Ureteroscopy more effective than ESWL for ureteral lithiasis

June 1, 2009

Ureteroscopy is more effective than extracorporeal shock wave lithotripsy for the treatment of proximal ureteral stones.

Stockholm, Sweden-Ureteroscopy is more effective than extracorporeal shock wave lithotripsy for the treatment of proximal ureteral stones, according to a prospective and comparative study presented at the European Association of Urology annual congress here.

The study, conducted by researchers at La Fe University Hospital, Valencia, Spain, involved 176 patients who were diagnosed with proximal ureteral lithiasis. Patients were offered either ESWL or URS, and were treated with the approach they preferred.

Seventy-four of the initial 176 patients (42%) underwent ESWL, and 102 patients (58%) were treated with semi-rigid or flexible ureterorenoscopy and intracorporeal holmium YAG laser lithotripsy and/or stone/fragment retrieval with endoscopic forceps under general or spinal anesthesia. Both series were comparable in terms of size, side, and composition of the stone and need for previous procedures.

Multivariate analysis confirmed the findings, he said.

The stone-free rate at 4 weeks for the URS group was 85.3% versus 71.2% for the ESWL group (p=.03). For the <1-cm lithiasis sub-group, stone-free rates for URS and ESWL, were 92.5% and 70.2%, respectively (p<.01). There were also a difference in the stone-free rate for stones >1 cm: 77.1% for the URS group and 73.9% for the ESWL group, although this difference did not reach statistical significance.

Complication rates similar

In case of treatment failure after first-line therapy, URS was the second-line therapy in both groups. Multivariate analysis by a logistic regression model using all factors showed type of treatment as the only significant variable. The probability of proximal ureteral stone clearance was 2.29 times higher in the URS group than in the ESWL group. Unexpectedly, there were no significant differences in complication rates in both groups (15.7% for URS and 16.4% for ESWL, respectively).

Speculating on why more patients chose URS over ESWL, Dr. Budía said, "We think that patients preferred to resolve their stones in only one session, and the treatment that has a higher probability of that is URS. In spite of that, we did not give any information about our results; the patients received all information about their stones, and they decided the kind of treatment."

According to the researchers, the preferred option for managing a stone smaller than 1 cm is URS, which is also probably preferred for stones larger than 1 cm, although the difference was not statistically significant in the latter group.

"I think the statistical significance will show when we present the final results of our study," Dr. Budía predicted. "On the other hand, there are special circumstances that can preclude URS: general anesthesia, etc. In our study, patients with special circumstances were excluded."