Echinococcosis of the liver

　　Echinococcosis of the liver is a common parasitic disease in pastoral areas. The main reason for human infection with echinococcosis is contact with dogs, or handling dog, wolf, or fox fur and accidentally ingesting eggs. The eggs hatch in the human stomach and duodenum, releasing oncospheres, which then migrate to the liver via the portal vein and cause echinococcosis of the liver.

　　When echinococcosis of the liver develops to a certain stage, it may cause a feeling of fullness in the upper abdomen, mild pain, or symptoms caused by compression of adjacent organs. For example, when the mass compresses the gastrointestinal tract, there may be discomfort in the upper abdomen, decreased appetite, nausea, vomiting, and bloating. Cysts located at the top of the liver can raise the diaphragm upwards, compress the lung, and affect breathing; cysts located in the lower part of the liver can compress the bile ducts, causing obstructive jaundice, and compressing the portal vein can produce ascites. It is more common for patients to seek medical attention due to various complications. For example, due to allergic reactions, there may be skin itching, urticaria, difficulty breathing, cough, cyanosis, vomiting, and abdominal pain. Secondary infection of the cyst is a very common symptom.

　　Echinococcosis of the liver is a common parasitic disease in pastoral areas, also known as hydatid disease of the liver. The following is an introduction to the clinical symptoms of this disease.

　　1. Cystic echinococcosis

　　Has a history of pastoral life or close contact with dogs. In the early stage, there are generally no symptoms, and then a slowly growing mass is gradually found in the upper right abdomen, with a feeling of fullness, discomfort in the liver area, and hidden pain. The liver is enlarged, and it feels like a cyst when touched. When the cyst compresses the common bile duct, jaundice may occur, and when it compresses the portal vein or the vena cava, ascites may appear, and edema of the lower limbs. Compression of the gastrointestinal tract can manifest as symptoms such as indigestion. Cyst rupture into the peritoneal cavity can cause severe abdominal pain and anaphylactic shock. When a bronchial fistula develops, sputum may contain a waxy-like substance.

　　2. Pulp echinococcosis

　　The growth is fast, and there may be tingling, distension, or even severe pain in the liver area. The liver is significantly enlarged, and the liver area can be touched with a hard mass, the surface of which is uneven. In the late stage, it is often accompanied by emaciation, jaundice, ascites, fever, and other symptoms.

　　Hydatid disease is a common parasitic disease in pastoral areas, patients often have a history of many years and the course of the disease develops progressively. The age of onset is most common between 20 to 40 years old. To prevent hydatid disease, the following points should be done:

　　1. Carry out extensive publicity on hydatid disease knowledge in pastoral areas.

　　2. Eradicate wild dogs, strengthen the management of domestic dogs, and children should not play with dogs.

　　3. Prevent the contamination of pastures, feed, and water sources with dog feces, prevent sheep from being infected, strengthen the management of slaughtering, and bury or burn the carcasses of sick sheep deeply.

　　4. Pay attention to personal hygiene.

　　6. Protect water sources and improve environmental hygiene.

　　Hydatid disease is a common parasitic disease in pastoral areas, most of which are caused by the误食犬绦虫卵误食犬绦虫卵, after hatching into hexacanth larvae in the stomach and duodenum, they reach the liver through the portal vein and develop into hydatid cysts. A few are caused by the larvae of the vesicular echinococcus, leading to vesicular echinococcosis. The right lobe is most commonly affected by hydatid disease, while the left lobe and both lobes are less common. What kind of examinations are needed for hydatid disease?

