Considering the EQ’s of most systems currently available, the newer electromagnetic machines (Compact, Dornier Lithotripter S) score equally good and even better than the Dornier HM3. The EQ’s of piezoelectric machines are generally low and not at all in the range of electrohydraulic or electromagnetic machines. However one should keep in mind that some certain machine related (smaller focus, improved imaging with better targeting), patient related (decrease in average stone size) as well operator related (better treatment strategies, greater experience) factors could affect the efficacy of a lithotriptor system in a considerable manner.
Imaging Systems: Advantages and Disadvantages
The success rates obtained by ESWL technique are largely influenced by the imaging system integrated with the lithotriptor. While the first and to some extent the second generation lithotriptors were equipped either with ultrasound or fluoroscopy; modern lithotriptors have both imaging modalities in an integrated fashion by offering simultaneous use of both localization systems .
Although the in situ treatment of all ureteral stones and shorter learning curve are the main advantages of this system; disadvantages include the ineffectivity for the localization of radiolucent and sometimes small stones, lack of real-time image and most importantly the radiation exposure .
In contrast to fluoroscopy, sonographic imaging has more advantages among which the easy targeting of radiolucent and smaller stones, real-time imaging during therapy, fast and practical use and lack of radiation exposure could be counted. However, in situ treatment of ureteral stones is possible only for very proximal and very distal ureteral calculi with this system and the learning curve is evidently longer than fluoroscopy .
What Do We Expect from a Lithotriptor?
In the light of the basic information given above, the endourologists prefer to work with a modern lithotriptor which will exhibit following characteristics;
Resulting in higher stone free rates with limited or no tissue damage and/or pain,
Being suitable for all kinds of stones, multifunctional and multidisciplinary use
Offering simplified handling and lower costs.
Integrated with a shock wave source with large aperture which allows simultaneous use of both fluoroscopy and ultrasound
Enabling the endourologist for an anesthesia free ambulatory treatments both in ESWL and ESWT.
Last but not least; this ideal lithotripsy system should be installed in a large EndoUrology suite equipped with a full range of endoscopic equipment and disposables for endourologic procedures. Well trained and knowledgeable nursing staff is another “must” to improve the efficiency and safety further. In addition to all qualifications above, published data so far did show that the use of slower pulse rates, ramping strategies, and adequate coupling of the shock wave head can significantly increase the efficacy and safety of ESWL.