Genitourinary tract anomalies constitute about one third of all
congenital abnormalities and occur in over 10% of the population.
The severity varies from lesions incompatible with life to insignificant
findings detected during diagnostic studies for unrelated reasons.
The anatomic abnormalities are often not intrinsically harmful,
yet they may predispose to infection, stone formation, or chronic renal
Bilateral absence of the kidneys is rare and is associated with
oligohydramnios, Potter facies, and pulmonary hypoplasia. It occurs
more often in males and results in death shortly after birth. Unilateral renal
agenesis is seen more often but is not usually associated with illness. Renal
agenesis is thought to be due to both lack of a ureteral
bud and lack of subsequent development of the metanephric blastema.
The trigone is absent on the affected side. Because adrenal gland development
is unrelated to kidney development, both adrenals are usually present
in the normal position. Rarely, more than two kidneys are seen,
a condition clearly dissimilar to ureteral duplication, as described
Abnormal ascent of the metanephros leads to an ectopic
kidney, which may be unilateral or bilateral. Lumbar, pelvic,
and the less common thoracic and crossed ectopic varieties are seen.
Ectopic kidneys are associated with genital anomalies in 10–20% of
cases. Fusion abnormalities are also associated with failure of
normal ascent and include fused pelvic kidneys and horseshoe
kidneys (the most common), which are typically fused at the
lower poles. Intravenous urography typically establishes the diagnosis.
The relationship of the kidneys to the psoas muscles is abnormal:
Instead of an oblique orientation with the medial border of the
kidney parallel to the psoas muscle, the kidneys are vertical and
the medial border intersects and crosses the psoas muscle. Horseshoe
kidneys have an elevated incidence of vesicoureteral reflux and
are at increased risk of ureteropelvic junction obstruction. The
latter may be related to a high ureteral insertion in the renal
pelvis, crossing of the ureter over the isthmus, or compression by
one of many anomalous arteries. Failure of rotation during ascent
results in “malrotated” kidneys and is rarely
Parenchymal anomalies include a variety of cystic and dysplastic
lesions. Polycystic kidney disease is hereditary and bilateral.
The autosomal recessive polycystic kidney disease (ARPKD), previously
called infantile PKD, has numerous small cysts that arise only from
the collecting ducts and result in bilateral symmetrical enlargement
of the kidneys. The autosomal dominant ADPKD, previously called
adult PKD, has cysts arising from all areas of the nephron, which
are usually larger and more variable in size than the ARPKD cysts.
ARPKD occurs in 1 in 40,000 births and may be detected in utero
by the presence of enlarged hyperechogenic kidneys and oligohydramnios.
Infants usually die of respiratory failure rather than renal problems;
however, the 1-year survival probability after the first month is
over 85%. These children have declining renal function
as well as severe hypertension and hepatic periportal fibrosis with
portal hypertension leading to hypersplenism and esophageal varices.
The genes mutated in ADPKD may include the PKD1 gene
(located on chromosome 16p13.3) in 85% of patients or the PKD2 gene
(on chromosome 4q21-23) in 12% to 15% of patients.
These genes code for the polycystin-1 and polycystin-2 proteins,
respectively. ADPKD occurs in 1 in 1000 individuals and is a major
cause of end-stage renal disease in adults. Cysts may also be present
in the liver, pancreas, and spleen, and cerebral arterial aneurysms
may occur. Renal cystic enlargement exerts pressure on normal parenchyma,
leading to its gradual destruction and glomerulosclerosis.
The diagnosis is often made during a workup for hypertension
or uremia discovered in the third to sixth decades. Hematuria with
or without flank pain is a common finding. An intravenous urogram
reveals the enlarged kidneys, with marked elongation of the calices,
which are compressed by large cysts. Ultrasonography or CT scan
readily makes the diagnosis.
Surgery is rarely warranted. Therapy is medical and ultimately
includes dialysis. The median age for reaching end-stage renal disease
is 54 years in PKD1 and 74 years in PKD2. Renal transplantation
is often indicated, though potential family donors must be carefully
screened to determine whether they have the same disorder. The leading
cause of death in ADPKD is cardiovascular disease, which may relate
to early untreated hypertension.
Medullary sponge kidney results from collecting tubular ectasia
(see section on Polycystic Kidneys) and is associated with recurrent
urolithiasis and an increased incidence of infection in 50% of
patients. The lesion is often bilateral and may involve all of the
calices. Intravenous urograms reveal dilated collecting tubules
as a “blush” in the renal papilla. Microscopic
hematuria is common. Specific antibiotics should be given for documented
infections, and prophylactic therapy for renal stones should be recommended
on the basis of metabolic stone evaluation.
Simple renal cysts are common (approximately 50% after
age 50) and are thought to arise from tubular dilation. They may be
solitary or bilateral and multiple. They rarely have pathologic
significance except in the differentiation from solid renal masses.
(See the section on Renal Adenocarcinoma (Renal Cell Carcinoma).)
Multicystic dysplastic kidney is a congenital abnormality consisting
of macroscopic cysts of variable sizes compressing dysplastic renal
parenchyma. It is usually associated with an atretic proximal ureter.
The disorder occurs in about 1 in 3000 live births and is frequently
noted on prenatal ultrasound. Rarely, it may occur bilaterally and
is associated with oligohydramnios and renal failure. It may be
distinguished from other causes of hydronephrosis by the absence
of any renal function on renal scan. There is an increased incidence
of contralateral ureteropelvic junction obstruction (5–10%)
and reflux (18–43%), either of which increases
the patient’s risk of subsequent chronic renal insufficiency.
The chance of developing a malignancy in multicystic dysplastic
kidney appears to be no greater than 1 in 2000. There may also be
an increased incidence of hypertension. These two factors constitute
a rationale for treatment by nephrectomy. However, conservative management
with routine ultrasound examinations at intervals of 6 to 12 months
is reasonable practice, since about half involute within 5 years.
Multiple renal arteries occur in 15% to 20% of
patients and are significant only when they cause ureteropelvic
junction obstruction. Congenital renal artery aneurysms are
infrequent; they are differentiated from acquired lesions by their location
at the bifurcation of the main renal artery or at a distal branch
point. The lesions are usually asymptomatic, but they can cause
hypertension. They require surgical treatment only if hypertension
is uncontrolled, if they are incompletely calcified, or if they
have a diameter of more than 2.5 cm. Congenital arteriovenous
fistulas are rare but may result in hematuria, hypertension,
or cardiac failure necessitating operative treatment.
Ureteropelvic junction obstruction is the most common cause of
antenatal hydronephrosis. The condition may be associated with compression
by anomalous renal arteries or intrinsic stenosis of the junction.
The diagnosis is not uncommonly made when gross hematuria follows
minor trauma. Renal ultrasound provides a safe screening technique
in patients suspected of having ureteropelvic junction obstruction.
Diuretic renal scan may confirm the diagnosis and suggest functional
significance. Intravenous pyelogram or retrograde pyelography may
further define the anatomy. Bilaterality is not uncommon, and the
condition requires surgical repair if symptomatic or severe. Percutaneous
incision of the obstruction with short-term stenting has been successful
in adults. Symptoms include intermittent flank pain, particularly
with orally induced diuresis.
Cooper CS et al: Antenatal hydronephrosis: evaluation
and outcome. Curr Urol Rep 2002;3:131.
Hateboer N: Clinical management of polycystic kidney disease.
Clin Med 2003;3:509.
