Biliary ascariasis and liver ascariasis

　　Biliary ascariasis and liver ascariasis are caused by ascaris entering the human body. After ascaris enters the bile duct, it mostly stays in the common bile duct, rarely entering the gallbladder, because the cystic duct is narrow and has a spiral-shaped Heister mucosal valve that hinders the entry of ascaris. Ascaris can also further ascend to the common hepatic duct or the right and left hepatic ducts, even entering the intrahepatic bile ducts.

　　6. The number of ascaris entering the bile duct in most cases is 1, generally not more than 10, but there are also reports of up to dozens or even hundreds of ascaris causing biliary ascariasis. The survival time of ascaris in the bile duct is generally 1 week to 1 month, and the longest survival period in fresh bile juice outside the body is 14 days. The occurrence of biliary ascariasis is roughly due to the following factors:

　　1. Ascaris can perform swinging, tortuous, flipping, and reversing movements and can move around in the intestine;

　　2. Generally, ascaris is located in the intestine with its head towards the stomach end, absorbing food residue and intestinal fluid. Ascaris has a preference for alkaline and aversion to acidic substances, and low gastric acid is one of the inducements for its upward movement. Studies have shown that the average gastric acid value of patients with biliary ascariasis is low. The higher incidence in children and pregnant women may also be related to their low gastric acid.

　　3. Ascaris has a drilling habit, when it ascends to the duodenum, it can enter the bile duct through the Oddi sphincter at the duodenal papilla.

　　4. When gastrointestinal function is disturbed and the intestinal environment changes due to systemic or local diseases, such as fever, nausea, vomiting, diarrhea, and pregnancy, it can enhance the activity of ascaris and promote its upward movement.

　　5. When the Oddi sphincter is pathologically or physiologically relaxed due to various reasons, such as after eating greasy food, or after surgery (gallbladder resection, choledocholithotomy), it is convenient for ascaris to钻入.

　　6. Improper use of tapeworm expelling drugs, such as insufficient dosage, can irritate the tapeworms, causing them to become excited and move blindly, making it easier for them to enter the bile duct.

　　The risk of biliary ascariasis and liver ascariasis lies in the fact that it can cause many serious complications. These complications can reach over ten, with liver abscess being the first, followed by suppurative inflammation of the bile duct and gallbladder, bile duct bleeding, bile duct perforation, acute pancreatitis, toxic shock, chronic cholecystitis, bile duct stones, liver cirrhosis, and so on.

　　1. Liver abscess:The entry of biliary ascariasis into the intrahepatic bile ducts or the ascending infection of the bacteria it carries can lead to intrahepatic cholangitis. The further development of inflammation can penetrate the bile duct to form an abscess. The tissue-toxic substances released by the dead tapeworm accelerate the formation and development of liver abscess. The clinical manifestations are similar to those of liver abscess caused by other reasons, including pain in the liver area, chills, high fever, liver enlargement, tenderness and percussion pain in the liver area, and increased white blood cell count. When there is a tapeworm in the liver abscess, it can perforate into the peritoneal cavity to form suppurative peritonitis, or it can perforate into the diaphragm to form a bile duct-trachea fistula. The tapeworm can enter the pleural cavity or be excreted out of the body through the trachea.

　　2. Cholangitis and cholecystitis:Pathogenic bacteria in the intestines can be carried into the bile duct by tapeworms, which can induce acute suppurative cholangitis and cholecystitis. In addition to the paroxysmal colic of biliary ascariasis, there can also be persistent dull pain, chills, high fever, jaundice, psychiatric symptoms, and toxic shock. If it is not an acute suppurative infection, it can develop into chronic cholangitis and cholecystitis.

　　3. Acute pancreatitis:When tapeworms enter the papilla of the duodenum, spasm and edema of the Oddi sphincter can block the excretion of bile and pancreatic juices. The retrograde flow of infective bile can activate pancreatic enzymes and induce acute pancreatitis. In mild cases, there is pancreatic edema, and in severe cases, there is pancreatic hemorrhage and necrosis. In a few cases, direct entry of tapeworms into the pancreatic duct can cause obstruction, bacterial infection, and the occurrence of acute pancreatitis.

　　4. Biliary tract bleeding:The pathogenesis of cholangitis and the mechanical injury caused by tapeworms can both lead to cholangitis. When cholangitis involves the hepatic portal area, the walls of the hepatic artery and portal vein branches in this area become fragile due to infection, and inflammation erosion and tapeworm movement can lead to rupture, with bleeding flowing into the bile duct. Before bile duct bleeding occurs, there are often symptoms of choledochosepsis such as chills, high fever, and right upper quadrant pain, followed by vomiting blood or black stools. When there is a significant amount of bleeding, the blood can coagulate, and blood pressure can gradually return to normal. However, if the infection is not controlled, bleeding can occur again, so bile duct bleeding can occur periodically and repeatedly, with an interval of about 1 to 2 weeks.

