【Abstract】Congenital hepatic cysts are a benign disease of the liver. Depending on the morphology, location, size, number, cystic fluid characteristics, liver function and systemic conditions of the cysts, corresponding treatment methods are adopted. This paper tries to make a review on the treatment progress of congenital liver cysts. Fai 【Keywords】 Congenital liver cysts;
Treatment
Hepatic cyst is a relatively common benign liver disease, divided into parasitic and nonparasitic, the former is more common in hepatic echinococcosis; the latter can be divided into congenital, traumatic, inflammatory and tumor. Clinical common is congenital hepatic cysts, the mechanism of its occurrence is not very clear, is generally believed to be intrahepatic vagus bile ducts and lymphatic ducts in the embryonic period of developmental disorders leading to congenital bile ducts growth, developmental abnormalities, vagus bile ducts source of the occurrence of retention cysts, or intrahepatic bile ducts occlusion of the small bile ducts, the distal part of the distal end of the gradual cystic dilatation and become; or due to the obstruction of local lymphatic lymphatic lymphatic lymphatic epithelial inflammatory hyperplasia, resulting in the lumen of secretions due to the retention of the ducts. Clinicopathologically, the cyst wall can be seen as columnar, cuboidal, monolayer of flat cells or absent. Hepatic cysts may be solitary but are often multiple (polycystic liver) and can occur at any age, but are most common in the elderly [1]. Cysts vary in size and the cyst wall is usually thin with an outer layer of collagen-like tissue. The cystic fluid is usually clear and transparent and does not contain bile. The detection rate of congenital hepatic cysts in the normal population has been reported to be about 5% to 10% in the foreign literature [2], and about 10% in the domestic literature [3]; they are slow-growing, and the majority of patients with hepatic cysts are asymptomatic, and most of them are detected by imaging examinations such as ultrasound, CT, and MRI, or during surgery. However, 15% of patients may develop symptoms when the cysts gradually increase in size and compress the liver and neighboring organs, including abdominal discomfort, abdominal distension, abdominal pain, abdominal mass, nausea, vomiting, jaundice, portal hypertension, and even exudative pleural effusion [4]. With the application and popularization of new endoscopic techniques such as ultrasound interventional therapy and laparoscopy, the treatment of congenital hepatic cysts has made great progress today. 1, interventional therapy 1.1 percutaneous transhepatic puncture sclerotherapy As early as the 1970s, someone carried out in the ultrasound-guided hepatic cyst puncture and drainage technology, but the recurrence rate of this method is very high; in 1981, Bean et al. took the lead in the use of ultrasound-guided puncture to aspirate the cystic fluid after injection of sclerosant – anhydrous alcohol treatment of hepatic cysts and was successful. This method greatly reduced the recurrence rate of simple puncture drainage. Today, percutaneous puncture intervention for liver cysts has become a safer, simpler and more effective treatment method; it can also be used in the treatment of liver cysts combined with infection [5]. Currently, the commonly used sclerosing agents include anhydrous ethanol, 10% calcium gluconate, tetracycline, povidone-iodine, and anti-hemorrhoidal spirit. Recently, the use of ethanolamine oleate [6], carbon dioxide [7], 50% dextrose [8], and polycinnamon [9] as sclerosing agents has also been reported, but anhydrous ethanol is still the most widely used. Its mechanism is: the sclerosing agent can make the cyst wall epithelial cell protein coagulation denaturation, precipitation precipitation, dehydration and astringency, so that its biological activity disappeared, the loss of secretion function, and then promote the adhesion of the cyst wall, sclerosis and closure of the cystic cavity closure, the cyst shrinks and gradually disappears. Percutaneous intervention has been recognized as one of the preferred methods for the treatment of congenital hepatic cysts, but the selection of cases is very important for the success or failure of interventional therapy. The indications are: ① symptomatic hepatic cysts with a diameter of 5-375px; ② polycystic liver with compression symptoms, and mainly larger cysts, need to alleviate the symptoms; ③ larger cysts and patients have urgent treatment requirements. It is worth noting