Editing Pediatrics: Prune-Belly Syndrome (section)

== Diagnosis and Evaluation ==

* '''Clinical Features'''
** '''Broad spectrum of severity''', with some children not surviving the newborn period and others being minimally affected
** '''The most important determinant of long-term survival is''' usually the severity of the urinary tract anomaly, in particular, '''the degree of renal dysplasia'''
** '''<span style="color:#ff0000">Major findings of PBS (3):'''
**# '''<span style="color:#ff0000">Deficiency of the abdominal musculature'''
**# '''<span style="color:#ff0000">Bilateral intra-abdominal testes'''
**# '''<span style="color:#ff0000">Genitourinary anomalies'''

=== Genitourinary Anomalies ===

# '''<span style="color:#ff0000">Kidneys'''
#* '''<span style="color:#ff0000">Non-obstructive hydronephrosis is the rule'''
#** Collecting system is characteristically dilated, often to a severe degree, however, the calyceal morphology may be well preserved
#** '''The degree of dilation does not correlate with the degree of renal dysplasia'''
# '''<span style="color:#ff0000">Ureters'''
#* '''<span style="color:#ff0000">Dilated and tortuous'''
#* '''Ureteral dysfunction is related to''':
#** Ureteral dilatation with failure of luminal coaptation during peristalsis
#** Reduced smooth muscle tissue and increased amount of fibrous connective tissue
#** Failure of propagation of an electrical conduction due to increased fibrous connective tissue.
#** Abnormal myofilament content in smooth muscle cells
#* '''The most normal portion of the ureter with the greatest amount of smooth muscle is in the proximal segment'''. This is the segment that should be preserved for reconstruction.
#* '''<span style="color:#ff0000">Vesicoureteral reflux is present in 75% of children'''
# '''<span style="color:#ff0000">Bladder'''
#* Usually massively '''enlarged with a pseudodiverticulum at the urachus'''
#* '''Urachus is patent''' at birth in 25-30% of children  
#* '''Wide bladder neck''' opening into a dilated prostatic urethra
#* Usually, urodynamics reveals
#** Excellent detrusor compliance; the end-filling pressure assumes a normal value; and the bladder functions well as a reservoir.
#** Delayed first sensation to void, and bladder capacity may be more than double the normal volume.
#** Presence of vesicoureteral reflux and reduced detrusor contractility.
#* '''≈50% patients void spontaneously with normal voiding pressures''', normal flow rates, and low postvoid residuals
# '''<span style="color:#ff0000">Prostate and Accessory Sex Organs'''
#* '''Prostatic hypoplasia'''
#** Thought to be a factor in the '''ejaculatory failure''' of PBS patients
#** '''Dilation of the posterior urethra is caused by prostatic hypoplasia and results in retrograde ejaculation'''
#* The vas and seminal vesicles are often atretic.
# '''<span style="color:#ff0000">Anterior urethra'''
#* '''Most common anterior urethral anomalies:'''
#** '''Urethral atresia'''
#** '''Hypoplasia and megalourethra'''
#*** The fusiform type of megalourethra involves deficiencies of the corpus cavernosum and corpus spongiosum, whereas the scaphoid variety involves a deficiency of corpus spongiosum only.
# '''<span style="color:#ff0000">Testes'''
#* '''<span style="color:#ff0000">Bilateral intra-abdominal testes</span>''' lying over the iliac vessels and adjacent to the dilated ureters are the most typical findings
#* '''No difference in germ cell counts''', '''Ad spermatogonia, and Leydig cells between PBS testes and non-PBS intra-abdominal testes'''
#** This implies that the environmental state of the abdomen is a major factor in their later spermatogenic potential

=== Extra-genitourinary Abnormalities ===

# '''<span style="color:#ff0000">Abdominal Wall Defect'''
#* The inferior and medial segments are the most consistently affected
# '''<span style="color:#ff0000">Cardiac Anomalies'''
## '''Patent ductus arteriosus'''
## '''Atrial septal defect'''
## '''Ventricular septal defect'''
## '''Tetralogy of Fallot'''
# '''<span style="color:#ff0000">Pulmonary'''
#* '''Pulmonary hypoplasia'''
#** Can result from severe oligohydramnios related to renal dysplasia or severe bladder outlet obstruction
#* '''Pneumomediastinum'''
#* '''Pneumothorax'''
#* '''Pneumonia and lobar atelectasis'''
# '''<span style="color:#ff0000">Gastrointestinal abnormalities'''
#* '''Increased bowel mobility with intestinal malrotation, volvulus, atresias, and stenosis'''

* It is exceptionally rare to encounter a normal urinary tract in association with the characteristic abdominal wall defect in a male. However, the converse is not unusual. Some patients (with pseudo-prune-belly syndrome) with a normal or relatively normal abdominal wall exhibit many or all of the internal urologic features. These features may include dysplastic or dysmorphic kidneys or dilated and tortuous ureters

=== Prenatal Diagnosis ===

* Prenatal US may demonstrate:
*# Hydronephrosis
*#* Can be diagnosed accurately in the second trimester and is present in ≈1% of all pregnancies
*# Enlarged bladder
*# Ascites presenting in the second trimester
*# Irregular abdominal wall circumference
** Although external genital anomalies such as bilaterally undescended testes and megalourethra occur with prune-belly syndrome, these would not be detected on prenatal ultrasound as abnormalities of external genital development.

=== Female Syndrome ===

* '''5% of PBS patients are female'''
* '''Females with PBS exhibit the abdominal wall deficiency and urinary tract dysmorphism without any gonadal anomaly'''