To deal with kidney stones that require surgical treatment, the most commonly used method is percutaneous nephrolithotripsy, but some patients still have stone remnants after one percutaneous nephrolithotripsy and need a second or even multiple surgeries, what are the reasons? The main reasons are: 1, the stones are complex stones such as antler-shaped kidney stones or multiple kidney stones, the stones are large in size and number, and some of them are very hard, so it is not possible to take out so many stones in the time to guarantee the safety of the patients, and they can only be operated in several times. 2. Complex deformity of kidney structure, such as once performed nephrectomy, horseshoe kidney, combined calyceal diverticulum, double renal pelvis, the number of calyces is particularly large, long calyceal neck of the kidney combined with the stone, the stone is often difficult to take a clean, the need for several times, may require more than one “hole” channel 3. Intraoperative bleeding The causes of bleeding are the patient itself Physical factors: the kidney is “one” kidney (one kidney, the other side has been removed or the other side is not functional or poor function), combined with diabetes, hypertension, poor liver function and other diseases; also with the operating skill level of the surgeon 4, urinary tract infection During the operation, pus is found in the kidney, which needs to be drained first, and then remove the stone in several times; or urogenital sepsis is found during the operation. Toxemia symptoms, the need to suspend the operation, control the infection, the second operation and then remove the stone 5, stone displacement After the stone is broken in surgery, some fragments will be moved around, sometimes moving to the place where the mirror can not be observed, resulting in the stone can not be removed at once 6, and the operator’s technical operation, if the surgeon’s skills are not up to the task, may not even be successful perforation, or perforation location is not selected properly, can not find the stone, or can only find a small part of the stone, or can only find a small part of the stone, or can only find a small part of the stone. If the surgeon’s technique is not good, the perforation may not even be successful, or the location of the perforation is not chosen properly, so that the stones cannot be found, or only a small part of the stones can be found, or the number of orifices is not enough, so that a lot of stones can not be taken out through a single perforation, or the operation is not proper, resulting in obvious intraoperative bleeding, or not according to the standardized operation, and failing to try to take out all the stones. In short, the reason why the stones are not taken out at one time has an objective factor: it is related to the patient’s own stone condition, kidney morphology, physical state, and the subjective factor, which is the skill level, is closely related to the surgeon. The objective factors exist objectively, and it is often difficult to remove all the stones in one operation. Objective factors exist objectively and are often difficult to change, which requires the surgeon to continuously improve his technical level, in order to ensure the safety of the patient’s life and to protect the kidney function as much as possible to remove the stones.