　　1. Immunological diagnosis

　　(1) Common methods: Intradermal test (ID), this method is simple and sensitive for diagnosis, but due to the lack of standardization in operation, positive criteria, and antigen injection quantity, it is prone to false positive reactions, which is its drawback. Indirect hemagglutination test (IHA) has a positive rate of about 91% and a false positive rate of 3.8%, with high sensitivity and low false positive rate, and has the advantages of rapidity and simplicity. Latex agglutination test (LAT) is simple in operation, and has high sensitivity and specificity. Agar gel diffusion (AGD) and arc 5 double diffusion (DDS) have sensitivities of 41%-97% and 82.1% respectively. Both methods are simple in operation, rapid in reaction, and require less reagent. Counter immunoelectrophoresis (CIEP), immunoelectrodiffusion (IED), enzyme-linked immunoelectrophoresis (ELIEP), and enzyme-labeled antigen counter immunoelectrophoresis (ELA-CIEP) are all sensitive and specific diagnostic methods. Pinon (1976) determined whether the hydatid cyst had ruptured based on the special glove finger shape of the CIEP precipitin band. CIEP becomes negative 3-7 months after surgery. Indirect immunofluorescence antibody test (IFA) and defined antigen substrate spheres (DASS) have sensitivities of 89%-100%. Radioimmunoassay (RIA) also has high sensitivity, specificity, and reproducibility. Enzyme-linked immunosorbent assay (ELISA) and avidin-biotin conjugated horseradish peroxidase complex (ABC-ELISA) are commonly used sensitive and specific diagnostic methods.

　　(2) Complement fixation test (CET): It can be used for efficacy assessment and has certain value for the diagnosis of recurrence. However, its sensitivity is low and the false positivity is high, so it is not very commonly used. The soapstone flocculation test (BFT) is simple to operate, although it is more specific than CFT, the false positivity is still high (3.0% - 27.8%), so it is also not commonly used.

　　Generally, the methods for diagnosing cystic echinococcosis can also be used to diagnose alveolar echinococcosis. The serum IgE decreases gradually as the hydatids disappear, and its measurement can be used as an efficacy assessment. The use of enzyme-labeled monoclonal antibodies against hydatid fluid antigens in competitive enzyme-linked immunosorbent assays (C-ELISA) is a new method with high specificity, good stability, and simple operation. Enzyme-linked immunoblotting technique (ELIB) uses nitrocellulose membranes with antigen epitopes of Echinococcus granulosus and Echinococcus multilocularis to detect echinococcosis, which has the characteristics of high sensitivity, specificity, and good reproducibility. At the same time, ELIB does not require antigen purification.

　　Knoblocn et al. (1988) isolated two glycoprotein antigens with molecular weights of 20,000 and 48,000 from the fluid of the hydatid cyst, which have strong specificity for echinococcosis. The antigen with a molecular weight of 20,000 can also differentiate between alveolar echinococcosis and cystic echinococcosis. Therefore, it can be used for the differential diagnosis of the two types of echinococcosis mentioned above.

　　PCR technology combined with fine needle aspiration biopsy technology, utilizing RT-PCR to detect the mRNA that is Em-specific in the lesion tissue, as a basis for diagnosis and efficacy assessment, to make up for the shortcomings of traditional imaging and serological diagnostic methods. RT-PCR gene diagnosis is more resolution, rapid, and simple than Northern blotting and in situ hybridization, suitable for distinguishing closely related transcripts without depending on their abundance, the results are not affected by DNA variation, and it is a highly specific and sensitive detection technology.

　　Two, Imaging examination of liver echinococcosis

　　(1) X-ray examination: Both large cystic hydatid disease and liver echinococcosis show liver shadow enlargement, elevated right diaphragm, and limited movement. The right diaphragm in the liver top shows hemispherical or wavy elevation. Breakage into the brain shows signs of right lower pleurisy, pleuro-pneumothorax, or lung parenchymal inflammation. Abdominal pneumography can be used to differentiate between superior and inferior diaphragmatic lesions. The calcified shadow of the cystic hydatid disease is round or elliptical, while the echinococcosis shows diffused cluster-like or small circular calcified shadows.

　　(2) Liver ultrasound examination: B-ultrasound tomography, cystic hydatids show clear boundaries of liquid dark areas, with light points or small light clusters inside, which are daughter cysts; vesicular hydatids show dense light points and light clusters of varying sizes, with the bottom light band often unclear.