Winyard P, Chitty L: Dysplastic and polycystic kidneys: diagnosis,
associations and management. Prenat Diagn 2001;21:924.
of the Ureter
Congenital obstruction of the ureter may be due to ureterovesical
and ureteropelvic junction obstruction or to neurologic deficits
such as sacral agenesis or myelomeningocele. Functional ureteral obstruction—also
known as primary obstructive megaureter—is
not uncommon. Symptoms are renal pain during diuresis or resulting
from pyelonephritis. Excretory urograms depict dilation above the
obstruction. Vesicoureteral reflux is uncommonly associated with
megaureter. Milder forms without symptoms or significant hydronephrosis
are the rule and do not require treatment if renal function is normal. When
treatment is necessary, it consists of division of the ureter proximal
to the obstruction and reimplantation of the ureter into the bladder,
often involving ureteral tapering or plication.
Bifurcation of the ureteral bud before it interacts with the metanephric
blastema results in incomplete ureteral duplication, commonly in
the mid or upper ureter. A second ureteral bud from the metanephric
duct leads to complete ureteral duplication (Figure
38–4; right kidney) draining one kidney. This represents
the most common ureteral anomaly, occurring in 1 in 125 people.
It occurs twice as often in females. The presence of more than two
ureters on each side is not common, but bilaterality of ureteral
duplication occurs in 40%. Usually, all of the duplicated
ureters enter the bladder; the ureter draining the upper pole of
the kidney enters closest to the bladder neck (due to its later
reabsorption into the bladder). Because of this relationship, the
ureter draining the lower pole often has a short intramural tunnel
and an inadequate surrounding musculature and is thus prone to vesicoureteral
reflux. The ureter draining the upper pole may be ectopic (because
of its late absorption) and thus empty into the bladder neck, urethra,
or genital structures (vagina or vestibule in the female and seminal
vesicle or vas deferens in the male [Figure
38–4; left kidney]). The ureter draining
the upper pole is prone to obstruction and may be associated with
a ureterocele, which is a common cause of obstruction. Duplication
becomes significant when hydronephrosis or pyelonephritis occurs. The
diagnosis is made by intravenous urography. Ureteral reimplantation
to prevent recurrent infection is necessary in some cases. An anastomosis
between the upper pole renal pelvis and the lower pole ureter or
a low ureteroureterostomy are alternatives in selected cases. The upper
pole of the kidney and its ureter may require removal if obstruction
is severe and renal function of that segment is poor.
Duplication of ureters and ectopic ureteral orifice.
Complete duplication with obstruction to one ureter with ectopic
orifice on left. The ureter with the ectopic opening always drains
the upper pole of the kidney.
Ureteral ectopia can occur in the absence of duplication and
drain into any of the abnormal positions mentioned previously. If
the orifice lies proximal to the external urinary sphincter, no
incontinence ensues, but vesicoureteral reflux is common. In contradistinction
to the female, the ectopic orifice in the male never lies distal
to the external sphincter, making incontinence an extremely rare
presentation. Should the ectopic orifice in the female drain into
the vagina or at the vestibule, there may be continuous leakage
of urine apart from voiding. Most ectopic orifices involve the ureter
draining the upper pole of a duplicated system, and most are observed
in females. Hydroureteronephrosis
of the involved segment frequently occurs due to ureteral obstruction
as it traverses the muscle of the bladder neck.
An ectopic orifice may be seen beside the urethral orifice or
in the roof of the vagina on endoscopy. Renal ultrasound or intravenous
urograms often demonstrates hydroureteronephrosis of the upper renal
segment. Cystography may show reflux into the ectopic orifice but may
require cyclic voiding first to decompress the obstructed segment
with bladder neck relaxation and subsequently to permit reflux.
In the rare case when there is significant upper pole renal function, the
ureter can be divided and reimplanted into the bladder or lower
pole ureter. Usually, however, heminephroureterectomy is necessary.
A ureterocele is a ballooning of the distal submucosal ureter into
the bladder. This structure commonly has a pinpoint orifice and
therefore leads to hydroureteronephrosis. If large enough, it may
obstruct the vesical neck or the contralateral ureter. It is most
common in females with ureteral duplication and always involves
the ureter draining the upper renal pole.
Most ureteroceles are now detected by prenatal ultrasound. Symptoms
are usually those of pyelonephritis or obstruction. Intravenous
urograms may show a negative shadow in the bladder cast by the ureterocele.
The ureter and renal calices may be normal or may reveal marked
dilation or no excretory function at all. A cystogram may show reflux
into the ipsilateral lower pole ureter.
Treatment of ureteroceles depends on multiple factors, including
the presence or absence of reflux in any or all of the ureters as
well as whether or not the ureterocele is completely contained within
the bladder (intravesical/orthotopic) or if a portion is
at the bladder neck or urethra (extravesical/ectopic). A
simple method of establishing drainage involves cystoscopy and puncture
of the ureterocele. Associated reflux, if present, can be managed
with prophylactic antibiotics until the child has grown larger,
at which time a technically easier ureteral reimplant may be performed
with a decompressed ureter. In the relatively uncommon situation
when there is no associated reflux, an upper pole heminephrectomy
is considered. Minimally obstructive ureteroceles within the bladder
in adults do not require treatment.
Cooper CS et al: Long-term follow-up of endoscopic
incision of ureteroceles: intravesical versus extravesical. J Urol
Fretz PC et al: Long-term outcome analysis of Starr plication
for primary obstructive megaureters. J Urol 2004;172:703.
The main function of the ureterovesical junction is to permit
free drainage of the ureter and simultaneously prevent urine from
refluxing back from the bladder. Anatomically, the ureterovesical
junction is well equipped for this function, because the ureteral
musculature continues uninterrupted into the base of the bladder
to form the superficial trigone. Additionally, the terminal 4 to
5 cm of ureter are surrounded by a musculofascial sheath (Waldeyer’s
sheath) that follows the ureter through the ureteral hiatus and
continues in the base of the bladder as the deep trigone (Figure 38–5).
Vesicoureteral reflux. The length and fixation of the
intravesical ureter and the appearance of the ureteral orifice depend
on the muscular development and efficiency of the lower ureter and
its trigone. A: Normal structures. B: Moderate
muscular deficiency. C: Marked deficiency results in
a golf hole distortion of the submucosal ureter.
Direct continuity between the ureter and the trigone offers an
efficient, muscularly active, valvular function. Any stretch of the
trigone (with bladder filling) or any trigonal contraction (with
voiding) leads to firm occlusion of the intravesical ureter, thus
increasing resistance to flow from above downward and sealing the intravesical
ureter against retrograde flow (Figure 38–6).
Normal ureterotrigonal complex. A: Side
view of ureterovesical junction. The Waldeyer muscular sheath invests
the juxtavesical ureter and continues downward as the deep trigone,
which extends to the bladder neck. The ureteral musculature becomes
the superficial trigone, which extends to the verumontanum in the
male and stops just short of the external meatus in the female. B: Waldeyer’s
sheath is connected by a few fibers to the detrusor muscle in the ureteral
hiatus. This muscular sheath, inferior to the ureteral orifices,
becomes the deep trigone. The musculature of the ureters continues
downward as the superficial trigone. (Adapted from Tanagho EA, Pugh RCB: The anatomy
and function of the ureterovesical junction. Br J Urol 1963:35;151.
Reproduced with permission of Blackwell Publishing, Ltd.)
Vesicoureteral reflux may be classified as primary reflux due
to developmental ureterotrigonal weakness or associated with ureteral
anomalies such as ectopic orifice or ureterocele, and secondary
reflux due to bladder outlet or urethral obstruction, neuropathic
dysfunction, iatrogenic causes, and inflammation, especially specific
infection (eg, tuberculosis). Primary reflux is associated with
some degree of congenital muscular deficiency in the trigone and terminal
Reflux is associated with an increased incidence of pyelonephritis
and renal damage. It also allows bacteria free access from the bladder
Reflux is the most common cause of pyelonephritis and is found
in 30% to 50% of children presenting with urinary tract
infection. It is present in over 75% of patients with radiologic
evidence of chronic pyelonephritis and is responsible for end-stage
renal disease in a large percentage of patients requiring chronic dialysis
or renal transplantation.