that this method is not suitable for those with poor coagulation mechanism, allergy to sclerosing agent and accompanied by a large amount of ascites. Especially when the extracted cystic fluid contains blood and bile, suggesting that the cyst may be connected with blood vessels and bile ducts, it is also inappropriate to inject sclerosing agents such as anhydrous ethanol, so as not to damage the important intrahepatic duct system. This is a contraindication to interventional therapy. The use of anhydrous ethanol as a sclerosing agent in the treatment of hepatic cysts has been reported to cause alcoholic coma [10]. The efficacy of polyglutamine is the same as that of anhydrous ethanol, but the incidence of adverse effects is lower than that of anhydrous ethanol [9] Compared with open surgery or laparoscopic surgery, ultrasound, CT, or MRI-guided perforation intervention has the following main advantages: (1) the operation is simple and safe, and the treatment can be carried out on an outpatient basis in the majority of cases, with a light economic burden for the patients, and it can also be carried out in the grassroots hospitals; (2) it has a wide range of indications, and it can be applied to the heart, lungs, and liver, Kidney insufficiency and should not be operated liver cysts patients, the elderly and frail, or combined with multiple organ diseases of the elderly patients is particularly suitable; ③ trauma, pain, less complications, patients are easy to accept; ④ can be repeated, and the efficacy is satisfactory, the cure plus the efficiency of the effect of up to 90%; ⑤ application of the flexible, can be used individually, but also can be used in open surgery or laparoscopic surgery, in order to further improve the overall effectiveness of the operation. The total efficacy can be further improved by combining it with open or laparoscopic surgery. However, pure interventional therapy also has the disadvantages of high recurrence rate, the need for multiple puncture and injection, and long total treatment period, and its overall therapeutic efficacy is still not as good as that of laparoscopic window surgery. 1.2 Super-selective hepatic artery embolization In recent years, it has been found that in patients with autosomal dominant polycystic kidney disease, the cysts in the liver are involved in blood supply by well-developed branches of the hepatic artery, and the portal vein is not involved in blood supply. The portal vein does not participate in the blood supply. Micro arteries regulated by angiogenic factors can grow toward the cystic area and supply the cystic blood supply. Transcatheter arterial embolization was used to occlude the hepatic artery branches supplying the cysts. After embolization, the cyst wall was ischemic and the source of cystic fluid was blocked, so the cysts became less tense and gradually shrunk and even disappeared, and the compressed hepatic parenchyma was able to expand and return to its normal position.Park et al[11] in 2007, in four patients with autosomal dominant polycystic kidneys combined with polycystic livers, ultra-vitonol particles and microcoils were used to perform selective hepatic artery embolization and considered it safe and effective. In China, Yan Jieyu et al [12] treated 21 patients with severe symptoms of polycystic liver with super-selective hepatic artery embolization, 18 patients showed significant improvement in symptoms, and 3 patients showed no improvement 12 months after the operation. Because these 3 cases had multiple percutaneous punctures to aspirate the cysts combined with ethanol injection before the operation, it may be related to the peritoneal adhesion and establishment of collateral circulation caused by multiple punctures. Indications for super-selective hepatic artery embolization for polycystic liver: patients with autosomal dominant hereditary polycystic kidney and polycystic liver, whose liver enlargement produces compression symptoms and seriously affects the patient’s quality of life, and other treatments are ineffective or unavailable; and patients with cystic hemorrhage, especially active life-threatening hemorrhage, and who are ineffective with conservative treatment. Unrecommended indications: cysts combined with infections: liver function Child-Pugh grade C, especially serum bilirubin, creatinine and the coagulation function of the prothrombin time International Normalized Ratio (INR) is higher than the upper limit of normal values; autosomal dominant polycystic kidneys combined with active liver damage. Or AST / ALT > 80 u / L; allergy to iodine; systemic infectious diseases; severe malignant disease; due to abdominal vascular anatomical factors (such as hepatic artery obstruction, abdominal aorta excessive tortuosity, etc.), the implementation of TAE is very difficult. 