　　(3) CT, MRI: Both cystic and vesicular hydatids show loculated lesions and display the location and extent of the lesions.

　　The main reason for human infection with hydatid disease is contact with dogs, or handling dog, wolf, or fox fur and accidentally ingesting eggs. The eggs hatch in the human stomach and duodenum, releasing six-hook larvae, which travel through the portal vein to the liver, causing liver hydatid disease. Liver hydatid disease is a common parasitic disease in pastoral areas, and patients with liver hydatid disease should avoid the following foods.

　　1. Sugar cane

　　Rich in sugar, promoting the growth of intestinal parasites in the intestines.

　　2. Fried steamed buns

　　Fried foods, not easy to digest, therefore, they stay in the intestines for a long time, providing food for parasites.

　　3. Potato chips

　　Fried foods, high in calories and difficult to digest, are unfavorable for this disease.

　　Liver hydatid disease is a common parasitic disease in pastoral areas, and surgical treatment is still the main treatment method. The principle of surgery is to clear the inner cyst, prevent the leakage of cyst fluid, eliminate the residual cavity of the outer cyst, and prevent infection. The specific surgical method depends on the size of the cyst, whether there is bile leakage and infection or calcification. Hydrocortisone 100mg can be administered intravenously before surgery to prevent allergic shock caused by the leakage of cyst fluid into the abdominal cavity during surgery, and the surgical method should be determined based on whether there is concurrent infection.

　　1. Excision of the inner cyst

　　The most commonly used method in clinical practice. Suitable for cases without infection. The incision is generally chosen at the most prominent bulge of the upper abdominal mass. After the hydatid cyst is exposed surgically, a wet gauze pad is used to protect the incision and surrounding organs, and a layer of gauze soaked in 10% formaldehyde solution is placed on the gauze pad. In the absence of bile leakage, 10% formaldehyde solution is injected to kill the scolex, and after 5 minutes it is aspirated. This process is repeated 2-3 times, and finally, the fluid inside the cyst is aspirated as cleanly as possible. The formaldehyde solution should not be too concentrated to avoid absorption poisoning and hardening or necrosis of the outer cyst wall. After the fluid is aspirated, the outer cyst incision is sutured inwards to eliminate the residual cavity. Generally, no drainage is needed inside the cyst. Complete excision of the inner cyst is the most ideal surgical method for liver hydatid disease, with strict indications, requiring good anesthesia, skilled surgical skills of the surgeon, and coordinated assistance. This procedure has a high risk factor. With the progress of hepatosurgery and the increase in knowledge of the pathophysiology of liver hydatid disease, surgery not only removes the ectopic cyst of the parasite but also removes the peri-cystic liver parenchymal lesions caused by the parasitic cyst, i.e., clearing or reducing the obstacles in the process of collapse and closure of the cyst cavity. Excision of the inner cyst with inversion suture of the outer cyst or excision of the inner cyst with inversion suture of the outer cyst and placement of a drain is a method that has been used for many years and is the most commonly used method in various places, accounting for about 96% of liver hydatid surgical patients, with definite efficacy.

　　2. Open Cystectomy

　　This technique breaks through some forbidden areas of treatment for liver echinococcosis in the past. The indications for open cystectomy are: ① Simple echinococcosis with complete removal of the inner cyst and puncture removal of the inner cyst. ② Liver echinococcosis with degeneration and necrosis of the inner cyst or regression of the inner cyst and calcification of the cyst wall. ③ Liver echinococcosis with mild infection and necrosis without systemic symptoms. ④ Liver echinococcosis with bile leakage, which is only minimally expressed through suture repair. This technique has a wide range of indications, with good short-term and long-term efficacy after surgery, without the formation of residual cavities. However, it must be performed according to the principle of tumor-free surgery, select and use local chemotherapy drugs properly, and select the appropriate indications.

