摘要Currently,the predominant therapy for urinary calculi is minimally invasive treatment,which could reduce injury to patients while enhancing the success rate,compared to traditional open surgery.Minimally invasive treatments in urinary system include extracorporeal shock wave lithotripsy (ESWL),percutaneous nephrostolithotomy (PCNL),ureteroscopic lithotripsy (URSL),laparoscopy,and so on.Despite the relative small injury,however,minimally invasive treatment is more expensive and has some potential risks.1,2 Therefore,small calculi that could be expulsed spontaneously and without clear surgical indications can be treated with conservative strategy.The medical expulsion therapy (MET) that is effective,safe,non-invasive,and suitable for outpatients is definitely an ideal option for patients who are eager to remove calculi but are only suffering symptomatic calculi in the upper urinary tract.It has become the focus for basic and clinical researches in recent decades.