In primary reflux, the child (on average, between 2 and 3 years
of age) usually presents with symptoms of pyelonephritis or cystitis.
Vague abdominal pain is not uncommon. Renal pain and pain with voiding
are relatively uncommon. On rare occasions, the patient may present with
advanced renal failure with bilateral renal parenchymal damage.
Significant reflux and its sequelae are more common in females and
are usually detected after a urinary tract infection. About one third
of the siblings of a child with reflux will also have reflux, and
one half of the children of a mother with reflux will also have
In secondary reflux, manifestations of the primary disease (neuropathic,
obstructive, etc) are usually the presenting symptoms.
With acute pyelonephritis, fever, chills, and costovertebral
angle tenderness may be present. Children usually do not have renal
pain but may complain of vague abdominal pain. Occasionally, daytime
frequency, incontinence, or enuresis may be caused by infection associated
with reflux. In cases of obstruction or neuropathic deficit, a palpable
hydronephrotic kidney or a distended bladder may be found. The diagnosis
may be elusive in infants who present with ill-defined symptoms.
Urinalysis usually reveals evidence of infection (pyuria and
bacteriuria). Urine cultures are mandatory when infection is suspected.
Renal function tests may be abnormal if reflux and infection have caused
The most useful study for conclusive diagnosis of reflux continues
to be voiding cystourethrography (Figure 38–7).
This study demonstrates the grade of reflux
as well as the urethral anatomy. Radionuclide voiding studies are
extremely sensitive at detecting reflux but do not demonstrate the
anatomic detail seen with a voiding cystourethrogram. Radionuclide
voiding studies are often performed as follow-up after an initial
voiding cystourethrogram because they offer the advantage of decreased radiation
Voiding cystourethrogram showing total (grade IV) left
Radioisotopic renal scanning provides accurate differential renal
function data and detection of renal scars. Ultrasound can provide
accurate measurement of renal
size and may demonstrate the presence of renal scarring and ureteral
or caliceal dilation. In many cases, there may be no abnormality
visible in the upper urinary tract, or only mild distal ureteral
dilatation may be seen.
A significant number of children with dysfunctional voiding present
with urinary tract infections and are subsequently found to have
reflux. These children contract the bladder against a closed external
sphincter. Elevated voiding pressures associated with dysfunctional
voiding may increase renal damage with an associated urinary tract
infection and may also lessen the chance for either spontaneous
or surgical resolution of reflux. When the history suggests the possibility
of voiding dysfunction (incontinence, frequency, urgency), urodynamic studies
are conducted to evaluate the voiding dynamics. Treatment of voiding dysfunction
may result in resolution of the reflux.
Although some children with lower grades of reflux may not require
antibiotics, traditionally any child with reflux was maintained
on prophylactic antibiotics to attempt to decrease the incidence
of urinary tract infections. Several recent studies suggest that
the practice of daily antibiotic prophylaxis in all children with reflux
may be of limited benefit in preventing urinary tract infection.
Prompt treatment of pyelonephritis prevents renal scar formation.
Factors causing secondary reflux—such as dysfunctional voiding
or obstruction—should be corrected.
In many children, reflux resolves with time. Reflux is graded
as seen on voiding cystourethrography as follows:
- Grade I: Contrast enters ureter
- Grade II: Contrast enters the renal collecting system
- Grade III: Slight dilation of the calices or ureter
- Grades IV and V: Progressively increased amounts of caliceal
dilation and ureteral dilation or tortuosity
Reflux most likely to resolve is of lower grade or detected at
a younger age. Over 70% of children with grades I, II,
or unilateral grade III reflux will have resolution within 5 years.
Resolution in children with grade V or bilateral grade IV reflux can
be anticipated in less than 10% of cases. Other factors
that appear to negatively affect the chance for reflux resolution
include early reflux during bladder filling, presentation with a
febrile urinary tract infection, renal scars, and voiding dysfunction.
In obstructive secondary reflux (eg, posterior urethral valves),
release of obstruction may cure reflux. Occasionally, surgical reimplantation
is still required. In neuropathic reflux, intermittent catheterization
for control of infection may allow return of valvular competence.
However, many cases require bladder augmentation for a noncompliant
bladder and ureteral reimplantation. In reflux associated with ectopic
orifices, duplication with ureterocele, and other congenital malformations,
reimplantation is generally required.
The aim of surgery is to correct the reflux. This is accomplished
by the creation of a longer submucosal tunnel for the ureter. With
bladder filling and increased pressure, the ureter is compressed
between the mucosa and underlying detrusor muscle. This flap valve
prevents reflux of urine. The necessary length of the tunnel to
stop reflux depends on the diameter of the ureter, with a 5:1 length-to-diameter
ratio being ideal. One of three methods is used in most cases: (1)
In suprahiatal repair (Politano-Leadbetter procedure), a new ureteral
hiatus is developed about 2.5 cm above the original one, and the
ureter—after passing through a submucosal tunnel—is
sutured to the cut edge of the trigone at the level of the original
orifice. (2) In the cross-trigonal repair (Cohen procedure), the
original hiatus is maintained, and the ureter is advanced through
a submucosal tunnel, extending across the trigone to the contralateral
bladder wall. (3) A totally extravesical ureteral advancement procedure
(extravesical ureteroplasty) achieves results similar to those achieved
with the intravesical methods, with a shorter hospital stay and
Injections of subureteric bulking agents have also been used
to increase submucosal support of the ureter. With proper placement
beneath the ureteral orifice under endoscopic vision, these injections act
to bolster the deficient antireflux mechanism. Concern regarding
late sequelae of Teflon injections (eg, particle migration) has
prevented use of this approach in the United States. Currently, hyaluronic
acid/dextranomer (NASHA/Dx) gel (Deflux) is the
only FDA-approved material for endoscopic injection to manage vesicoureteral
reflux in children. Short-term success in stopping reflux with the
injection techniques appears to be around 75%. The long-term
success rates with agents other than Teflon remain to be determined.
The long-term prognosis is excellent for patients with mild to
moderate reflux successfully treated with antibiotic prophylaxis.
There are few instances of recurrent infection or renal insufficiency. Patients
with more significant reflux or persistent urinary tract infections
may benefit from subureteric injection or surgical reimplantation;
the success rate is approximately 95% with the open surgical
technique (cessation of reflux, clearance of renal infection, and
absence of obstruction). Unfortunately, for patients with advanced
disease (irreversible ureteral decompensation and severe bilateral
scars), the prognosis is less favorable. These patients account
for a significant proportion of patients with end-stage renal disease
who ultimately require chronic dialysis, renal transplantation,
Austin JC, Cooper CS: Vesicoureteral reflux: surgical
approaches. Urol Clin North Am 2004;31:543.
Cooper CS, Austin JC: Vesicoureteral reflux: who benefits from surgery?
Urol Clin North Am 2004;31:535.
Cooper CS et al: The outcome of stopping prophylactic antibiotics
in older children with vesicoureteral reflux. J Urol 2000;163:269.
Elder JS et al: Pediatric Vesicoureteral Reflux Guidelines Panel
summary report on the management of primary vesicoureteral reflux
in children. J Urol 1997;157:1846.
