At present there are multiple scales measuring the lithiasic morphology (Guy, the STONE nephrolitometry score system and the nomogram of the Office of Clinical Investigation of the Endourology Society - CROES) which allow to evaluate the degree of complexity of the stone, the possibility of residual stones and the risk of complications. These tools allow us to do a better analysis of the risk factors of the patient who will be taken to this type of endoscopic procedure in order to decrease morbidity and complication rates.