Unrecognized obstruction can lead to urinary infection, gradual loss of renal function, and ultimately death from renal failure. When recognized early an obstruction can be repaired, even in the newborn, giving normal renal function and longevity. Urinary incontinence, which accompanies certain urological disorders, can adversely affect social development of the child. Similarly, genital malformations, when repaired properly, can produce a good cosmetic result and self-image for the child. Functional and social disasters await the child who grows without expert surgical correction of genital malformations. There are tumours unique to the paediatric urinary tract, which although highly malignant, have a high rate of cure when treated by modern therapy.

Table 1 569 outlines the categories of disease to be described and the major conditions to be included. Several problems may occur in one condition: for example, ectopic ureters can be associated with both obstruction and incontinence. Similarly, epispadias is both a congenital malformation of the genitals and a cause of urinary incontinence because the bladder neck is usually deficient. Furthermore, a child's urinary tract may have multiple associated problems, such as urethral valves, ureterovesical junction obstruction, and ureteropelvic junction obstruction.

Vesicoureteral reflux, the backwash of urine from the bladder up the ureters to the kidney, is the most common cause of serious urinary tract infection in young patients. Reflux is usually caused by congenital maldevelopment of the ureterovesical junction. Normally, a ureter enters the bladder trigone at an oblique angle and has a submucosal segment of ureter with muscle behind it. This anatomy produces a valve-like mechanism that prevents backflow of urine during voiding. If the ureter is located more laterally than normal, often having a straight course through the bladder wall, this valve mechanism is deficient. Figure 1 2159 contrasts normal ureterovesical junction anatomy with that usually seen with reflux, and illustrates how reflux can be corrected surgically by reimplanting the ureter.

Since reflux is often familial, asymptomatic siblings of an affected child should undergo screening tests. These include ultrasound examination of the kidneys to exclude cortical scarring and caliceal dilatation, together with voiding cystourethrography to visualize the urethra, bladder neck, the process of bladder emptying, and the absence of backwash. A simple static cystogram of the full bladder is insufficient: reflux frequently occurs only during voiding. A voiding study in males also excludes the presence of urethral valves, an obstruction that can cause high pressures in the bladder during voiding and may cause a relatively normal ureterovesical junction to backwash. An experienced endoscopist can predict the presence of vesicoureteral reflux by the configuration of the ureteral orifice: a normal ureteral orifice is small and elliptically shaped. A refluxing orifice is sometimes so dilated that the endoscope can be passed from the bladder up into the ureter.

Every congenital malformation occurs in a wide spectrum of severity, ranging from almost normal anatomy to obvious abnormality. The treatment of vesicoureteral reflux also varies with its severity, and also depends on whether the upper urinary tracts are normal or scarred, and whether the abnormality is minimal or severe. Some reflux will disappear in time: a congenitally short ureterovesical tunnel can elongate as a child grows.

Reimplantation of the ureter is a well established operation that should correct reflux without creating obstruction, in virtually all cases. A poor operation can have disastrous results, causing obstruction of the ureter or persistent reflux. A child with an unscarred upper urinary tract and mild reflux can be treated by observation and antibiotic therapy, with frequent monitoring of urinary cultures. Children with dilatation and/or scarring of the upper urinary tract or very abnormal anatomy which is not likely to improve require surgical treatment.

Subureteric injection of Teflon paste to provide an artificial backing to the ureter can stop reflux in some patients. This technique has not met universal approval because its long-term safety is not established.

Three anatomical conditions predispose to vesicoureteral reflux: paraureteral diverticulum, in which the lower ureter lacks muscle backing; duplex ureters, in which the lower pole orifice, which lies more craniad in the bladder, has too short a tunnel, and ureteral ectopia, in which the ureter enters the bladder neck or urethra and has a straight course that allows reflux. These anomalies are best managed surgically. Figure 2 2160 illustrates how severe renal atrophy can occur when reflux and infection are allowed to persist.

Obstruction at the upper end of the ureter is one of the most common surgical problems in infants and children occurring twice as often in boys as in girls (Fig. 3) 2161. Histological examination of the narrow ureteropelvic junction segment usually discloses disordered smooth muscle bundles and excessive collagen in the wall of the ureter. In about 10 per cent of cases an aberrant artery to the lower pole of the kidney crosses anterior to the point of obstruction, and 20 per cent of cases are bilateral. Since the advent of antenatal ultrasound examination, a large proportion of these cases are detected antenatally. If the condition is not detected before birth, symptoms leading to its clinical detection include urinary infection, abdominal pain, palpation of an abdominal mass, and haematuria. For some patients the condition is not diagnosed until adulthood, when long-term stasis may lead to stone formation. Relatively minor trauma can rupture a hydronephrotic kidney and lead to the diagnosis of congenital obstruction.

The diagnosis of hydronephrosis due to ureteropelvic junction obstruction is not difficult. Hydronephrosis can be detected by ultrasound examination of the kidneys, radionuclide scan with delayed emptying, or intravenous pyelogram. If the contrast agent is not seen on early films, delayed films should be obtained after 4 to 8 h, or even later. A voiding cystogram should also be obtained to rule out the presence of associated vesicoureteral reflux. Massive vesicoureteral reflux produces tortuosity of the ureteropelvic junction, which can mimic primary ureteropelvic junction obstruction. In some cases, correcting reflux allows the ureteropelvic junction tortuosity and apparent obstruction to disappear. In other cases, however, tortuosity is permanent and both ends of the ureter require corrective surgery. The ureter is often not seen in an intravenous pyelogram, and a retrograde pyelogram should be performed to define accurately the extent of narrowing and rule out the presence of a second level of narrowing.

Figure 4 2162 shows the goal to attain in correcting ureteropelvic junction obstruction. The kidney is approached through a flank incision. The area of narrowing is sometimes reached more easily from behind, but in other cases access is easier from an anterior approach. The ureter is not widely mobilized to avoid injury to its blood supply. The ureteropelvic junction itself is divided, and the dilated renal pelvis is mobilized widely; if the renal pelvis is extremely large, it can be subtotally resected. A moderately enlarged renal pelvis does not require reduction since relief of obstruction is followed by reduction in volume of the renal pelvis. The ureter is spatulated along its lateral aspect to allow a wide anastomosis to be made in a dependent position on the renal pelvis. A water-tight anastomosis of adequate calibre does not require stenting, and a nephrostomy tube is only used to drain the kidney when there is extreme hydronephrosis. The majority of patients do not require temporary nephrostomy drainage, but the flank is always drained in case there is leakage of the anastomosis, although this is rare when the operation has been performed properly.