　　5. Biliary tract stones:The decomposed fragments of the tapeworm body in the bile duct can be excreted with bile, but the chitinous cuticle it contains is rich in keratin and not easily decomposed. In addition, the tapeworm eggs deposited in the bile duct system can serve as a core for stone formation, acting together with other stone-forming factors to cause the precipitation of bilirubin and cholesterol, leading to the formation of intrahepatic and extrahepatic bile duct stones, and gallbladder stones. Most reports indicate that a considerable proportion of gallstone cores are tapeworm fragments or eggs. Some scholars have also placed tapeworms or eggs into the bile ducts and gallbladders of dogs, finding that bile pigments or calcium salts precipitate on their surfaces, making them prone to stone formation. After the formation of bile duct stones, they can present with an attack of Charcot's triad or simply with painless jaundice.

　　Biliary ascariasis is characterized by a sudden onset of severe, 'drilling' pain under the xiphoid process, with sudden onset and disappearance, intervals as normal (hence described as: coming like a sudden thunderbolt on a clear day, and going like smoke and clouds dissipating). It can be accompanied by vomiting of worms, with severe symptoms and mild signs, and generally without fever and jaundice in the early stage of the disease.

　　Liver ascariasis often appears after the sudden and severe symptoms of biliary ascariasis, and its clinical manifestations are more complex and diverse compared to the latter. The main manifestations are symptoms and signs of liver abscess and its complications (such as bile duct hemorrhage, peritonitis, empyema, and pulmonary infection, etc.). Liver granuloma due to ascariasis can be complicated by bile duct hemorrhage, and chronic cholangitis and pericholangitis caused by ascariasis can lead to liver pain and jaundice, and a few can cause the manifestation of ascariasis-induced liver cirrhosis.

　　Biliary ascariasis and liver ascariasis are relatively common, especially in rural areas. To prevent this disease, it is necessary to first prevent intestinal ascariasis, and the whole society should be mobilized to do a good job in water and feces management, health prevention and control, active publicity, and everyone should develop good health habits, not eating unclean vegetables and fruits, and preventing disease from entering through the mouth. When intestinal ascariasis is present, regular anthelmintic treatment should be given. If biliary ascariasis is diagnosed, treatment should be followed strictly according to medical advice to avoid the retention of worm eggs and remnants in the bile duct, leading to gallstones. Biliary ascariasis can be mostly cured with integrated traditional Chinese and Western medicine treatment. If treatment is ineffective, symptoms worsen, and complications occur, surgical incision of the bile duct for worm removal and bile drainage, and other corresponding treatments can be considered. Some people also advocate for worm removal under endoscopic direct vision.

　　For the diagnosis of biliary ascariasis and liver ascariasis, B-ultrasound examination, duodenal barium meal examination, and intravenous cholangiography should be performed, as follows:

　　1. Ultrasound examination

　　Ultrasound examination is simple and non-invasive, showing bile duct dilation, and sometimes it can also detect the echogram of worms in the common bile duct.

　　2. Barium meal examination of the duodenum

　　When the pain symptoms are initial and the worms have not fully entered the bile duct, cord-like filling defects can be seen at the duodenal papilla (worm shadow).

　　3. Intravenous cholangiography

　　Intravenous cholangiography shows bile duct dilation and cord-like filling defects in the intrahepatic or extrahepatic bile ducts.

　　4. Endoscopic retrograde cholangiopancreatography (ERCP)

　　In recent years, it has been more widely used in China, and bile drainage can be performed simultaneously during the contrast study to check for worm eggs. If diagnosed, treatment such as worm removal, flushing, and medication administration can be done simultaneously.

　　5. Routine blood test

　　The early white blood cell and neutrophil count is normal or slightly elevated, and it significantly increases when complications occur. Eosinophilic leukocytes are often elevated, and the detection of ova in vomit, duodenal lavage fluid, bile, or feces is positive for diagnosis.

　　6. Percutaneous liver puncture bile drainage for worm egg examination

　　The above auxiliary examination methods can be selected according to the patient's condition and medical conditions. It should be noted not to overemphasize the detection of worm eggs in bile, and to actively treat and alleviate the patient's pain at the same time.

　　Patients with biliary ascariasis and liver ascariasis should pay attention to light and reasonable dietary搭配. Good hygiene habits should be cultivated, and unclean vegetables and fruits should not be eaten to prevent illness from entering through the mouth. In addition, patients should also pay attention to avoid spicy, greasy, and cold foods.

　　The treatment of biliary ascariasis and liver ascariasis includes two major categories: non-surgical treatment and surgical treatment. In the early days, treatment was mainly surgical, due to insufficient understanding of the pathology and the fear of missing the opportunity for surgery, plus the fact that a large number of ascaris often occurred when biliary ascariasis occurred. The current treatment principle is to relieve spasm and pain, promote bile and expel worms, and prevent infection. Non-surgical therapy can usually cure the disease, but for patients who are ineffective with non-surgical treatment or have serious complications, corresponding surgical treatment can be considered.