2. Laparoscopic surgery for liver cysts 2.1 Laparoscopic hepatic cyst windowing The traditional laparoscopic surgery is hepatic cyst windowing, which is considered to be the stereotypical surgical treatment of hepatic cysts, i.e., an incision is made in the free surface of the cyst wall to open the window for the cyst, the cystic cavity is opened, and cystic fluid is flowed into the abdominal cavity to be absorbed through the peritoneum. The disadvantages of this procedure are: trauma, pain, long duration of disease, slow recovery, and many complications. 1991 Paterson-Brown et al. reported the first case of laparoscopic hepatic cyst windowing to successfully cure congenital hepatic cysts, and since then, hepatic cysts have made the most significant advances in the treatment of hepatic cysts. This procedure has rapidly become the most important treatment for congenital hepatic cysts because of its advantages of less trauma, less pain, and quicker recovery, and it is especially suitable for older patients with hypertension, diabetes mellitus, and other diseases.Kashiwagi et al. reported that in an 83-year-old patient with a large hepatic cyst that was compressing the inferior vena cava and the right ventricle and was accompanied by chronic cardiac insufficiency and thrombus in the inferior vena cava, the cystic fluid was extracted from 2000 ml of the cyst to improve the symptoms with a fine needle. First, 2000 ml of cystic fluid was withdrawn with a fine needle to improve the symptoms, and then laparoscopic hepatic cyst opening was performed 6 days later, which successfully cured the patient [13]. In China, there is also a report of laparoscopic hepatic cyst windowing curing a case of huge hepatic cyst in an 80-year-old man [14]. The clinical efficacy of laparoscopic hepatic cyst windowing combines the advantages of puncture and open surgery into one: ① the efficacy is exact, and few surgical complications occur; ② the surgical method is simpler and shorter, and can be popularized and applied in units with laparoscopic equipment; ③ the trauma is small, the blood loss is small, the scar is small, the pain is light, and the recovery is fast; ④ the hospital stay is shorter, and reduces the medical cost. The indications are: ① symptomatic congenital simple solitary or solitary multicompartmental hepatic cysts with a diameter of more than 125px; ② multiple confined hepatic cysts with mainly larger cysts; ③ cysts with superficial location and superficial cystic wall not more than 25px away from the surface thickness of the liver tissue; and ④ hepatic cysts found during laparoscopic cholecystectomy. Contraindications are: ① centrally located deep hepatic cysts, the surface of the liver tissue is thick (more than 25px from the surface of the liver), there is a risk of injury to the bile ducts, blood vessels causing bile leakage and bleeding; ② huge cysts with thickened cyst wall; ③ diffuse multiple congenital hepatic cysts; ④ recent history of cyst puncture treatment; ⑤ preoperative imaging found to be connected with the biliary tract; ⑥ a history of diffuse peritonitis, history of abdominal surgery, and abdominal adhesions are heavy. If there is a history of diffuse peritonitis, heavy abdominal adhesions; ⑦ cyst is located in the right posterior lobe of the liver or liver diaphragm between the extensive adhesions, laparoscopy is difficult to access; ⑧ intracystic hemorrhage or infection; ⑨ bleeding tendency, coagulation disorders; ⑩ oncological, parasitic hepatic cysts. Indications for intermediate open surgery: intraoperative discovery of cysts and bile duct communication, there is obvious bile leakage, laparoscopy can not continue to deal with; intraoperative hemorrhage; intraoperative discovery of cysts for the neoplastic, especially malignant tumors; intraoperative exposure of the cyst is not clear, difficult to deal with laparoscopy. Complications: Laparoscopic hepatic cyst enucleation may be associated with complications such as bleeding, bile leakage, ascites, pleural effusion, dyspnea, fever, liver function abnormalities, etc. due to the selection of cases and different conditions of the cysts, but ascites and bile leakage are the most common among them. These complications can often be cured gradually with appropriate therapeutic