What are urinary stones? What are kidney stones? The human urinary system is divided into four parts: kidney, ureter, bladder and urethra, of which the kidney + ureter is the upper urinary tract and the bladder and urethra are the lower urinary tract. Stones that occur in these organs are collectively known as urinary stones or urinary tract stones. Statistics show that more than 90% of upper urinary tract stones are produced in the kidneys and less than 10% in the ureters. Lower urinary tract stones are mostly found in the bladder. Can stones really jump out? It is really possible! The human ureter, on average, is about 7 mm in diameter. In theory, it is possible for stones below 5 mm to be discharged in a conservative way (e.g. drinking more water, taking herbal medicines such as lithotripsy, changing the position including jumping, etc.) Of course, there are great differences among individuals, and some people’s ureters can be very dilated, so some people can discharge stones with a diameter of about 1 cm. Some people have a thin diameter ureter, a narrowing of the whole section, or a small section that is particularly thin. In such people, if they have a stone, there is a high risk of obstruction (i.e., getting stuck in this narrow channel) during the stone removal process, which can lead to fluid in the kidney. This is a condition that must be treated in the hospital. How is surgery for upper urinary tract stones done? In the past, there was only one option for open surgery. In other words, the ureter with the stone was found through the abdominal cavity or extraperitoneally, and the ureter was cut open to remove the stone. In the last one or two decades, various advanced instruments and equipment have emerged one after another. Instead of traditional open surgery, patients with stones can undergo minimally invasive surgery. Minimally invasive surgery for urinary tract stones is divided into two main categories: one, transnatural lumen: such as the mouth, urethra, and vaginal opening, generally for urinary tract stones less than 2 cm in diameter and not too many in number. Secondly, percutaneous nephrolithoscopy: first, X-rays are used for localization, then a direct pelvic channel (open hole) is established, found, lithotripsy is used, and the stones are removed. This method is often used to deal with stones that are larger in size in the kidney, or in more complex situations.