Giant hydronephrosis is defined as a kidney that occupies the hemiabdomen, crossing the midline, extending vertically the length of five vertebrae. At least 50 per cent of those kidneys can be salvaged: they have a surprisingly large degree of function. Radionuclide scans can be helpful in assessing the amount of function present. Temporary decompression with a percutaneously placed nephrostomy tube may be used to decompress the kidney and to measure its function by creatinine clearance determination. When a kidney provides less than 10 per cent of the total renal function, and if the other kidney is normal, nephrectomy is usually the best option. An aberrant vessel, if present, should never be divided, since this can devascularize that segment of the kidney and lead to hypertension. The ureteropelvic junction should be divided, and reanastomosed with a spatulated pyeloplasty, which is usually placed anteriorly to the artery.

Figure 4 2162 illustrates moderately severe hydronephrosis of the left kidney in a 10-year-old boy who presented with left flank pain. He had a normal right kidney and moderately severe hydronephrosis of the left kidney. Percutaneous antegrade pyelography disclosed no drainage through the ureteropelvic junction and reproduced the patient's pain. There were two areas of narrowing in the upper ureter. Study after dismembered pyeloplasty showed free flow of contrast through the ureteropelvic junction.

Megaureter refers to a dilated and sometimes tortuous ureter resulting from intrinsic obstruction at the lower end of the ureter or from massive vesicoureteral reflux (Fig. 5) 2163. Wide ureters may be a primary problem caused by maldevelopment of the ureterovesical junction, but with an otherwise normal bladder and urethra; it can also be a secondary condition. Neurogenic bladder, in which emptying is impaired or pressures are high, may produce ureteral dilatation, as may urethral valves with severe outlet obstruction. A ureter that is ectopic in the bladder neck or urethra may be functionally obstructed at rest, but demonstrate massive reflux during micturition. A ureter can also be dilated due to extrinsic compression by a pelvic mass or scarring by previous surgery. Extremely abnormal ureters are seen in rare conditions such as ‘prune belly syndrome’, which appears to be due to a primary muscular maldevelopment.

The function of the ureter is to transport urine from the kidney to the bladder: it cannot function properly if the ureteral walls do not coapt during peristalsis. If the ureters contain a large volume of urine, stasis can promote urinary infection and stone formation. Surgery can benefit many of these patients, the majority of whom are infants and children who present with urinary tract infection. When the megaureter is clearly not a secondary problem, its surgical repair should be considered, with shortening and tapering of the lower ureter, which is reimplanted into the bladder with a long tunnel to prevent reflux. The tortuosity of the upper ureter often improves spontaneously. In some patients, however, persisting upper ureteral tortuosity can produce partial obstruction at the ureteropelvic junction. Tortuosity can be assessed by serial radiographic examinations, antegrade pressure–perfusion studies, and radionuclide scans with frusemide washout, to measure the speed of emptying of the dilated upper system. If drainage is impaired the upper ureter can be shortened, straightened, and sometimes tapered to enhance its emptying, as is performed in patients with ureteropelvic junction obstruction. The blood supply of the ureter must be maintained when surgery is undertaken. The striking improvement that can result from surgery for megaureter is illustrated in Figure. 6 2164.

Ureterocele is a term that describes a sacular, cyst-like dilatation at the lower end of a ureter. It occurs in several anatomical forms (Fig. 7) 2165, the least severe of which is a small ureterocele at the end of a single ureter that is moderately dilated. These patients are usually boys. More commonly, there is a duplex collecting system in which the ureterocele is actually the lower end of the ureter to the upper aspect of the kidney which itself is dysplastic or hydronephrotic. This form is more common in girls. A ureterocele is ‘normotopic’ when it is confined to the bladder, although a large normotopic ureterocele can obstruct the bladder outlet. An ectopic ureterocele is one in which the muscle defect extends down into the bladder neck and urethra. The entire back wall of the urethra may be affected, and the ureterocele can rupture into the vagina, causing total urinary incontinence.

The diagnosis of a ureterocele can be made from an intravenous pyelogram (Fig. 8) 2166. A small ureterocele is revealed as a round accumulation of contrast in the lower ureter, termed a ‘cobra head’ or ‘spring onion’. These patients are usually older children. A duplex collecting system typically appears as a large filling defect in the bladder, which does not contain contrast medium because there is poor renal function of the upper pole moiety associated with the ureterocele. The lower pole of the kidney is usually displaced laterally and downward by the hydronephrotic upper pole. Cystography should be performed in these patients, in whom there is often vesicoureteral reflux along the adjacent lower pole ureter which is located on the summit of the ureterocele. The ureterocele lacks muscle backing, as do patients with primary reflux. There is often reflux along a contralateral single ureter. In the worst cases bilaterally duplicated systems with two large ureteroceles fill the bladder outlet.

The treatment of a child with a ureterocele varies greatly. A small ureterocele in a single system is best managed by resecting the ureterocele and reimplanting the ureter to create a non-refluxing tunnel, after relieving its obstruction (Fig. 9(a)) 2167. Many years ago these patients were managed by ‘unroofing’ the ureterocele to relieve its obstruction: this practice merely substituted reflux for obstruction. Surgical correction in the duplex system most often involves removing the ureterocele, its ureter, and the upper pole of the kidney, while repairing the defect in the bladder trigone and reimplanting the adjacent ipsilateral lower pole ureter (Fig. 9(b)) 2167. Occasionally, the upper pole of the kidney contains enough renal parenchyma to merit its salvage by pyelopyelostomy.

These patients are frequently small infants severely ill with urosepsis. Initial therapy may be drainage of the bladder with a small plastic catheter, and antibiotic treatment of urinary tract infection. Upper pole partial nephroureterectomy can remove the large reservoir of urine that predisposes to infection, causing the ureterocele to collapse. Alternatively, the obstructed upper pole can be temporarily relieved by inserting a percutaneous catheter or puncturing the ureterocele endoscopically to drain it, followed by upper pole nephroureterectomy a few days later. Sometimes a child improves dramatically following removal of the upper pole and its ureter. If there is no associated reflux, it may be possible to delay the lower reconstruction for several years. Although some surgeons would not undertake the lower reconstruction at all in these circumstances, late complications may arise from the defunctionalized ureterocele. These include stone formation within it, or bladder outlet obstruction caused by the diverticulum-like defect associated with the ureterocele. A ureterocele occasionally prolapses from the urethra, causing total urinary obstruction.