　　3. Bag-shaped Suturing Technique

　　Applicable to cysts that have already been infected. After thoroughly removing the inner cyst and the contents of the cyst cavity, the outer cyst wall is sutured in full layer around the incisional abdominal wall, and gauze is used to pack and drain the cavity. This type of surgery often forms an infected sinus tract that does not heal for a long time.

　　4. Liver Resection

　　This method can completely remove the echinococcus, with the best therapeutic effect. From the perspective of modern hepatobiliary surgery, the resection of the liver infected with parasites (standard resection or extensive resection) is an ideal method, but it should be cautious when performing liver resection due to echinococcosis, on the one hand because liver echinococcosis is a non-malignant lesion and is often a multifocal biological disease, on the other hand because the liver resection involves postoperative management and the regeneration ability of the liver tissue after surgery, therefore, liver resection for echinococcosis is only applicable to pericystectomy when it cannot remove the liver tissue with lesions that have already failed to recover to normal, including: the cyst has destroyed the whole liver segment, lobe, or half liver; there are a large number of multiple cysts in the liver lobe or segment, which overlap and make it difficult to preserve the normal function of the liver parenchyma between the cysts; the echinococcal cysts in the liver parenchyma break through the bile ducts of some liver segments or areas, causing uncontrollable bile leakage; there are cystic bile duct fistulas in the liver parenchyma. Especially, the surgical difficulty is higher for the cysts located in the superior, portal, and central portal vein areas of the liver. Liver lobectomy or partial liver resection can be considered for the following conditions: ① localized in the left lateral liver lobe or right half liver, with a large, single, thick-walled or calcified cyst that is not easily collapsed, while the liver tissue on the diseased side has atrophied; ② localized multiple cysts in a lobe of the liver; ③ post-drainage cyst cavity that does not heal for a long time, leaving a fistula; ④ chronic abscesses with thick walls formed after cyst infection; ⑤ localized cystic echinococcosis.

　　5. Laparoscopic Resection

　　Laparoscopic surgery for the treatment of liver echinococcosis is a minimally invasive and effective method. In 1992, Xinjiang was the first to carry out laparoscopic liver echinococcal internal resection in China. It can be said with certainty that this technique has minimal trauma to patients and fast postoperative recovery, but strict selection should be made before surgery. The selection criteria for the surgical object are: the diameter of the liver echinococcal cavity should be less than 10 cm, if greater than 10 cm, the possibility of communication with the intrahepatic bile duct is high, and postoperative bile leakage is likely to occur; there is no abdominal multi-organ echinococcosis and no infection in the echinococcal cavity. Echinococcal cysts deep in the liver or posterior in position are not easily visible and are not suitable for laparoscopic surgery; the main reason for the infection in the echinococcal cavity is its communication with the bile duct, which is likely to cause bile leakage after surgery; secondly, the adhesion between the surrounding organs and the echinococcal cyst is heavy, making the operation difficult. Due to the strict requirements for surgical indications and high requirements for surgical technical level of laparoscopic liver echinococcal cystic resection, the biggest drawback is the risk of cyst fluid leakage. By improving the technical level of the operation, using sponges soaked in antischizogonist agents to protect the puncture site, and applying benzimidazole during the operation, the risk can be reduced. Laparoscopic surgery can also allow surgeons to more minutely explore the cyst cavity during the operation, thereby avoiding any missed residual cysts or channels with the bile duct. Surgical indications: The patient has an attack of liver echinococcosis, is generally in good condition, and has no complications. For small cysts located deep in the liver substance that are difficult to resect, (

　　Due to the clinical discovery of liver cystic echinococcosis mostly in the middle and late stages, less than 30% of the cases can achieve radical resection of the lesions, and most patients have invasion of the porta hepatis and inferior vena cava, which cannot be resected, seriously affecting the quality of life and survival rate of patients, and a number of patients die within 5 years. By adopting techniques such as

　　7. Other Techniques

　　Techniques such as Roux-Y anastomosis with internal drainage, echinococcal cyst resection, lobectomy, partial hepatectomy, and omental packing of the peritoneal cavity are only suitable for patients with special types of diseases.