In a small study, maximal stent therapy successfully treated ureteral strictures in renal transplants.

SAN DIEGO—Maximal stent therapy, which has been used successfully to treat anastomotic biliary strictures, also may be effective for ureteral strictures following renal transplantation, investigators reported.

“We actually got the idea from our gastroenterologists, who reported in early 2007 on success with biliary anastomotic strictures using maximal stent therapy. They would put up to four stents across the stricture after they dilated it,” said researcher Scott Kriegshauser, MD, assistant professor of radiology at the Mayo Clinic in Phoenix. “So we used that information to develop a protocol.”

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Ureteral strictures occur in 2% to 3% of renal transplant recipients. To date, percutaneous treatments have been associated with high recurrence rates. Maximal stent therapy involves routine percutaneous drainage and balloon dilatation, with tandem internal ureteral stents (TIUS) placed if simple balloon dilatation does not relieve the narrowing sufficiently.

Dr. Kriegshauser and his colleagues reviewed 12 cases of renal transplant ureteral strictures treated with percutaneous therapy. Six patients were treated with nephroureteral (NU) stents and six were treated with TIUS. The researchers considered the percutaneous procedure successful if a patient remained catheter/stent free for three months, during which the patient showed no evidence of significant hydronephrosis or rise in serum creatinine level.

Only one (17%) of the six patients in the NU group had a successful procedure compared with four (66%) in the TIUS group. The first TIUS failure occurred in a patient who did not receive pre-stent dilatation. The second failure was in a patient treated percutaneously following a failed surgical revision.

Dr. Kriegshauser’s group observed no significant complications. One patient was successfully treated for a urinary tract infection with antibiotics. The TIUS approach has the added advantage of not requiring long-term external percutaneous drainage, he said.

“The 66% [success rate] is very comparable to other reported techniques,” Dr. Kriegshauser said. “We work very closely with the urologists and the transplant surgeons.  That makes a huge difference. Some of our urologists do percutaneous procedures themselves.”

This team approach has led to improved care for renal transplant patients, he said. 

“I think this is a very promising approach,” Dr. Kriegshauser said. Combined with other techniques, it may allow for a protocol that could lead to a 90% success rate. “That is our goal,” he said.