Most urethral valves are an accentuation of folds seen in the normal male urethra. The principal types of urethral valves were described more than 70 years ago (Fig. 10) 2168. The clinical picture in boys with urethral valves varies with the degree of obstruction caused. In some boys this obstruction is minimal and allows the bladder to empty normally, although at slightly higher pressures than normal. At the other end of the spectrum is high-grade obstruction with extreme hydronephrosis and greatly compromised renal function. Symptoms in boys with valves include bed wetting, urinary infection, daytime wetting, urinary frequency, dribbling, and sometimes a poor urinary stream. Curiously, a history of a poor stream is often not obtained, even in patients with high-grade urethral obstruction. Residual urine is not always found in boys with valves because any hollow viscus can compensate for partial obstruction by hypertrophy, which allows emptying despite obstruction, up to a point. The intravesical pressure in such cases may be 80 to 100 cm of water, which is three to five times higher than normal. Back pressure from obstruction causes inadequate development of the fetal kidney and results in persistent hydronephrosis, tubular ectasia, and dysplastic morphology in extreme cases.

The diagnosis of urethral valves is made by voiding cystourethrography (Fig. 11) 2169. Even in the newborn, satisfactory voiding films can be obtained by slowly filling the bladder through a small plastic urethral catheter or through a needle inserted suprapubically, obtaining spot films when the patient voids. Treatment of boys with urethral valves depends on the age of the patient, whether there is impaired renal function, and whether the patient has infection and uraemia at the time of presentation. An ill, acidotic, uraemic neonate is often best treated initially by passing a small, non-reactive, plastic catheter to drain the bladder, and treating infection and acidosis with appropriate antibiotics and fluid replacement.

Endoscopic relief of valve obstruction can be accomplished in all but the smallest premature babies, whose urethra is too small to accept a 7.5 Fr endoscope. In this circumstance, a temporary vesicostomy to drain the bladder may be advisable. Valves can be incised using a small wire electrode, taking care not to touch the nearby urethral sphincter, the verumontanum, or the bladder neck (Fig. 12) 2170. When obstruction is mild and the upper urinary tract is normal or near normal, valve resection alone will usually suffice. Vesicoureteral reflux is common in these patients. It may disappear when normal intravesical voiding pressures are achieved by relieving the urethral obstruction. Spontaneous improvement of hydronephrosis may be observed following relief of obstruction (Fig. 13) 2171. When there is massive vesicoureteral reflux or ureteral obstruction without reflux despite valve ablation, a major reconstruction may be required to preserve renal function. The newborn kidney has a creatinine clearance capacity about 20 per cent of that seen in the adult. Normally, clearance increases in the first year of life to attain adult clearance values of about 100 l/m² body surface area/day. There is some evidence to suggest that early relief of obstruction allows recovery of maximum function in an obstructed renal unit. Late relief of obstruction can give a disappointing degree of improvement in renal function of that kidney. This fact has led us to pursue an aggressive attack on massive reflux or ureteral obstruction in infant boys with seriously compromised upper tracts (Fig. 14) 2172.

Even with aggressive therapy about one-third of these boys develop renal failure because they lack the renal reserve to support the increased body muscle mass attained at or before puberty. Prenatal relief of urinary obstruction has been attempted by intrauterine placement of drainage catheters or ureterostomy to divert the urine. Results to date have been disappointing, however. We believe that the principal benefit of antenatal identification of urinary obstruction is the knowledge of its presence, which allows therapy to begin immediately after birth and before urinary infection occurs. Some boys with severe urethral valves develop a thick-walled non-compliant bladder, which may be improved by augmentation of the bladder with bowel.

A urethral valve-like obstruction is rarely encountered in girls. These valves are best demonstrated by passing a malleable probe bent into a hook. The probe is passed through the urethra alongside the endoscope, hooking the leaflets and pulling them into view out of the urethral orifice.

Reimplantation of the ureter has been described briefly in association with correcting vesicoureteral reflux, which is the principal cause of pyelonephritis in children. Ureteral reimplantation is also necessary in patients with ureterocele and ureteral ectopia, and in some of those with urinary incontinence, or tumours. Whatever the indication, the general principle remains the same; the ureter must be joined to the bladder or a bowel augmentation in such a fashion that there is a submucosal tunnel which prevents backwash and does not permit angulation of the ureter when the bladder fills. Prevention of reflux, whichever technique is used, requires a tunnel length to ureter diameter ratio of about 5:1. The most common mistakes made when reimplanting a ureter are angulation of the ureter where it re-enters the bladder and devascularization of the ureter by dissecting too close to it during mobilization. These errors result in fibrosis and obstruction.

This is a useful procedure for achieving drainage when two satisfactory ureteral reimplantations cannot be performed or when one ureter is too short to reach the bladder. The ureter can be drained across the abdomen retroperitoneally and joined to the opposite ureter (Fig. 15) 2173. Devascularization of the ureter to be drained can be avoided if it is mobilized with all of its periureteral tissue, and often with the gonadal vessels adjacent to the ureter. Infarction of an ovary or testicle following ligation of the ovarian or testicular vessels in the lower abdomen and their retention with the ureter to be mobilized is rare. It is important to avoid angulating the ureter beneath a mesenteric vessel; there must be no tension on the anastomosis.

Increasing the size of the bladder was originally used for the treatment of vesical contracture secondary to genitourinary tuberculosis. The bladder can be augmented using colon (Fig. 16) 2174, or a similar segment of small bowel. The bowel must be reconfigured and not used as an intact segment, which can cause incontinence if pressures produced by peristaltic waves exceed the resistance of the bladder neck and external sphincter. Caecum can also be used, the terminal ileum being inverted and sewn to the adjacent wall of the caecum as a type of nipple to prevent reflux. This method is only used when neither ureter can be tunnelled into the bowel wall for reimplantation. When the bladder is augmented, it must be opened widely, to avoid the augmented segment behaving as a diverticulum and trapping urine.

Stomach has increasingly been used for augmentation of the bladder (Fig. 18) 2176 and has certain metabolic advantages over the small bowel and colon. Small bowel and colon both absorb chloride and excrete fixed base, aggravating metabolic acidosis in patients with poor renal function. Gastric segments, however, actively excrete chloride and can actually improve acidosis in some patients. A patient with a gastrocystoplasty, however, can develop hypochloraemic alkalosis rapidly, with vomiting and consequent inadequate salt intake. Patients in whom small bowel and colon are used for augmentation have mucus in the urine, which may serve as a nidus for stone formation. This complication has not been seen in patients with a gastrocystoplasty. Bacilluria is more easily controlled in patients with gastrocystoplasty: the urine tends to have an acid pH, which discourages growth of bacteria. Some of these patients have complained of pain following bladder augmentation by stomach. This is sometimes relieved by administration of H&sub2; receptor antagonists.

Bladder augmentation has made urinary tract reconstruction possible in many patients who were previously treated by urinary diversion. Augmentation provides adequate urine storage capacity and bladder compliance. The ability to empty the bladder spontaneously is governed by the degree of neurological control of the bladder neck and/or external urethral sphincter. If the patient has neurological impairment, due to conditions such as spina bifida and myelomeningocele, or if there is a fixed resistance at the bladder outlet as is seen in many patients following bladder neck narrowing procedures, spontaneous voiding may be impossible. Any patient for whom augmentation is planned should understand that intermittent self-catheterization may be required to empty the bladder. Failure to empty the augmented bladder leads to over-distension and to spontaneous perforation.

