Quantification of Preoperative Stone Burden for Ureteroscopy and Shock Wave Lithotripsy: Current State and Future Recommendations

ObjectivesTo determine which preprocedure imaging modality was used and how the stone burden quantification was assessed before shock wave lithotripsy (SWL) and ureteroscopy (URS) in published studies.Material and MethodsReferences were searched in the MEDLINE database using the terms “shock wave lithotripsy” and “ureteroscopy,” excluding “percutaneous nephrolithotomy” from January 2007 to January 2009. The inclusion criteria for our study included clinical trials published in English with >20 patients and measurement of pretreatment stone size.ResultsOf the 198 studies in our initial MEDLINE search, 101 met the inclusion criteria. Of the 101 studies, 61 had evaluated SWL and 40 had evaluated URS. Also, 78 studies (77%) had quantified the stone burden in 1 dimension, 19 (19%) in 2 dimensions, and 4 (4%) in 3 dimensions. For SWL, the imaging modalities used to assess the stone burden included 24 mixed (40%), 10 noncontrast-enhanced computed tomography (16%), 12 plain abdominal film (20%), and 5 intravenous urography (8%); 10 studies (16%) did not mention the imaging modality used. For URS, the imaging modalities used to assess the stone burden included 15 mixed (38%), 8 noncontrast-enhanced computed tomography (20%), and 3 plain abdominal film (7%); 14 studies (35%) did not mention the imaging modality used.ConclusionsHeterogeneity exists in the published data regarding the imaging modality used both before URS and SWL. Up to one third of all studies for both URS and SWL did not mention the imaging modality used to quantify the stone burden. Standardization of preprocedure imaging and its reporting in published studies is needed to better assess the pretreatment stone burden and compare the treatments of stone disease.