problems of cloacal exstrophy.