1, Primary Intrahepatic Stones (PIS) refers only to stones originating from the bile ducts at all levels in the liver, and is highly prevalent in China, Southeast Asia and Taiwan, and rare in Western countries. Although it is a benign disease, there is no relatively uniform and reliable surgical treatment, and the causes of the disease are complex and diverse, so it cannot be effectively prevented at the first level, and the disease cannot be effectively cured at an early stage, which makes the disease recurrent, and often leads to septic cholangitis, biliary liver abscess, infectious shock, and even cholestatic cirrhosis, secondary intrahepatic cholangiocarcinoma and other serious complications that affect the quality of life, and even endanger life. even life-threatening. Since intrahepatic bile duct stones are usually multisegmental, multilobar, widely distributed and associated with intrahepatic bile duct stenosis, it is impossible to completely remove intrahepatic bile duct stones and stenosis by one type of surgery alone. Therefore, it is a benign disease that is difficult to treat.3 Primary intrahepatic choledocholithiasis is a multifactorial, combined disease: the cause of primary intrahepatic choledocholithiasis (PIS) is not fully understood. It is currently believed to be associated with specific geographical location (rural, mountainous, fishing villages), economic status (underdeveloped areas), dietary habits (high sugar, low fat, low protein), nutritional conditions (anemia, malnutrition), chronic parasitic diseases (ascaris, liver flukes, etc.), biliary bacterial infections, congenital and acquired biliary diseases and anatomical abnormalities. PIS is divided into calcium bilirubin stones, cholesterol stones and mixed stones according to their chemical composition, with calcium bilirubin stones accounting for 66.9% of the stones. Cholesterol stones account for 17.8% and mixed stones account for 15.3%. 4.Comprehensive treatment study of primary intrahepatic bile duct stones: individualized treatment 4.1.Biliary tract exploration, T-tube drainage with fibrinobiliary microscopy for stone extraction: This procedure is the basis of all surgeries. It is simple to operate, with little damage to the organism, few complications, and the normal structure of the extrahepatic bile duct is not affected, and the postoperative recovery is fast, accounting for about 50% of the surgical ratio. The best indication is for patients with single or multiple stones without intra- and extrahepatic bile duct stenosis and hepatic atrophy, and to ensure that the stones can be removed with fibrinoscopy. This method is easily accepted by patients, with rapid recovery from surgery and postoperative fibronectomy via the T-tube sinusoid. However, because of the complication of intrahepatic biliary stenosis which is not easily diagnosed before surgery, it leads to an increased recurrence rate of stones due to the presence of biliary stenosis after surgery despite the removal of stones by fibroneuroscopy. Therefore, Huang et al. proposed early systematic hepatic segmental resection for intrahepatic bile duct stones. By separating and severing the blood vessels and bile ducts through the hepatic portal section, the diseased liver tissue is removed in strict accordance with the blood supply and bile duct drainage, normal liver tissue is preserved, and the development of intrahepatic bile duct stones is interrupted, so as to achieve a cure by radical removal of the lesion. This method achieves the treatment principle of “removing lesions (stones and strictures), relieving obstruction and unobstructed drainage”, and has good efficacy. The problems are that surgery is very traumatic, has many complications, slow recovery, not easily accepted by patients and requires solid surgical skills, so it is not widely performed in the treatment of early intrahepatic choledocholithiasis. 4.2. Hepatectomy, T-tube drainage with fibrinoscopic stone extraction: The left outer lobe of the liver, the right posterior lobe of the liver and the caudate lobe of the liver are good sites for stones. Long-term stone history with recurrent cholangitis may lead to liver tissue atrophy or even malignancy, which requires surgical resection. The best indications for hepatic resection are: ① lesions limited to one section, lobe or side of the liver with significant atrophy and fibrosis of liver tissue; ② bile duct stones and bile duct strictures, which are difficult to be removed and corrected by other methods; ③ intrahepatic bile duct stones and cystic dilatation of bile duct on one side; ④ regional intrahepatic bile duct stones with liver abscess; ⑤ intrahepatic bile duct stones and bile duct cancer. At present, left (external) lobe resection has become the classic procedure for the treatment of left lobe intrahepatic stones because of its easy operation, small trauma and good results, and low residual stone rate. The right lobe of the liver and caudate lobe, on the other hand, are only performed in some of the larger medical centers with extensive surgical experience because of their difficult anatomy, high surgical trauma, and high technical requirements, but they do not account for a high percentage of the total number of stones, which is