PUJO or pelvi ureteral obstruction is a congenital condition with obstruction in the drainage of urine from the kidneys. This leads to progressive kidney enlargement and damage. This can be easily corrected with pyeloplasty which is the surgery done for its correction.
PUJ obstruction is blockage in the area that connects renal pelvis to ureter. This leads to obstruction in the drainage of urine out of the kidney and hence an increased intrapelvic pressure and distension causing progressive irreversible damage to kidney.
In children, most cases of PUJO are congenital (by birth). It can occur due to intrinsic wall defect of PUJ or extrinsic mechanical factors such as crossing vessel causing compression / intraluminal ureteral valves, all leading to poor drainage of urine.
The incidence of PUJ obstruction is 1 in 1250 births. It is more commonly seen in boys. There is predilection for the left side in children. PUJ obstruction can sometimes occur in both kidneys.
PUJ obstruction can affect infants, adolescents and adults. Most of the time babies with PUJO are asymptomatic and are diagnosed by prenatal ultrasonography. Other cases of PUJO present with abdominal mass, recurrent UTI, failure to thrive, hematuria (blood in urine), feeding difficulties and kidney stones. Typically, post natal infants are asymptomatic and school aged children are symptomatic.
PUJ obstruction leads to obstruction of the drainage of urine from the kidneys. This increases the intrapelvic pressure (within the kidney) and distension causing progressive irreversible damage to kidney. In due course of time the kidney gets completely non functional.
Ultrasonography (USG) of kidneys can diagnose distension of renal pelvis. Possibility of PUJ obstruction should be considered if there is prenatal or postnatal renal pelvis dilatation on ultrasonography. The investigations which can prove obstruction are renal scintigraphy scans (EC / DTPA scans) or CT intravenous urography.
Nearly 50% to 80% of antenatally diagnosed renal pelvis dilatation resolve spontaneously on follow up. The remaining develop progressive increase in dilatation with diminution of function. These children will require surgery (Pyeloplasty). The surgery involves complete removal of narrowed segment and reapproximation of renal pelvis with ureter. It can be done by open technique through a small flank incision or by minimally invasive technique (laparoscopic or robotic) with much smaller incisions. Robotic pyeloplasty is one of the most common pediatric surgeries performed by robotic platform with excellent results.
Pyeloplasty when performed at early stage of PUJ obstruction shows improvement in renal functions or prevents further deterioration. The success rate is more than 95%.