measures and seldom require laparotomy. Studies have concluded that laparoscopic hepatic cyst opening for congenital hepatic cysts is associated with shorter operation and hospitalization time, less bleeding, and quicker recovery than open surgery, and there is no significant difference in the surgical complications and recurrence rates between the two [15]. With the continuous maturation of single-incision laparoscopic surgical techniques in recent years, transumbilical single-port laparoscopic techniques have been applied to the treatment of hepatic cysts and it has been concluded that with the use of common laparoscopic operating instruments, transumbilical single-port surgery can achieve the same therapeutic level of conventional multiorifice laparoscopic surgery for cases of hepatic cysts that are suitable for laparoscopic surgery [16-17]. With the advancement of endoscopic techniques and the generation of new instruments, soft-scope transumbilical hepatic cyst opening [18] and transgastric endoscopic hepatic cyst opening [19] have been reported. 2.2 Laparoscopic hepatectomy Laparoscopic lobectomy or segmental resection is indicated when the cysts are enlarged to occupy an entire lobe or segment or two of the liver, or when the multicystic liver involves an entire segment or lobe but is limited to two to three adjacent segments or half of the liver, in order to achieve a near-radical therapeutic effect. Laparoscopic hepatectomy is limited to the defects of laparoscopy itself, and the selection of this indication is narrower than that of open hepatectomy. If the cyst is located in the right posterior lobe of the liver or there is extensive adhesion between the liver and the diaphragm, which makes it difficult for laparoscopy and instruments to access, this surgery is not suitable. Hepatic cysts that are tipped and suspended in the abdominal cavity can be completely resected laparoscopically. Surgery should be performed on the tip of the liver in close proximity to the titanium clips and then make a resection of the tip. 3.Open hepatectomy For patients with hepatic cysts without cirrhosis, when the cysts are large, multiple cysts have involved the whole liver segment or lobe; or complicated with infection, intracystic hemorrhage, cysts connected with bile ducts; or adenomatous cystic degeneration can not be excluded, and there is a possibility of malignant transformation of the cysts. If the patient’s general condition and liver function can tolerate the operation after comprehensive evaluation, and if the patient has rich experience in hepatic resection, hepatic segmental resection or hepatic lobe resection is feasible. Partial hepatectomy combined with cyst wide opening is currently an effective treatment for severe adult polycystic liver disease [20], and the indications are (1) significant clinical symptoms that cannot be resolved by non-open surgical treatment, which seriously affects the patient’s quality of life, and a score of 2-3 on the Oriental Oncology Collaborative Group Physical Condition Score, and (2) imaging examination confirms that the patient has more than 3 segments of normal liver parenchyma and normal liver function. For intrahepatic parenchymal cysts should be preserved as much liver parenchyma as possible while opening the window to reduce postoperative complications and symptomatic recurrence is the basic principle of surgical treatment. In China, Chen Wei et al [21] retrospectively analyzed the preoperative symptoms, signs, and postoperative complications and prognosis of 33 patients with severe adult polycystic liver disease treated with partial hepatectomy combined with cyst wide opening. It was concluded that partial hepatectomy combined with wide opening of hepatic cysts is an ideal treatment modality for severe adult polycystic liver disease, and despite the high incidence of postoperative complications, the overall prognosis is good, and staging can be used to evaluate the postoperative complications of patients. 