　　1. Non-surgical treatment

　　1. Relieving spasm and pain

　　Anticholinergic drugs such as atropine can be used to relieve spasm by intramuscular or subcutaneous injection, with an adult dose of 0.5-1mg per time and a child's dose of 0.01-0.03mg/kg per time. Scopolamine (654-2) can also be used for intramuscular injection or intravenous drip. If the analgesic effect of antispasmodic drugs alone is poor, analgesics can be added, such as 50-75mg of pethidine hydrochloride injected intramuscularly, which may need to be repeated every 4-6 hours if necessary. Because intravenous analgesics may cause spasm of the Oddi sphincter, exacerbating pain, analgesics must be used in combination with antispasmodics to achieve better efficacy. In addition, intramuscular or acupoint injection of vitamin K and progesterone also has a role. Acupuncture at commonly selected acupoints such as Stomach (ST) 36, Yanglingquan (GB34), and may also add Taichong (LR3), Neiguan (PC6), and gallbladder points, using strong stimulation or purgation method, which can often achieve good analgesic effects during acute colic.

　　2. Promoting bile and expelling worms

　　(1) 33% magnesium sulfate solution, 10ml, 3 times daily, taken orally.

　　(2) 9g of black plum pill, twice daily.

　　(3) Daochu driving decoction: 12g of black plum, 9g of Sichuan pepper, 15g of kernel of the husk of areca, 9g of bitter magnolia bark, 9g of sandalwood, 9g of shell of hawthorn, 12g of Corydalis yanhusuo, 9g of rhubarb (added last), one dose daily, taken twice.

　　(4) Aspirin 0.5g, vinegar 100-150ml, 3 times daily, taken with warm water. The above medications all have the effects of promoting bile secretion, anti-inflammatory, and expelling worms. The elimination of intestinal ascaris should be carried out during the remission period of symptoms. Medications that paralyze the worms, such as piperazine (citric acid piperazine) (driving ascaris), diacetyl piperazine, tetramizole (driving worm net), thiabendazole (driving worm net, thiophenylmethylpyrazole), thiabendazole (antiascaris), and albendazole (intestinal worm cleaner), should be chosen. It is not advisable to use vermifuges that cause spasms and contractions of the worms, such as saudagos (driving worm), and vermifuge Dan (one pill). The principle of promoting bile and expelling worms is to increase the secretion of bile, make the bile acidic, paralyze and inhibit the worms, and relax the Oddi sphincter. After the symptoms subside, it is still necessary to persist in promoting bile and expelling worms for 1-2 weeks until the ova in the stool turn negative.

　　3. Prevention and treatment of infection

　　The above Chinese and Western drugs with choleretic effects have certain anti-inflammatory effects, and antibiotic drugs can be temporarily omitted in the early stage. However, when the infection is evident, using them may delay the disease. To prevent serious complications, according to the current principles of anti-infection treatment, antibacterial drugs should be used early in large doses and for a short period of time against Gram-negative bacilli, and attention should be paid to the treatment of anaerobic bacteria. Antibiotics can be selected from aminoglycosides such as amikacin (butamycin), tobramycin, or third-generation cephalosporins such as cefoperazone, ceftriaxone (cefotaxime), etc., combined with intravenous infusion of metronidazole.

　　4. Nutritional support, correction of water and electrolyte metabolism disorders and acid-base imbalance

　　For patients with biliary infection, severe systemic toxic symptoms, or frequent abdominal pain and vomiting, or other complications, fasting, intravenous fluid administration, and vitamin supplementation should be given to maintain acid-base balance. High-calorie fluids and fresh frozen plasma may be given if necessary.

　　Second, surgical treatment

　　1. Indications

　　(1) Severe colic due to frequent发作 of ascaris lumbricoides disease, difficult to control with various non-surgical treatments, and at risk of secondary infection and other complications.

　　(2) Complicated with biliary calculi, prone to obstructive suppurative cholangitis.

　　(3) Imaging examination shows multiple ascaris in the bile duct.

　　(4) In cases of cholangitis, severe biliary infection, biliary hemorrhage, or biliary perforation.

　　(5) In cases of acute pancreatitis where non-surgical treatment is ineffective.

　　(6) After treatment, the acute phase symptoms are relieved, but there is still dilatation of the common bile duct or residual dead worms in the bile ducts after 4-6 weeks of non-surgical treatment.

　　2. Surgical methods

　　In the case of ascaris lumbricoides disease without complications, cholecystotomy can be used to remove the worm and T-tube drainage, and intraoperative cholangiography can be performed if conditions permit to avoid missing multiple worms. After the operation, T-tube drainage is placed for local medication or irrigation. If there is residual ascaris in the gallbladder, gallbladder resection may be necessary.