Comparison Between Two Shock Wave Regimens for Treating Urinary Stones

NCT ID: NCT01222325

Last Updated: 2010-10-18

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 302 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2008-06-30
• Study Completion Date: 2009-08-31

Brief 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.

Detailed 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.

Conditions

Urinary (Renal or Ureteral) Stones

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

swl 3000 impulses- 60 imp/min

patients in this group were submitted to extracorporeal shockwave lithotripsy (SWL) 3000 impulses at 60 impulses per minute under general anesthesia. Unique session

Group Type: ACTIVE_COMPARATOR

extracorporeal shockwave lithotripsy (SWL)

Intervention Type: PROCEDURE

patients were submitted to one session SWL at a Dornier Compact Delta lithotripter under general anesthesia under supervision of an anesthesiologist and an urologist.

swl- 4000 impulses - 90 impulses /min

patients in this group were submitted extracorporeal shockwave lithotripsy (swl) to 4000 impulses at 90 impulses per minute under general anesthesia- unique session

Group Type: ACTIVE_COMPARATOR

extracorporeal shockwave lithotripsy (SWL)

Intervention Type: PROCEDURE

patients were submitted to one session SWL at a Dornier Compact Delta lithotripter under general anesthesia under supervision of an anesthesiologist and an urologist.

Interventions

extracorporeal shockwave lithotripsy (SWL)

patients were submitted to one session SWL at a Dornier Compact Delta lithotripter under general anesthesia under supervision of an anesthesiologist and an urologist.

Intervention Type: PROCEDURE

Other Intervention Names

lithotripsy; shock waves

Eligibility Criteria

Inclusion Criteria

• patients with renal or ureteral stones from 5 to 20 mm

Exclusion Criteria

• pregnancy
• coagulation disturbs and antiplatelet treatment
• urinary tract infection
• aortic aneurism bigger than 2 cm
• clinical contraindication to general anesthesia
• refusal in participating of the protocol

• Minimum Eligible Age: 6 Years
• Maximum Eligible Age: 80 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University of Sao Paulo General Hospital

OTHER

Sponsor Role: lead

Responsible Party

University of Sao paulo General Hospital

Principal Investigators

eduardo mazzucchi, md

Role: PRINCIPAL_INVESTIGATOR

univesrity of sao paulo general hospital

Locations

University of Sao Paulo General Hospital

São Paulo, São Paulo, Brazil

Countries

Brazil

Other Identifiers

1183/06

Identifier Type: -

Identifier Source: org_study_id