4. Hepatic cystectomy When the liver cysts are tipped and suspended in the abdominal cavity, or when the cysts grow at the edge of the liver and most of them protrude from the surface of the liver, complete resection of liver cysts is feasible. In the former case, it is enough to resect the cyst close to the liver; in the latter case, a stripping surface should be found between the outermost and middle layers of the cyst wall, and the whole cyst should be removed, and the trauma can be opened after careful hemostasis or spray coagulation with an electric knife, which is similar to the “window operation”, only that the window is opened to a larger extent; in this case, the inner layer of the cyst wall is stripped away from the middle layer of the cyst wall, which eliminates the secretion of the cyst wall, and avoids the recurrence of the cyst. This method removes the inner and middle layers of the cyst wall, eliminating the secretory effect of the cyst wall and preventing recurrence of the cyst. This procedure can also be done laparoscopically. However, in cases where the concavity is deeper into the liver, a hepatic suture is required to close the dead space. For the treatment of hepatic cysts that are connected to the bile ducts, extensive cyst wall resection is performed to close the passage between the cyst and the bile ducts [22]. When the cyst is connected with the bile duct and the wall of the cyst is thick, if there is still a possibility of bile leakage after treatment, internal drainage of the cyst is feasible. The commonly used procedure is cyst-jejunum Roux-en-Y anastomosis. This procedure is highly susceptible to secondary infections and may be accompanied by external drainage of the catheter. Before the recovery of intestinal function, the external catheter can give full play to its drainage role, reducing the anastomotic tension, which is conducive to its healing; in addition, the catheter should preferably use a 24-gauge long arm T-tube, which has a better supportive effect on the anastomosis, and conforms to the direction of the intestinal drainage and does not fall off easily. In case of secondary infection in the lumen of the capsule, the catheter can also be used for flushing treatment. The combined application of internal and external drainage is obviously superior to simple internal or external drainage. Liver transplantation Liver transplantation is suitable for patients with polycystic liver combined with irreversible hepatic failure or patients with polycystic liver whose clinical symptoms cannot be relieved and quality of life is seriously affected after drainage or open window drainage. Currently recognized indications for liver transplantation should be limited to patients with clinically significant type 2 or 3 diffusely growing liver cysts and those who are refractory to prior therapy. Combined or late renal transplantation should be considered simultaneously in patients with combined renal cysts [23]. Of course, liver transplantation also has problems such as shortage of liver source, higher cost, more traumatic, rejection can occur, and liver failure. The number of patients requiring liver transplantation for polycystic liver alone is very small, accounting for about 0.9% of the causes of liver transplantation [23]. Although liver transplantation can offer hope to patients with polycystic liver, the complexity of the procedure, postoperative complications and mortality should also be considered. It has been suggested that in patients who have previously undergone aspiration, sclerotomy, windowing, hepatectomy, and those with huge livers [24, 25], the difficulty of reperforming liver transplantation and the risk of postoperative complications are increased. In conclusion, for patients with congenital hepatic cysts that require therapeutic intervention, the appropriate treatment should be selected based on the morphology, location, size, number, cystic fluid characteristics, liver function, and systemic condition of the cysts. For symptomatic liver cysts, available treatments include percutaneous sclerotherapy, laparoscopic or open cystotomy, hepatectomy, and liver transplantation. Growth inhibitor-like hormones and lanreotide reduce the volume of polycystic liver cysts with mild clinical efficacy [26]. Simple cyst drainage is avoided if possible. Complex polycystic liver requires a combination of hepatic resection, cyst opening, and sclerosing agent injection. Interventional therapy is currently the preferred modality for the treatment of congenital liver cysts [27]. With the technology becoming more and more mature, laparoscopic hepatic cyst windowing has a tendency to gradually replace traditional open surgery due to its advantages of less trauma, less pain, and quicker recovery; for cysts that are difficult to handle with interventional therapy and laparoscopy, open surgery should still be used, which is traumatizing but well-treated with precise efficacy; hepatic lobectomy is still needed for diffuse and potentially malignant hepatic cysts; only a small number of patients require liver transplantation [2, 28].