Garin EH et al: Clinical significance of primary vesicoureteral
reflux and urinary antibiotic prophylaxis after acute pyelonephritis:
a multicenter, randomized, controlled study. Pediatrics 2006;117:626.
Jodal U et al: Infection pattern in children with vesicoureteral
reflux randomly allocated to operation or long-term antibacterial
prophylaxis: the international reflux study in children. J Urol
Knudson MJ et al: Predictive factors of early spontaneous resolution
in children with vesicoureteral reflux. J Urol 2007;178:1684.
Anomalies of the bladder are infrequent and include the following:
(1) agenesis, or complete absence, which results in
a persistent cloaca; (2) bladder duplication, which
may be complete, with separate ureteral openings drained by duplicated urethras,
or incomplete, with a septum or hourglass deformity; and (3) urachal anomalies, which
in the most severe forms appear as a patent opening at the umbilicus
and are usually associated with some form of bladder outlet obstruction.
In less severe forms, a urachal diverticulum may be
present at the dome of the bladder or a urachal cyst along
the course of the partially obliterated urachus. These latter conditions may
cause abdominal pain and umbilical or bladder infection requiring
surgical treatment. Occasionally, adenocarcinoma develops in a urachal
remnant (see section on Tumors of the Bladder).
Failure of cloacal division results in a persistent cloaca. Incomplete
division is more frequent (though still rare) and results in a rectovesical,
rectourethral, or rectovestibular fistula (usually with imperforate
anus or anal atresia).
Exstrophy of the bladder is the most severe bladder anomaly—the
result of a complete ventral defect of the urogenital sinus and
the overlying inferior abdominal wall musculature and integument. The
lower central portion is devoid of skin and muscle. The anterior
bladder wall is absent, and the posterior wall is contiguous with
surrounding skin. Urine drains onto the abdominal wall, the rami of
the pubic bones are widely separated, and the open pelvic ring may
affect gait. In males, the penis is shortened and the urethra is
epispadiac. The exposed bladder mucosa tends to be chronically inflamed.
Currently, the favored treatment is bladder salvage, which includes
closure of the bladder in the newborn period. Urethral closure and
penile reconstruction have also been advocated at the time of the
initial bladder closure. Ureteral obstruction or vesicoureteral
reflux may develop and require ureteral reimplantation. The closed
bladder may have a small capacity, and incontinence is often a complication.
Patients frequently require multiple operations, including bladder
augmentation and bladder neck reconstruction. Good results have
been observed in more than half of all patients treated, with preservation
of renal function and continence.
Cooper CS et al: Pediatric reconstructive surgery.
Curr Opin Urol 2000;10:195.
Prune belly syndrome consists of a triad of abnormalities: deficient
abdominal wall musculature, bilateral cryptorchidism, and variable
amounts of dilation of the urogenital tract. The cause is not known. Almost
all children with prune belly syndrome have reflux. The incidence
of eventual renal failure is 25% to 30%. Risk
factors for renal failure include bilateral abnormal kidneys on
ultrasound or renal scan, a serum creatinine that never falls below
0.7 mg/dL, and clinical pyelonephritis. These children
are managed with prophylactic antibiotics and frequent urine cultures,
followed by prompt treatment of any urinary tract infections. Abdominoplasty
may be performed to help correct the abdominal wall defect.
Noh PH et al: Prognostic factors of renal failure
in children with prune belly syndrome. J Urol 1999;162:1399.
Congenital neurovesical dysfunction frequently accompanies a
posterior myelomeningocele or sacral agenesis, with associated spinal
abnormalities. Both conditions may result in incontinence and recurrent
urinary infection with late sequelae (ureteral reflux, pyelonephritis,
and renal failure). These children require frequent evaluation of
their kidneys and kidney function because high bladder storage pressures
may harm the kidneys.
Hypospadias results from failure of fusion of the urethral folds
on the undersurface of the genital tubercle. The urethral meatus
is ventrally displaced on the glans on the shaft of the penis or
more proximal at the level of the scrotum or perineum. With more
proximal displacement, chordee (ventral curvature of the penile
shaft) frequently occurs and requires treatment, or it precludes straight
erections and normal intercourse (Figure 38–8).
The midscrotal hypospadiac penis may resemble
female external genitalia with an enlarged clitoris and labia. Sexual
assignment in these latter infants requires hormonal and chromosomal
Hypospadias, penoscrotal type. Redundant dorsal foreskin
that is deficient ventrally; ventral chordee.
In hypospadias with the meatus positioned proximal to the corona,
the prepuce is abnormal—not forming a complete cylinder
due to a ventral defect. Circumcision should not be done in these patients,
as the prepuce can be used later in surgical repair.
The degree of hypospadias dictates the need for repair. If the
opening is glandular or coronal (85% of patients), the penis
is usually functional both for micturition and procreation, and
repair is done primarily for cosmetic reasons. Openings that are
more proximal on the shaft require correction to allow voiding while
standing, normal erection, and proper sperm deposition during intercourse.
Surgical plastic repair of hypospadias is currently accomplished
by a variety of highly successful one-stage operations and is routinely performed
between 6 and 18 months of age. The most common complications of
hypospadias surgery include meatal stenosis and fistula formation;
however, improved techniques have decreased the incidence of these
Epispadias is a rare congenital anomaly that is commonly associated
with bladder exstrophy. When it occurs alone, it is considered a
milder degree of the exstrophy complex.
The urethra opens on the dorsum of the penis, with deficient
corpus spongiosum and loosely attached corpora cavernosa. If the
defect is extensive, it may extend to the bladder neck, causing
incontinence because of deficient sphincter muscles. The pubic bones
are separated, as in exstrophy. Marked dorsiflexion of the penis
is usually present.
Treatment consists of correction of penile curvature, reconstruction
of the urethra, and reconstruction of the bladder neck in incontinent
Congenital urethral strictures are rare but when present are
most common in the fossa navicularis (just proximal to the meatus)
and in the bulbomembranous urethra. Commonly, these strictures are thin
diaphragms that may respond to simple dilation or to direct vision
internal urethrotomy. Rarely is open surgical repair necessary.
Congenital urethral strictures in girls and meatal stenosis in boys
are uncommon. When the latter does occur, it appears to be acquired,
as it is seen only in circumcised boys.
In males, urethral diverticula are nearly always in the pendulous
or bulbous urethra. They are often associated with an obstructive
flap of the urethral mucosa (anterior urethral valve), thought to
represent incomplete closure of the urethral folds. Treatment by
endoscopic unroofing is usually successful, though most diverticula
are small and require no therapy. In females, they occur in adult
life and are usually manifested by irritative symptoms and recurrent
infection. The cause is unknown, but the disorder is most likely
congenital. Treatment is usually by transvaginal excision. Diverticula may
occasionally harbor stones or tumors.
Posterior urethral valves are the most common obstructive urethral
lesion in newborn and infant males and the most common cause of
end-stage renal disease in boys. They consist of obstructive folds
of mucosa, which originate at or are attached at some point to the
verumontanum in the prostatic urethra. The embryologic derivation
is indefinite. They are partially obstructive and thus lead to variable
degrees of back-pressure damage to the urinary bladder and upper
urinary tract. Dilation and obstruction of the prostatic urethra
are always present. Spontaneous urinary ascites from the kidneys
is often seen in neonates. This clears when the obstruction is relieved.
About one third of children with posterior urethral valves are
now diagnosed by prenatal ultrasound. Another one third are diagnosed
in the first year of life, with the remaining third presenting later.
Clinical manifestations consist of difficult voiding, a weak urinary
stream, and a midline lower abdominal mass that represents a distended bladder.
