Early Stage squareA ureterocele is birth defect characterized by swelling that occurs in the bottom of one of the tubes (ureters) that carry urine from the kidney to the bladder. The swelling usually creates a blockage where the ureter enters the bladder. As the urine collects and the walls of the ureter become stretched, a pouch of fluid forms. In some cases, the urine begins to flow back toward the kidney (reflux). Patients can experience a range of symptoms including abdominal pain, pain while urinating, or blood in the urine.

While most diagnoses are made prenatally with ultrasound, ureteroceles can present in adolescents and adults. In 80 percent of cases, ureteroceles result from a congenital defect which causes a dual collection system (2 ureters drain the same kidney instead of one) and one of the ureters develops a ureterocele. Early diagnosis is important as complications from ureteroceles include kidney stones, permanent kidney and bladder damage, and recurring urinary tract infections. If one of the two kidneys is working properly, kidney failure should not be a problem. Ureteroceles affect 1 in every 4000 people, 80 percent of which are female.

Current Treatment

Antibiotics are usually prescribed as prophylactic management because ureteroceles predispose a patient to infection.

Various types of surgery can be performed to treat ureteroceles. Endoscopic puncture is the least invasive method, and it involves inserting a tube with a camera on the end into the urethra to gain access to the ureterocele. An electrode is then used to make a small puncture in the ureterocele to drain the fluid.

Upper pole nephrectomy is recommended if the upper part of the kidney is not functioning properly. In this case, the non-functioning part of the kidney is removed, usually through a small incision under the rib cage. Complete nephrectomy is indicated in cases where the entire kidney has been affected by the ureterocele. This is usually done laparoscopically.

In more severe cases where reflux is present, complete removal of the ureterocele and ureteral implantation is required. This procedure requires the bladder to be opened so that the ureterocele can be removed. The bladder is then reconstructed and the ureters are reimplanted to eliminate reflux. This surgery has a high success rate (90 to 95%) and can be done through a small incision in the abdomen. There is some risk that reflux can persist or another obstruction is created.

Surgery to connect the upper and lower portions of the ureter can be performed if the upper portion of the ureter (above the ureterocele) is properly functioning. This procedure is also done through an incision in the abdomen and has a high success rate (95%).

Focused Ultrasound Research

Focused ultrasound could potentially treat ureteroceles because of its ability to non-invasively destroy target tissue through cavitation (histotripsy). However, research is still in the early preclinical stages. In a recent feasibility study, scientists at the University of Washington were able to use successive pulses of focused ultrasound to achieve tissue fractionation (punctures) in a tissue model of a ureterocele wall. More research is needed to establish the safety and efficacy of this procedure before research can proceed to the clinical stages.

Notable Papers

Maxwell AD, Hsi RS, Bailey MR, Casale P, Lendvay TS. Noninvasive ureterocele puncture using pulsed focused ultrasound: an in vitro study. J Endourol. 2014 Mar;28(3):342-6.

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