Pyeloplasty is surgical reconstruction of a part of the kidney called the renal pelvis. This surgical procedure is used to treat a condition called uretero-pelvic junction obstruction. Pyeloplasty is most commonly carried out on young children, because uretero-pelvic junction obstruction tends to be a congenital condition, but this condition also can be diagnosed in older children and adults. Uretero-pelvic junction obstruction is more common in male children than in female children and has an overall frequency of between one in 5,000 and one in 8,000.
Uretero-pelvic junction obstruction occurs when there is a blockage in the junction of the renal pelvis of the kidney and the ureter to which it connects. This prevents the kidneys from draining correctly, leading to inflammation and enlargement of the kidney, kidney pain and the development of a mass at the site of blockage. In children, it also leads to a failure to thrive. Children with this condition are at higher risk of urinary tract infections, which, in addition to flank pain, a flank mass and blood in urine, are the most common symptoms.
Most cases of uretero-pelvic junction obstruction are thought to be the result of defects that occur during early fetal development. Several events might lead to uretero-pelvic junction obstruction, including differentiation of renal cells at five weeks and differentiation of ureter cells at 16 weeks. Minor abnormalities can cause obstruction that eventually resolves itself as the child grows; major abnormalities require pyeloplasty to correct.
During the pyeloplasty surgical procedure, the patient is given general anesthetic. An incision is made below the level of the obstruction, in the lower flank. The renal pelvis section of the kidney is removed, because this section generally is enlarged and unhealthy as a result of chronic obstruction. Once this section of kidney has been removed, the ureter is attached to the remaining renal pelvic tissue to create a new, unobstructed uretero-pelvic junction.
In some cases, a small tube called a stent is inserted into the ureter to ensure that the ureter remains functional while the new junction is healing. The stent is flexible but firm, preventing the ureter from collapsing and helping the kidney to drain properly. Tubes that drain to the surface of the skin also might be placed to ensure that fluid build-up does not occur at the pyeloplasty site. After these have been placed, the procedure is complete. The entire procedure usually takes between two and three hours.
Once surgery is complete, the patient can return home after two or three days. Drainage tubes are removed after one or two weeks. The patient must take oral antibiotics for two weeks or more after the procedure to prevent infection, and follow-up ultrasounds are scheduled at regular intervals to monitor kidney health. Prompt medical attention should be sought in the event of symptoms such as difficulty urinating, high temperature, vomiting and any symptoms that were experienced before the surgery.