Hitching the bladder to the psoas muscle prevents angulation of the ureter when the bladder fills. It also allows longer tunnelled ureteral reimplantation into the bladder to be achieved.

The normal bladder outlet has a bladder neck or internal sphincter, which opens involuntarily during voiding, and an external, voluntary urethral sphincter. When normally innervated these two sphincters provide continence. Generally, continence is still possible after the loss of one sphincter, but not following the loss of both. For example, fracture of the pelvis in males often disrupts the voluntary external sphincter, yet the patient can usually maintain continence with the bladder neck. The bladder neck may be abnormally wide or absent in patients with some congenital malformations, including congenital epispadias and ectopic ureters (Fig. 20) 2178. Both sphincters are often deficient particularly in those with complete epispadias or bladder exstrophy. Outlet resistance can be improved by enlarging the abnormal bladder outlet and urethra (Fig. 21) 2179. This exposure can be improved by splitting the pubic symphysis. The ureters are usually moved upward in the bladder and are reimplanted by cross trigone advancement. This technique allows mucosa to be removed from the wide bladder outlet on both sides and a strip of mucosa to be retained in the centre. A tube is created from this and muscle is closed over it to create a new bladder neck with greater outlet resistance.

Diversion of the urinary tract, both temporary and permanent, is being performed less frequently today than in the past as emphasis is put on the reconstruction of malformations and intermittent catheterization for bladder emptying. Temporary loop cutaneous ureterostomy or pyelostomy (Fig. 22) 2180 was often used to drain the kidneys in boys with urethral valves. Fortunately, this practice has largely waned. End cutaneous ureterostomy has also been used extensively. This often does not provide good drainage and makes final reconstruction difficult.

The ileal loop urinary diversion was introduced as a means for draining the urinary tract in adults undergoing cystectomy for bladder cancer. It was also widely used in children with various obstructive uropathies in whom reconstructive surgery had not been successful. The ileal loop was a simple segment of small bowel into which the ureters were joined end to side. This was then extended to the surface where urine was collected in an external appliance worn on the abdominal wall. Reflux in these loops results in ascending pyelonephritis, stones, strictures, and renal failure, and the non-refluxing colon conduit was therefore introduced (Fig. 23) 2181. Non-refluxing tunnels can be constructed more effectively in the colon wall than in the wall of the small bowel. Although the ileal loop urinary diversion is still used widely in many patients with bladder cancer, especially when life expectancy is short, it is not suitable for young patients with a long life ahead of them. In the rare circumstances when a conduit is required, a non-refluxing technique should be used. A conduit can also be constructed using caecum, following preparation as for the caecal bladder augmentation (Fig. 17) 2175.

Cutaneous vesicostomy is a form of urinary drainage used when long-term, but temporary drainage of the lower urinary tract is required. The opening in the bladder must be high in its dome, where it will drain adequately. An opening in the front wall of the bladder may become occluded by prolapse of the back wall of the bladder against the cutaneous opening.

Chronic drainage of the bladder by an inlying suprapubic tube was a common surgical procedure several decades ago, results in chronic bladder infection, stones, and fibrosis with contracture of the bladder. Short-term percutaneous tube drainage of the bladder is useful after reconstructive bladder outlet surgery or pelvic trauma with urethral disruption.

In recent years, continent urinary diversion has been employed in adult patients following radical extirpative pelvic surgery for malignancy, and in paediatric patients whose bladders were considered to be non-reconstructible. This technique involves the creation of an internal reservoir to hold a volume of urine approximately equal to that of normal bladder capacity for that age, preventing reflux to the kidneys, and preventing leakage at the abdominal stoma. Emptying is accomplished by intermittent catheterization of the continent reservoir, several types of which are in vogue (Figs 24–26) 2182,2183,2185. Complications common to these pouches include chronic low grade bacilluria, stone formation, leakage, solute resorption, and spontaneous perforation if the pouch is not emptied regularly. In the past, too many urinary diversions were performed for reconstructible urinary tract disease and it is possible that more continent diversions are currently being performed than may be necessary. Certainly, when functional repair is possible, any type of urinary diversion, continent or otherwise, is a poor second choice.

Many patients who underwent urinary tract diversion in the past are suitable for urinary tract reconstruction. Figure 27 2184 shows the anatomy of an ileal loop urinary diversion and the surgical options that might be possible for reversal of this diversion. Obviously, this procedure depends on the length of the ureters and the condition of the bladder. Experience with nearly 200 reversals has emphasized several important concepts. First, the duration of a previous diversion is not important: reconstruction can be achieved in patients who have worn a bag on their abdomen for nearly three decades. Secondly, poor urinary tract function is not a contraindication to reconstruction: patients with urinary diversions should be re-evaluated in the light of the surgical advances made since their original diversions were performed.

Epispadias refers to a dorsal opening of the urethra—the opposite of hypospadias. Like all malformations, epispadias occurs in various degrees of severity. In males there may be a simple cleft in the dorsum of the glans; in more severe cases a widely open urethra may extend back through the bladder neck, urinary incontinence resulting from the open external urethral sphincter and the internal urethral sphincter (the bladder neck). Although most malformations are more common in a mild form, epispadias is commonly severe, with complete urinary incontinence. Incontinence in these patients is restored by increasing bladder outlet resistance, often also moving the ureters upward to lengthen the urethra (Fig. 21) 2179. The wide urethra is closed. In the male, the penile shaft and the glans penis must be reconstructed. In females, the two clitori are reapproximated to restore a normal anatomical appearance. Some patients with epispadias require bladder augmentation.

This is one of the most devastating abnormalities in the newborn. If a sound were introduced into the normal urethra of the male or female, passing the sound up to the dome of the bladder, then cutting down upon the sound from the navel to the urethral meatus, exstrophy of the bladder with complete epispadias would be reproduced.

Until the mid-1950s the majority of patients with exstrophy of the bladder were treated by internal diversion of the urine into the colon (ureterosigmoidostomy). Many patients succumbed to urinary infection ascending from the faecal stream to the kidney. There is also a 10 per cent risk of carcinoma of the colon developing at the site of the ureterosigmoidostomy anastomosis. Success can only be achieved by tunnelling of the ureters into the colon.

