Ureteral Pelvic Junction Obstruction (UPJ)
The ureter, which is the drainage tube from the kidney to the bladder, is 10 inches (25 cm) long and has three constrictions along its course:
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where the pelvis of the ureter joins the ureter.
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where it is kinked as it crosses the pelvic brim.
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where it pierces the bladder wall.
[diagram of kidney, ureters, bladder]
Blockage of the ureter can be congenital (something one is born with) or acquired. Congenital causes include malformation of the ureteral muscle, which cannot function to help push urine down to the bladder. This is more common in children. In adults, an extra artery or vein to the lower portion of the kidney can cross over the ureter as it exits the kidney causing a slow, progressing kinking which leads to obstruction. Both of these congenital entities are known as ureteropelvic junction obstruction or UPJ. UPJ obstruction usually has symptoms of back pain, multiple kidney infections, and/or kidney stone formation.
When blockage is above the level of the bladder, unilateral dilatation of the ureter (hydroureter) and renal pyelocalyceal system (hydronephrosis) occurs. The pain resulting from UPJ obstruction is relatively steady and continuous, with little fluctuation in intensity, and often radiates to the lower abdomen, testes, or labia. Other symptoms include polyuria (excessive urination) and nocturia (frequent nighttime urination).
Confirming the diagnosis is straightforward. Either IVU (intravenous urogram - Xray study) or a CT scan will show a sluggish, stretched-out kidney pelvis with little drainage of the IVU dye from the kidney to the ureter. Next, a renal scan will look at the kidney function and measure the transit time of the injected dye from the kidney to the bladder. The transit time of the dye is normally under 10 minutes but can be as long as hours in the blocked kidney.
Endoscopic techniques, which use an instrument that is threaded through the urethra and bladder, can look into the ureter and cut the blockage. This procedure, called an endopyelotomy, can be performed as long as no crossing blood vessel is found on CT. While these are relatively quick procedures to perform, the success rates are limited to only 40-60% with a greater difficulty for future laparoscopic reconstruction of the ureter.
Another technique for cutting the obstruction involves abdominal surgery, called an open pyeloplasty. This surgery requires full anesthesia and a long hospital stay because it is requires opening the abdomen to get at the ureters.
Laparoscopic pyeloplasty is a minimally invasive approach to the standard open pyeloplasty. The surgery involves cystoscopy (looking in the bladder), stent placement (drainage tube in the ureter), and reconstruction and re-connection of the ureter through three small puncture holes. The procedure has a 95% success rate.
Emory University urologists are considered national experts for this type of complex laparoscopic surgery.
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