A/2. Developmental disorders of the kidney, the ureter and the bladder Flashcards
Renal agenesis
- (unilateral/bilateral)
- Agenesis means absent organ due to absent primordial tissue
unilateral renal agenesis symptoms
If unilateral, majority of cases are asymptomatic with compensatory hypertrophy of the contralateral kidney;
but abnormalities of the contralateral kidney are
common
Renal hypoplasia
Kidney is smaller than normal (hypoplastic), usually structurally normal.
- Associated with reduced number of functional nephrons, with increased risk of developing kidney failure
DEVELOPMENTAL DISORDERS OF THE KIDNEY
- Renal agensis
- renal hypoplasia
- Multicystic
dysplastic kidney - horseshoe kidney
- potter sequence
Multicystic
dysplastic kidney - pathology
Ureteric bud fails to induce differenciation of metanephric mesenchyme -> non-functional kidney consisiting of cysts and Connective tissue
- Predominantly non-hereditary and unilateral; bilateral leads to potter sequence
multicystic dysplastic kidney- it unilateral or bilateral?
- Predominantly non-hereditary and unilateral;
- bilateral leads to potter sequence
unilateral multicystic dysplastic kidney is it hereditary?
predominanly Non-hereditary
Horseshoe kidney def
Inferior poles of both kidneys fuse abnormally > as they ascend from the pelvis (during normal embryogenesis)
–>horseshoe kidney get trapped under the inferior mesenteric artery
how is renal function in horseshoe kidney
Renal function is usually normal
horseshoe kidney is associated with ?
increases risk for
- hydronephrosis (ureteropelvic junction obstruction)
- stone
- infections
- increased risk of cancer
Potter sequence what is it
oligohydramnios
> compression of developing fetus
> limb deformities
> facial anomalies
> compression of chest and lack of amniotic fluid aspiration into fetal lung
> pulmonary hypoplasia
causes of potter sequence
- ARPKD
- obstructive uropathy
- bilateral renal agenesis
- chronic placental insufficiency
- BILATERAL MULTICYSTIC dysplastic kidney
DEVELOPMENTAL DISORDERS OF THE COLLECTING SYSTEMS AND URETERS
- Duplex collecting system
- Ureteropelvic junction obstruction (UPJ)
- Vesicoureteral reflux (VUR
- Ureterocele
- Posterior urethral
valve
Duplex collecting
system what is it
- ## Y-shaped bifid ureter
duplex collecting system what is associated with
Associated with
* vesicoureteral reflux (VUR)
* and/or ureteral obstruction
* increased risk of UTI
Ureteropelvic
junction obstruction etiology
- Congenital (inadequate canalization)
or - acquired (trauma, fibrosis)
Ureteropelvic
junction obstruction presentation
- May be asymptomatic,
- or present with recurrent UTIs
- stone disease
- palpable mass
- hydronephrosis
Ureteropelvic
junction obstruction treatment
Pyeloplasty is the treatment of choice,
but if the affected kidney possesses < 10%
of total renal function, nephrectomy should be performed
when is nephrectomy indicated in ureteropelvic junction obstruction
Pyeloplasty is the treatment of choice,
but if the affected kidney possesses < 10%
of total renal function, nephrectomy should be performed
Vesicoureteral
reflux (VUR) definition
- Retrograde regurgitation of urine from the urinary bladder up the ureter and into the collecting system of the kidneys
Vesicoureteral
reflux (VUR) is a end result of
several anomalies related to the functional integrity of the
* ureter
* bladder dynamics
* and the anatomic composition of the ureterovesical junction (UVJ)
Vesicoureteral
reflux (VUR) presents with
- recurrent UTIs,
- chronic pyelonephritis > may develop CKD (‘reflux nephropathy’)
Ureterocele def
Cystic out-pouching of the distal ureter into the urinary bladder
Ureterocele presentation
- May be asymptomatic
- or present with recurrent cystitis
- bladder outlet obstruction; eventually may develop CKD
Posterior urethral
valve defintion
Membranous remnant in the posterior urethra in males;
it’s persistence can lead to urethral obstruction
persistance of posterior urethral valve can lead to
urethral obstruction
Posterior urethral
valve can be diagnosed prenatally how?
can be diagnosed prenatally by
* bilateral hydronephrosis
* and dilated or thickened bladder wall on US
Most common cause of bladder outlet obstruction in male infants
posterior urethral valve
posterior urethral valve is associated with
oligohydramnios in cases of severe obstruction
DEVELOPMENTAL DISORDERS OF THE URINARY BLADDER
- Urachus
anomalies
* Patent
urachus
* Urachal cyst
* Vesicourachal
diverticulum
2.Bladder exstrophy
Urachus- what is it
duct between the fetal bladder and umbilicus
Urachus
anomalies are associated with increased risk of
associated with :
* UTI and
* increased risk of bladder adenocarcinoma
Patent
urachus - what is it
Total failure of urachus to obliterate > urine discharge from umbilicus
Urachal cyst definition
- fluid-filled cavity lined with uroepithelium, between umbilicus and bladder
- Cyst can become infected and present as painful mass below umbilicus
Urachal cyst etiology
Partial failure of urachus to obliterate; fluid-filled cavity lined with
uroepithelium, between umbilicus and bladder
complication of urachal cyst and its presentation
Cyst can become infected and present as painful mass below umbilicus
Vesicourachal
diverticulum - definition
Slight failure of urachus to obliterate > outpouching of bladder
Bladder exstrophy def
Protrusion of the urinary bladder through a defect in the abdominal wall
Bladder exstrophy presentation
- Usually present with a wide range of congenital anomalies, affecting the
1. pelvic bones,
2. genitals,
3. reproductive tract,
4. and gastrointestinal tract