the biggest obstacle to stone residual after surgery. The proportion of those who perform multidirectional and multisegmental hepatectomy to treat stones is even smaller. Stones and strictures are like twins, and the rate of intrahepatic bile duct stones combined with strictures is about 25%-65%, and strictures are an important pathological factor for stone recurrence, so hepatectomy should remove both stones and strictures to achieve the best results, otherwise it is bound to cause stone recurrence after surgery. Therefore, it is important to define the site of bile duct stricture before surgery. For intrahepatic bile duct stenosis of grade 2 or higher, it can be removed together with the stone with good results. In the case of hilar bile duct stenosis, it is more difficult to deal with, and bile duct formation and bile-intestinal anastomosis are required. In some cases, the stones are too extensive to be removed by any kind of hepatectomy, so intraoperative and postoperative extraction of the stones by fibrinoscopy is required to reduce the residual stone rate. 4.3. Biliary-intestinal anastomosis and hepatectomy with fibrinoscopy: In the past, hepatectomy and fibrinoscopy were not performed for intrahepatic bile duct stones, resulting in a high residual stone rate after surgery. In this case, it was hoped that through bile-intestinal anastomosis, the intrahepatic stones would “collapse” and be discharged into the intestine through the wide bile-intestinal anastomosis. However, this is not the case. Since the bile ducts inside and outside the liver do not have physiological emptying function like the intestine and ureter, the effect of stone discharge and “collapse” cannot be achieved by bile secretion and flushing alone, and the stones may gradually increase instead of decrease after surgery, while intestinal fluid reflux after bile-intestinal anastomosis further leads to recurrent cholangitis and worsening jaundice. Therefore, it is currently believed that strict indications are needed for the performance of choledoenterostomy, and it is not a universal procedure for the treatment of intrahepatic bile duct stones. However, even if the indications are strictly chosen, the formation of parallel jejunal “artificial papillae” may lead to high intestinal fluid reflux, recurrent cholangitis, recurrence of stones and obstructive jaundice over a long period of time. At present, choledoenteric anastomosis is usually used for: (1) those with extrahepatic bile duct dilatation of 2.5 cm or more and relative stenosis; (2) those with hilar bile duct stenosis that cannot be surgically removed and undergo pelvic choledoenteric anastomosis via hilar bile duct formation; (3) those who believe that the possibility of recurrence of bile duct stones is high after surgery and undergo choledoenteric anastomosis with subcutaneous blind collaterals of the proximal jejunum in order to prepare for postoperative fibrinoscopic stone extraction via blind collaterals; and residual intrahepatic bile duct stones and stenosis. and strictures are contraindications to bile-intestinal anastomosis. Since intrahepatic bile duct stones and strictures often coexist, it is currently considered inappropriate to perform choledochal jejunostomy for those with only clean stones and residual intrahepatic bile duct strictures, as intestinal reflux leads to recurrent episodes of cholangitis and eventual stone recurrence. In this case, the stenosed bile duct should be cut and shaped, and a bile duct pelvic-jejunostomy should be performed, which not only removes the stone and relieves the stenosis, but also significantly reduces the chance of cholangitis due to postoperative intestinal reflux. There are also studies that have reported the use of the gallbladder wall, gastric wall, and tipped jejunal segment to repair the defect formed by stenosis bile duct incision in order to preserve the functional integrity of Odis sphincter and prevent intestinal fluid reflux, which have also achieved good results and deserve further studies. In conclusion, primary intrahepatic bile duct stones are a benign common disease and a difficult disease. It has a high incidence in areas with poor economic conditions and low living standards, seriously affecting the health of patients and causing poverty and disability due to the disease. Because of its complex and diverse etiology, primary prevention cannot be achieved. Intrahepatic bile duct stones are widely distributed, extensive, combined with stenosis and malignant changes, making treatment methods diverse and individualized treatment plans must be implemented. Different surgical approaches are chosen according to the preoperative disease assessment and the level of medical care. Hepatic resection is the most complete, with the best results in removing both the stone and the stricture lesion. Biliary-intestinal anastomosis is not a one-size-fits-all procedure, and postoperative cholangitis is prone to recurrence, so the indications must be strictly controlled. At the same time, active intraoperative and postoperative cooperation with fibrinoscopy and treatment is a strong guarantee to determine the residual stones and reduce the rate of residual stones after surgery, which is worthy of wide application.