Percutaneous nephrolithoscopy is a minimally invasive procedure, but there are risks involved. Both the surgeon and the patient should be well aware of them. Bleeding Intraoperative bleeding is the most common and very dangerous complication. The kidney is an organ with rich blood circulation and fragile texture. The blood vessels of the kidney are divided into subdivisions, and the renal arteries are divided into two groups, anterior and posterior, with a non-vascular area called Brodel’s line in the middle, with the anterior group being the apical, superior, middle and inferior. Therefore, it is necessary to avoid damaging these large vessels during the operation, and try to choose a puncture site located near the Brodel line, and the puncture should not be too deep, preferably to the dome of the renal calyx. During the surgical puncture, if a slightly larger vessel is penetrated, or the operation takes too long, it will cause excessive bleeding. The choice of the puncture site should be considered comprehensively, and the least number of puncture channels should be used to achieve the best results, the cleanest stones, the fastest stone removal, the least damage to the kidney, and the least bleeding in the main sample. At the same time, the location of the puncture should also maximize no damage or less damage to the surrounding organs. The methods to prevent bleeding: First, adequate preparation before surgery, blood preparation, preoperative hematological examination, and contraindication to surgery for patients with anemia and abnormal blood clotting function. Second, minimize the number of punctures, and try to choose a puncture site on the dorsal side of the kidney or a vascular juvenile site. Third, the operation time should be minimized, and the stone can be removed in several operations if necessary. Fourth, the renal drainage tube can be temporarily clamped after surgery to stop bleeding. Fifth, try not to move or swing the mirror body drastically during the operation, because this will tear the kidney parenchyma and cause bleeding. Sixth, the patient’s status and bleeding should be noted at all times during the operation, and the operation should be terminated in time, and the stone can be removed in the second stage if necessary. If a large blood vessel is found to be punctured during surgery, take appropriate measures or change to open surgery or use interventional surgical methods to stop the bleeding treatment so as not to delay the surgery. During the surgical puncture, if the parenchyma of the kidney is thick, or the mirror body is too active after the puncture, it will be found that the color of the filling wash is heavy, or there is bright red blood flowing from the puncture channel. If it is a vein or renal parenchymal tear, the bleeding will not be very aggressive, and the bleeding can usually be stopped after terminating the surgery with local compression and clamping the drainage tube. If it is arterial or large vascular bleeding, interventional treatment with highly selective renal vascular tethering should be performed. Second, laceration of the renal pelvis Laceration of the renal pelvis is due to injury during puncture, or can be caused by ballistic laser or ultrasound during lithotripsy. Patients who have fragile local tissues due to local inflammation or a history of previous surgery are also prone to injury. In most cases, these injuries can be recovered as long as the drainage is ensured to be unobstructed. Third, water toxicity During percutaneous nephrological procedures, a large amount of saline flush should be applied to keep the operative field clear. If the operation time is too long or the pressure of the flushing solution is too high, the patient absorbs too much water, which can cause water intoxication. As the patient is usually under general anesthesia, the clinical manifestations are not obvious, mainly manifested as fast heart rate, later as irregular heart rate, fluctuating blood pressure and hypothermia. Due to some patients with prolonged surgery, doctors should be aware of this. For patients with a history of cardiovascular disease, special attention should be paid to cardiovascular manifestations to prevent the occurrence of heart failure. For patients with long operation time, renal parenchymal injury and renal pelvis laceration, attention should be paid to the pressure of flushing fluid. Intraoperative injury to surrounding organs During percutaneous nephrolithoscopy, whether during puncture or lithotripsy, there is a risk of injury to surrounding organs, such as injury to pleura, intestinal canal, peritoneum, important blood vessels, ureter and so on. Therefore, in the process of establishing the operating channel for kidney puncture, we should not only pay attention to the direction of puncture, but also pay attention to the control of the depth of puncture at all times – preferring shallow to deep, operating lightly and delicately, and making accurate judgment of any situation that may arise at any time during the operation. As seen in the diagram, the organs surrounding the kidney are: the spleen on the left side, the spleen on the left side, the descending colon on the left side, the stomach on the left side, and the tail of the pancreas on the right side. On the right side, outside of the kidney is the liver, anteriorly inside is the descending duodenum, and anteriorly below outside is the ascending colon, while posteriorly in the bilateral kidneys, there are fewer organs and the suprarenal pole has the diaphragm immediately attached to it. All of these organs are at risk of injury. 1. Pleural injury: For patients undergoing puncture through the eleventh intercostal space, this puncture site has the advantage of good puncture angle and close proximity. During ultrasound-guided puncture, the ultrasound image of the eleventh intercostal space is clear and easily accessible to the stone, but it is more likely to damage the pleura. Therefore, attention should be paid to the performance in the operative field and whether there is abnormal performance of gas spillage in the intraoperative channel, and closed drainage of the chest cavity should be done if necessary. 2, injury to the intestinal canal: during the puncture process, choose a direct channel to avoid puncture channels through the abdominal or thoracic cavity and thus damage the organs. Pay attention to the changes in the area operated on at any time during the operation, to exclude at any time that there is damage to other organs, and if necessary, it should be changed to open surgery. 3, ureteral injury: percutaneous nephrological procedure either in the process of ureteral cannulation ureteral lithotripsy or in the process of nephrolithotripsy, there is the possibility of injury to the ureter. In the process of ureteral intubation, for the ureteral orifice is not clear, when the orifice is ectopic, do not operate roughly, first try to find the ureteral orifice and insert the guidewire before entering the ureteroscope. After entering the guidewire in the process of entering the mirror, adjust the direction of the ureteroscope in multiple directions gently into the mirror to prevent damage to the ureteral orifice, which can cause laceration and contusion of the ureteral orifice in light cases and failure of the mirror in heavy cases. Often the ureteral orifice is difficult to identify and cannot be inserted, be patient to find, you can empty or fill the bladder and look along the inter-ureteral ridge, or look for the contralateral orifice first, the ureteral orifice is mostly located in the vascular rich area of the bladder triangle, adjust the distance between the ureteroscope and the orifice, the orifice is often located on the outer upper side of the ureteral fissure, you can look along the muscle fiber of the orifice, if necessary, you can replace the cystoscope to observe, or Intravenous injection of melphalan, the orifice can be looked for where there is an outflow of orchid urine. During the ureteroscopy into the ureter, always keep entering the mirror under direct vision, moving into the mirror, always keep the guidewire as the pilot, do not be rough, pay attention to the resistance situation during the advancement, and keep rotating the mirror to keep the field of view clear. In the process of ureteral lithotripsy, due to the thin wall of the ureter and inflammation, edema and congestion, it is easy to cause damage to the wall of the ureter, the lighter the contusion and bleeding, the heavier the perforation and tearing or avulsion of the ureter. Small perforations or conservative treatment by placing double J tubes, large lacerations or avulsions are treated with open surgery.