What is hydronephrosis?
Dilation of the renal pelvis by urine (from back pressure)
When a kidney has a severely enlarged renal pelvis from hydronephrosis, why is the kidney surgically removed?
As the pelvis grows in size, there is less functioning kidney left and more urine stasis in the enlarged pelvis. Urine stasis makes the kidney prone to infection so, in these cases, the kidney is removed.
What is the most common cause of pediatric hydronephrosis?
Ureteropelvic junction obstruction.
Is ureteropelvic junction obstruction more common in boys or girls?
Is ureteropelvic junction obstruction more common in the left or right side?
More common in the left side (67%)
What are signs and symptoms of ureteropelvic junction obstruction?
Abdominal mass, pain, UTIs
True or False: Ureteropelvic junction obstruction coexists with other congenital abnormalities in almost 50% of cases.
What is the embryological cause for ureteropelvic junction obstruction?
Incomplete canalization of the ureteric bud at 12 weeks gestation and/or local abnormality of smooth muscle fibers with increased fibrosis impeding peristalsis
What is hydroureter?
Dilation of the ureter by urine
What is ureteral duplication?
This is the most common renal abnormality occurring in about 1% of the population and about 10% of children with UTIs. This abnormality causes repetitive UTIs and is more common in females.
It is a complete ureteral duplication in which 2 ureters ipsilaterally enter the bladder. It has a propensity for vesicoureteral reflux into the lower pole and obstruction of the upper pole, which may insert ectopically into the bladder or end in a ureterocele/blind pouch (80% of the time).
What are signs and symptoms for ureteral duplication?
Failure to toilet train or continuous drip incontinence
What is vesicoureteral reflux?
Urine traveling back up the ureter upon contractoin of the detrusor muscle of the bladder, usually resulting in hydroureter and hydronephrosis if severe.
What is a ureterocele?
A cystic dilatation of the terminal intravesical (portion within the bladder wall) ureter. The ureter terminates in the wall of the bladder without communicating into the bladder lumen. An ectopic ureterocele is at the bladder neck or the urethra, regardless of the position of the orifice.
It can often be obstructive if the orifice is stenotic or ectopically located and can cause reflux if the orifice is patulous.
True or False: Ureteroceles are often diagnosed prenatally when they are associated with hydronephrosis
Also often diagnosed during workup of UTI.
What is a urachal remnant?
It is a congenital abnormality where the urachus connects the dome of the fetal bladder to the allantois in the umbilical cord. Normally, the urachus involutes to form the median umbilical ligament.
This can cause pain and retraction of the umbilicus during micturition.
A cyst forms 30% of the time causing a painful midline mass between the umbilicus and the suprapubic area.
A sinus or fistula leads to drainage of clear or purulent urine at umbilicus and sometimes UTI.
What is megalocystis (megacystis)?
Chronic abnormal distension of the bladder by urine due to bladder outlet obstruction.
What are posterior urethral valves?
Abnormal congenital obstructing membrane located in the posterior male urethra. This results from abnormal insertion of the mesonephric duct on the cloaca prior to its dividing into the urogenital sinus and the anorectal canal. This causes abnormal development of all upstream structures due to chronic increased intraluminal pressure.
It is the most common cause of bladder outlet obstruction in boys. It is usually diagnosed prenatally or with anuria and bladder distention. The older boys may have a poor urine stream, UTI, or urinary incontinence.
What is a bladder diverticulum?
It is an outpouching of the bladder mucosa through a weakness in the muscular wall.
What is hypospadias?
This is when the orifice (meatus) of the penile urethra is incorrect. It's usually at the tip of the penis but in hypospadias the location can be anywhere along the ventral aspect of the penis. This results from abnormal fusion of urogenital folds from androgen insufficiency.
What is chordee?
A fibrous band causing the penis to curve toward its location, usually associated with hypospadias or epispadias
What is epispadias?
This is when the location of the urethral opening is on the dorsal aspect of the penis.
This is sometimes associated with bladder exstrophy (exposure of the bladder mucosa due to absence of the abdominal wall).
What causes exstrophy-epispadias complex?
Arises from failure of separation by the urorectal septum of the primitive cloaca into the urogenital sinus and anorectal canal at 6 weeks gestation.
This happens in every 3 in 100,000 births and is more common in males.
What are the consequences of fetal urinary tract obstruction or renal agenesis?
- Inability to excrete urine
- decreased amount of amniotic fluid
- less room for fetal movement
- loss of "normal" in utero respiration and impaired lung development (pulmonary hypoplasia. respiratory insufficiency is the cause of death)
What is potter's facies?
These are facial changes that happen due to lack of amniotic fluid during gestation (from fetal urinary obstruction or renal agenesis)
- large, flattened ears
- flattened nose
- infraorbital skin folds
What is amnion nodosum?
Nodules of squamous cells on the amniotic membrane. This happens in oligohydramnios. It appears as white spots on the placenta.
What is prune belly (eagle-barrett) syndrome?
Much less common.
Atrophy of anterior abdominal muscles due to megalocystic. Presents with undescended testes.