Torricelli FC et al, 2015: Extracorporeal shock wave lithotripsy in the treatment of renal and ureteral stones.
Torricelli FC, Danilovic A, Vicentini FC, Marchini GS, Srougi M, Mazzucchi E.
Hospital das Clínicas, Medical School's, University of São Paulo, São Paulo, SP, Brazil.
HC, FM, USP, Brazil.
Abstract
The use of certain technical principles and the selection of favorable cases can optimize the results of extracorporeal shock wave lithotripsy (ESWL). The aim of this study is to review how ESWL works, its indications and contraindications, predictive factors for success, and its complications. A search was conducted on the Pubmed® database between January 1984 and October 2013 using "shock wave lithotripsy" and "stone" as key-words. Only articles with a high level of evidence, in English, and conducted in humans, such as clinical trials or review/meta-analysis, were included. To optimize the search for the ESWL results, several technical factors including type of lithotripsy device, energy and frequency of pulses, coupling of the patient to the lithotriptor, location of the calculus, and type of anesthesia should be taken into consideration. Other factors related to the patient, stone size and density, skin to stone distance, anatomy of the excretory path, and kidney anomalies are also important. Antibiotic prophylaxis is not necessary, and routine double J stent placement before the procedure is not routinely recommended. Alpha-blockers, particularly tamsulosin, are useful for stones >10mm. Minor complications may occur following ESWL, which generally respond well to clinical interventions. The relationship between ESWL and hypertension/diabetes is not well established.
Rev Assoc Med Bras. 2015 Jan-Feb;61(1):65-71. doi: 10.1590/1806-9282.61.01.065. Epub 2015 Jan 1.
Comments 1
This review article summarizes data from literature reports on SWL. A selection of reports was used to discuss factors of importance for optimal treatment results. The article, that in fact does not contain any new information, concludes that SWL is a good treatment alternative for stones with a diameter up to 2 cm as well as for ureteral stones.
Two factors that are discussed are firstly that the use of internal stents is not necessary because they do not increase fragment passage nor do they reduce the development of steinstrasse. This conclusion is in line with other reports and is to some extent true. But for large stones treated in the kidney it needs to be emphasized that albeit a stent does not prevent gravel accumulation in the ureter, the presence of a stent significantly reduces the risk of obstruction and thereby reduces the negative effects on renal function. The stent thus allows for a safe expectation while waiting for fragment elimination, with or without repeated SWL sessions directed towards the accumulated fragments. It is my own personal view that a clinically relevant steinstrasse is a combination of a column of fragments in the ureter and obstruction to the urine flow.
The second point that deserves a comment is the poor disintegration that is the result of long SSD. This condition is explained by reduced energy during the long shockwave path. It should be further studied if increased shockwave energy in these patients can be used to counteract the energy losses and maintain a good disintegrating power at the stone.