Evaluation of a synchronous twin-pulse technique for shock wave lithotripsy: a prospective randomized study of effectiveness and safety in comparison to standard single-pulse technique.
OBJECTIVE
To asses the efficacy and safety of bidirectional synchronous twin-pulse extracorporeal shock wave lithotripsy (ESWL) compared with standard ESWL.


METHODS
Between March 2003 and December 2006, 240 patients with a radio-opaque single renal stone of <or=25 mm were randomized to treatment either by the Twinheads (TH) lithotripter (FMD, Lorton, Virginia, USA) or the Dornier Lithotripter S (DLS, Dornier MedTech Europe GmbH, Germering, Germany). Before and after ESWL, urinary N-acetyl-B-glucosaminidase (NAG) levels were assessed and patients were evaluated with dynamic MRI. The efficacy and complications were compared, with success defined as no residual fragments.


RESULTS
For stones of >10 mm the rate for the failure of disintegration was 13.3% for the DLS vs 1.4% for the TH (P = 0.009). For stones of <or=10 mm the stone-free rate was 74.4% for the TH vs 67.7% for the DLS (P = 0.6), while for stones of >10 mm it was 78.1% and 66.7%, respectively (P = 0.14). The median (range) number of sessions in both groups was 2 (1-5). After ESWL urinary NAG levels were increased significantly in both groups; in the TH group it declined below the level before ESWL after 2 days, while in the DLS group it remained high after 7 days. In the DLS group four patients developed subcapsular or parenchymal haematoma after ESWL, vs none in the TH group. There was loss of corticomedullary differentiation after ESWL in three patients in the DLS group and only one in the TH group. In the DLS group there was a statistically significantly decrease in bilateral renal perfusion after ESWL, but no changes in the TH group.


CONCLUSIONS
Synchronous twin-pulse ESWL has clinical advantages over standard ESWL in terms of safety and efficacy.
Sheir
Khaled Z
KZ
Department of Urology, Urology and Nephrology Center, Mansoura University, Mansoura, Egypt. kzsheir@hotmail.com
Elhalwagy
Samer M
SM
Abo-Elghar
Mohamed E
ME
Ismail
Amani M
AM
Elsawy
Essam
E
El-Diasty
Tarek A
TA
Dawaba
Mohamed E
ME
Eraky
Ibrahim A
IA
El-Kenawy
Mahmoud R
MR
D000118:Acetylglucosaminidase / Q000652:urine; D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007669:Kidney Calculi / Q000628:therapy*; D017602:Lithotripsy, Laser / Q000009:adverse effects / Q000379:methods / Q000592:standards*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
D000118:Acetylglucosaminidase