In some cases, the kidneys are palpable and the child may have signs
and symptoms of uremia and acidosis. Urinary incontinence and urinary
tract infection may occur. Laboratory findings include elevated
serum urea nitrogen and creatinine and evidence of urinary infection.
Ultrasound shows evidence of bladder thickening and trabeculation, hydroureter,
and hydronephrosis. Demonstration of urethral valves on a voiding
cystourethrogram establishes the diagnosis, as does endoscopic identification
of valves. Up to 70% of children with valves may have vesicoureteral
Treatment consists of destruction of the valves by endoscopic
incision. In a premature infant with a small urethra prohibiting
transurethral resection, a temporary cutaneous vesicostomy may be
required to provide drainage and improve impaired kidney function.
The prognosis depends on the original degree of kidney damage
and the success of efforts to prevent or treat infection. Rates
of chronic renal failure or end-stage renal disease range from 25% to
67% of boys with valves. Poor prognostic factors include
the presence of bilateral reflux or an elevated nadir serum creatinine
in the first year of life. Many of these children have delayed development
of urinary continence due to bladder changes and impaired urinary
Snodgrass W: Snodgrass technique for hypospadias repair. Br
J Urol (Int) 2005;95:683.
Ylinen E, Ala-Houhala M, Wikström S: Prognostic factors
of posterior urethral valves and the role of antenatal detection.
Pediatr Nephrol 2004;20:874.
Neonatal testicular torsion (extravaginal torsion) is an extremely
rare condition. The entire testicle and the tunica vaginalis are
twisted. No trigger mechanism associated with the torsion has been identified.
Although the vast majority are necrotic and nonsalvageable, several studies
have reported salvage of testicular tissue when torsion is detected
immediately following birth. Any scrotal swelling in the neonate
requires close follow-up. Intravaginal testicular torsion in adolescents
is described later in this chapter.
Cooper CS et al: Bilateral neonatal testicular
torsion. Clin Pediatr 1997;36:653.
Congenital scrotal lesions include hypoplasia of the scrotum
(unilateral or bilateral) in association with cryptorchidism and
bifid scrotum with extensive hypospadias. Midline inclusion cysts
may also occur.
True undescended testicles stop along the normal path of descent
into the scrotum. They may remain in the abdominal cavity (least
common), in the inguinal canal (canalicular), or just outside the
external ring (suprascrotal, most common). Testes may also pass
through the external ring and then be located ectopically, most
commonly in a superficial inguinal pouch. The incidence of undescended testicles
increases from 3% to 5% in full-term infants to 30% in
premature infants. Most undescended testicles descend within the
first 6 months of life, and by 1 year of age the prevalence is 1%.
The left testicle is affected more often, and 1% to 2% of
children with cryptorchidism will have both testicles affected.
Twenty percent of boys who present with cryptorchidism have one
nonpalpable testis. Of nonpalpable testes, 20% are intra-abdominal;
40% are canalicular, scrotal, or ectopic testes; and 40% are
atrophic or absent.
The diagnosis of cryptorchidism relies on physical examination.
Absence of an identifiable testicle with ultrasound, computed tomography,
or magnetic resonance imaging does not prove testicular agenesis
and therefore does not alter the need for surgical exploration.
Testicular examination in the infant and young child requires two
hands, with the first hand being swept from the anterior iliac spine
along the inguinal canal to gently express any retained testicular tissue
into the scrotum, which is palpated with the other hand. A true
undescended or ectopic inguinal testis may slip or “pop” under
the examiner’s fingers. To distinguish a retractile testicle,
the testicle is brought into the scrotal position, holding it in
place for a minute to fatigue the cremaster muscle. After this,
a retractile testicle remains in the scrotum, whereas an ectopic
or undescended testis immediately snaps back out of the scrotum.
If a testis cannot be palpated in the inguinal canal or the scrotum,
or in the typical ectopic sites, evaluation for a nonpalpable testis must
A child with bilateral nonpalpable testes should undergo hormonal
evaluation for testicular absence. Elevations in luteinizing hormone
(LH) and follicle-stimulating hormone (FSH) and absence of detectable
müllerian-inhibiting substance suggest testicular absence.
Testicular absence is confirmed by a negative human chorionic gonadotropin
(hCG) stimulation test. The hCG stimulation test is performed by
the administration of intramuscular hCG (2000 IU/day for
3–4 days). Raised gonadotropin levels (FSH and LH) and a
lack of a testosterone rise from hCG indicate bilateral absent testes,
and a formal surgical exploration is unnecessary. When one or both
components are lacking or there is detectable müllerian-inhibiting
substance, surgical exploration is warranted.
Treatment of the undescended testicle offers the possibility
of improved fertility, correction of patent processus vaginalis, prevention
of testis torsion, and improvement in body image. There is controversy
whether orchidopexy decreases the risk of malignancy, but placement
of an undescended testicle in the scrotum assists physical examination
of the testis. Histologic changes related to infertility occur in
the undescended testicle as young as 1 year of age, and spontaneous
descent rarely occurs after 6 months of age, making this the optimal
time for surgical correction.
Almost 90% of undescended testes have an associated patent
processus vaginalis, which predisposes to formation of a hydrocele
or hernia. Occult inguinal hernia in patients with untreated undescended
testis can present at any time with the typical symptoms or complications,
Prior to any surgical intervention, the patient is reexamined
while under anesthesia because on occasion a retractile testicle
descends under anesthesia or a previously nonpalpable testicle becomes palpable.
For a palpable testicle, an open inguinal approach is performed.
For the nonpalpable testicle in a child, a laparoscopic approach
is preferred, but an open inguinal approach may be performed.
Success rates following orchidopexy are 74% for the
abdominal testis, 87% for canalicular, and 92% for
those distal to the external ring. The most significant complication
is testicular atrophy, which occurs in 1% to 2% of
cases of orchidopexy, while complete devascularization of the testis
is rare. Paternity rates have been reported at 65%, 90%,
and 93% in men with bilateral cryptorchidism, unilateral
cryptorchidism, and normally descended testicles, respectively.
If only one testis is undescended, the sperm count is subnormal
in 25% to 33% patients, and serum FSH concentration
is slightly elevated. These abnormalities suggest that both testes
are abnormal, perhaps congenitally, although only one fails to descend.
If both testes are undescended, sperm count usually is severely subnormal,
and serum testosterone may be reduced.
Hormonal therapy is an option in the treatment of cryptorchidism
because the condition may be related to hypogonadotropic hypogonadism.
hCG is the only hormone approved for use in the treatment of cryptorchidism
in the United States. Side effects of hCG treatment include enlargement
of the penis, growth of pubic hair, increased testicular size, and aggressive
behavior during administration. The likelihood of success with hormonal
therapy is greatest for the most distal undescended testes or for
testes that have been previously descended. Some suggest that hormonal
therapy is effective only for retractile and not truly undescended
testes. Although hormonal therapy may not be effective in achieving
testicular descent, it may improve fertility in cryptorchid boys.
Hutcheson JC et al: The anatomical approach to
inguinal orchiopexy. J Urol 2000;164:1702.
Lee MM et al: Measurements of serum müllerian inhibiting
substance in the evaluation of children with nonpalpable gonads.
N Engl J Med 1997;336:1480.
Lee PA et al: Fertility after bilateral cryptorchidism. Evaluation
by paternity, hormone, and semen data. Hormone Res 2001;55:28.
Lesions of the Genitourinary Tract
Obstruction is one of the most important abnormalities of the
urinary tract, since it eventually leads to decompensation of the
muscular conduits and reservoirs, back-pressure, and atrophy of
renal parenchyma. It also invites infection and stone formation,
which cause additional damage and can ultimately end in complete
unilateral or bilateral destruction of the kidneys.