In the past three decades there has been increasing emphasis on functional reconstruction of the bladder in these patients. When the bladder size is adequate relatively normal bladder function may be possible; for many patients however, the bladder is too small. Bladder augmentation with intermittent catheterization is appropriate for many patients with bladder exstrophy and urinary diversion is now rarely required. Surgical repair can produce functional genitalia with much better success than might be imagined possible: this is generally performed in a series of carefully planned stages. The bladder is closed surgically as soon after birth as possible, before infection or metaplasia of the exposed bladder surface occurs. The wide apart pubic bones can be brought together with strong sutures in the first few days of life. After the first week an iliac or pubic osteotomy may be useful to approximate the halves of the pubic symphysis. Later the ureters are reimplanted, a bladder neck is reconstructed, and the epispadias malformation is corrected. Reoperation is often needed to gain greater outlet resistance if insufficient continence is achieved and augmentation is necessary if the bladder remains small. A series of operations producing an ultimate success is preferable to a urinary diversion.

Artificial sphincters are now available. These consist of an inflatable cuff placed around the bladder neck or proximal urethra, a reservoir of fluid, and a mechanism for transfer of fluid under pressure from the reservoir to the cuff to provide outlet resistance. They do, however, have a high incidence of late complications, including erosion of tissues compressed by the sphincter. Such complications are particularly likely in patients who have undergone extensive surgery to the bladder neck and urethra, such as those with exstrophy and epispadias. The best indication for use of an artificial sphincter in young patients is a neurologically impaired bladder with relatively normal tissues of the bladder neck and urethra.

There are many ectopic positions of the ureter, all distal to the normal location of the interureteric ridge. In males, the ureter may empty into the bladder neck, a seminal vesicle, or even into the vas deferens (Fig. 31) 2189. Crossed ectopia refers to the condition where the ureter crosses the midline and drains a kidney on the opposite side. The ectopic ureter is always above the level of the external urethral sphincter. These patients however, are not incontinent, and usually present with urinary infection. Paradoxically, an ectopic ureter in the bladder neck can show both obstruction and reflux: in the resting state the muscle of the bladder neck compresses the lower ureter and obstructs it; during voiding, when the bladder neck opens, the same ureter may exhibit massive reflux.

In females an ectopic ureter can be located in the bladder neck, the urethra, or just outside of the urethra. In the latter case constant moisture typically appears from the ectopic orifice. The renal tissue with an ectopic ureter is usually dysplastic and is not visualized by intravenous pyelography. If its presence is suspected, however, careful study of the renal shadow may disclose a small amount of non-functional tissue medial to the upper pole of the kidney. Intravenous contrast media such as indigo carmine or methylene blue dye is not concentrated sufficiently to reveal the blue dye at the ectopic orifice. The ectopic orifice can sometimes be located by observing the perineum after administration of a large water load. In the female an ectopic orifice may rarely be located in the vagina, cervix, or even the uterus. Removal of the dysplastic tissue and the ectopic ureter cures the associated poor continence. When an ectopic ureter is located within the bladder, the renal segment associated with it may have good function. Reimplantation of the ureter to prevent reflux is the proper treatment.

‘Bilateral single ectopic ureters’ is a rare condition in which both ureters are located distally to the bladder neck. These patients also have an inadequate bladder neck and must be treated in the same way as patients with complete epispadias and incontinence.

Spina bifida and myelomeningocele are common in infancy and are frequently associated with neuropathic changes in the bladder. An apparently normal urinary tract can soon deteriorate if its innervation is faulty.

Many of these children were previously treated by urinary diversion, which cured incontinence but often at the expense of gradual deterioration of the kidneys. Today, more emphasis is placed on intermittent catheterization of the neuropathic bladder if it is of adequate size and its pressures are low. Many of these bladders, however, have high pressures and a small capacity and augmentation cystoplasty is required. Although ureteral reimplantation is frequently indicated, this is a technical challenge for the surgeon: the bladder wall is often thick and inflamed. Increasing bladder outlet resistance is needed to control poor continence in some patients. Urodynamic evaluation should be performed to measure their bladder volume, sensation, pressures, and outlet resistance.

Unfortunately, some children with spinal defects are confined to a wheelchair; they are unsatisfactory candidates for intermittent self-catheterization of the urethra. Creating a continent reservoir may offer the best means of achieving continence and of preserving the upper tracts with a catheterizable abdominal stoma.

In hypospadias the urethral opening lies on the ventral aspect of the penis: the opposite of epispadias. This condition occurs in various degrees, and is often associated with chordee, or ventral curvature of the penis. In minimal hypospadias the urethral meatus may be just a little proximal to the tip of the penis, without chordee. Perineal hypospadias represents the severe end of the disease spectrum, the urethral opening is at the base of the scrotum, which may be bifid, and the penile body is bent so that the glans is tethered to the perineum. The management of hypospadias has changed drastically in the past two decades. Early repair in the first year or two of life is now common practice. The goal is to straighten the penis, construct a urethra that extends to its tip, reshape the glans penis when it is abnormally splayed open, and provide a normal cosmetic appearance. The majority of these repairs can be achieved in a single operation.

A variety of techniques have been described and are in current use. The most severe cases may require a staged repair. At the first operation the penis is straightened and the skin is rearranged to cover the shaft, deferring urethroplasty until 6 to 12 months later. A urethra can be constructed using a graft of extragenital skin or bladder mucosa. The repair of hypospadias and chordee should not use skin of the perineum or scrotum, which will ultimately grow hair since this predisposes to formation of stones in the adult. There is no reason today why a child born with hypospadias and chordee should not grow up with a functionally and cosmetically satisfactory penis if repair is performed by a surgeon conversant with modern surgical techniques. Hypospadias may occur in multiple male members of a family, as may vesicoureteral reflux. Severe hypospadias, where testicles are not palpable in the scrotum, may be an intersex state.

The treatment of cryptorchidism has changed in recent years. A testis that has not descended into the scrotum by 1 year of age seldom descends spontaneously. If it is located in the inguinal canal, or higher, it is subject to a higher than normal ambient temperature which impedes its development. Undescended testes are therefore, treated much earlier than was customary two decades ago. The testis and its spermatic cord are mobilized in the inguinal canal through an inguinal incision, separating cremasteric muscle fibres. In the majority of patients there is an inguinal hernia sac that is dissected free from the cord and is ligated at a high level. The spermatic cord is usually then dissected up into the retroperitoneal region to obtain enough length of spermatic vessels and vas deferens to bring the testicle into the scrotum without tension.

Some undescended testes are abnormal and have failed to descend in utero for that reason. Orchidopexy will not improve the long-term prognosis for testicular function in such patients. The classic example of this is the prune belly syndrome, in which the testes are located intra-abdominally and uniformly show abnormal development microscopically. An impalpable testis is often non-functional as a result of torsion in utero. The spermatic vessels and vas deferens will be found to end blindly, usually at the level of the internal inguinal ring. A prosthetic testis ensures that the child will not grow up with an empty scrotum: the prosthesis can be upgraded to adult size at puberty. There is a slight increase in the incidence of malignancy in patients with cryptorchidism, and this does not seem to be altered by orchidopexy.

