The diagnosis of Pelvi-Ureteric Junction Obstruction (PUJO) is often first suspected by using ultrasonography(USG). The presence of hydronephrosis on USG raises suspicion of PUJO. Hydronephrosis is the distension and dilation of the renal pelvis and calyces and is usually caused by obstruction of the free flow of urine from the kidney.
All patients with hydronephrosis, defined by a renal pelvic diameter greater than or equal to 5 mm are investigated for PUJO at our institution.
All patients undergo USG for determining the anteroposterior renal pelvis diameter, thickness of the renal cortex, presence of concomitant ureteric dilatation on the same side and evaluation of the opposite kidney and the urinary bladder.
A micturating cystourethrogram (MCU) is performed as part of the initial investigations to rule out associated vesicouretric reflux.
In a number of infants with PUJO, hydronephrosis is spontaneously resolving without apparent signs of loss of renal function.
Therefore, currently close surveillance of PUJO is the norm (patients are started on prophylactic antibiotics to prevent urinary infections) and surgical intervention is indicated only in case of worsening renal pelvic dilatation, thinning of the cortex of the affected kidney and occurrence of urinary infections secondary to the PUJO.
The operation to correct the obstruction at the pelvi-ureteric junction is known as pyeloplasty.
The indications to proceed with pyeloplasty are:
Patients who have a pelvic dilatation of at least 10 mm and obstructive pattern on MAG3 scans with associated findings of thinning of renal cortex and worsening of renal pelvic dilatation on USG or confirmed urinary tract infections.
Historically, the first pyeloplasty was performed in 1891. The gold standard dismembered pyeloplasty that is so widely practiced today was originally described by Anderson and Hynes in 1949.
Laparoscopic dismembered pyeloplasty was first described in both adult and paediatric populations in 1993. Although there are no strict indications for the laparoscopic approach to pyeloplasties in children; an ideal candidate is an older child with a PUJO in an extrarenal pelvis.
With the advent of miniature instrumentation, it may be possible to offer laparoscopic and even robotic pyeloplasties in the future.