Both the level and the degree of obstruction are important to
an understanding of the pathologic consequences. Any obstruction
at or distal to the bladder neck may lead to back-pressure affecting
both kidneys. Obstruction at or proximal to the ureteral orifice
leads to unilateral damage unless the lesion involves both ureters
simultaneously. Complete obstruction leads to rapid decompensation
of the system proximal to the site of obstruction. Partial obstruction
leads to gradual progressive muscular hypertrophy followed by dilation,
decompensation, and hydronephrotic changes.
Acquired urinary tract obstruction may be due to inflammatory
or traumatic urethral strictures, bladder outlet obstruction (benign
prostatic hyperplasia or cancer of the prostate), vesical tumors,
neuropathic bladder, extrinsic ureteral compression (tumor, retroperitoneal
fibrosis, or enlarged lymph nodes), ureteral or pelvic stones, ureteral
strictures, or ureteral or pelvic tumors.
Regardless of its cause, acquired obstruction leads to similar
changes in the urinary tract, which vary depending on the severity
and duration of obstruction.
Proximal to the obstruction, the urethra dilates and balloons. A
urethral diverticulum may develop, and dilation and gaping of the
prostatic urethra and ejaculatory ducts may occur.
Early detrusor and trigonal thickening and hypertrophy compensate
for the outlet obstruction, allowing complete bladder emptying.
This change leads to progressive development of bladder trabeculation,
cellules, saccules, and, finally, diverticula. Subsequently, bladder
decompensation occurs and is characterized by the above changes
plus incomplete bladder emptying (ie, postvoid residual urine).
Trigonal hypertrophy leads to secondary ureteral obstruction owing
to increased resistance to flow through the intravesical ureter.
With detrusor decompensation and residual urine accumulation, there
is stretching of the hypertrophied trigone, which appreciably increases
ureteral obstruction. This is the mechanism of back-pressure on
the kidney in the presence of vesical outlet obstruction (while
the ureterovesical junction maintains its competence). Catheter
drainage of the bladder relieves trigonal stretch and improves drainage
from the upper tract.
A very late change with persistent obstruction (more frequently
encountered with neuropathic dysfunction) is decompensation of the
ureterovesical junction, leading to reflux. Reflux aggravates the
back-pressure effect on the upper tract by transmitting abnormally
high intravesical pressures and favors the onset or persistence
of urinary tract infection.
The first change noted is a gradual increase in ureteral distention.
This increases ureteral caliber and stimulates hyperactive ureteral
contraction and ureteral muscular hypertrophy. Because the ureteral
musculature runs in an irregular helical pattern, stretching of
its muscular elements leads to lengthening as well as widening,
causing the dilated ureter to assume a tortuous, serpiginous course, weaving
back and forth across the relatively straight course of the ureteral
vessels, which are unaffected by the ureteral obstruction. This
is the start of ureteral decompensation, where tortuosity and dilation
become apparent. These changes progress until the ureter becomes
atonic, with infrequent, ineffective, or completely absent peristalsis.
The renal pelvis and calices, subjected to increased volumes
of retained urine, distend. The pelvis shows evidence first of hyperactivity
and hypertrophy and then of progressive dilation and atony. The calices
show similar changes to a variable degree, depending on whether
the renal pelvis is intrarenal or extrarenal. In the latter, caliceal
dilation may be minimal in spite of marked pelvic dilation. In the
intrarenal pelvis, caliceal dilation and renal parenchymal damage
are maximal. The successive phases seen with obstruction are rounding
of the fornices, followed by flattening of the papillae and finally
clubbing of the minor calices.
With continued pelvicaliceal distention, there is parenchymal
compression against the renal capsule and, more importantly, compression
of the arcuate vessels results in a marked drop in renal blood flow
leading to parenchymal ischemic atrophy. With increased intrapelvic
pressure, there is progressive dilation of the collecting and distal tubules,
with compression and atrophy of tubular cells.
The findings vary according to the site of obstruction.
Infravesical obstruction (eg, due to urethral stricture, benign prostatic
hypertrophy, bladder neck contracture) leads to difficulty in initiation
of voiding, a weak stream, and a diminished flow rate with terminal
dribbling. Burning and frequency are common associated symptoms.
A distended or thickened bladder wall may be palpable. Urethral
induration due to stricture, benign prostatic hypertrophy, or cancer
of the prostate may be noted on rectal examination. Meatal stenosis and
impacted urethral stones are readily diagnosed by physical examination.
Renal pain or renal colic and gastrointestinal symptoms are commonly
associated. Supravesical obstruction (eg, due to ureteral stone,
ureteropelvic junction obstruction) may be completely asymptomatic
when it develops gradually over a period of months. An enlarged
kidney may be palpable. Costovertebral angle tenderness may be present.
Evidence of urinary tract infection, hematuria, or crystalluria
may be seen. Impaired renal function may be noted in cases of bilateral
obstruction. Postrenal azotemia (serum changes reflecting impaired
renal function due primarily to obstruction) is suggested by elevation
of serum urea nitrogen and serum creatinine with a ratio greater
Radiologic examination is usually diagnostic in cases of stasis,
tumors, and strictures. Dilation and anatomic changes occur above
the level of obstruction, whereas distal to the obstruction, the
configuration is usually normal. This helps in localizing the site
of obstruction. Combined antegrade imaging by intravenous urograms
and retrograde imaging by ureterograms or urethrograms is sometimes
needed to demonstrate the obstructed segment. In supravesical obstruction,
demonstration of stasis and delayed drainage is essential to establish
and quantitate the severity of obstruction.
Ultrasonography reveals the degree of dilation of the renal pelvis
and calices and allows for diagnosis of hydronephrosis even in the
prenatal period. Color Doppler ultrasound can reveal blood flow and
restrictive indices to help determine functional impairment.
A technetium-99m DTPA scan or MAG-3 scan portray the degree of
hydronephrosis as well as renal function. Use of diuretics during
the scan can provide specific data on the significance of the obstruction
and the need for treatment. Multiple studies can reveal ongoing
CT scan is of particular value in revealing the degree and site
of obstruction as well as the cause in many cases. The use of contrast
(CT urogram) agents allows estimation of residual renal function.
Magnetic resonance imaging provides anatomic images and identification
of the site of obstruction. With dynamic contrast-enhanced MR urography,
functional information is also obtained without the use of ionizing
Antegrade urography via percutaneous needle or tube nephrostomy
is valuable when the obstructed kidney fails to excrete the radiopaque
material on excretory urography. The Whitaker test requires percutaneous
catheter access to the collecting system above the site of suspected
obstruction. This permits fluid introduction into the renal pelvis
and simultaneous measurement of urine flow rate and pressures in
the bladder and renal pelvis, thus providing a quantitative assessment
of the degree and severity of obstruction. The fluid transport can
be measured and the degree of obstruction estimated by the use of
a pressure monitor.
The most important complication of urinary tract obstruction
is renal parenchymal atrophy as a result of back-pressure. Obstruction
also predisposes to infection and stone formation, and infection occurring
with obstruction leads to rapid kidney destruction.
The first goal of therapy is relief of the obstruction (eg, catheterization
for relief of acute urinary retention). Definitive therapy often
requires surgery, but minimally invasive techniques are becoming utilized
more often. Simple urethral stricture may be managed by dilation
or internal urethrotomy (incision of the stricture under direct
vision through the resectoscope). However, urethroplasty (open surgical
graft or flap of skin or buccal mucosa to replace urethral diameter) may
be required and have better long-term success. Benign prostatic
hyperplasia classically requires excision, but laser techniques
are providing satisfactory outcomes with less morbidity. Impacted
ureteral stones may either be removed or bypassed by a catheter
unless it is thought that they may pass spontaneously.