The birth of an infant with ambiguous genitalia should be regarded as an emergency; it is a social disaster for parents not to know whether their new baby is a boy or a girl. Evaluation of these babies includes family history, physical examination, cytogenic characterization, radiographic examination, biochemical evaluation, and, sometimes, endoscopy and laparotomy with gonad biopsy. If the undifferentiated gonad becomes a testis it secretes Mullerian-inhibiting substance, causing the Mullerian ducts to involute. Simultaneously, androgen from the testis stimulates the Wollfian ducts to differentiate as male. If the undifferentiated gonad becomes an ovary or if there is an absent gonad, the Wolffian ducts disappear and the Mullerian duct structures develop. In experimental animals these phenomena are unilateral: a testis on one side causes the expected male development on that side, whereas an ovary or no gonad on the other side results in female development of those structures. Simultaneously, the external genitalia develop as male or female, depending on the presence of androgen and androgen receptors in the genital anlagen.

Some of these conditions are familial, especially the adrenogenital syndrome with salt loss. Affected infants have adrenal hyperplasia and, in the severe form, have the appearance of a male with a well developed phallus, but an empty scrotum. There is a wide spectrum in the degree of masculinization of the genitalia in these babies. An infant with the salt-losing syndrome may develop adrenal crisis with shock, usually at about 1 week of age. Immediate administration of cortisone and electrolyte solution is life saving. Some of the intersex states are inherited as sex-linked recessive traits. On physical examination an attempt should be made to feel the gonads. The immature uterus can be felt, if present, on rectal examination. Chromosome study should be performed. However, the most important fact in guiding gender choice is the anatomy with which the surgeon must deal. The surgeon should enlist the help of a paediatric endocrinologist in evaluating these babies. The decision for gender assignment is a group decision based on the information that can usually be gathered in 3 to 4 days. If there is no phallus a genetic male should not be raised as a male, since an anatomically inadequate male is a social disaster. A child reared as a female is more able to cope socially even if anatomical structures are incomplete. Feminizing genitoplasty and vaginal construction are surgically possible.

Cystourethrography can prove useful in delineating the anatomy of the lower urinary tract and disclosing whether a vagina and cervix are present (Fig. 35) 2193. Biochemical testing includes determination of 17-keto steroids, and 17-hydroxycorticoids to detect adrenocortical hyperplasia syndromes. Levels of serum testosterone, pituitary gonadotropin follicle stimulating hormone, and luteinizing hormone should also be determined.

The adrenogenital syndrome is the most common condition presenting with genital ambiguity. These children are genetically normal females with normal ovaries, fallopian tubes, uterus, and upper vagina. The external genitalia, and sometimes the lower urinary tract, show masculinization. In extreme cases there may be a well formed ‘penis’ with a urethra which comes to its tip; in these the vagina will communicate with the urethra between the external urethral sphincter and the bladder neck.

Mixed gonadal dysgenesis is the second most common type of intersex state. The internal and external structures are variable. The characteristic karyotype is 45,X/46,XY, but there are several chromosome variants in this condition. There is usually a dysplastic testis on one side and a streak ovary on the other. Gonads should eventually be removed when the Y chromosome is present since malignant gonadoblastoma may develop in later years.

There are several other male and female pseudohermaphroditism states which must be considered. One of the most interesting is the so-called feminizing testis syndrome. These patients have a male chromosome karyotype and intra-abdominal testes but a phenotypically female appearance. Sometimes the diagnosis will be made when repairing an inguinal hernia in an apparently female child upon finding a testis in the hernia sac.

Surgical treatment of intersex states usually entails feminizing genitoplasty. An enlarged phallic structure should be recessed, not amputated as was customary a generation ago. Vaginoplasty techniques allow a high vagina to be exteriorized, or a vagina to be created. Figure 36 2194 shows the genitalia of a child with true hermaphroditism before and after feminizing genitoplasty.

There is clearly male psychological ‘imprinting’ in some children with the Y chromosome who have been raised as female. Some genetic females subjected to high levels of testosterone in utero also show male behavioural characteristics.

Cloaca is the Latin word for sewer. Anatomically it denotes confluence of the urinary, genital, and gastrointestinal tracts into a common chamber. The 7.5-mm human embryo passes through a cloacal stage. Subsequently, the urorectal septum descends, dividing the structure into a posterior rectal passage and an anterior urogenital sinus. Many aberrations can occur during this complex development, but their anatomy should not be confused with intersex states; they are female babies with imperforate anus and a persisting urogenital sinus. Laparotomy is required at birth to vent the colon, preferably by a right-transverse divided-loop colostomy. Decompression of the obstructed urinary tract can usually be accomplished by intermittent catheterization of the urogenital sinus. Drainage of the urine-filled vagina prevents the development of hydronephrosis and urinary tract infection. In the majority of these patients the defect can be successfully repaired by a posterior sagittal approach; some also require laparotomy.

This rare condition, which occurs only once in 250 000 births, was once uniformly fatal. Today a satisfactory surgical outcome can usually be accomplished. Magnetic resonance imaging of the spine should be performed in these babies because all have a tethered spinal cord. Some will benefit by neurosurgical release of the tethered spinal cord to avert progressive neurological sequelae. A typical patient with cloacal exstrophy has omphalocele, just below which is a bowel opening, which is typically the caecum (Fig. 39) 2197. The terminal ileum may prolapse out through the ileocaecal junction as an ‘elephant trunk’. On each side of the bowel fistula is characteristically an exstrophic hemibladder, and the anus is imperforate. Although half of these infants are boys and half are girls, it may be difficult to determine the gender if the observer is not familiar with the condition. Boys usually have a testis in widely separated scrotal sacs, and two rudimentary penises which are far apart. It is seldom appropriate to rear a child with this malformation as a male, since males rarely have anatomy from which a satisfactory penis can be made. As shown in Fig. 40 2198 the colon is usually rudimentary, hanging down in the pelvis as a blindly ending tube. This rudimentary colon should never be discarded: it has the ability to grow and function as a colon if given the chance.

The omphalocele is repaired at birth, and the caecum and terminal ileum are separated from the hemibladders and closed, thereby producing a functional colon, the end of which can be exteriorized as a temporary end colostomy. Because the colon is small, a decompressive temporary ileostomy may be desirable to protect the caecal closure from leakage. An immediate pullthrough of the colon may be considered if the baby does not have a caudal meningocele. The two hemibladders are joined and closed, as for any newborn with exstrophy of the bladder. Further urinary tract reconstruction must be undertaken later, at the age of 1 to 2 years, when a catheterizable urinary reservoir is created and the bladder is augmented.

