Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT01222325 |
| Other study ID # |
1183/06 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
October 5, 2010 |
| Last updated |
October 14, 2010 |
| Start date |
June 2008 |
| Est. completion date |
August 2009 |
Study information
| Verified date |
August 2009 |
| Source |
University of Sao Paulo General Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
Brazil: National Committee of Ethics in Research |
| Study type |
Interventional
|
Clinical Trial Summary
In order to check if a reduction in the frequency and total number of shocks delivered
during extracorporeal shockwave lithotripsy (SWL) results in a great number of stone-free
patients,the investigators compared two different ways of treating urinary stones using SWL.
Description:
Purpose: Two different regimens of SWL delivery for treating urinary stones were compared.
Methods: After informed consent, patients with previously untreated renal and ureteric
stones were admitted for an initial treatment by SWL between June 2008 and May 2009.
Patients were randomly divided into two groups; one group received 3000 impulses at a rate
of 60 impulses per minute, and the other received 4000 impulses at a rate of 90 impulses per
minute. Patients submitted to re-treatment of the same stone were excluded. All treatments
were done using the Dornier Compact Delta lithotripter. Stones were located by x-ray or
ultrasound. Prior to treatment, patients were submitted to laboratory tests and a
cardiologic evaluation when indicated. Urinary infections were treated prior to the SWL
session. All procedures were performed under general anesthesia. Briefly, Tramadol 1-2 mg/kg
associated to Propofol 2.5-3.0 mg/kg and scopolamine were employed in the majority of the
procedures. Patients received 50-100 mg of diluted Tramadol and 20 mg of scopolamine just
before the beginning of the SWL session and Propofol was maintained on continuous bomb
infusion during the treatment and interrupted three minutes before the end of the session.
All patients were maintained under spontaneous breathing, and a facial or a laryngeal oxygen
mask was used according to the anesthesiologist's judgment. The potency of the lithotripter
was increased progressively by 300 shocks until reaching the final stage, which occurred at
a mean of 1500 shocks. The maximum potency employed was level 4 (equivalent to 14 kV) for
renal stones and level 6 (16 kV) for ureteric stones.
All patients were treated on an outpatient basis and were discharged from the hospital six
hours after treatment. All patients received non-steroidal anti-inflammatory drugs (NSAIDs)
and Dipyrone in combination with to Hyoscine for three days postoperatively unless
contraindicated and were instructed to come to the emergency department in case of severe
pain, fever or hematuria.
The final results for each patient were assessed with a kidney and urinary bladder scan
(KUB) plus an abdominal ultrasound three months after the procedure. Success was defined as
stone-free status or the detection of residual fragments ≤ 3 mm on final evaluation. Partial
fragmentation was considered to have occurred if a significant reduction in the stone burden
was observed but residual fragments bigger than 3 mm remained.
We evaluated overall stone-free rates, the incidence of unchanged stones and the occurrence
of partial fragmentation as well as the occurrence of significant complications in both
groups.
The sample size required was based on the assumption that the estimated success rate would
be 70% in the 3000 impulses at 60 impulses per minute group and 50% in the 4000 impulses at
90 impulses per minute group, with a type I error of 0.05 and a type II error of 0.05 (power
of 80%). This yielded a projected sample size of 93 stones in each group.
Data were analyzed using the Fischer's exact, Chi-square and Mann-Whitney tests; a level of
significance of 5% was adopted.