Ureteral or ureteropelvic junction obstruction requires surgical
repair; however, endoscopic approaches within the ureter or by laparoscopy
may be equal to open repair. Renal stones may be removed instrumentally
via retrograde or antegrade percutaneous approach by direct extraction
with baskets or by ultrasonic or laser lithotripsy or by irrigation through
a tube placed directly into the kidney.
Preliminary drainage above the obstruction is sometimes needed
to improve kidney function. Occasionally, intestinal urinary diversion
or permanent nephrostomy is required. If damage is advanced, nephrectomy
may be indicated.
The prognosis depends on the cause, site, duration, and degree
of kidney damage and renal decompensation. In general, relief of
obstruction leads to improvement in kidney function except in seriously
damaged kidneys, especially those destroyed by inflammatory scarring.
Grattan-Smith JD et al: MR imaging of kidneys:
functional evaluation using F-15 perfusion imaging. Pediatr Radiol
Padmanabhan P, Nitti VW: Primary bladder neck obstruction in
men, women, and children. Curr Urol Rep 2007;8:379.
Stenosis of the renal pelvis outlet is commonly due to congenital
narrowing of the junction or compression by anomalous vessels. However,
the lesion may be acquired. Presentation in adults often includes
the abrupt onset of flank pain usually following ingestion of large
amounts of fluids. Presentation in childhood is now most often made
following the diagnosis of hydronephrosis by prenatal ultrasonography.
The diagnosis may be confirmed with a diuretic nuclear renal
scan or intravenous urography, which reveals hydronephrosis with
a dilated renal pelvis and slow drainage of either radiotracer or contrast
medium. Occasionally, patients present with intermittent hydronephrosis and
normal urograms, except during attacks of pain, when x-rays show
typical obstruction. These patients generally have normal renal
parenchyma. Retrograde ureteropyelography is usually needed in patients
with chronic moderate to severe obstruction to determine the extent
of the lesion and to provide assurance that the distal ureter is
normal. Marked obstruction may make it difficult to determine whether
kidney function is surgically salvageable. In these cases, it may
be necessary to perform either (1) differential radioisotope renography
with use of a diuretic during the study or (2) percutaneous nephrostomy
and creatinine clearance by 24-hour urine collection.
Severe obstruction with minimal remaining renal function is best
treated by unilateral nephrectomy. If renal function is adequate
(> 10% of total renal function or > 10 mL/min
creatinine clearance), surgical repair of the stenosis, either by creation
of a renal pelvis flap or by resection of the stenotic area and
reanastomosis, is warranted. The use of ureteroscopy or percutaneous
nephroscopy with endopyelotomy, incising the strictured ureteropelvic
junction, offers an alternative method of therapy. This approach
appears less successful in the presence of a crossing vessel, poor
renal function, and significant hydronephrosis. Laparoscopic repair
has proponents as well. The surgical results of these methods are
excellent in terms of functional preservation, improvement of urine
flow, and relief of symptoms, but dilation of the calices may persist.
Tan BJ, Smith AD: Ureteropelvic junction obstruction
repair: when, how, what? Curr Opin Urol 2004;14:55.
Ureteral stenosis can be secondary to congenital or acquired
lesions. Congenital causes can include compression by an anomalous
vessels such as a lower pole renal artery in ureteropelvic junction obstruction
or a retroperitoneal vein or primary megaureter where the distal
ureter is partially obstructed. More commonly, the ureter is secondarily obstructed
due to acquired conditions such as inflammation from chronic ureteral
stones, trauma secondary to gynecologic or vascular surgery, or
external penetrating trauma from a knife or gunshot wound. Enlarged
pelvic lymph nodes or an iliac artery aneurysm or retroperitoneal
fibrosis may obstruct the ureter, as can intrinsic ureteral cancer
or bladder cancer infiltrating the ureter at its insertion into
the bladder. Finally, infection such as urinary tuberculosis can cause
distal ureteral strictures, and bilateral ureteral obstruction can
occur from bladder neck obstruction with urinary retention secondary
to benign prostatic hyperplasia.
Chronic conditions with slow development may not cause symptoms,
whereas acute obstruction such as that from a stone will cause severe
flank pain that may radiate to the groin or testes/labia. Diagnosis
is most often made by a CT urogram with contrast that will show delayed
function and a dilated renal pelvis and ureter down to the site
of the obstruction. This is often an unsuspected finding on a CT
done for other reasons in an asymptomatic patient.
Treatment depends entirely on the cause. Severe stenosis may
require resection of the lesion and spatulated end-to-end anastomosis
of the ureter. Less severe obstruction may be managed by cystoscopy
and ureteral or balloon dilation of the narrowed area under direct
vision via a ureteroscope. Placement of an indwelling ureteral stent
may dilate the stenosis over time and be a useful treatment as well
in selected patients.
One or both ureters may be compressed by a chronic inflammatory
process, usually of unknown cause, which involves the retroperitoneal
tissues of the lumbosacral area. Patients treated for migraine with
methysergide may develop this fibrosis. Sclerosing Hodgkin disease and
fibrosis from metastatic cancer have also been implicated. Symptoms
include renal pain, low backache, and those associated with uremia.
Some patients present with complete anuria. Urinary infection is
unusual. If both ureters are obstructed, the serum creatinine is
Excretory urograms show hydronephrosis and a dilated ureter down
to the point of obstruction. The ureters are displaced medially
in the lumbar area. Retrograde ureterograms show a long segment
of ureteral stenosis, though a catheter passes easily through the
ureter. Sonograms and CT scans may demonstrate fibrous plaques with
proximal hydroureteronephrosis. If the patient is anuric, indwelling ureteral
catheters or percutaneous nephrostomy should be done. When the patient’s
condition has improved, definitive therapy can be accomplished.
If methysergide is suspected to be the causative agent, fibrosis
may subside when the drug is discontinued. These patients may benefit
from administration of corticosteroids. Chronic indwelling ureteral
stents have also been used successfully. If these methods fail,
ureterolysis must be performed to free the ureter from the fibrous
plaque. The involved ureter should be dissected from the plaque, moved
to a lateral position, and wrapped with omentum to prevent recurrent
entrapment. This has been accomplished quite successfully with a
- Prostatism: nocturia, hesitancy, slow stream, terminal
- Residual urine.
- Acute urinary retention.
- Uremia in advanced cases.
The cause of benign prostatic enlargement is not known but is probably
related to hormonal factors. The mechanism for opening and funneling
the vesical neck at the time of voiding is altered by hyperplasia
of the prostate, which causes increased outflow resistance. Consequently,
a higher intravesical pressure is required to accomplish voiding,
causing hypertrophy of the vesical and trigonal muscles. This may lead
to the development of bladder diverticula—outpocketings
of vesical mucosa between the detrusor muscle bundles. Hypertrophy
of the trigone causes excessive stress on the intravesical ureter,
producing functional obstruction and resulting in hydroureteronephrosis
in late cases. Stagnation of urine can lead to infection; the onset
of cystitis exacerbates the obstructive symptoms. The periurethral
and subtrigonal prostate enlargement produces the most significant
The prostate in young men has an anatomic capsule like an apple
peel. In men with prostatic enlargement, there is a thick “surgical” capsule
similar to an orange peel, composed of peripherally compressed true
prostatic tissue (“peripheral zone”). The hyperplastic benign
periurethral glands correspond to the “transition zone” and
are the cause of the obstruction (Figure 38–9).