Wilms' tumour, the most common solid tumour of childhood, is a malignant tumour of the kidney that often presents as a large palpable, abdominal mass in a young child (Fig. 41) 2199. It may also present as haematuria. The diagnosis is usually made by intravenous pyelography, which discloses a renal mass with excretory function, but with distorted caliceal architecture. The extent of these tumours should be assessed by CT scanning: they may extend into the renal vein and along the vena cava. Occasionally Wilms' tumour occurs bilaterally.

The mainstay of therapy is radical surgical extirpation. However, the tumour is sensitive to chemotherapy (especially actinomycin D and vincristine), and also usually responds well to radiation therapy, which is used in selected patients. The current overall cure rate of patients presenting with Wilms' tumour is approximately 85 per cent, a figure that includes some patients who have pulmonary metastases. Other renal tumours that rarely occur in children include angiomyolipoma, renal cell carcinoma, transitional cell carcinoma, and mesoblastic nephroma.

Neuroblastoma is the second most common solid tumour of childhood. It commonly occurs in the adrenal glands and it can arise from neural crest cells at any level adjacent to the spine, from the neck to the pelvis. Afflicted children with a large tumour frequently appear pale and cachectic. Although some neuroblastomas are encapsulated and surgically removable, many are locally infiltrative and defy surgical excision. Chemotherapy is also less effective for neuroblastoma than for Wilms' tumour. In general, the prognosis is better when neuroblastoma is discovered in the first year of life rather than later in childhood. One special category of neuroblastoma is characterized by a small primary in an adrenal gland and diffuse metastatic disease through the liver. Although this situation would seem hopeless, there is a high rate of spontaneous disappearance of the tumour.

Rhabdomyosarcoma is the most common malignant tumour seen in the genital tract of children. It occurs in the bladder, vagina, uterus, and in the prostate in the male. Once uniformly fatal, rhabdomyosarcoma of the genitourinary tract can now be cured with a combination of chemotherapy, radiation therapy, and surgical excision. ‘Sarcoma botryoides’ is a term used to describe the gross appearance of this tumour as it presents in the genitourinary tract: typically the tumour has the appearance of a bunch of grapes with multiple fronds of tissue (Fig. 42) 2200. Functional reconstruction of the urinary tract is possible in some of these patients, despite the presence of large tumours which need major surgery for removal (Fig. 43) 2201.

The treatment of gonadal malignancies in children is based on the same principles as those applied to adults. A testicular mass in a child should not be examined by biopsy through the scrotum. As in the adult, an inguinal incision is made, isolating the spermatic cord, occluding it with a non-crushing clamp and delivering the testis for inspection. If the tumour is malignant the cord is divided high and the testis is removed. Evaluation of these patients includes CT scan of the retroperitoneum and chest, and measuring levels of tumour markers, human chorionic genadotropin and &agr;-fetoprotein. If lymph nodes are involved, as is common in patients with rhabdomyosarcoma, retroperitoneal lymphadenectomy should be performed as a secondary procedure, usually in conjunction with chemotherapy.

Most ovarian masses in young girls are benign cysts, but teratoma and adenocarcinoma can occur. Ultrasound and CT scan can help to define the nature of an ovarian mass in a child. Treatment is surgical excision.

Vesicoureteral reflux

Arant B. Vesicoureteric reflux and renal injury. Am J Kidney Dis 1991; 17: 491.

Van den Abbeele AD, Vesicoureteral reflux in asymptomatic siblings of patients with known reflux: radionuclide cystography. Pediatrics 1987; 79: 147.

Ureteropelvic junction obstruction

Berstein GT, Mandell J, Lebowitz RL, Bauer S, Colodny AH, Retik AB. Ureteropelvic junction obstruction in the neonate. J Urol 1988; 140 (part 2): 1216.

Cockrell SN, Hendren WH. The importance of visualizing the ureter before performing pyeloplasty. J Urol 1990; 144 (part 2): 588.

Crooks KK, Hendren WH, Pfister RC. Giant hydronephrosis in children. J Pediatr Surg 1979; 14: 844.

Hendren WH, Radhakrishnan J, Middleton AW, Jr. Pediatric pyeloplasty. J Pediatr Surg 1980; 15: 133.

Lebowitz RL, Johan BG. The coexistence of ureteropelvic junction obstruction and reflux. Am J Radiol 1982; 140: 231.

Megaureter

Hendren WH. Operative repair of megaureter in children. J Urol 1969; 101: 491.

Peters CA, et al. Congenital obstructed megaureter in early infancy: diagnosis and treatment. J Urol 1989; 142: 641.

Ureterocele

Ashcraft KW, Hendren WH. Bladder outlet obstruction after operation for ureterocole. J Pediatr Surg 1979; 14: 819.

Decter RM, Roth DR, Gonzales ET. Individualized treatment of ureteroceles. J Urol 1989; 142 (part 2): 535.

Gross RE, Clatworthy HW. Ureterocele in infancy and childhood. Pediatrics 1950; 5: 68.

Hendren WH, Mitchell ME. Surgical correction of ureteroceles. J Urol 1979; 121: 590.

Kroovand RL, Perlmutter AD. A one-stage surgical approach to ectopic ureterocele. J Urol 1979; 122: 367.

Rich MA, Keating MA, Snyder HM, III, Duckett JW Jr. Low transurethral incision of single system intravesical ureteroceles in children. J Urol 1990; 144: 120.

Stephens FD. Caecoureterocele and concepts on the embryology and aetiology of ureteroceles. Aust NZ J Surg 1971; 40: 239.

Ectopic ureter

Johnson JH, Davenport TJ. The single ectopic ureter. Br J Urol 1969; 41: 428.

Mandell J, Bauer SB, Colodny AH, Lebowitz RL, Retik AB. Ureteral ectopia in infants and children. J Urol 1981; 126: 219.

Posterior urethral valves

Hendren WH. A new approach to infants with severe obstructive uropathy: early complete reconstruction. J Pediatr Surg 1970; 5: 184.

Hendren WH Posterior urethral valves in boys. A broad clinical spectrum. J Urol 1971; 106: 298.

Hoover DL, Duckett JW Jr. Posterior urethral valves, unilateral reflux and renal dysplasia: a syndrome. J Urol 1982; 128: 994.

Peters CA, et al. The urodynamic consequences of posterior urethral valves. J Urol 1990; 144 (part 2): 122.

Young HH, Frontz WA, Baldwin JC. Congenital obstruction of the posterior urethra. J Urol 1919; 3: 289.

Techniques

Ureteral reimplantation

Cohen SJ. Ureterozystoneostomie. Eine Neue Antireflux Technik. Aktuel Urol 1975; 6: 1.

Hendren WH. Ureteral reimplantation in children. J Pediatr Surg 1968; 3: 649.

