Geert Tailly reported on a high penetration version of the current EMSE 220F-XXP used in conjunction with the Dornier Lithotripter S. The aperture is smaller but the focus area (89 mm x 6 mm) and treatment depth (17 cm) are greater. Among their 162 patients with a mean stone size of 67 mm2 the average BMI was 26 (19-36); the overall stone free rate was 87% with an efficiency quotient of 68%. There were no SWL complications. Unfortunately, a subanalysis of the patients based on BMI was not done. While this machine may prove of benefit for the obese patient and appears to have an improved complication profile, the overall stone free rates and EQ appear to be little changed from earlier generation lithotripters.
In a separate report, Anjum and colleagues reported on their experience with the Direx Duet, dual head electromagnetic lithotripter. There were 133 patients treated in the dual shock wave mode under IM and oral analgesia. The mean stone size was 8.8 mm. The overall stone free rate was 83% (on a KUB) with a retreatment rate of 38% (no data were provided on auxiliary procedures); of note, stone free rates (73-85%) did not appear to vary significantly among stone sizes ranging from 5 mm to 2 cm. In sum, at the very best the EQ would be 60% and likely much lower if standard tomography or plain CT scanning had been used.
It is 2011, nearly 30 years since SWL was created by Chaussy and colleagues – and yet, despite advances in our technical and imaging abilities, there is no SWL machine capable of delivering a single effective treatment in more than 70% of patients (i.e. stone free in one treatment with no auxiliary procedures). I wonder why we can not do better – is it the machine, the surgeon, patient selection, the method of reporting (i.e. lumping all stones together), or stone parameters that are thwarting improvements in treatment outcome?
Also: New dual electromagnetic shock wave lithotripter in the management of upper urinary tract calculi under analgesia
by Faqar Anjum
Presented by Geert G. Tailly at the 29th World Congress of Endourology & SWL (WCE) - November 30 - December 3, 2011 - Kyoto International Conference Center - Kyoto, Japan
Reported for UroToday by Ralph V. Clayman, MD, Chair, Department of Urology, University of California-Irvine Medical Center, Irvine, CA
View Full WCE 2011 Meeting Coverage