Benign prostatic hyperplasia. The enlarged periurethral
glands are enclosed by the surgical capsule. The true prostate has
Typically, the patient has lower urinary tract symptoms and notices
hesitancy and loss of force and caliber of the stream. The urgent
need to void when the bladder is nearly full may be an early sign.
He may also be awakened by the urge to void several times at night
(nocturia). Postvoid dribbling (“terminal dribbling”)
is particularly disturbing. The complication of infection increases
the degree of obstructive symptoms and is often associated with
burning on urination. Acute urinary retention may supervene. This
is associated with severe urgency, suprapubic pain, and a distended,
The size of the prostate rectally is not of primary diagnostic
importance, since there is a poor correlation between the size of
the gland and the degree of symptoms and amount of residual urine. The
American Urological Association (AUA) developed a 7-item, self-administered questionnaire (AUA symptom score)
that can assist the patient and physician in evaluating the patient’s lower
urinary tract symptoms.
Urinalysis may reveal evidence of infection. Residual urine is
commonly increased (> 50 cc), and a timed urinary flow rate is decreased
(< 10–15 cc/s). The serum creatinine may be
elevated in cases with prolonged severe obstruction.
Excretory urograms are often normal and not diagnostic and are
thus not required. In late-stage cases, the study may show hydroureteronephrosis
if severe obstruction is present. This almost always resolves after
prostatectomy. The enlarged gland may cause an indentation in the
inferior surface of the bladder, which may result in a J-hook
deformity of the distal ureter. The postvoiding film may reveal
varying amounts of residual urine. Renal ultrasound examination
may obviate the need for urograms; however, imaging is not required
to make the diagnosis or to determine the need for or method of treatment.
Pelvic ultrasound in the office setting accurately predicts the
amount of residual urine and thus obviates bladder catheterization.
Bladder cystoscopy reveals secondary vesical changes (eg, trabeculation)
and enlargement of the periurethral prostatic glands; however, cystoscopy
is not required to make the diagnosis. It may identify other conditions
such as bladder stones or tumors in selected cases.
Simultaneous physiologic monitoring of bladder filling and emptying,
urethral sphincter activity, abdominal pressure, and pelvic floor
muscle activity (electromyography) can be extremely useful in documenting
whether bladder outlet obstruction, poor bladder function, or other
causes are responsible for lower urinary tract symptoms. While urodynamic
studies are not required for diagnosis in all cases, they are helpful
in cases with large postvoid residual volumes or underlying neurologic
disease to help determine appropriate management.
Neuropathic bladder may produce a similar syndrome. A history
suggesting a neuropathic difficulty, such as diabetes mellitus,
stroke, or spinal cord injury or compression, may be obtained. Neurologic
deficit involving S2-4 is particularly significant.
Cancer of the prostate also causes symptoms of vesical neck obstruction.
Serum prostate-specific antigen may be elevated in patients with
benign prostatic hypertrophy, and the level increases as the volume
of the prostate increases. Thus, an absolute value is not diagnostic,
but in general, if it is over 10 ng/mL, the possibility
of cancer should be evaluated.
Acute prostatitis may cause symptoms of obstruction, but the
patient is septic and has infected urine. The prostate is exquisitely
Urethral stricture diminishes the caliber of the urinary stream.
There is usually a history of gonorrhea or local trauma. A retrograde
urethrogram shows the stenotic area. A stricture blocks the passage
of an instrument or catheter.
Obstruction and residual urine lead to vesical and prostatic
infection and occasionally pyelonephritis; these may be difficult
The obstruction may lead to the development of bladder diverticula.
Infected residual urine may contribute to the formation of calculi.
Functional obstruction of the intravesical ureter, caused by the
hypertrophic trigone, may lead to hydroureteronephrosis.
The indications for operative management are impairment of or
threat to renal function and bothersome symptoms. Because the degree
of obstruction progresses slowly in most patients, conservative
treatment may be adequate. Drugs that relax the prostatic capsule and
internal sphincter (α-adrenergic blocking agents)
or decrease the volume of the prostate (5α-reductase
inhibitors or antiandrogens) have been tried with considerable success.
Treatment of chronic prostatitis may reduce symptoms. The resolution
of a complicating cystitis usually affords some relief. In order
to protect vesical tone, the patient should be cautioned to void
as soon as the urge develops. Forcing fluids over a short time causes
rapid vesical filling and decreasing vesical tone; this is a common
cause of sudden acute urinary retention and thus should be avoided.
Patients with urinary obstructive symptoms should avoid the use
of cold remedies, including antihistamines, because they are also
a common cause of urinary retention. These conservative measures
are of only temporary help—if any—in patients
with prostatic hyperplasia. There has been recent great interest,
particularly by patients, in the use of phytotherapy for treatment
of lower urinary tract symptoms, including saw palmetto, pumpkin
seeds, and other plant extracts. Despite the claim of efficacy,
however, adequate scientific studies have not been done.
Controversy surrounds choices in the treatment of benign prostatic
hyperplasia. No treatment (watchful waiting) may be appropriate
in patients who complain of mild to moderate symptoms and thus have
low AUA symptom scores and residual urine less than 70 cc to 100
cc. Interest has also focused on nonoperative medical therapy for
those with more significant symptoms. α-Adrenergic blocking agents
relax the internal (bladder neck) sphincter and prostatic capsule.
Selective agents that are long-acting and preferentially work for
this purpose include doxazosin and tamsulosin. 5α-Reductase
inhibitors block conversion of testosterone to dihydrotestosterone (the
androgen active in promoting prostate growth) and are useful for
large glands, particularly in combination with an alpha-blocker,
which has been shown to best prevent urinary retention and other
common progressive symptoms of prostatic obstruction.
Catheterization is mandatory for acute urinary retention. Spontaneous
voiding may return, but a catheter should be left indwelling for
3 days while detrusor tone returns. If this fails, treatment is
There are four classic approaches used in prostatectomy: transurethral,
retropubic, suprapubic, and perineal. The transurethral route is
preferred in patients with glands weighing under 50 g to 70 g because
morbidity rates are lower and the hospital stay is shorter. Larger
glands may require open surgery, depending on the preference and
experience of the urologist. The death rate is low in each procedure
(1–2%). Potency is at greatest risk when the transperineal
exposure is used, but impotence occasionally results following transurethral
resection of the prostate.
An alternative approach to the treatment of benign prostatic
hyperplasia is transurethral incision of the prostate. This procedure
consists of incision of the prostate at the bladder neck up to the verumontanum,
allowing expansion of the entire prostatic urethra. It is especially
effective when the primary point of obstruction is caused by a “median
bar” or high posterior lip of the bladder neck without
lateral lobe obstruction.
Additional alternative treatments are transurethral vaporization,
laser prostatectomy, transurethral microwave thermotherapy, transurethral
needle ablation, and high-intensity focused ultrasound ablation
of the prostate. Laser prostatectomy seems to have the most promise
at present, and recent data suggest that Holmium and KTP (potassium
titanyl phosphate) laser may have nearly the same efficacy as transurethral
resection of prostate, with less morbidity. However, long-term results
of randomized trials are pending.
Most patients with marked symptoms receive considerable relief
and substantial improvement in urine flow following surgical treatment;
however, those with milder forms may benefit from drug therapy.
American Urological Association: Clinical guidelines.
Management of BPH. Available at www.auanet.org
. Accessed February
Lam JS, Cooper KL, Kaplan SA: Changing aspects in the evaluation
and treatment of patients with benign prostatic hyperplasia. Med
Clin North Am 2004;88:281.
Tan A et al: Meta-analysis of holmium laser enucleation versus transurethral
resection of the prostate for symptomatic prostatic obstruction.
Br J Surg 2007;94:1201.