Hendren WH. Reoperation for the failed ureteral reimplantation. J Urol 1974; 111: 403.

Hendren WH. Reoperative ureteral reimplantation: management of the difficult case. J Pediatr Surg 1980; 15: 770.

O'Donnell B, Puri P. Endoscopic correction of primary vesicoureteric reflux: results in 94 ureters. Br Med J 1986; 293: 1404.

Politano VA, Leadbetter WF. An operative technique for the correction of vesicoureteral reflux. J Urol 1958; 79: 932.

Transureteroureterostomy and psoas hitch

Hendren WH, Hensle TW. Transureteroureterostomy: experience with 75 cases. J Urol 1980; 123: 826.

Hodges CV, Moore RJ, Lehman TH, Behnam AM. Clinical experience with transureteroureterostomy. J Urol 1963; 90: 552.

Bladder neck reconstruction

Leadbetter GW Jr. Surgical correction of total urinary incontinence. J Urol 1964; 91: 261.

Peters CA, Hendren WH. Splitting the pubis for exposure in difficult reconstructions for incontinence. J Urol 1989; 142 (part 2): 527.

Young HH. An operation for the cure of incontinence associated with exstrophy. J Urol 1922; 7: 1.

Bladder augmentation

Adams MC, Mitchell ME, Rink RC. Gastrocystoplasty: an alternative solution to the problem of urological reconstruction in the severely compromised patient. J Urol 1988; 140: 1152

Goodwin WE, Winter CC, Barker WF. “Cup-patch” technique of ileocystoplasty for bladder enlargement or partial substitution. Surg Gynecol Obstet 1959; 108: 240.

Hendren WH, Hendren RB. Bladder augmentation: experience with 129 children and young adults. J Urol 1990; 144 (part 2): 445.

Leong CH. Use of stomach for bladder replacement and urinary diversion. Ann R Coll Surg Engl 1978; 60: 283.

Urinary diversion

Athausen AF, Hagen-Cook K, Hendren WH. Non-refluxing colon conduit: experience with 70 cases. J Urol 1978; 120: 35.

Bricker EM. Bladder substitution after pelvic evisceration. Surg Clin N Am 1990; 30: 1511.

Duckett JW, Jr. Cutaneous vesicostomy in childhood. The Blocksom technique. Urol Clin N Am 1974; 1: 485.

Goodwin WE, Harris AP, Kaufman JJ, Beal, JM. Open transcolonic ureterointestinal anastomosis: new approach. Surg Gynecol Obstet 1953; 97: 295.

Middleton AW, Jr, Hendren WH. Ileal conduits in children at the Massachusetts General Hospital from 1955 to 1970. J Urol 1976; 115: 591.

Retik AB, Perlmutter AD, Gross RE. Cutaneous ureteroileostomy in children. N Engl J Med 1967; 277: 217.

Richie JP, Skinner DG, Waisman J. The effect of reflux on the development of pyelonephritis in urinary diversion: an experimental study. J Surg Res 1974; 16: 256.

Richie JP, Skinner DG. Urinary diversion: the physiological rationale for nonrefluxing colonic conduits. Br J Urol 1975; 47: 269.

Smith ED. Follow-up studies on 150 ileal conduits in children. J Pediatr Surg 1972; 7: 1.

Urinary tract refunctionalization

Hendren WH. Urinary tract refunctionalization after long-term division. A 20-year experience with 177 patients. Ann Surg 1990; 212: 478.

Continent urinary diversion

Duckett JW Jr, Snyder HM, III. Continent urinary diversion: variations on the Mitrofanoff principle. J. Urol 1986; 136: 58.

Rowland RG, et al. The Indiana continent urinary reservoir. J Urol 1987; 137: 1136.

Skinner DG, Lieskovsky G, Boyd SD. Continuing experience with the continent ileal reservoir (Kock pouch) as an alternative to cutaneous urinary diversions: an update after 250 cases. J Urol 1987; 137: 1140.

Artificial urinary sphincter

Bosco PJ, Bauer SB, Colodny AH, Mandell J, Retik AB. The long-term results of artificial sphincters in children. J Urol 1991; 146: 396.

Hypospadias

Devine CJ, Horton CE. Hypospadias repair. J Urol 1977; 118: 188.

Hendren WH, Keating MA. Use of dermal free graft and free urethral graft in penile reconstruction. J Urol 1988; 140 (part 2): 1265.

Hendren WH, Ceasar RE. Chordee without hypospadias: experience with 33 cases. J Urol 1992; 147: 107.

Epispadias

Hendren WH. Penile lengthening after previous repair of epispadias. J Urol 1979; 121: 527.

Peters CA, Gearhart JP, Jeffs RD. Epispadias and incontinence: the challenge of the small bladder. J Urol 1988; 140 (part 2): 1199.

Bladder exstrophy

Lepor H, Shapiro E, Jeffs RD. Urethral reconstruction in males with classical bladder exstrophy. J Urol 1984; 131: 512.

Cryptorchidism

Gross RE, Replogle RL. Treatment of undescended testes. Opinions gained from 1967 operations. Postgrad Med 1963; 34: 266.

Huff DS, Hadziselimovic F, Snyder HM, III, Duckett JW, Jr, Keating MA. Postnatal testicular maldevelopment in unilateral cryptochidism. J Urol 1989; 142 (part 2): 546.

Neuropathic bladder

Spindel MR, et al. The changing neurourologic lesion in myelodysplasia. JAMA 1987; 258: 1630.

Intersex states

Donahoe PK, Hendren WH. Perineal reconstruction in ambiguous genitalia in infants raised as females. Ann Surg 1984; 200: 363.

Hendren WH, Crawford JD. The child with ambiguous genitalia. Curr Probl Surg 1972; Nov: 1.

Hendren WH, Donahoe PK. Correction of congenital anomalies of the vagina perineum. J Pediatr Surg 1980; 15: 751.

Cloacal anomalies

Hendren WH. Cloacal malformations: experience with 105 cases. J Pediatr Surg 1992; 27: 890.

Cloacal exstrophy

Diamond DA, Jeffs RD. Cloacal exstrophy: a 22-year experience. J Urol 1985; 133: 779.

Hurwitz RS, Manzoni GAM, Ransley PG, Stephens FD. Cloacal exstrophy: a report of 34 cases. J Urol 1987; 138: 1060.

Paediatric urologic tumours

D'Angio GJ, et al. Treatment of Wilms' tumor. Results of the Third National Wilms' Tumor Study. Cancer 1989; 64: 349.

Evans AE, D'Angio GJ, Koop CE. The role of multimodal therapy in patients with local and regional neuroblastoma. J Pediatr Surg 1984; 19: 77.

Loughlin KR, et al. Genitourinary rhabdomyosarcoma in children. Cancer 1989; 63: 1600.