Not true about congenital PUJ obstruction is -
It was earlier believed that the aberrant renal vessels is responsible for causing the cong. PUJ obstruction Bailey writes that - "Aberrant vessels probably do not cause hydronephrosis, although a hydronephrotic renal pelvis may bulge between renal vessels."
Cambells Urology writes - "whether the aberrant vessel causes obstruction or is a co variable that exists along with an intrinsic narrowing is unclear"

Important points about Congenital PELT obstruction 

Cong. PUJ obstruction is the most common cause of significant dilatation of the collecting system in the fetal kidney.
Incidence is more in boys (2:1)
Usually unilateral but bilateral in 10-40% of cases (I could not find 10-15% of cases, but option 'C' can be taken as correct, weighing it against option D)
More common in left side
Associated anomalies -



Renal dysplasia
Multicystic dysplastic kidney
Renal agenesis

(Cambell urology writes - "Unilateral renal agenesis has been noted in almost 5% of children")

Vescico - ureteric reflux
PUJ obstruction was noted in 21% of children with the VATER group of anomalies


(VATER stands for vertebral defects, imperforate anus, tracheoesophageal fistula, radial and renal dysplasia)
Most common presentation of cong. PUJ obstruction is asymptomatic. Cambell writes - " Now the almost
universal use of prenatal sonography has made discovery of PUJ obstruction a common occurance"

Diagnostic tools -

Majority of cases are diagnosed prenatally with the help of ultrasound.
Whitaker test (pressure - flow studies) can be used to find out obstruction to flow of urine,
In whitaker test catheters are placed in renal pelvis and bladder. Fluid is infused into the kidney and the pressures are measured. A differential pressure between kidney and bladder could then be indicative of obstruction to the flow.
Retrograde pyelography can be useful to locate the site of obstruction.

Surgical repair

Congenital PUJ obstruction are corrected by either-open surgical techniques or -endoscopic and laparascopic approaches
Out of the 'open' techniques the Anderson- Hynes Dismembered Pyeloplasty is the most commonly employed technique.
Endoscopic approaches include,
endoscopic pyelotomy
ballon dilatation
stent placement
Can be associated with renal agenesis
Can be diagnosed antenatally
b/l in 10 - 15% of cases
Abberant vessels is the most common cause.